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View Full Version : Cheaper, simpler airbox kit. $5



scott2ride
02-23-2004, 12:23 AM
I'm sorry this effects Kens and Millemans excellent airkits (And Jorges Renegade kit for that matter!).

But lets face it...It had to happen didn't it!

Here is the "almost free" version of how to do the airbox mod.

A friend of mine just did it on his 04.

The only cost is for some high density closed cell foam. The sort of foam they use on those cheap camping/sleeping mats.

It is quite firm so needs no support (Does not need a Ram air blade).

Cut the foam to shape then hold it in place with the bottom portion of the old airbox lid. Just cut the top off the lid and bolt it back on.

This is the rough version and the front of the airbox was left in place to hold the airfilter down. But dont do that...just cut the front section off as well and screw the front of the filter down.

Also, the blue foam still needs a trim around the inside of the airbox to even it up with the inside of the air box.

HOWEVER....

You will still need to order one of Kens excellent hi-flow filters from www.evoluzione.net (http://www.evoluzione.net)


EDIT: I have a new version now, better and simpler... go here http://www.apriliaforum.com/forums/showthread.php?s=&postid=361854#post361854

... :D

scott2ride
02-23-2004, 12:24 AM
Pic 2

scott2ride
02-23-2004, 12:25 AM
Pic 3.
And note, it still holds that other filter thingy down too.

Merto
02-23-2004, 01:30 AM
Dont know if Id be brave enough to hack the airbox lid up.....whats cheaper, the Evo kit or a new lid?

Seems to make sense though.... be interesting to see a performance comparison

:plus:

Kiwi_M5
02-23-2004, 05:24 AM
Originally posted by Merto
Dont know if Id be brave enough to hack the airbox lid up.....whats cheaper, the Evo kit or a new lid?

Seems to make sense though.... be interesting to see a performance comparison

:plus:

Hey sweet, my number eight wire invention made the net :D But credit goes to Scott whose current design accidently created the above.

Metro, yeah I thought about the cost of the cover, but once I get my filter and tidy up with something better than a hack saw, its gonna look sharp as if it were manufacturered. Hell, I dont plan on selling the thing anytime soon so what I save now, I can spend on more goodies. :)

RSVracer
02-23-2004, 06:08 AM
how does it seal against the bottom of the tank though?

HixX
02-23-2004, 07:46 AM
Looks good to me.

clarkie49
02-23-2004, 09:39 AM
good old kiwi injuniaty (pity we cant bloody spell though :D )

jack of all trades, matser of none - thats the kiwi moto

and we did fly before the wright brothers did! the americans just spent more of their budget on marketing :D

milleman
02-23-2004, 10:38 AM
Right on Bro! that is lookin good! use some weather stripping

Scootopia
02-23-2004, 11:22 AM
The 04 Airbox lids are $14.45 and listed as in stock at Aprilia USA.

Scootopia
Louisville, KY 40217
502-634-4007
www.scootopiaonline.com

pan
02-23-2004, 12:00 PM
great job. this definitely looks good. I wish i had seen that before i spent that money on the airbox

scott2ride
02-23-2004, 02:00 PM
I wouldnt worry if you've already bought an airkit because the Evoluzione, Milleman and Renegade kits are excellent. Whats more the Rene and the Evoluzione include the filter. And you still need to buy one for this.

Personally I'd get the Evo filter not a K&N. (The Rene obviously doesnt fit this).

But glad to share the idea to help the Aprilia brotherhood!:peace:

RSVracer
02-23-2004, 02:18 PM
scott, how does a hard plastic airbox lid seal to the bottom of the tank? I'm assuming thats what you are going for here similar to the Evo kit.

scott2ride
02-23-2004, 02:23 PM
As far as performance goes, I cant imangine why there would be any difference between this, the Evo and the Milleman kit (Provided they all used the Evo filter)

BUT...this home jobbie and the Milleman kit possibly retain better ram air pressure at speed than the current Evo design.

As to how it compares to Jorges Rene kit is another matter and I dont know the answer to that. His is a good kit!

Time for a comparo?????

Who has a Rene kit installed and is thinking of putting it on the dyno...and is prepared to experiment and make up one of these $5 budget jobbies to compare????

I did this exact thing with my 02 Mille. I had bought a Rene kit and then made my own airkit (Similar to this but I glued foam to the SIDE of the lower airbox...cos I wanted to retain my original lid. [Which was a waste of time]) I also bought an Evo filter.

I then dyno'd them all together on the same day.

The result????

And before I tell you, I stress that this was specific to my bike... your's may have reacted differently...

The result (On the 02 Mille) was that the Rene was better than the "Home job with standard filter", but not quite as good as the "Home job with Evo filter". So I kept the Evo filter and home job and sold the Rene kit.

So if one of you cares to do the comparison between your Rene kit and the 'home job with std filter', then we will be forever in your debt! (We'll forget you as soon as the next interesting post appears.... but you'll think we still love you :D )

Thunder Factory
02-23-2004, 02:28 PM
Scott

The only person who could do this currently is Jorge at Renegade as his kit is not released yet.

Do you want to ask him or shall I? :banana:

scott2ride
02-23-2004, 02:30 PM
Originally posted by RSVracer
scott, how does a hard plastic airbox lid seal to the bottom of the tank? I'm assuming thats what you are going for here similar to the Evo kit.

The remnants of the hard plastic lid doesn't actually touch the tank. It just holds the blue 'high density firm foam' in place, in just the same way as the aluminium ring holds the rubber in place on the Evo and Milleman kits.

It is the blue foam that seals to the inner edge of the tank.

Oh, and make sure you put some silicon gel or similar around the top outer edge of the blue foam to help ensure it seals to the tanks underside.

Note, once you have put the silicon gel (Or similar) on it, close the tank firmly, then re-open it and check to see that there is gell all around the underside of the tank. This will show if it is sealing against the tank all the way around.

scott2ride
02-23-2004, 02:35 PM
Originally posted by Thunder Factory
The only person who could do this currently is Jorge at Renegade as his kit is not released yet.

Do you want to ask him or shall I? :banana:

Hmmm.... let me think about that for a minute!

Ok...


You go for it! But make sure you do it in person!

