Proper ITB sizing
 

Hello,

I have a 99 Miata, and was wondering after looking up various ITB sizes what everyone else's opinion was. I've seen anywhere from 40-50mm. I know people do the gsxr swaps (42mm) and are supposedly fine, but people also put 45-50mm on. Basically looking for a setup that will mean something else other than the intake is holding performance back. Possibly achieving around 150whp. I have a stock engine except for the exintake swap and the stock jdm exhaust header.

If you have power numbers I would be delighted to see them too!

Thanks!

I found this highly educational;

http://www.texasnissans.com/tx/forum...ead.php?t=2307

Thanks for that link. Always love some theory. I'll try and check out the sims he used.