Exup Vs. HP

Does the exup make a noticable difference with HP ?I just finished my R1 banshee and had it dyno'd at a place locally today(Anahiem, Ca... by an accomplished exhuast builder who also does top secret kind of work for various manufacturers). we were both supprised to find that my bike only made 81.30 hp / 40lbs torque @ 11,000rpm. That seems really low considering the motor in stock form puts out 154hp/77.4 lbs @ 10,500 / 8,500 rpm. the fuel map was right on (the reason I took it down to begin with) and he said that the motor is running fine (exhaust was/intake were fine). the original gear ratio is 16/43, but I am running a 16/65. He did say that at the tires were spinning through the 16 runs and he even aired down to 11lbs but the tires still spun slightly at 11,000rmp. he estimated that that would only waste 6-8 hp or so. I'm new to this whole dyno thing and I am really at a loss to explain why these numbers would be so low ? I've ridden it and it seems to have more than 80hp pulling 25" 14 paddle extremes up comp hill in 3rd gear. His only explanation was possibly the gearing change. He told me about a recent stunter GSXR that he did with a huge sprocket on the rear that only dyno'd at 115hp, but added that hp should be the same no matter what the ratio is??? Don't know if this helps ? 2002 R1 (fuel injected) K&N on the throttle bodies custom exhaust (1 1/2" at header / 2" back) no exup valve (smog device / low rpm power valve-sort of) Any ideas ?

I'm not too sure, u should be making alot more power then that, well into the 100's at the wheels at back. Hope u get it sorted out. btw post some pics of that machine, how much did it cost to build something like that? Curby

got pics?

DP315 - Is your dyno guy open to the public? I'm looking for someone to custom tune my stock R1 with a heavily modded exhaust (straight pipe with a packed baffle). Please let me know...

Heres a few pics. I've now ridden it a few trips and it works pretty well so far. After another trip or 2 I'll tear it down for chrome and power.

he said the wheels where spinning so thats prob why its such low figures

From What I've Heard The Exup Is Only There To Give The Motor More Low-mid Power. The Butterfly Valves Open More As The Rpm's Rise. Do You Have A Power Commander? I'd Look Into Your Mapping....

Oh Ya........bad Ass Quad

Firstly, top job on a crazy quad mate :thumbup The gearing you're running won't affect the power output on the dyno at all. The exhaust doesn't look too extreme either. With a Power Commander, that exhaust and filter setup, a good dyno guy would be able to bring that power to as close to standard at least as not to make much of a difference. Bottom line, if the wheels were spinning, that's your answer. I'd stake my life on the fact you're not only losing 6-8hp that way... Did you get a printout of the final run where the wheels were spinning? That will show you very clearly as you will be able to see the point they spin and going from expected power at the revs where they spun, you'll be able to pinpoint the power loss to that. :corn

I do have a PC on it. I actually took it down to have the fuel re-mapped since the air filter system is now less restrictive and the exhaust was changed. I do have the printout and it power curve looks awsome. Its a steady increase all the way through with somewhere around 45ft/lbs all the way through it also. Since my original post I have finally put some hard runs on it and I firmly believe that those dyno numbers are way off. with those 25" 16 paddles I'm running 68MPH up the hill (10,000RPM/3rd gear). To put that into perspective most modified 450's (quads) are at 38 to 42MPH. Last time out there was a guy with a banshee and a turbo'd Hyabusa in it. He was putting out 243HP and did the hill at 83MPH. It seems to me that the 15mph difference is a little more explainable with a 100HP difference vs. a 160HP difference (assuming the 140HP for my motor)