What really surprised me was the difference between his dyno tires, which I assume are TT tires, and the knobby's(last dyno chart). Almost 7 horsepower difference. I wonder if the difference is because of tire slippage or tire height.

 

probably a combination of slippage and power lost from mashing those ***** on a little drum, they dont have much surface area to sit on so they prolly get kinda mashed and rob some power.

 

I too was wondering weather or not to do the exhaust cam mod. You retard it one tooth? I am just unsure about doing this, it kind a sounds like a "jimmy rig". I think I may end up just doing it right, and buying the yzf exhaust cam. It will give the same good results of retarding the stock one, but it will aleast be done right. The yzf exhaust cam is only $143. Then you would have a complete yz motor, just with a shorter stroke and diffrent piston (11:9, appose to the yz 12:5). I think It will be too big of a hastle to modify it to a 450 though, for the little results that you get. Performance vs. money! I may consider doing the 13:1 piston though. I have my questions on it though too? How can that thing still run on premium unleaded? Wouldnt that thing need race gas. Wonder why yamaha didnt just offer the 12:5 piston found in the yz? For all you guys out there thinkig of doing that, and the kick starter kick.......oooffffffff...........Its going to be a little harder to kick over then the stock 11:9! And then if you do the piston, and keep the electric start, I wouldnt' think your poor starter motor will be long for this world? I don't know, tell me what you think. I am just thinking about different ways to go.
Also, wouldnt it be nice to find a way to get the yzf exhaust, and put it on the yfz450. From what I have heard, that is the best performing exhaust for that bike, and its a factory exhaust! Pretty crazy that they actually made a stock exhaust worth a hoot.

 

anyone know how much the kicker kit is going to cost?

 

Yea I was looking at a YZF 450 yesterday and the exhaust was made out of Ti !!!!!!!!!!!

 

yep, its a pretty sweet exhaust. Just need to figure out a way to put it on the yfz. It kinda funny that yamaha bothers to even make a gytr slip on for the yz450, theres no reason to, except ofr looks. It doesnt perform better then the stocker on the yz. Funny!

 

Yeah but did you see how much the titanium exhaust costs! OUCH..[img]i/expressions/face-icon-small-shocked.gif[/img]

 

If you go with the 13:1 piston you will have to run a higher octane. I talked with sparks about it and you will have to go with at least a 50/50 trick fuel setup. But the extra power is worth it for me. I have been buying trick fuel for years for my R.

 

Did he say if he thought the high compression piston will help much?

 

From what I hear the exhaust cam mod is worth it. For one its free and gives you the same results the yz cam gives. My cousin did it on his wr 450 and said it revved noticably further.