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19E-299
03-29-2009, 12:16 PM
Hi,

Maybe some of you know my RSi from youtube, but for everyone else whos interested i would like to introduce to you my little project i was doing the last month. First let me introduce myself: My name is Daniel, im 30 and im studying automotive engineering. Im working with engines since im 13 and i really like it :)

But lets get into detail:

Back in 2007 i bought a 1997 RS 125 in pretty good condition. The stock 34mm carb was worn out and the engine never ran as good as a wanted it to. So i took one of my free programmable ecus, bought a throttle body, modified the airbox and the intake stack and wired a harness (to be honest, there was much more to do :D).

After a feew weeks of modifications the engine fired up for the first time :spankie: It ran really rich so i had to lean the maps pretty much.
Getting the engine to idle from -10C ambient to 80C watertemp was hard work, but finally it ran nearly perfect.

But lets get to the interesting part :)

http://www.directupload.net/images/user/11738/temp/U56RZN5f.jpg (http://www.directupload.net/file/u/11738/U56RZN5f_jpg.htm)

Thats what i bought. New tires, chain, brake pads, polini cylinder and overhauled fork.

http://www.directupload.net/images/user/11738/temp/z2uL8PO9.jpg (http://www.directupload.net/file/u/11738/z2uL8PO9_jpg.htm)
http://s2.directupload.net/images/user/070806/temp/jP97BJb2.jpg (http://s2.directupload.net/file/u/11738/jP97BJb2_jpg.htm)

First i tried to install the throttle body and the fuel lines.

http://s3.directupload.net/images/user/070816/temp/V5gvGNSv.jpg (http://s3.directupload.net/file/u/11738/V5gvGNSv_jpg.htm)
http://s5.directupload.net/images/user/071007/temp/jrlivyl8.jpg (http://s5.directupload.net/file/u/11738/jrlivyl8_jpg.htm)

The exhaust was heat wrapped and a wideband o2 sensor was installed.

http://s4.directupload.net/images/user/080608/temp/tkpi3gpd.jpg (http://s4.directupload.net/file/u/11738/tkpi3gpd_jpg.htm)

Wiring all those stuff was really much work and there is also enough work to be done.

http://s3.directupload.net/images/user/080815/temp/5f83qjyj.jpg (http://s3.directupload.net/file/u/11738/5f83qjyj_jpg.htm)

Once the engine was idling i took her for some rides.

http://s8.directupload.net/images/user/080912/temp/qh2kga35.jpg (http://s8.directupload.net/file/u/11738/qh2kga35_jpg.htm)

The stock CBR injector maxed out at 15hp (installed the Rave2 wrong way :rolleyes:), so i had to modify the airbox to take the second injector.

To get a better overview over the progress:

http://www.youtube.com/watch?v=S1xvr_VXzx4
http://www.youtube.com/watch?v=j5FOUn7V3nc
http://www.youtube.com/watch?v=WBaiMJb6ntY
http://www.youtube.com/watch?v=pZl5KPwvm0s
http://www.youtube.com/watch?v=SDHDBneCf4o

By now the engine ran really good, sadly a few weeks ago some bearings got damaged after a few miles at topspeed and i had exams so i couldnt take a look whats really damaged. But i will let you know when i find out :)


kind regards
Daniel

ThisEndUp
03-30-2009, 09:17 AM
Hallo und heit willkommen.


Come on over to NJ and sort out my bike. I'll buy the bratwurst and beer.

:cheers:

RZRob
03-30-2009, 09:35 AM
Very nice! Where were you when the Bimota 500VDue needed sorting out? Keep us posted on developments. Can you reproduce this for an RS250?

RZ Rob

19E-299
04-03-2009, 08:00 AM
Shure this can be done to RS250 also, but the angle between both cylinders makes it more difficult to align both throttle bodies. generally it should be easier to modify as my rotax123 where i had big problems to find a suitable position for the crank trigger sensor.

the good news is, my exams are finished by now and the weather is really good, so im looking forward to pull out the engine and find some broken bearings.

kind regards
Daniel

coffee
04-04-2009, 12:40 PM
This sounds awesome, keep all posted on how it goes. how are you dealing with the oil?
Are you making it pre mixed?
Will this effect the life of the injector?
If i am correct, injection makes the motor more responcive and creates more power ddue to the fact that the injector atomises the fuel much better than a carb. If this is the case, how will the oil effect this process. Will it atomise as much and if better, will it force the oil to walls rather the bearings?

