Ok, I was thinking of doing some tweeking with the race bike. VFR400 NC30

1st, what other fairings and seat unit will fit without to much messing about. ( Viper has said that Cagiva seat might fit) Dont want tyga set up too expensive.
2nd, can RVF piston be fitted, is it staright swap and if so what difference will it make.
3rd, how easy is it to get an underseat exhaust fitted and will it affect the power or what are possible suspension problems.

This is what is currently done to it.

Quieting cams removed,
Runs total loss (revs like mad, great)
Full system

So basically standard and putting out 59BHP (feckin pants)

59bhp isn't crap at all! These bikes were designed to make that so it looks like you have a really healthy motor to start with.

A few extra bhp can be had from a free flowing exhaust / dyno set-up but anything esle will require more than just a tweak!

What condition is your suspension system in? A new / uprated rear shock / front fork kit will improve lap times much more than a couple of extra bhp :)

There is free flow system on it and the jetting has been done.

I have a set of race tech fork coming soon - Cheers Aly (ABRMOTO)

I pick up RS250 resr shock tomorrow but it will be going to get service and re-sprung.