With more power (forced induction) we face the need for taller gears. Quckest way to do this is to change the final drive gearing.

That said, here's a ludicrous question: Does tC's 4AT final drive fit on 5MT tC? I know it is much taller, even too tall, but please indulge my curiosity.

Yeah, 3.333 final drive would be a better choice, but not having that choice, above question does seem appropriate...

Thanks!

planning to go faster than 130mph eh?

I don't see how that'd work, but hey...

I do agree with getting taller gears for boost. At the same time, you need a speed cut defenser such as one made by HKS. That will get your ECU to let you go faster than 130. Taking your tranny to a machine shop might be your best bet. You could have a specific ratio fabbed up to suit what you need, and what speed vs acceleration you're looking for.

Yeah, custom gears would indeed be the best solution. Especially, since our 1st and 2nd gears have a 2500rpm diff between them (meaning, shifting at 6000rpm from 1st, you get to 2nd at 3500rpm approx.) and that is before turbo's full spool, so you'd have a small lag - not optimal.

However, custom things aside, final drive swap is usually a quick and cheap way to lengthen/shorten your gears. E.g., on my 350Z, 5AT final drive (3.35) will fit comfortably in place of stock 6MT (3.54), or I can plug EVO3.9 FD (yup, 3.9) and get 10% boost in accel for the price of shorter gears.

Since my tC already has problems with grip, and that is with stock engine hp/tq, I can imagine the slipping and maniacal shifting I'd have to do with any forced induction. I'd rather have some use of that 1st gear :).