Noassmblyrqired
04-04-2009, 09:15 PM
Injecting at the Throttle body isn't the only way to do make this type of system work. Fuel could be added at any point of the fuel stream. The high velocities offered by the reeds would make for a really great injection point. There is also no reason why oil needs to be injected at the same time/place as the fuel. Direct injection (injecting at the piston) works quite well with 2 strokes and fights of dreaded detonation and throttle response!!! Obviously, direct injection is more sophisticated and requires more complicated hardware but on a 2 stroke is very effective. It would also solve the packaging issues for the RS250.

2-stroke technology has come a long way on the research level and can surpass 4-strokes in many ways including emissions and fuel economy when done properly. Most of this technology will never make it to market because 2-strokes have a reputation of being dirty and inefficient.

19E-299 I commend your work and enjoy seeing projects like this!

coffee
04-05-2009, 12:40 AM
Is great to see someone trying different things and others offering their knowledge to try and assist, keep it flowing and lets see a fuel injection system for all to make use of. Surely that would see other modifications doors open.

banzairx7
04-05-2009, 01:26 PM
I'm working on injecting a Derbi GPR125 myself. For those interested you can find the info on what Ive got done so far here- http://www.125ccsportsbikes.com/forums/index.php?showtopic=63480

I've just finished amassing the parts for project and started some bench testing. In a few more weeks it will start going on the bike.

torqsoft
04-05-2009, 02:19 PM
Well done on a very interesting project.

I notice that you are using a wideband o2 sensor. For what purpose do you use the readings from this sensor and what is a typical afr/lambda when cruising?

coffee
04-06-2009, 06:33 AM
Thats awesome, hope you both work together. two heads are always better than one and gets these both sorted. Great stuff guys!

19E-299
05-10-2009, 02:48 PM
Well done on a very interesting project.

I notice that you are using a wideband o2 sensor. For what purpose do you use the readings from this sensor and what is a typical afr/lambda when cruising?


Lambda while cruising is around 1, it could be raised up to 1,2 but actually its hard work without a good dyno. im limited to drive tests on open streets, so the progress is a bit less than i would prefer it to be.

of course the value is used to calculate the air fuel mixture corresponding to the exhaust gas temperature. both are very good indicators for a good running engine.

As i thought, one of the main bearings got damaged. the bearing cage melted, actually i dont know exactly why.

http://s3b.directupload.net/images/user/090501/temp/rqnv6z2j.jpg (http://s3b.directupload.net/file/u/11738/rqnv6z2j_jpg.htm)

but the good news is, the engine is taken apart and the search for more hp can go on :)

@banzairx7

sadly i cant answer in yout thread, but be aware of the thinking that 260ccm/min would be enough for your requirements. as stated in the first post ~250ccm/min is just enough for around 15hp. so if you really want to get close to rs125 horsepower you definately need much more fuel flow. but you will find out once the system is at the bike :)

Gman2005
05-10-2009, 04:04 PM
Ring up Aprilia and share your work lol. If they can adopt this to the Mass RS 125 production line, the RS won't die :)

random0082
05-10-2009, 05:39 PM
b@llocks to Aprilia, sell it aftermarket if you head into production! lol

Gman2005
05-11-2009, 03:51 AM
well unless he wants to paying out for a million rebuild and people sueing him all the time lol.

rgv250
11-09-2009, 01:56 PM
Hi Daniel!
I'm french and I'm riding a rgv 250 and I want to do the same thing as you on it. I'm also doing engineering studies. I'm wondering where you found your ECU and if you can told me how do you have set your injection ( sorry my nglish isn't perfect).

banzairx7
11-09-2009, 02:34 PM
I got mine here- http://www.diyautotune.com/catalog/microsquirt-engine-management-system-p-131.html

Micah / AF1 Racing
11-09-2009, 03:18 PM
Using a lambda sensor, even wideband for feedback is going to have limitations just like a mass airflow meter would in this case. The reason is that during the portion of the piston's downward stroke and return from BDC there is a LOT of air and fuel (homogeneous charge) that "short circuits" from the transfer ports and out into the exhaust port and chamber, only during periods where the engine is working in the resonant frequency range of the pipe and exhaust port is trapping efficiency or VE high. To summarize the above statement just think that "no matter what there is going to be a LOT of unburned air in the pipe" and the o2 sensor will indeed see this, hence the reason you feel that yu have had to massively lean out the mixture.

