Realistic power available GSXR / Gear ratio...

I have a 2011 GSXR 600 with a yoshimura head gasket, and that is the only engine modification I am aware of. Dyno'ed at 104 hp at 5800 ft elevation. I feel like with a SS motor I should be able to pull above 110 hp. I am just looking at what others are making on similar builds and what I might be able to expect out of my engine.

Second thing is I am running a 15 tooth front sprocket and a 47 tooth rear currently. I have a 48 tooth rear, but I feel that I should not run it.... I also don't want to go to small in the front and cause binding of the chain. In our last shorter course, was only red lined in 5th. I have not been using the full gear box for most of this season. Needing some advice here too.

 

I can't comment on a 600 but I have a 750 with a SS build and made like 136-142 or 140 I'd have to check my sheets depending on the fuel I was running. I wouldn't think think you should have any problems getting over 110hp.

As far as gearing what track are you referring to? I would not go any smaller than a 15 upfront. The one track I race at where I only run 5 gears is NJMP Thunderbolt, and I run a 16/44.

 

power loss is around 3% per 1000 feet of elevation. so, 104 hp at 5800 feet, that's a bike that makes around 125hp at sea level. your dyno may vary...

 

as he stated above, i don't know anyone, anywhere, that runs a 14t up front, and there are a number of tracks you likely won't use 6th gear.
Also, it would be best to compare your bike hp to other bikes on THAT dyno. just ask the tuner how it stacked up to other 600's

 

All the common dynos apply a correction factor for elevation. 104 hp for a 2011 gsxr600 is not terrible, but it's not great either, a little more than stock. Your gearing has to suit the track. 15/48 is crazy short gearing, and you have a giant sprocket in the rear causing chain pull issues. Find out what the other guys in your class who are winning or at least fast are running. R6 and GSXR gearing are almost identical, so you can ask those guys too. That will often change for a new track.

 

I am the only guy in the top 10 with a GSXR 600. Only other Suzuki's are 1000cc. I did not feel comfortable running anything smaller than a 15t and was worried about going larger than the current 47t rear. What is chain pulling??

The guys local I have talked to with GSXR 600's were older and clearly had a different trans gearing, because after talking with them they were blown away at what I was having to run to get the power delivery I need...

 

Thank you, that puts it into perspective well. I would kill to see 125hp!

 

Is the effect the chain has on the rear suspension. As you increase the size of the rear sprocket, it alters the angle the chain pulls in relation to the angle of the swingarm.

If you'd like a deep dive explanation of it you can watch Dave Moss get into it, I think it starts around 13 minutes in.

http://www.ustream.tv/recorded/6031806

 

are you using 1st gear? if not, u could always gear it taller and start using 1st for more drive. its not some requirement of racing to use the whole gearbox. u just gotta find what is fastest for u. using 1st-4th might be faster than 2nd-5th, or maybe better drives off 1st will still allow u to click 5th for a bit.

comparing drive on track is difficult. maybe u can see when the other riders touches the throttle. but they could be WOT 40ft before u, smoking u down that straight. maybe u blame it on HP or gearing, but its really a riding issue.

 

The above statement is very true. I personally know someone that would rather use 3-6 at a particular track rather than 2-5. He is geared very differently. I tried his setup, didn't like it.

 

That is a good point on getting a better drive. Those guys that are beating me are the same guys saying their R6's made 115-119 hp.... So would 115hp on a full super sport build be a realistic expectation? Not sure if I should build my motor, or buy a ex-AMA bike or something. I DO need to work on my drive out of the corners. This is going to be my focus for the rest of the season now that you mention it. Thank you.

That is very interesting on the rear chain effecting the rear suspension, I have been noticing in some pictures that the rear is seeming to look more loaded than it used to, I was attributing it to my times getting quicker through this season.

 

can sort of see it here:

 

I noticed a while back that more often than not (although I'm sure the massive HP they have and the need to be geared occasionally to exceed 200mph might be a factor) but MotoGP and other race bike tend to have small'ish looking rear sprockets for that same reason to not introduce those excessive pulling forces on the rear suspension

 

Absolutely true. Smaller sprockets are better. Swingarm angle is so important for grip, don't put any unnecessary moments of inertia into it

 

im sure 250+HP introduces a ton of chain pull issues. a 110HP Superstock600, not as much. i can barely feel it when i make a sprocket change that doesnt also move the axle.

 

Granted more torque will be applied on a more powerful motor, but it's visible on shock data on a 600. You may not feel it but it feels you.

You would have to change both front and rear sprockets to make a sprocket change that doesn't move the axle. You do that a lot?

 

how big of a diff can u see on a 600? steeper chain angle increases anti-squat, so the rear should end up higher esp on hard drives. for a 2nd gear pull, do u see 1mm, 2mm, more?

not a lot. i wanted to experiment with 1st gear so i went from 15/44 to 16/43.

 

Those pictures make it clear! So then I need a smaller front then, but does anyone track with a 14t front?????

 

I run 14/44 on my SV superbike. we have a VERY short track. most guys in our club are running a 14T front.

 

I had a 2006 GSXR600. Bone stock...-1F/+2R gearing seemed to work well on all tracks.

Made 104Hp stock...had it dyno tuned at Karns Performance and got it to 108. All it had was an Arrow Slip-on exhaust on it.