I'm just curious guys? Can an aftermarket really make such a significant improvement? I've seen companies claiming between 7-12 hp differences from stock!?! When I was racing dirtbikes, it was pretty impressive to gain 2-3hp. Are the stock exhaust systems that poorly designed that that much of an advantage can be gained? I know that there are magazine companies out there(as well as aftermarket companies) that will blow smoke up your @#$ about how much of a difference certain mods will make. Whats the real deal guys? Anyone had THEIR ride dyno'd to tell the difference? Or even how about seat of the pants? I just want to make sure its gonna put the grin on my face before I give someone the money. On motocross bikes it really didn't add much in the feeling of the power, just where it hit in the power band. Thanks as always for the responses.

 

I would say 7 HP is beleivable on a raptor.

 

It will not feel like the same bike after the pipe.

 

I know that alot of the companies say pulling the airbox lid helps, but how much water will get in then? I'm not a mud bogger or anything, but I do take the occasional creek crossing at speed. Should I just leave the lid on? I've already pulled the snorkel, and "modded" the divider in the inlet.

 

In ATV sport they did a artical on curtis sparks pipe on a stock YZF450 they were @39.8 hp stock and 43.7 after the pipe they did all the jetting and air box modes sugested and also retarded the exhaust cam as instructed this is one of the more realistic test ive seen in awhile and i have personaly dyno'ed many pipes and the average is 3-6 hp gain and you should be able to feel 3 hp [img]i/expressions/face-icon-small-happy.gif[/img]

 

3.9 HP for the price of the pipe and filter set up is crazy plus cam mod. i race one this weekend at glamis with all the mods quite a few times on my trike seemed like it was making some good HP.

 

I've seen plenty of dyno graphs that show a piped Rappy will vary by the pipe you choose making between 7-10 HP. Most of the higher numbers are pipes that had the jetting uped and minor airbox mods. The Rappy exhaust is VERY limiting on that big engine, pipe and silencers help soooo much!

 

They just pick some spot on the curve where it made alot more than the stocker and make their claim from that. They arent talking peak hp.

 

i have see dyno test on a 350 rancher with aftermarket exhaust ,jetted and k&n filter with gains a little over 1 hp and almost 2 ft lb of torque that stock is about 15 hp with a cost of about 250.00

 

And we have a winner!! Where the claims look too good to be true, dig up a dyno sheet. You'll see the comparison at like 8000 rpm where the stocker has fallen way off, but the aftermarket pipe has just begun to lose power, and they'll pick that lopsided and somewhat misleading spread for their advertising comparison.

But back to the Raptors, you do get upwards and sometimes more than 10 hp at peak power levels just with the pipe and airbox/jet mods.