need more  "go fast"  toy's

well a friend of mine told me about this site...
and said I would get a lot of help from all of you so.

what will a  K&N air filter do for me on a other wise stock bike, all I have right now is yosh bolt ons

also what will a tre do for me. is there any con's to this mod.

and last I'm thinking of  either going down 1 in the front gear or going up in the rear 2  which is better.
With bolt on exhausts and a high-flow air filter (such as K and N) you might gain a touch of power. Perhaps a HP or two. Mostly the benefit of slip-ons is improved sound -- deeper and louder. The K and N airfilter will help the engine draw air easier which can help your gas mileage too.

The TRE and adjustable version (ATRE) are a source of some debate among Hayabusa owners. Some will claim a much improved throttle response and smoothness in 1st and 2nd gears. Some will claim that the TRE will eliminate the top speed restriction. Others say it does neither.

With gearing changes it is going to depend on the riding you do. Drag race a lot? Wheelies? Top end screaming? If what you what is more rapid acceleration and don't mind lossing ten or so MPH off the top end, then either add two teeth in back or drop a tooth up front. Some guys here have done both, giving them twice the effect. If you like wheelies a lot, this is not a bad way to go. Just keep in mind: loosing one tooth up front is similar to adding three in back. The farther from stock you go (17/40) the more top end you loose and the more acceleration you get. Yes, I know that is an over-simplification... but it's close enough.
Welcome to the board BT.

I agree with FLCN.......not many ponies with just the bolt-ons and a filter.......maybe even none at all.
If yer looking for simple bolt-on hp the try the Hindle BDE stepped full exhuast, or the HMF Big Bird full exhaust.
Then do the small box mod, for more air flow, and remove the pair valve while yer at it......stops the backfiring you'll get from the exhaust mod.
Then you'll want a PC2 or PC3r depending on the year of yer bike so it can be mapped correctly........take it to a respectable dyno shop and have them do a custom map for biggest numbers.
This should put you in the neighbourhood of 175 hp at the rear wheel........stock is around 155.
If yer lookin for more, Yosh makes "drop in" cams that should put you near 185 hp.
If you want more then that, you'll have to turbo it or build a stroked motor or get some help from NOS. :beerchug:

And the gearing thing........check out some of the threads in the modifications section........they should be able to help you make yer decision.

As far as the TRE.......that's been a huge debate here for quite some I could suggest is buy one and try it.......if it works..... great..... if not......sell it.