Venom made a modification to their headpipes. The headpipe now has a tighter bend and tucks tight against the motor. Shorter overall length. Has showed a gain on every machine that has been dynoed with it so far.
New vs old headpipe for a yfz.




Dyno runs from my yfz. All that was changed was the headpipe.


They will be selling the shorter headpipes seperate for anyone that would like to upgrade their current pipe. Contact Venom for more info.

Looks exactly like the dyno I did of a before and after on a stock bore. If you want I could add the graph here with yours?

Feel free to post it.

Cool...

Here it is on a stock bore motor.....

whats the price of them

$175

you guys just love making me spend money
pretty impressive on the stockbore!

Here is the test I did with out the A/F on the scale...

I think you answered my question already Eric but I wanted to ask (Eric,Chuck) if your jetting changed when you went to the tighter bend head pipe? I got the tighter head pipe and haven't made it to John's dyno yet. I did have to go up one size on my pilot jet. No big deal at all and I really like how there's more room between the pipe and my leg. And it looks better IMO too.

This graph had the same jetting in it before and after the head pipe switch. So I did not have to change up the jetting. As you can see the shorter head pipe leaned out the A/P shot as well, which some may have to adjust the leak jet for. I however had the R&D adjustable leak jet in the carb so I just turned the knob. :)

My jetting didnt change either. I dont think I got a printout with A/F readings.

thanx so much for the thread and info Mr.Witti... :)

and thank you Mr. Terse for adding in more dyno info...!

a couple days ago , sredrum & gang were here for some dyno tuning on their way up to silver lake dunes.... i'll start a thread soon with his results on his Venom 501YFZ.... the A\FR and powerband results are the same as you guys have already posted...he went from 60HP to 62HP with no jetting changes needed....

gotta love it when a development leads to all gains and no minuses...:)