Oh, and If you are reading this Jorge... :rambo: it was originally Thunders idea...honest

Mr Moderator.. if you are watching this board, then can I have a :ban: on Thunder... I dont want him getting me in any more trouble :crowbar:

lunchbox
02-23-2004, 10:25 PM
instead of that blue foam you could use latex foam wich i think would seal better than the blue foam. but with the latex foam you might need mille mans ram air blade. just a thought:cheers:

scott2ride
02-23-2004, 11:35 PM
Originally posted by lunchbox
instead of that blue foam you could use latex foam

I wonder I could use the Latex outfit I got for the wife? Since havin kids it simply hangs around...unused....a bit like my old fella!:tired:

Merto
02-24-2004, 12:31 AM
[QUOTE]Originally posted by Scootopia
[B]The 04 Airbox lids are $14.45 and listed as in stock at Aprilia USA.[QUOTE]

If thats all a new lid costs, its a bit of a no brainer IMHO. If you want to convert back to standard for re sale later, just buy a new lid when/if the time comes.:plus:

One thought though, it might be necessary to change the foam now and again as it will compress and eventually loose the ability re form to its original thickness (more so than an elastomer seal), so the seal effectiveness will probably reduce...... Just means you have to curl your legs up a bit more next time you go camping:happy:

Kiwi_M5
02-24-2004, 04:38 AM
Originally posted by Merto
[QUOTE]Originally posted by Scootopia
[B]The 04 Airbox lids are $14.45 and listed as in stock at Aprilia USA.[QUOTE]

If thats all a new lid costs, its a bit of a no brainer IMHO. If you want to convert back to standard for re sale later, just buy a new lid when/if the time comes.:plus:

One thought though, it might be necessary to change the foam now and again as it will compress and eventually loose the ability re form to its original thickness (more so than an elastomer seal), so the seal effectiveness will probably reduce...... Just means you have to curl your legs up a bit more next time you go camping:happy:

Just got home from a ride and checked the foam - it has softened from when I did on Saturday (72 hours ago). But it definitely seals. Its easy to see whats got contact and what hasnt. I'll try and take some pics tomorrow to show it.

I havent put any gel on it yet but will once I get the width right. I left too much foam hanging out and its just bent over a bit too much which means air will spill at ram air speeds. A trim of this will naturally stiffen up the seal but I actually like Lunchbox's idea, so I'll be trying a few things out before I settle for version 2.

Doesnt that latex come in handy when your wife is out Scott :D

scott2ride
02-24-2004, 06:00 PM
To improve on this already great idea of yours Dean (Kiwi), I suggest 2 things.

1. Add some support to the existing blue foam by glueing some more of the blue foam around the outside edge of the airbox. Basically, glue it below the existing foam (and on the side of the airbox), but have it butted up against the bottom/underside of the existing foam to give it support from below. You will probably need to layer it so as to make the strips wider.

2. If you were extra fussy and ultra concerned about the unlikely entry of dust, you could attach a soft rubber (Not foam) seal to the top outer edge of the blue foam. The type of 'soft rubber seal' I'm refering to is the sort that they use for self adheasive draft strips around doors and windows. It would then be the point of contact against the underside of the tank and would seal beautifully.

(As a side thought...My jacket used to leak through the zip. So I used the soft flexable self adheasive rubber draft seal along the inside of the zip flap of my Cordura Tourex Spidi bike jacket. It leaked through the zip, but after putting a strip down the inside of the flap and another strip down the jacket portion of the flap...no leaks. They seal perfectly against each other!)

RSV4ME
02-24-2004, 06:54 PM
You know what they say about Kiwi's, they are the Irish of the South Pacific Ocean!:p:
Can anyone else here imagine spending that sort of money on a bike, only to butcher it for the sake of a couple of hundered bucks? Why don't you run down to the hardware store, pick up yourself some cans of spray paint and do your best paint job? Who do you think you are, John Britten?:shooter: :aussie:

scott2ride
02-24-2004, 07:15 PM
Christ...another friggen Ozzie on the forum. :bond:

I must talk to the Moderator about raising the standards.

And yes.... to answer your question...I am John Britten!

Or at least I’m a friend of his wifes, friends, hairdressers, brothers, uncles, sisterinlaw!

Anyway, as you are an Ozzie, would you like me to make my explanation a little easier to understand? :happy:

It is just typical of you critical and disparaging Ozzies, that when you are shown how to do something better and cheaper… all you can do is moan...and then still insist on paying the higher price for the old style, inferior item.

In addition… instead of being able to do the job immediately (Like us hard working creative Kiwi’s), you seem to think it’s better to wait several weeks for the inferior and expensive item to arrive…and then when it does, you still have to install it yourself!

Meanwhile us Kiwis are out riding with our superior machinery and winning races….a bit like that John Britten fella you mentioned.
:kidding: :bump: :chillpill

He he

RSV4ME
02-24-2004, 07:31 PM
I was hoping that would get your feathers ruffled, is a Kiwi just a little Emu? Anyway, anyone who doesn't know about John Britten, he was a brilliant bloke who lost his way and ended up in NZ as a frustrated Aussie, he basically built his own bike in his back yard with a group of friends and won Daytona on it. This was in the late eighties early nineties? But the bike was reputedly producing around 180hp! Also a stunning looking bike. It's worth a search on the web to check it out. But he tragically died of cancer a couple of years ago, needless to say his body was flown back to it's rightful resting ground, Australia.:happy:

scott2ride
02-24-2004, 09:07 PM
I will not bite at your childish attempt to wind me up by calling John Britten an Ozzie.... No sir.... not me!






Damn! Where did I put that 'seek and distroy' virus????

Arh.... there it is....
Hmmm....now.... program it to seek out the hard drive of RSV4ME...and WALLOP! :gunner: :aussie:

Ozzie can't log on any more! :banana:

He hehehehehe evil snicker!:banana:

Steptoe
02-24-2004, 10:01 PM
Don't mind him. Must've snuck in with the Humans :p:

On the topic of John Britten, I watched "The Britten Bike Story" again the other day. Still fascinating. (haven't watched in for over 5 years). I read that it was re-released on DVD (different title), but not seen it anywhere yet. Don't know if there is any new material.

Just bought his Biography (by Tim Hanna). I'll get to that when I learn how to read;)

RSV4ME
02-24-2004, 10:32 PM
Hey Al, who's side are you on? Why don't you join me in that great tradition of Kiwi bashing, it's so easy... watch this.

Ah Scott, I see your "seek and destroy virus" didn't work... could it be it was home made? Come on Scott, tell us, did you find a couple of old commodore 64 tapes lying around and you tried to make your virus program from these?

Also, wasn't the comment about the

"Or at least I’m a friend of his wife’s, friends, hairdressers, brothers, uncles, sister-in-law!"

A rather exposing reference to the limited gene pool of NZ?

And the racing Kiwi greats you mention, I assume you're referring to guys like Mick Dooan, Troy Baylis, Wane Gardner, Anthony Gobert, Troy Corsa, Anthony West, Casy Stoner, Chad Reed, McCoy, ect ect ect...... oh hang on, they are all Aussies...... I wish I could think of a Kiwi one...... Ok maybe one, they guy with the funny hair cut riding the honda.. what was his name again?

Also the "hard working" comment..... is it true you are actually at work at the moment.... jerking off on the boss's time????