Using a combination of feedback from a detonation sensor and an EGT probe located about 100-125mm from the piston skirt will provide a far more accurate feedback loop as long as you can find a thermocouple to use which scales in the 0-5V range and then you will need to determine what your ideal temps are for the rpm and throttle position range. For instance on most 2t racing engines 1200F at wide open and in the resonant range or close to this is usually considered the upper limit of EGT before the engine begins to detonate. You use this feedback loop of EGT versus Det Count to trim fueling accordingly. When detonation is detected the map shifts globally richer and the timing globally backs off a few degrees to reduce detonation and cool the engine after a detonation event has occurred.

I am really impressed with your work thus far on the project and envious that you have done it, and gotten it to work so well.

BTW, the EGT chosen for a given rpm and throttle position must be given considerable consideration. I like part throttle EGT in the range of 800-900F, rich, this cools the piston during the transient move from closed throttle to open throttle and allows for a longer interval of higher EGT numbers to follow before detonation events occur again. The same is true of closed throttle, for instance at the track after a long straight when you chop the throttle you want fueling to be impossibly rich, you are using this impossibly rich mixture to cool the now superheated piston and rings quickly on decel. For street use you still use this over-rich closed throttle bit a little, though not nearly as much over fueling is required due to not operating at the same peak EGT's.

If you have access to a CO (Carbon Monoxide) meter this is a far more precise tuning implement for an injected or carbureted 2T. Even samples taken from the middle of the expansion chamber will reflect only data about what is actually happening during the combustion events, not how much unburned air and fuel has short circuited the transfers and out the exhaust port.

EFI delivers on the promise of wider power bands and finite control of a dynamic airflow environment, no carb can be set up ideally for the entire rev range and still work right in all of these dynamic spots in the rev/tps range. You can extend the power band easily by over fueling with rich mixtures below the native resonant frequency of the pipe since this frequency is controlled by both the local speed of sound and the design of the pipe and conversely under fueling and retarding timing in the rpms above the torque peak to raise the exhaust gas temp and increase the frequency of the local speed of sound.

At the same time with EFI you can make the bike run cleanly as possible in all "off pipe" conditions and absolutely minimize the anti-resonant stumble as the rpm transitions into the beneficial resonant range of the pipe.

Hats off to you, excellent job mate, your work is inspirational to me.

banzairx7
11-09-2009, 03:29 PM
Glad this topic came back from the dead. Im getting close to finishing mine up. As always great advice from Micah(who will be playing with my injected bike on his dyno soon enough). It was good to revisit your install pics for me. I ended up with the injector a little further back then I would have liked. Yours is pretty far back and causing no harm so Im not going to sweat it.

Again good work. Seeing your bike was what gave me the push to do my own.

the brit
11-09-2009, 04:59 PM
I got mine here- http://www.diyautotune.com/catalog/microsquirt-engine-management-system-p-131.html

I run a full megasquirt setup on one of my cars, with individual throttle bodies etc. Microsquirt is a neat option, as are the options to run it with a Palm OS setup..

Good stuff :plus:

Socket
11-11-2009, 06:18 PM
EGT isn't the best way to tune. Bottom line AF will be with a good wideband setup. The problem with EGT is the variables on not only fuel, but timing and amount of premix ran in the system can cause the reading to vary a lot.

Micah / AF1 Racing
11-11-2009, 07:22 PM
Socket, the problem with the whole lambda thing in a 2T is the massive amount of extra oxygen in the pipe from short circuiting from the transfer ports through the exhaust port(s). Yes, you can use lambda but the values are nothing like in a 4T because you have to account for all that extra o2 out in the pipe.

There is no perfect system...

Socket
11-11-2009, 08:20 PM
Socket, the problem with the whole lambda thing in a 2T is the massive amount of extra oxygen in the pipe from short circuiting from the transfer ports through the exhaust port(s). Yes, you can use lambda but the values are nothing like in a 4T because you have to account for all that extra o2 out in the pipe.

There is no perfect system...

You've got me there. I have _never_ tuned a fuel injected 2 stroke.

Micah / AF1 Racing
11-12-2009, 12:35 AM
I have yet to tune a 2t with port efi either, no worries. Just a trend I noticed tuning carbureted 2t's when you look at data from residual o2 left in the expansion chamber, mainly in off "peak" rpms. A lot of people have played with o2 sensors in the expansion chambers of two strokes with carbs, their impressions run the gamut.

