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RB20 -red top turbz with silver topturbo

HRthirtyone
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HRthirtyone Rising Star

HRthirtyone

Posted
Posted

RB20 -red top engine with silver top turbo...

just wondering if anyone has done this mod, and wondering if it is worthwhile... ????

because i can get one real cheap.

My turbo is in perfect nic, it just looses 4psi by the time it hits 6,000rpm (maybe this is a wastegate prb?)

i was told that stock RB20 silver top turbos will hold their boost until about 6,000rpm....true????

red17 Experienced

red17

Posted
Posted

Dyno indicates my silver top hits peak boost at about 4500rpm and drops nearly 2psi to redline. Tiny stock turbos run out of efficency quickly, no amount of boost control electronic or otherwise is going to help it.

Ive never heard of this mod before, always figured both turbos were the same but the intake systems are different between the 2 motors. Im sure an RB head will correct me :D

Red17

Cubes Grand Master

Cubes

Posted
Posted

I don't have boost drop until around 12.5psi (152rwkw).

Anything over that and it starts to boost drop.

I fitted the EBC and it will hold boost at 15psi BUT it is a little wavy and you can definately tell the EBC is working hard to hold the boost.

Fitting the EBC picked my power up from 155rwkw to 164rwkw.

But yer go the RB25 turbo and don't bother with the RB20 turbo.

HRthirtyone Rising Star

HRthirtyone

Posted
  • Author
Posted

"Put an exhaust on it!! My car has had 3" the whole time i've had and never had the boost drop off. The R32 turbo is much better to drive as it spools up a lot sooner."

yea thats what i was wonderin... i do have a 3" mandrel zaust, but i still loose heaps of boost up top

GTS20X Enthusiast

GTS20X

Posted
Posted

Sorry guys my car has always had a R32 turbo on it, non Skyline non ball bearing at first and then when i changed engines a ball bearing one which spools up alot sooner (about 2000rpm sooner!). But both engines started to lose power about 6500 they still reading full boost.

Carlos

HRthirtyone Rising Star

HRthirtyone

Posted
  • Author
Posted

nice one 32-gts, i was told bout the later model turbos but i dont know how to identify them, and i didnt know what years they were made... Yea i was surprised at actually how small the compressor wheel was when i took the intake piping off to have a look...!! didnt measure it but looks hell of a lot smaller than a standard t25 off an sr20..

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

11psi with zorst and cooler?

Nah... somethings not right my car and others... usually rise to about 9-10 psi with zorst/cooler.

11psi... hrmm...

My old coupe hit around 8.5-9 psi with the zorst.

does a bigger cooler help increase boost?

wouldn't imagine that it would.

and joel... full boost meanss the point where you turbo hits the desired psi.

If you set a belled value to say 20psi for instance, then when you hit 20psi is classed at full boost.

Make sense?

GTS20X Enthusiast

GTS20X

Posted
Posted

Sorry guys, i'm wrong, i watched the boost guage today and it does drop a couple psi above about 5000-5500rpm. Time to make up a dump now.

Nismoid, its a pretty good cooler kit, the guy who makes them designed it on his stock R33 which gained 40HP at the wheels with just the cooler, standard exhaust as well. The R31 coolers are just shit, even a standard R32 cooler will probably make a difference on a R31.

Carlos

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