:happy: :happy: :happy: :happy: :happy: :happy: :happy: :happy:

clarkie49
02-24-2004, 10:46 PM
Originally posted by RSV4ME
And the racing Kiwi greats you mention, I assume you're referring to guys like Mick Dooan, Troy Baylis, Wane Gardner, Anthony Gobert, Troy Corsa, Anthony West, Casy Stoner, Chad Reed, McCoy, ect ect ect...... oh hang on, they are all Aussies...... I wish I could think of a Kiwi one...... Ok maybe one, they guy with the funny hair cut riding the honda.. what was his name again?

wetsy is a punk kid with a dad who spent $500K in his first year riding club and national stuff, i know some good stories about how westy's dad was banned from GP's by HRC, so he used to call them in the pits bitching about how slow his kids bike was during qualifying and hat he was paying good money for a fast bike

now Broc Parkes is a damm good rider with a genuine attitude and the skills to go all the way, and his dad les didnt buy him a ride, Broc earned everything he has

its actually kinda funny how guys like Mugga, Glen Richards and the like were really nothing special in OZ but they went to europe and worked hard to get themselves to where they can earn a pretty good living

oh yeah, and i used to have a mohawk

cheers

aaron

Thunder Factory
02-25-2004, 01:46 AM
Originally posted by RSV4ME
You know what they say about Kiwi's, they are the Irish of the South Pacific Ocean!:p:


Just what does that mean then?

scott2ride
02-25-2004, 02:24 AM
BITCH!!!!:ban: :ban: :ban: :ban: :ban:

RSV4ME
02-25-2004, 04:13 AM
Oh Scott, dry your eyes princess, where's the fun gone? :devilbat:

Seriously, are you not a little worried about the seal on the tank? What about a hi-breed style where you have the box top open, seal on the tank like your ..........creation...sorry I know I should stop it...... , filter is removed from the air duct and a pod style go's over the trumpets? You would then keep the pressurized box with no chance of filtration worries?:peace:

Speedy
02-25-2004, 08:34 AM
Scott........great idea , good work for no $$ !
Would rebuild mine immediatly ('00.5) but i just don't trust the sealing , not only yours but Ken's EVO system either .
I just can't help but feel that sooner or later you will get in trouble due to dirt getting in the TB's .
It's also one of the reasons why i dumped the Renegade system.
I ride an 10.000km/year and not planning on opening or lifting the tank every 200km to check if all's ok.
It's just not worth it IMO .

Still.......like your idea.

Cheers,
Danny

mille108
02-25-2004, 11:35 AM
The dealer just checked for me..... a brand new airbox lid will set you back a stunning 9....... yes 9! euro's
So..........:D

HixX
02-25-2004, 11:38 AM
Maybe you should try two-layers of foam. At the botton a semi-rigid type to hold it all together, then a soft, flexible type for the seal. It would be easy enuff to bond them together.

Worth a try ?

scott2ride
02-25-2004, 03:19 PM
OK ladies.

Rest your weary brains.

Save yourself a lot of worrying and simply use medium firm closed cell foam. I have used this on my 02 Mille for 25,000 km and NO crap or dust has got in. (I regularly check).

BUT....(there is always a but!!!). Here is the thing. Forget what you have just seen. Here is what to do.

1. Don’t cut up your airbox lid...you don’t need it at all. Put it on a shelf in the garage.

2. Dont place the foam on the top lip of the open airbox (As is shown in the previous pictures). The pictures show blue foam being used in the same way that Ken or Milleman used a thin rubber seal. Dont do this.

3. If the foam is placed on the top lip of the 'open' airbox, then it needs to be held in place with either an aluminium ring or the 'chopped off' bottom half of the airbox lid.

4. But remember...we are not doing that! So instead of putting the foam on the top edge of the airbox lid. Glue a thick strip of it to the SIDE of the airbox base. Butt it up so it is even with the top edge of the open airbox.

5. Don’t use the blue style foam. Instead use 'high density closed cell foam". It is softer and more flexible, but bounces back much better and seals much better.

6. The closed cell foam needs to be at least 30mm thick. Cut it into strips 2 inches wide, and long enough to go all the way around the outside edge of the airbox. You'll notice the curve of the inner tank tapers inwards. This means that when the tank is closed it slides over the edge of the foam and as the tank is lowered down further the hole 'tightens' up, and the seal around the airbox gets firm and tight (You Ozzie blokes wouldnt understand that)

7. Glue the closed cell foam to the side of the airbox. Also glue a strip along the front, top lip of the airbox, where the tank closes and bolts down.

8. Put some vaseline, silicon or similar sticky gewy shit on the outside edge of the foam and close the tank down. It should be a firm fit...quite tight in fact (Which is something Ozzie women seldom get from Ozzie men!) :D Lift the tank back up and check that it has some vaseline, silicon or similar sticky gewy shit all the way around its inner edge (Thigh?). This will show it is contacting all the way around.

9. Screw down or attach (Somehow) the front of the air filter to make sure it stays in place.

10. Close the tank, secure the bolts, go for a ride and feel the power! :peace:

(Alternative Ozzie version). Re-read this 30-40 times...then get help with the big words...then when you have had it all fully explained to you...go and order Kens kit from Evoluzione or the Milleman kit. Spend your hard earned dollars (No doubt acquired via the unemployment benefit)..then get someone else to explain the instructions with their kits. Wait weeks for it to arrive while we are out riding. Then install the kit you bought with 4 months wages. Then install it again, but this time the right way around. Now go and ride and enjoy the power....up until 200kph, then the ram air kicks in and the Kiwi's with their home made kits keep accelerating away... bye!
:gunner: :aussie: :fangs: :D :D :D :o

Thunder Factory
02-25-2004, 03:40 PM
Originally posted by Speedy
Scott........great idea , good work for no $$ !
Would rebuild mine immediatly ('00.5) but i just don't trust the sealing , not only yours but Ken's EVO system either .
I just can't help but feel that sooner or later you will get in trouble due to dirt getting in the TB's .
It's also one of the reasons why i dumped the Renegade system.
I ride an 10.000km/year and not planning on opening or lifting the tank every 200km to check if all's ok.
It's just not worth it IMO .

Still.......like your idea.

Cheers,
Danny

Danny

I've fitted an Evo kit on the bike and recently added Millemans "air blade " to it to increase the seal.

You can feel the increase in the seal when you first close the tank and having tried the "vaseline" test I can confirm all parts of the ring make and maintain contact.

Just for info, like you I don't want to be lifting the tech often, but I do want increaed air flow.

:banana:

Slowpoke
02-27-2004, 11:37 PM
Clarkie says...

and we did fly before the wright brothers did! the americans just spent more of their budget on marketing

Icarus flew before the Americans as well.....And look what happened to him:O)~

Hey, better late then never haha

lunchbox
02-28-2004, 12:40 AM
scott2ride, you say you used high density closed cell foam, is that the hard black foam that im thinking of? also what kind of glue did you use? and what air filter did you use? i plan to do this mod to my 01 but i wanted to know what filter i needed to buy.

mille108
02-28-2004, 02:12 AM
this is how i did it....

mille108
02-28-2004, 02:14 AM
Ive glued an extra layer of foam underneath,the seal is perfect now.
And i didnt use vaseline................ i used chain lube nice and sticky:D

scott2ride
02-28-2004, 02:51 PM
Originally posted by lunchbox
scott2ride, you say you used high density closed cell foam, is that the hard black foam that im thinking of? also what kind of glue did you use? and what air filter did you use? i plan to do this mod to my 01 but i wanted to know what filter i needed to buy.

