My haynes roadster is fitted with a megajolt and ZX6R carbs to a RS2000 I4 2.0l engine. Also has a innovate LC1 wideband and gauge fitted.

I got a set of ZX9R carbs with the car and was wondering would it actually be worth the hassle to fit them? Im assuming the only thing Id actually have to buy/make is a manifold?

I have no previous experience of tuning carbs (but I do have experience of tuning a Megasquirt from scratch on a mx5) so do you think by roughly "copying" the setup of the zx6r carbs id be in the right ball park and it would at least drive?

Or should I just not bother and go do 2 trackdays for the price of the mani!

If the 6R carbs have a venturi which is already bigger than the port diameter of the head, there is no value in going to the bigger carbs at all.

IIRC the head will be 32mm and the carbs are either 36 or 38mm, so going to the 9R carbs will do you no good without increasing port sizes significantly.

Thanks for the input. I kinda guessed that would be the case. Only so much air you can force in there I suppose without boost!