so much misinformation about the rb20
yes it is not a easy engine to do big power, but you can't say it's a shitty engine. it's a nice rev happy engine. call me if you want to know how to make power with 20, but the only thing that is cheap is the engine itself.
Alex knows what he's talking about.. I'm running 300 to the wheels, and 300 lbs of tq now at 18psi, 3900 rpm full spool with my RB20 on 91 pump gas. 23 psi is in the 354 area which is in the the 410bhp area - aka RB25 tranny swap (unless you plan on gutting your car down to the 1000kg mark). The ONLY way to make a well performing, high hp and torquey RB20 is in the head work. The RB20 head flows minimal CFM's compared to the 25, so it's already at a restrictive loss off the bat. With some serious headwork, front facing plenum (to reduce both lag by shortening the IC piping, and to increase flow via a larger tb), cams (260's maybe, i'm running Poncams which are 254/8.5), valve springs (obviously, for the larger lift) yada yada..
The turbo will have to be a GT30 and up.. And where you can gain some much needed response is in the IC pipe length. If you chop it down as much as possible, you can return spool to the 3k zone.
RB20 stock bottom end will see over 400 bhp. It's been done, DOZENS of times. Follow some SAU builds and you'll see for yourself. So until it explodes, dont waste your time on building a 2.2 or wtv because it's more than capable for your needs. The stock bottom end was used in ALL the Gibson Touring cars in 89. The Silvertop with cosworth pistons at stock bore produced 400 whp without a hiccup. Like i said, its all in the delivery - the more air you can move the better your RB20 will be at producing power. If you wanna go nuts, extrude hone your exhaust housing and stock manifold (Which doesnt become turbulent until 400+) and gasket match EVERYTHING.
If you wanna go nuts, run water meth. You'll be able to pull so much more timing, and for the price, its an unbeatable setup for high hp/tq numbers.
All in all, you can do an rb20 build (assuming the motor is in good shape - ie. >140 compression warm) for less than 4500$ if you shop around..
Cams, headwork and turbo are your greatest expense..