I used the EVO filter. Definitely the best!

The foam I used was black, but it wasnt hard. It was softish to touch and very flexable.

I got it from a car uphostry place for nothing.

However it didnt need to be hard/firm to touch, as I didnt use it as a "Blade" attached to the top of the airbox (As these pics show). Because you glue it to the 'side' of the airbox you want a softer foam (But still closed cell). I have pics on another thread I did a while back. But the pics suck and the job was messy!

I glewed it to the side of the airbox using Ados instant contact adhesive.
Its been there over a year and still in place with no leaks.

NoNick
02-28-2004, 08:07 PM
Just installed the ram-air-blade to my bike (EVO and additional foam was already installed). Found out four things:
1.) My EVO and Foam sealed it very well there was a nice line around my tank of aprox. 8mm wide. No dust could be found inside

2.) The Ram-Air blade mad it sael so well I am a little worried about possible fibration to tank tank that could do damage?

3.) Found some oil inside the airbox. There were 2 oil rings/lines (black/brown) just above the throttle-valve inside the TBs.

4.) Looked inside and found black-brown (and wet because it was reflecting light) residue on the 4 inlet valves.

I wanna now if some-one else also found 3+4 or what it is and if I should worry? Before you answer: my bike still is on MAP1 (did ride 15 KM with the Tigs . . . . .). I did a dry start 1 hour ago in my garage to scare the shit out of some friends :fangs:

Plzzz advise me . . . . :confused:

kchan1100
02-28-2004, 08:27 PM
I, too, just installed the air blade yesterday but did not find 3 or 4. I did however modify the blade a bit.:eek: Milleman advised me that the Evo rubber seal is not made of the same material as his airbox kit and that the blade may wear the Evo seal a bit. So what I did was use a very fine sandpaper and rounded out the outer edge of the blade (both bottom and top). Applied a very light coat of petro jelly to the rounded edge and slapped it all together. Don't know if that will prolong the life of the Evo seal but it sure made me feel better.:D :D :D

Just my .02

scott2ride
02-29-2004, 09:30 PM
A little bit of oil in the airbox is very common and nothing to worry about.

Cant comment on the black/brown residue on the bike, except that it clearly shows your bike is totally rooted and not likely to last the month!

However I am prepared to do you a favour, and buy it off you for parts. I'll give you $1,000.:D

NoNick
03-01-2004, 02:08 AM
Originally posted by scott2ride
A little bit of oil in the airbox is very common and nothing to worry about.

Cant comment on the black/brown residue on the bike, except that it clearly shows your bike is totally rooted and not likely to last the month!

However I am prepared to do you a favour, and buy it off you for parts. I'll give you $1,000.:D

Is it that bad. Clearly the Ohlins shockbreakers and OZ-Wheels are not affected so it won't go away for $ 1,000. :bond:

scott2ride
03-01-2004, 02:52 PM
Originally posted by NoNick
Is it that bad. Clearly the Ohlins shockbreakers and OZ-Wheels are not affected so it won't go away for $ 1,000. :bond:

I hate to break it to you NoNick... but it is widely accepted amongst those in the know, that deposits like that above the throttle butterfy have occoured due to hidden hairline fractures in the Oz wheels, and these fractures result in sub-atomic.... possibly even 'quantum', osilations that pulse throughout the bike, and end up totally destroying the sensitive Ohlins suspension.

The frame wont go unscathed and the damage to instumentation by these osilations us unspeakable.

It's sad and scary I know!:( I mean, just think of the consequences of your Oz wheel disintergrating when you go over 97k[h... sending you crashing down th road to your death. I know what you are thinking :WTF: but I'd hate to hear the sad news here on the forum.....

However, as you are such a stand up guy, I'm prepared to pull out the stops and ramp up the offer to $1,235.00

You wont get a better offer!!!:devilbat:

PS. As a one time offer I'm prepared to trade the bike for a nice stretch of realestate. It's worth considerably more than the bike.... and is about a mile long and 50 meters wide & has lovely sea views, right on the waters edge. We can view it at low tide today. :bitchslap

NoNick
03-01-2004, 02:59 PM
Originally posted by scott2ride
However, as you are such a stand up guy, I'm prepared to pull out the stops and ramp up the offer to $1,235.00

You wont get a better offer!!!:devilbat:

PS. As a one time offer I'm prepared to trade the bike for a nice stretch of realestate. It's worth considerably more than the bike.... and is about a mile long and 50 meters wide & has lovely sea views, right on the warters edge. We can view it at low tide today. :bitchslap

I've always dreamt about a piece of realestate in New Zeeland! Scuba-diving is an other passion of my so I don't mind if it's beneath the water now and then. But I don't trade it with the TigCrafts. I'll switch them for the stock-pipes. Anyone in for some second-hand Tigs with only 25 KM's on them?

scott2ride
03-01-2004, 03:24 PM
OK, I'll organise the deal and the swap...

Tigs.... you didnt mention Tigs!

My GOD man!!!! The Tigs are a time bomb waiting to explode!

You see, the osilations build up and become trapped in the exhaust chamber of the Tigs. (Not so bad on the original pipes as they have the osilation absorbing catilitic soundwave converter in them. But the originals are worthless so I'll take em off ya hands anyway!)

So, back to the Tigs... yep... once the buildup occours in the Tigs there is no going back. You cant remove them from that point onwards... and this usually occours at about the 24km mark. How many km has yours done? :rolleyes:

Thunder Factory
03-01-2004, 03:31 PM
Nick and Scot

You pair need to get out more PMSL at the last couple of posts:banana: :plus:

PS Was buying into the whole thing until you dared mention the Tigs:D

scott2ride
03-01-2004, 03:49 PM
Originally posted by Thunder Factory
PS Was buying into the whole thing until you dared mention the Tigs:D

What!!!! You calling me a LIAR!!!!!

Thems fightin words gov'ner :bond: :bond:

Speedy
03-02-2004, 03:29 AM
I don't think this is still healthy ?:rolleyes: :(

Thunder Factory
03-02-2004, 03:44 AM
Originally posted by Speedy
I don't think this is still healthy ?:rolleyes: :(

Relevent? No, healthy? yes :banana: :D

crash
03-03-2004, 01:06 AM
Hey I just saw this post. I thought that I would point out to anyone who has not yet cut up thier airbox that this is a very bad idea. If you have attempted this mod you can call Seacoast Sport and order a new top for your airbox. Anyone who cuts up thier airbox for this mod has no idea how an airbox (or an intake system for that matter) works.

You end up with a larger volume airbox but so what. There is something much more important than volume when designing an airbox. The most important principle is resonance not volume. An airbox works on a pretty simple formula known as the Helmholtz Resonance Formula. That is physics. (The concept of physics will eventually make its way to New Zealand ;) (only kidding, John Britten was an amazing man, someone to be revered)).

