I've defected!

[speedfiend41]

After the last half dozen years on Aprilias I've done the unthinkable and returned to a Jap bike! Flew to Sydney and rode it home - through the night! Fucking roos almost killed me twice and I almost froze but it was a fun 1300 km.

It's an 03 GSXR1000 with a Yoshi and other mods. After so long with the v twins I started to miss that inline four howl. And as far as I'm concerned, the only big bikes I buy will be pre 2007, when emission laws killed off midrange.

I'll keep this until I've saved enough for a Tuono V4...

[Wot_bike_isit]

Not so sure it's emissions that killed off the midrange, rather the search for high peak hp figures.

If I were looking for a Jap I4 1000 the K5 would be at the top of my list. As stock as possible.

[steve p]

05-06 gsxr1000 ftw

[Thom]

[Micah / AF1 Racing]

My GSXR preference might be slightly odd? The 00-03/04' 750cc is the one for me. With a good pipe, right bolt on parts, well setup motor (degree cams, that's about all) and well tuned they make about 120-122bhp on our dyno at the shop. I am working on a K7 in gixxer speak right now on the dyno. It has a a slip on, and a PCV I am tuning. I expect even this 10k mile street bike will be in the 112-115bhp range, same as a well setup V990 on a stock bore. Remember our dyno reads low compared to "magazine numbers" types of Dynos and setup. Basically this is more than enough for me, I can wheelie it pretty much at wil and even on 10k mile stock suspension you can feel the potential in the chassis. The years I prefer have a bit more stroke, a bit less weight and complexity, relatively simple electronics that are FULLY hackable! No additional tuning device required once you learn the system for talking to the Suzuki ecu directly. I am not familiar with the process on a personal level really but have seen a lot of the serious Suzuki guys in land speed using this "open" hack of the ecu. It is beautiful to a tuner.

The 750cc is the right size for me like the thousand-ish cc twin is as well. I f you need fast you just turbocharge it using a kit for a GSXR 1k, then it should be fast enough for most anyone. Good bikes they used to be. I like the extruded beam frame models, when they went to cast frame and swingarm they lost me.

[photoRotor]

Thom, that's frikkin' brilliant. To have the thought "Oh the humanity" is pretty funny. The cartoon gives it 4 1/2 stars!

Amen Micah, an older 750 gixxer is my new track bike - after I find it and the little lady approves the distribution of funds.

[derbybrit1]

I recently bought a 2006 GSXR 1000 K6 for track duty...but kept my Aprilia(s). Best of both worlds.

[JAndrewG]

My brother has a K5 GSXR 1000 that the previous owner worked over with bigger cams, head work, and a full Akra exhaust. I was ahead of him on my MV F4 1000 with the throttle pinned, banging gears when the shift light came on at 12,300. He didn't even realize I was 'going for it'. Said he didn't think about it, just gave it a little more gas to keep up. That bike is friggin' fast.

Still, I really miss my RSVR. I'm still collecting parts after being rear ended last December. I love the power delivery of a v-twin.

[maxpower220]

After years of twins, my last purchase was a 07 GSXR 750. Except for the rear shock, the bike is pretty amazing in stock form. The Yoshi pipe is nice as it is fairly quiet below 7000 rpm and then lets out a great scream above that.

[Micah / AF1 Racing]

The stock shock on the GSXR's blows donkey dick. Posted from the dyno room, where I am tuning an 07' GSXR750...probably take it home for the weekend, well no, fuck that, going to be too hot, but the next one on a nice weekend I might take home for a little play time.

[Micah / AF1 Racing]

So tuning is finished, this is nothing more than a slip on, a crappy one at that and a PCV on a GSXR 750 built in 2007. For comparison a graph is also overlayed from a superstock prep of one of our 04 RSVR race bikes, 106/109 cam timing, proper tuning and a full system from Leo Vince...it is obviously not the one turning 14k rpm.

I would own a GSXR750...please don't tell anyone!

[Axecent]

My GSXR preference might be slightly odd? The 00-03/04' 750cc is the one for me. With a good pipe, right bolt on parts, well setup motor (degree cams, that's about all) and well tuned they make about 120-122bhp on our dyno at the shop. I am working on a K7 in gixxer speak right now on the dyno. It has a a slip on, and a PCV I am tuning. I expect even this 10k mile street bike will be in the 112-115bhp range, same as a well setup V990 on a stock bore. Remember our dyno reads low compared to "magazine numbers" types of Dynos and setup. Basically this is more than enough for me, I can wheelie it pretty much at wil and even on 10k mile stock suspension you can feel the potential in the chassis. The years I prefer have a bit more stroke, a bit less weight and complexity, relatively simple electronics that are FULLY hackable! No additional tuning device required once you learn the system for talking to the Suzuki ecu directly. I am not familiar with the process on a personal level really but have seen a lot of the serious Suzuki guys in land speed using this "open" hack of the ecu. It is beautiful to a tuner.

The 750cc is the right size for me like the thousand-ish cc twin is as well. I f you need fast you just turbocharge it using a kit for a GSXR 1k, then it should be fast enough for most anyone. Good bikes they used to be. I like the extruded beam frame models, when they went to cast frame and swingarm they lost me.

When you tuned that 04' 750 GSXR for me, that was all the bike I would ever need....first bike that seemed scary fast on a race track for me. That was back in the North Lamar days, huh? That seems like such a LONG time ago.

And I'm with you on some of the older engines. The '98 R1 engine was really sweet. If I was out to buy another R1, I'd have to give that model consideration. After spending time getting the suspension right, I really loved that machine, too.

[speedfiend41]

Micah, as someone who obviously plays with engines a lot, what's your pick of the Japanese 1000 cc engines and era? Everything I've read suggests the K5/K6 Suzuki is the best for torque and power...

[Micah / AF1 Racing]

My picks will be broken down a bit. Best midrange carbureted 1000cc engine ever was the 98-99' Yamaha R1 motor, best injected was a 2001 GSXR 1000 wih only mild work, I think up to 04' they had the same stroke, my favorite screamer is whatever the last year of extruded frames were on the GSXR 750cc. Best upper end Jap motor prior to the new ZX10r was the 07' R1 but it is RBW so I am out on that.

Akro EVO series pipe, degreed cams, equal length intake stacks, proper ignition curve for high octane fuel and bad ass tuning would make over 80 ft/lbs torque at useable rpms on my dyno, bit short of 150 bhp on top for a 2001 GSXR 1000cc. I tuned one 05' for a guy with +4mm stroke, +3mm bore, busa tb's and race gas with same Akro system along with port job (done at home and guy is a nurse) and once tuned on MR9(I think it was) it cranked over 165/90 bhp / ft/lbs on our dyno. It did 208 on a dynojet with BST rear wwheel and hearing for a top spewed of 168...it was like nothing I have ever ridden. The owner built it 100% on his own and I tuned it, awesome.

Let me put his in perspective . I also got to break in the Factory Ducati Corsa bikes used in the 1999 WSBK season on the dyno for Terry who bought hem to run Bostrom in AMA. the best motor put down 150.6 bhp at about 13,800 rpm.

[speedfiend41]

Thanks mate. Always good to hear from someone with expertise in the field!

Really like the throttle response on my Gixxer, but I'm having to re-learn how to pull a wheelie - it's such a different engine and technique to a big v-twin!