19E-299
12-21-2009, 01:00 PM
Hi Daniel!
I'm french and I'm riding a rgv 250 and I want to do the same thing as you on it. I'm also doing engineering studies. I'm wondering where you found your ECU and if you can told me how do you have set your injection ( sorry my nglish isn't perfect).

sorry for the very late reply but i had several injuries in the last month and i bought a new car, so the rsi project has little to nothing progress :pissed:

the engine is still ripped apart and waiting for a overhauled crank. the barrel needs some real porting and milling and at the end of the day i still have problems with the current draw from the fuel pump.

actually im learning for my last 5 exams and i hope i can use the rsi as my diploma thesis which could then be converted to direct injection (to have something unique :worship:).

to answer your question, my ecu is a english project called mini-ms. the idea behind it is to have a more little layer then the original design.

the software settings arent that hard if you are capable of technical english.

kind regards
Daniel

19E-299
01-03-2010, 10:36 AM
finally, the engine is overhauled and completely modified as i wanted :devilbat:

http://s5.directupload.net/images/user/100102/temp/6j85l5bm.jpg (http://s5.directupload.net/file/u/11738/6j85l5bm_jpg.htm)

:spankie:

Micah / AF1 Racing
01-03-2010, 12:02 PM
Looking good, the throttle body looks so proper, like the way these bikes should have come from the factory for the last decade or so!

Keep us posted.

19E-299
03-12-2010, 05:50 PM
Just a little update, im allowed to use the RSi as subject of my diploma thesis :spankie: :worship:

i dont think i will be able to convert it to DI as that would require some serious financial background which i dont have by now. so i guess it will be about converting the engine and getting it tuned properly on one of our engine dynos. maybe im able to have a stock barrel and my polini tuned, but i have to see how much work it is to implement the engine on the bench.

but the good news is, i can tune the engine steady state in every field of the maps and im going to convert it to free programmable ignition also, whereas the ignition is by now controlled via the stock sem box.

lets see what a injected rotax can put out :devilbat:

19E-299
06-03-2010, 02:05 PM
just a little update:

http://www.youtube.com/watch?v=Pv10fEW_yoQ

it should run at the weekend if im not to lazy :)

Dieterly
06-03-2010, 08:06 PM
Thanks for the update...

Micah / AF1 Racing
06-03-2010, 08:56 PM
I have an injected (megasquirt/microsquirt) Derbi GPR125 coming in for tuning next week. I am actually thrilled about this will be happy to share what I learn!

19E-299
06-04-2010, 02:26 AM
i guess i know that guy from an other forum... i hope he learned and mounted a adequate fuel injector.:rolleyes:

zapped
03-18-2011, 06:58 PM
This sounds awesome, keep all posted on how it goes. how are you dealing with the oil?
Are you making it pre mixed?
Will this effect the life of the injector?
If i am correct, injection makes the motor more responcive and creates more power ddue to the fact that the injector atomises the fuel much better than a carb. If this is the case, how will the oil effect this process. Will it atomise as much and if better, will it force the oil to walls rather the bearings?

at best fuel injectors can be more accurate in fuel/air mixture than a carb, -not necessarily any more power than another properly jetted sytsem or carb.

-the oil in a two stroke doesn't atomize. the fuel vaporizes, and the oil separates out and forms into drops that blow-through with the intake air...
with pre-mix or oil injection... either way the oil separates from the fuel vapor in the inlet tract, back into oil droplets-

becyk
05-23-2011, 10:21 AM
Would love to inject my RS500. Lack of time, money and knowledge are holding me back! lol

Awesome! I like when people do stuff just because it isn't good enough from the factory. Nice job

bigpt
11-12-2012, 01:34 PM
Av you still got it

Micah / AF1 Racing
02-08-2019, 11:15 PM
So..know this is old ancient thread, but I have a new carb incoming for testing some mods on one of our trackday bikes. Squish sorted now easily on lathe....bought a rebuild kit and an old 34mm jet ski pumper carb, basically mechanical low pressure fuel injection to try out. 34mm throttle...we shall see. Mixture will be adjustable on the fly for low and high speeds and loads. Anybody else ever try a tillitson style carb?

ShiverSteve
02-11-2019, 12:04 PM
I just picked up a RS125 from Dallas that has a Dell Orto 34 mm carb with the Polini 154 piston. What will the benefit of this setup be other than the on the fly adjustments? Also, on a side note, can I bring the bike in to have its Italkit inner rotor racing ignition kit installed while I watch the installation and timing so I don't screw it up myself?

Micah / AF1 Racing
02-11-2019, 10:18 PM
No problem there, be happy to show you how. My Mikuni Super BN (ROUGHAS HELL, THANKS EBAY) arrived today, along with full rebuild kit. Basically since I tune against EGT and CHT on the fly or dyno remote mixture adjustment like I have in my airplane will be baller as shit if I can sort it out, pics to come....it’s REALLY rough right now, comically so.