Have you ever noticed that no manufacturer makes an airbox out of rubber or foam? Why? Because its stupid. Making a foam donut for your airbox top is like making a violin or drum out of foam. It doesn't work because it muffles the what? The resonant signal.

The only reason you could get away with this on a Mille and not realize the horror of your mistake is that a Mille is fuel injected. If you did this on a carbureted bike you would have a flat spot a mile wide.

My sarcasism is tongue-in-cheek and I really like this forum and I mean no disrespect but this "solution" is a mistake.

In the spirit of full disclosure I wanted to mention I just opened an airbox company. Yeah I was at the grocery store and I saw a whole box of airboxes, 20 for $3.00. Sure it said outdoor trash and garbage bags on the box but I know the truth. These are the good ones, 30 gallons! Can you top that a 30 gallon airbox! I am selling a universal onesize fits all model airbox kit that includes one bag and roll of duct tape.

Ram air complicates the situation considerably. And is another thread for another day.

crash
03-03-2004, 01:12 AM
Modifying the size of your airbox will have absolutley no positive effect of achieving a "raimair" system. Raimair is can only be achieved in the air intake feeds and how they mate to the airbox.

mille108
03-03-2004, 02:02 AM
Originally posted by crash
Modifying the size of your airbox will have absolutley no positive effect of achieving a "raimair" system. Raimair is can only be achieved in the air intake feeds and how they mate to the airbox.

So what your saying is that the Evo kit and the milleman kit are not working:confused:

NoNick
03-03-2004, 02:25 AM
Originally posted by crash
Hey I just saw this post. I thought that I would point out to anyone who has not yet cut up thier airbox that this is a very bad idea. Bla bla bla bla . . . . . . . .

This thread is getting full of bull-shit. Just keep it clean, a joke is fun but this is getting out off hand :ban:


PS: You almost got me "crash" . . . . .

crash
03-03-2004, 04:26 AM
"So what your saying is that the Evo kit and the milleman kit are not working" -mille108

No. What I am saying is that an airbox needs to be made of a hard material like plastic or carbon fiber. Like a guitar body it must be able to resonate. If you add a soft material like foam you are absorbing the signal that the intake produces and therefore are reducing the efficiency of the airbox.

I have never seen an Evo kit or a milleman kit and if someone has one I think thats great. But I am willing to bet that they are designed to be rigid.

I believe that the Aprilia Mille would respond favorably to a larger airbox. Big twins and big single take HUGE gulps of air on the intake stroke (singles one giant gulp, twins 2 gulps, 4's 4 smaller gulps)and this depletes the available air in the airbox faster. Again I am all for a bigger airbox but a rigid airbox.

What I am saying is the resonate signal is required to help draw air back into the airbox and anything that is done to absorb that signal disrupts the process.

If you do not agree with me that is fine. If I am wrong then why not simply remove the airbox entirely and just run an air filter?

Look at airboxes on MotoGP and WSBikes and show me a single instance where a factory has not subscribed to the concept of a rigid airbox?

Again it is not my intention to offend anyone :) If you feel that I am wrong then show me that I am wrong. I always like to learn.

crash
03-03-2004, 04:29 AM
I am sorry that I opened my mouth.

Thunder Factory
03-03-2004, 04:36 AM
Can i just claify something for a moment.

Nick what prompted your comments about Crash's post, maybe it's a bit early in the morning for me but I can't see an issue.

Crash is adding to the whole debate about air box's which has been going on in the world of the Aprilia for quite a while only it's generally called the Evo v Renegade debate.

I'm just confused why the reaction?

:peace:

Merto
03-03-2004, 04:45 AM
Originally posted by crash

No. What I am saying is that an airbox needs to be made of a hard material like plastic or carbon fiber.

I have never seen an Evo kit or a milleman kit and if someone has one I think thats great. But I am willing to bet that they are designed to be rigid.

I believe that the Aprilia Mille would respond favorably to a larger airbox. Again I am all for a bigger airbox but a rigid airbox.

Again it is not my intention to offend anyone :) If you feel that I am wrong then show me that I am wrong. I always like to learn.

Dont apologise, looks like you have raised a good point but equally dont be offended if you are questioned....we are all learning:D

The larger air volume (you agree is a good thing for a twin) is achieved by removing the airbox cover. The Evo kit it designed so that you then have a seal against the underside of the fuel tank, with any foam padding removed Effectively the underside of the rigid fuel tank is now your airbox lid.

More volume and still resonates:)

mille108
03-03-2004, 05:45 AM
Originally posted by crash
"So what your saying is that the Evo kit and the milleman kit are not working" -mille108

No. What I am saying is that an airbox needs to be made of a hard material like plastic or carbon fiber. Like a guitar body it must be able to resonate. If you add a soft material like foam you are absorbing the signal that the intake produces and therefore are reducing the efficiency of the airbox.

I have never seen an Evo kit or a milleman kit and if someone has one I think thats great. But I am willing to bet that they are designed to be rigid.

I believe that the Aprilia Mille would respond favorably to a larger airbox. Big twins and big single take HUGE gulps of air on the intake stroke (singles one giant gulp, twins 2 gulps, 4's 4 smaller gulps)and this depletes the available air in the airbox faster. Again I am all for a bigger airbox but a rigid airbox.

What I am saying is the resonate signal is required to help draw air back into the airbox and anything that is done to absorb that signal disrupts the process.

If you do not agree with me that is fine. If I am wrong then why not simply remove the airbox entirely and just run an air filter?

Look at airboxes on MotoGP and WSBikes and show me a single instance where a factory has not subscribed to the concept of a rigid airbox?

Again it is not my intention to offend anyone :) If you feel that I am wrong then show me that I am wrong. I always like to learn.

Im not offended in any way,just curiuos..... :cool:
I think the best solution is something like the EVR box....but the price :crybaby: is a bit too much for me
http://www.edovignaracing.it/
And its not availeble yet for the 04

Don
03-03-2004, 07:14 AM
This whole airbox thing interests me and 'crashs' reference to resonance got me thinking! :rolleyes:

It seems to me it's the air in the airbox which resonates and the airbox needs to be rigid so it doesn't interfer with this. Maybe the airbox resonance acts something like the twostroke exhaust expansion chamber, only in reverse. :confused: With the twostroke, the resonance provides negative pressure at the right timing to aid exhaust gas extraction, but only over a limited rev range.

Similiarly, could the airbox provide positive pressure to aid the engine induction? Again, this could only occur over a limited rev range. Increasing the airbox volume would lower the airbox resonance and move any benefit to a lower rev range - improving the mid range? :p:

I don't know, but just thinking aloud. Sorry for rambling on, it's probably all crap!! :o I just like to understand - I suspect much of the knowledge with exhausts and intakes and all that is largely empirical.

