between the stk w/end cap and the ron woods it was 1 hp diff...

 

Did you use stock or flat track tires? You're about 4hp over mine on gas with similar mods.[img]i/expressions/face-icon-small-smile.gif[/img] I should've gone with the HPR ported intake[img]i/expressions/face-icon-small-wink.gif[/img] Longer arm next?

 

I like the numbers.... and my exhaust kept the tq and the HP over every bit of 2500. I was very impressed with the curve. And yes, I dip in tq between 8k and 9k as well. But my bike makes a pot full between 5500 and 7500.

Randall, are the valves making the differenece in the HP? Obviously they are much bigger than stock, however I would think that the bigger the valves the more the motor would like a bigger cam. And with the bigger cam paired with a bigger valves, is low end on the more aggressive cams still an issue with bigger riders? In other words, do the bigger valves negate some of the issues I'd have with the HPR4 nitrous cams? Just trying to do some figurin' in my feeble brain.

HAPPY NEW YEAR!!!!!!

BD

 

crazypainter i was running flat track tires. hey what is the website for little sahara for reserving a camp spot. i yes i have to figure what to do now since it did alot better than we thought. decide on exhaust to let keep power up the top and maybe different cams. THANKS FOR ALL OF YOU GUYS INPUTS AND TO HILLBILLY PECKERHEAD RACING (HPR).[img]i/expressions/face-icon-small-smile.gif[/img]

 

lspsonline.com for little sahara. When I switched from the end cap to the woods pipe I picked up 1.6 hp and that wasn't till over 6500 rpm's and lost torque eveywhere. That was with the web 110 cams and the old style woods 11.5 piston on gas.

 

crazy i do not plan using a ron woods pipe because of what it did to your bike. i just figure out if this good enough or try to get more to stay up with yamascotty banshee. but if i can beat him he would just do more mods to it.

 

Don't get me wrong on the pipe it pulls harder on the top end with it. I think it will take about 75 hp to keep up with Yammascotty, unfortunately I don't think we're there yet.

 

yeah it going to take a little bit to stay up with him but one thing that he don't have much of is torque which we have more of.

 

hmmm... on a bone stock bike, about 1.5hp difference in the peak hp numbers between the 2 pipes....that sounds about right. I think it's only because the full pipe is trying to take the stockish motor up to an RPM it doesn't want to be at.
But... on modified motors, I've been seeing much bigger differences- Definitely, the cam, porting, and headwork would affect how much gain or loss between the two exhausts because of the different power ranges the engine is wanting to run in.

BigD: that's a question that requires an essay, but in short.... the small valves are starving your engine. Your existing cams will still like the big valves. Contrary to the way I used to think, GOOD porting and valves don't sacrifice power in the bottom end- in fact, bottom end will increase when the porting is right. So, with that in mind, if your bottom end is sufficient now, you could go to HR4730 cams with GOOD porting and break even on bottom end. I wouldn't go all the way to HR4 nitrous cams at your weight though, even with big valves and good porting.

222

 

That's what I had figured. Not looking to go more aggressive, just wanted to talk "BENCH" and get the sum of the parts kind of a thing.

My HPR3's are like GOLD. Did some rock crawling this weekend, and let me tell you... those puppies performed admirably. There were times when your clutch work isn't perfect, and the cams were able to lug through with no problem. The HV48 didn't have 1 bad characteristic. VERY HAPPY!!!! Rode with a pumped up Shee, a Vforce, Z400 and a Polaris Scramy 500. Wasn't close in the open desert, two guys came off trying to keep up with me. IN the slow stuff, guys were getting the bars ripped from their hands. Not me, just worked the Bigdaddy DS Donut like there was no tomorrow. To bad there isn't HPR for Shee's. He was one hurtin fella after 42+ miles of desert. After all the stops for these guys crashing and complaining, the ride took 4.5 hours. I did nothin but smile! Then again, I take people on this ride about every month. Everyone wishes they had my bike after. Hense the reason my bike isn't set up to drag.

But I'll drag ya never the less.