Hi - Just saw this post -kawiben said:
If you want to ride fast - good, well tuned suspension will allow you to go faster than more power - so - if you have a budget, do suspension first.
As far as the stacks, our V Stacks are designed for a stock engine with stock cams and the lengths and that we provide for the 636 work better in that case -
We do make 15mm, 21mm, 25mm, 30mm, 35mm, 45mm and 60mm lengths - so - we have a wide selection for a tuner to use to dial in a modified engine.
The Kaw "kit" stacks are better than stock, as far as power on a stock cammed engine - they are probably designed for an engine equipped with the Kaw "kit" cams (at least that's the logical assumption), but, the stack set that we sell is specifically for a bike with stock cams and make a couple more hp than they do -
The Roadracing World ZX6rr bike that made 114+ DJHP on pump gas had our stacks on it and tuning with an EC997 dyno, a kit ECU and no power commander.
As far as stacks always being longer on the inside - not always! - The carbureted R6 worked better with longer stacks on the outside, for example.
I think that the 636 worked best with 15mm outside and 21mm inside (WAY different than the Kawasaki kit stacks!) and that's what we normally sell to Kaw guys - no lowend or midrange loss and better topend -
If you have any more questions or want a set, you can give us a call -
Thanks!!!!
Marc