I'll go to bed now! ;) :D


:aussie:

clarkie49
03-03-2004, 07:23 AM
never thought i would say this, but a gotta agree with crash on this one.

but i guess i could use all that foam i bought to make a giant finger :D

i do like the way crash brings up the point about factory race teams, if they arent doing it, it probably doesnt work, like titanium shock springs.....but thats a whole other thread

Jony2Stones
03-03-2004, 07:26 AM
Originally posted by clarkie49
like titanium shock springs.....but thats a whole other thread


Penske-----ohhhh---Ti spring....


You sayin' it's not worth it???


Even if it's not, it'd be hot to point at for the curb-monkeys....:D

clarkie49
03-03-2004, 07:31 AM
penske yes, ti spring no :D

i talked with the Ohlins guy that actually builds all the race shocks at the Indy show (Joey) and he went into it in depth about molecular rigidity, and all this other crap that confused the crap out of me.

holy shit, just when i started to get a handle on in-depth suspension theory i talk to 'the man' and i feel like a lost kid again, i did get to play with the Gas forks and a $4500 race shock though :D

Jony2Stones
03-03-2004, 07:38 AM
So what---the theory is that over time a Ti spring would be more brittle (sp) than a standard spring...

I guess I can see some point in not using a Ti spring, everything that's lighter cant always be better...:p:

clarkie49
03-03-2004, 07:50 AM
yeah something like that, i have heard of two ti springs breaking on race bikes :( things may have changed since then but then again the serious factory teams still dont use them

mille108
03-03-2004, 08:46 AM
Originally posted by clarkie49
never thought i would say this, but a gotta agree with crash on this one.



i do like the way crash brings up the point about factory race teams, if they arent doing it, it probably doesnt work,

But youre 140 hp monster does use the EVO box is it?

clarkie49
03-03-2004, 09:18 AM
the evo kit is not foam, that is what crash is talking about.

the rubber is hard enough to create a firm seal between the tank and the airbox.

i am just agreeing about the foam possibly not being as good as a carbon or rubber (read hard) seal

mille108
03-03-2004, 09:37 AM
I guess i have to start looking for a piece of rubber then......:D

Speedy
03-03-2004, 11:02 AM
I've got it , i've got it !!!:eek:

Don't change anything (airbox-wise) ........the bike runs/pulls fine like it is .:D :D


Unless you're a track-racer and a very good one;)

bartho
03-03-2004, 01:53 PM
Your right speedy for the most of us 100 hp is alraedy enough.

NoNick
03-03-2004, 02:15 PM
Originally posted by Thunder Factory
Can i just claify something for a moment.

Nick what prompted your comments about Crash's post, maybe it's a bit early in the morning for me but I can't see an issue.

Crash is adding to the whole debate about air box's which has been going on in the world of the Aprilia for quite a while only it's generally called the Evo v Renegade debate.

I'm just confused why the reaction?

:peace:

Yep, I understood that crash was saying that adjusting your airbox is a bad idea because you would alter the way it was meant to resonate. But I read some more comments and I understand that he just meant the airbox need to be "solid" so I guess I didn't read it right.

But to go with the idea: if you would add a foam or rubber seal (even with the ram-air-blade) the air-chamber wouldn't resonate like it was meant to do so you would loose power. But with the greater volume you would add power so as long as the delta is positive you're Ok.

scott2ride
03-03-2004, 05:13 PM
Sorry Crash and Clarkie. I have to disagree with you on this one.

Actually it is not that I disagree with the theory on resonance. I believe it is quite sound.... in theory.

However the rubber seal like in the Evo or Milleman kits is very flexible around the edges and that flexibility could dramatically affect any "resonance"....in theory that is. But in reality they work!

The foam on the other hand is actually reasonably firm. In fact even using the soft foam and putting it around the edge of the airbox still results in only about 20 millimetres of foam exposed around the top lip of the airbox, and this will in fact be quite compressed and very firm once the tank closes down against it.

CRASH, I'm not wanting to argue with you about this at all, I'm simply responding to your informative post because you raised some valid points.

You also mentioned in your post about...
"Have you ever noticed that no manufacturer makes an airbox out of rubber or foam? Why? Because its stupid. Making a foam donut for your airbox top is like making a violin or drum out of foam. It doesn't work because it muffles the what? The resonant signal"

I suggest you don't mention this to Jorge at Renegade. Because he makes an excellent high-performance pure foam filter that does away with the airbox altogether, and most importantly, it is very effective at increasing Hp. Many of us here on the forum have bought it and sware by it.


HOWEVER>>> let's put this all into perspective and forget about theory for a moment.

In real-world tests on the road and using a Dyno, the larger airbox volumes created by the EVO kit, Milleman kit, Renegade "No airbox at all foam filter" kit and the home-made "foam around the edges" kit, all result in considerably higher horsepower numbers than the standard solid plastic airbox.

I personally did a back-to-back comparison on the Dyno with the homemade kit, the Evo filter, the Renegade Foam kit and the standard airbox. And I can assure you that ALL were considerably better than the standard airbox. In fact the homemade 'foam edged' airkit had the best result (On my bike on that day), so I onsold the other kits.

I'm not disputing the fact that resonance as an important issue with respect to the effectiveness of airboxs. All I'm saying is that using foam around the edge does not create a resonance problem in this instance. It increases horsepower through out the range.

But I should reiterate, when the tank closes over the rubber seal or over the foam edging, it ends up compressing down quite tightly on them, hence why it may not create a resonance issue.

CRASH, you also mentioned...
"Look at airboxes on MotoGP and WSBikes and show me a single instance where a factory has not subscribed to the concept of a rigid airbox?"

Need I remind everyone that the Aprilia RSV SP model came as standard with NO airbox lid. It used the underside of the tank and a rubber seal around the edging. In fact I daresay that the SP airbox is what Ken (from EVoluzione) originally designed his airbox around.

As I understand it (and I may be wrong on this as it was 'second hand info), Im told a number of Ducati's also have no airbox lid and utilise the underside of the tank as the "top" of the airbox and have a rubber seal.

I don't know if the current MotoGP and WSBikes use this type of airbox when racing, but if they don't it wouldn't surprise me that the reason they don't is due to rules and restrictions placed on them by the governing race bodies.

As far as other bikes are concerned, the placement of the existing airbox, throttle bodies, and the shape of the underside of many petrol tanks (not to mention numerous potential sealing issues with some tank shapes) will no doubt prevent many bikes from utilising this type of airbox modification.

Also,CRASH, I think you may have misunderstood the comments about the ram air.
You said...
"Modifying the size of your airbox will have absolutley no positive effect of achieving a "raimair" system. Raimair is can only be achieved in the air intake feeds and how they mate to the airbox."

Your statement is true, however the reference to ram air was referring to the fact that with the Evo style of rubber seal it has the potential to allow air to blow past it at ram air speeds once the airbox gains positive pressure. Milleman created the ram air blade as a solution for the problem, and using high-density foam around the edge of the airbox also eliminates this problem as it creates a firmer and tight seal.

So in a nutshell, I do agree with both yours and Clarkie's comments that resonance is important. But in the real-world it has shown that in this instance, with the RSV airboxs, they are very effective at increasing performance and are also widely used and proven amongst both race teams and performance tuners..

