I am getting a number of mods for my stock banshhee including: Vito Pistons, 4 degree key, Pro-Design Cool Head, and either Toomey T-4's or some FMF Gold Series Pipes. I am also going to get it ported for some trail riding. I am wondering about how big of HP increas will I see. I know that a lot of factors go into this, especially with the porting, but I want a rough estiamte of how much difference all this should make. I also have a question about what jetting should I use after these mods. Thanks for the help.

 

well im not expert but if you gonna use the superstock pistons thats good for 6 and the pipes with silencers should be at least five the keys are suppose to give you 2 and the head will probley give you 1 or 2 and and if you get some good porting( id go for mx porting ) then you can expect at least 10( from a good porter) so all that adds up to around 20 hp thats if you get some good porting im no expert but thats my idea of what youd get

 

I would say around 60....maybe a tad more. Get the FMF's for trail riding.....my bro has a set on his 'shee and they work well. He runs 300 mains and 32.5 pilots with no lid at around sea level.

 

Oh yea....their are better alternatives to the Pro Design Head (I hear it does'nt cool well). My bro wound up shaving his stock head. Also, the stock pistons will outlast ANY aftermarket piston....something to think about if you ride a lot. Also, Vitos pistons actually simulate porting....so it would'nt make sense to port the engine and use the pistons that simulate porting too.

 

I was thinking it would be about 55+ hp. So if the vito pistons simulate porting I should wait to get the porting done. Thanks for the jetting info. I ride at about 1500-2500 ft above sea level so what should my jetting be.

 

Personally, I woulld use stock pistons and porting. You can use vitos pistons and forget about porting (cheaper). Jet too rich and work your way down....don't use someone else's jetting specs for YOUR Banshee....just use them as an indicator of very roughly where you should be.

 

Yep, everything Garyc66r said. Vitos and porting are not a proper match. Also, stock (at least forged) pistons are the way to go. While most aftermarket mods will work well together some don't. Also, consider the effect of high compression heads and advanced timing... Go to far and you'll be running race gas because pump gas will result in pre-ignition/detonation.

Jetting... Start high and work your way down.