Sorry for the long rave. :blah: :blah: :blah: :blah:

The bottom line is.... that it is okay to use this type of airbox and that it DOES WORK effectively. :banana: :gunner: :rambo: :fangs: :ban:

zx6racer
03-03-2004, 07:28 PM
With all this talk about airbox mods is it worth all the pain of lifting the tank every 300 miles to make sure the filter did not move ???? not to me is there any other way to do the mod like on the older bikes had the metal ring that went between the lid and the airbox it self ???



:peace: :bond:

scott2ride
03-03-2004, 08:02 PM
Originally posted by zx6racer
With all this talk about airbox mods is it worth all the pain of lifting the tank every 300 miles to make sure the filter did not move ???? not to me is there any other way to do the mod like on the older bikes had the metal ring that went between the lid and the airbox it self ??? :peace: :bond:

Sure there is!

You dont need to check it ever again (Except at general maintenance intervals) once you've installed it correctly.

The filter will NOT come loose if you put a small screw at ech end, at the front of the air filter. This will hold it in securely and you need never worry about it again!:cool:

mike71
03-04-2004, 05:34 AM
i thought the intake trumpets were the factor when it came to air box resonance. Different length trumpets shift the "most efficient" rev range (ie at certain revs the induction pulse assists aspiration).

I didn't think making the airbox larger affected the (intake) primary resonance forces.

:confused:

Rutan
03-04-2004, 06:02 AM
I am a firm believer in the air box resonance therory. My other bike is a Yamaha YZF600r, and some guys on that list group have tried altering their intake and airbox to make more air flow in. Nobody could make the bike any better. Also, the K&N highflow airfilter makes that bike loose power. The old racers for that bike say it is because the stock resonance is the best for that system.

However...

If therory states that resonance is the best thing, and application states that airbox volume is what works, then make a large airbox with good resonance.

Or just go for what works

Marcus

Merto
03-04-2004, 08:37 AM
It would seem that the ideal resonance for a given RPM range is a function of intake (ram) pipe dimensions, airbox volume and throttle body dimensions. Altering any will affect the pressure waves.

Interestingly, the resonance chambers attached to airboxs are there to create a dead air space to dampen out some resonance (and therefore pressure) simply to reduce noise. I guess this is preferable to inserting sound deadening material and restricting airbox volume for the same quietening effect.

Tech heads click HERE (http://www.grapeaperacing.com/GrapeApeRacing/tech/intakehelmholtz.cfm) for an explanation.

scott2ride
03-04-2004, 02:57 PM
As Rutan put it...."Just go with what works!"

The Evo kit works... Millemans kit works (And I personally believe his ram air blade improves the design... The Renegade kit works (Well it did for the old modle and I'm confident it will for the new one)..... the home-made 'firm' foam", attached to the top lip of the airbox, works... and the softer closed cell foam glued around the edge of the airbox works.

They all work better than the standard airbox.

Which you choose is uo to you and your budget and with the exception of the Renegade (Which hasnt been released yet) they will all perform about the same.!

crash
03-04-2004, 07:54 PM
Thank you Merto for your insight. As I stated I don't have the answers but I think you are asking the right questions.:) Your link is awesome! Thank you for posting it.

To anyone who doesn't believe in the helmholtz theory I would like to point out that it does exist. When you hear that intake honk from your airbox at speed that is resonance at work.

The theory is relevant and very important to performance. It is also relevant and factored into the design of exhaust systems. Header length, shape and overall exhaust volume play a major role in engine performance. Same theory, other end of the combustion process.

The easiest way to manipulate resonance is to change intake and exhaust runner length and maintain a consistant diameter. In this way you control the variables and can review your results and make changes accordingly. You can also change the signal through porting and valve size and carb/throttle body size. Bigger isn't always better. Since CV carbs work on the vacuum signal, (it is vacuum that determines slide position) CV's are very sensitive to resonant signal. Get anything wrong on the intake or exhaust side and you end up with flat spots in your power curve. Flatslide carbs are less effected since you manually pick up the slide with the throttle cables. This masks small errors but still effects overall performance.

Anyway I hope that I didn't cause too much trouble in pointing this out. I want to also point out that I learned these basic princibles the hard/expensive way. How would you feel about running freshly built motor on the Dyno for 6 hours with 3 sets of different carbs and an entire book of jets and different needles only to find out that your exhaust system is 4" too long!

pbrown
03-04-2004, 07:55 PM
All the 916 -998 range used the petrol tank as the top of the air box with a rubber seal - the only problem being that depending on road conditions you occasionally got dust / rocks into the air box.

As far as I am aware Ram air effect is dependant upon the total length of the intake and is only good over very specific rev range (hence variable length trumpets in F1)
The way it works is based upon refracted pressure waves that are created with the valve opening and closing.

The reason the airbox is a certain size is to act as a Helmholtz resonator and to try and counteract the negative effects of the ram air principle when it is outside of it's ideal range.

If you change the airbox volume then it does not stop the Helmholtz effect but just changes the rev range at which this occur's.
Also it maybe that the increase shown on the Dyno with the lid removed is because the airbox lid was too close to the mouth of the air trumpets (nothing should be closer than 1 trumpet diameter and preferably 1.5) as the refraction of the pressure waves does not occur at the trumpet mouth's but 1 diameter above the trumpet.

This is a very complex area of engineering and manufacturer's and race teams pay good money for Computational fluid dynamic
program's and the people that can use them.

There again it's allways good fun to change things and knowing the above never stopped me from cutting the top off airboxes.

Final note - a number of well known and respected engine tuners in the UK sold foam filter's to go over the trumpets of 916 etc. to keep out the above mentioned dust and also to give more air flow, It has been found on various Dyno runs that these filters gave less power ? It was also noted that the air filters were very close to the trumpet mouths.
It just goes to show that we can all get it wrong

Rutan
03-05-2004, 05:07 AM
SOOOO.... what we need to invent is an airbox snout that expands and contracts in length due to the optimum calculated resonance at X speed and Y RPM with Z ammount of aibox pressure, and for broke :banana: , Q inner airbox air speed. Imagine how precise you could get the tuning on the bike if it came to life.

Marcus

MaxFromUK
03-05-2004, 06:26 AM
The Helmholtz theory only works for a regular firing order (or so the article says) so how does that apply to a 60 deg V twin?

I'm with the guys who have tested and have actually improved the performance. Theory is worth diddley squat if it doesn't tranfer to practice and like an earlier poster said the SP used the tank as a lid. I would also share the worry about dirt ingestion. I do fancy making myself one though. Another point to mention Jorge has said in the past with regard to the rene airkit that it matters not whether you remove the foam from the underside of the tank. That kind of also goes against the resonant frequency effect.

Interesting thread though,

Max

derrickhackman
12-23-2005, 07:32 AM
Scott, with this mod did you remove the foam on the underside of the fuel tank? I am thinking that you did.

Over time, how has this held up? I think I will be hacking my air box in the same manner.

CDaniel525
12-23-2005, 09:17 AM
Derrick...
I did something similiar to mine, but just took off the airbox and molded some auto weatherstripping around the bottom half of the air box and held it in place with the screws for the top. It worked pretty good but isnt 100% sealing and looks kind of sloppy due to silicone sealant to make some sealing points... sounds a little to sloppy doesnt it!? But in any case, its definitely a worthwhile mod.

I did also remove the foam from the underside of the tank, which should be done to keep it from breaking off and going in the TBs... Also make sure to clean off any left over glue or flaking paint.

After seeing Scott's version of the airbox, I bought an extra use lid off AF1 for like $7 and im gonna hack that one up and make it as Scotts suggests so I can get the 100% seal...

derrickhackman
12-23-2005, 10:33 AM
Scott's version (use part of the top of the air box to hold the foam seal) looks to be the trick. I really do not want to do a hack job but at the same time I can't bring myself to spend the bucks on nothing more than a ring with a rubber seal.

I know the air box has been beat to death with the number of posts put up against it but a cool DIY mod like Scott has in place is worth the time and posts IMHO.

I am going to source the material and take some good photos once I get in there and start sawing away.

CDaniel525
12-23-2005, 12:18 PM
I am going to source the material and take some good photos once I get in there and start sawing away.

Thats the only thing I havent figured out yet... what to use for cutting the box?? Hacksaw, dremel, sawzall:gunner:

derrickhackman
12-23-2005, 01:00 PM
I was thinking of using my Husky 340 chainsaw for the rough cut and then finish it off with a hack saw then dremmel.

The chainsaw may be a little too much .. i am gonna have to eye it up and see.

CDaniel525
12-23-2005, 01:41 PM
The chainsaw may be a little too much .. i am gonna have to eye it up and see.
Hehe... that might be a lil overkill bro :-D Im leaning towards the sawzall for the rough cut, using a fine metal blade the more I think about it. TOO BAD I DONT HAVE THE BIKE TO PUT IT ON!!! CAN'T WAIT TO GET IT BACK! ARGHHHH

scott2ride
12-23-2005, 11:58 PM
I have a new version now... Much better!

Go here...

http://www.apriliaforum.com/forums/showthread.php?s=&postid=361854#post361854

derrickhackman
12-24-2005, 07:22 AM
:worship: :worship:
Scott, you rock. If I can get close to this I will be happy. Thanks and Merry Christmas.

Tee-Dub
12-24-2005, 10:36 AM
That one does look like it seals better, but for over $200 usd you don't even get an air filter with it, and its just made of plastic. If you could just buy the plastic ring with rubber gasket for $100 or so, that would be a good deal.

I do agree, it often baffles me when guys spend big bucks on a bike, then try to come up with every home creation instead of spending a couple hundred bucks. Sort of like my last bike, a 2004 Honda CBR1000rr, the previous owner took a hacksaw to the rear fender instead of spending $150 on a proper fender eliminator. $11,000 for the bike and you can't drop $150 on the right part?

Now, I do understand some guys are just tinkerers and that is cool. But, to really know if your's was working properly, you'd need to buy the kit, do a dyno run, install your homemade kit and do another dyno run, then compare results.

Other guys claim to be tightwads and wont spend the money, but really, how much of a tightwad can you be if you bought an Itallian motorcycle? These guys forget how much their own time is worth, and will spend hours on some project making it themselves, just to save a couple hundred bucks. :soap:

Dr. Thrillride
12-24-2005, 11:39 AM
That one does look like it seals better, but for over $200 usd you don't even get an air filter with it, and its just made of plastic. If you could just buy the plastic ring with rubber gasket for $100 or so, that would be a good deal.

I'd agree that that one is a little pricey. There's a carbon airbox from an italian maker for 750 Euros if you're really into it. I'm following Clarkie's lead and just putting the evoluzione metal ring between the two halves of the airbox. In fact, I will see if two rings will fit, since I got a replacement for the older style that did not have the cross member to hold the filter down.


I do agree, it often baffles me when guys spend big bucks on a bike, then try to come up with every home creation instead of spending a couple hundred bucks. Sort of like my last bike, a 2004 Honda CBR1000rr, the previous owner took a hacksaw to the rear fender instead of spending $150 on a proper fender eliminator. $11,000 for the bike and you can't drop $150 on the right part?

There is a guy on the ducati forum with an 05 999s who did the same thing. He took a razzing because he didn't even bother to sand the edge of the cut plastic.

Italijet
12-24-2005, 12:51 PM
Guys, I'm all together with the resonance theory, however there is a little (grand canyon sized) flaw in the theory. If you don't believe me think of how an Engine really works. The Fuel and Air needs to be mixed to a ratio of approximately 14 parts air to 1 part fuel.

So, If your letting the engine "Suck" in the air by depressurising the cylinder during the down stroke (with the inlet valve (chamber seal) open) then all you need to do is ensure that there is enough available air to "equalise" the pressure in the chamber. Here resonance plays a part, but not by GP teams for the resons that were previously quoted.

Hard constructed Air boxes are used to ensure that the air being scooped up by the inlet ducts is compressed in the air box. The effect of this compression is that when the inlet valves open Air is Pushed into chamber in a larger volume than the decompression by the piston would naturally allow. Force feeding the chamber with air causes the need for more fuel to meet the 14:1 ratio. The more fuel and air the bigger the "bang" and the faster the piston accellerates from just past TDC.

This is the theory behind forced aspirated engines (turbo charged and compressor (blown) engines. Hard walled air boxes are beter at maintaining even pressure. Where as soft walled construction are better at increasing pressure once inflated, it's difficult to keep a soft walled airbox inflated and the right size for the intake due to size restrictions under the fuel tank.

Force feed a fire with oxygen, it will burn faster, feed it faster than it can get fuel and it will go out. This is not because the oxygen enriches the flames, it is because the fire needs more fuel to use up the available oxygen. Restrict the flow of oxygen and the size of the flames diminish, becuase the fire needs less fuel to maintain the equilibrium.

I'm planning on obtaining an air box and modifying it to be pressurised at 10 foot pounds at all speeds above 20mph. Keeping the air box pressure constant (non return inlet valves and "waste gate outlet valves) makes performance tuning so much easier, the amount of air being forced into the inlet is constant, where as traditional "ram air" systems pressurise more at higher speeds, leading to a lean top end and rich bottom end of the rev range.

Ram Air is the "free" version of the turbo charger, F1 teams have been using this technology ever since turbo's were banned. So much so that the rule makers enforced a 6 foot pound air box pressure limit on the teams some years ago.

:blah:

CETME
12-24-2005, 02:06 PM
the stochiometric combustion for gasoline (14.7:1) just means its the required ratio for "complete" combustion.

at W.O.T we dont want anything that lean... we want to be closer to 12.5-13 to one.....

and resonance bounce (correct me if i'm wrong) stops with the throttle body, or the first sharp bend in the intake plumbing.