Jump to content
SAU Community

Recommended Posts

Hey,

Just got my first turbs car as a new toy to play with (rb20) with ARC front mount(not sure what size), blitz bov, HKS pod, avcr boost controller, factory dump and cat, 3inch cat back. Atm its on 0.75 bar (which is about 10psi). I cranked it to 0.85 yesterday, and I believe that is about 12psi. Pls correct me if you disagree with these conversion.

Two questions:

1). Wondering what psi can I safely go up to, with these mods. (I have been reading around these forums and it seems like 12psi is safe with bolt ons + factory intercooler). Since I have front mount I'm assuming I can go up a bit more.

I will run standard boost for daily driving but just want to know for once off moments ;)

2). My boost comes on from 3.5k rpm for each gear - so increasing the boost should not make boost come on in lower rpm right? but rather when u hit boost (3.5rpm) itll kick in harder? Correct me if im wrong.

Look forward to ur feedback

Andy

Link to comment
https://www.sau.com.au/forums/topic/108270-safe-psi/
Share on other sites

1. Mods have very little to do with the safe PSI limit. It is predominantly a function of the construction of the turbo itself. The factory turbo is built with a ceramic turbine wheel, and it is this component that is the "weakest link". As you increase boost, you increase the rpm at which the wheel spins. At a certain point, the ceramic unglues itself from the shaft and shatters. Best case is it sprays the front of any following car; worst case, it gives your engine's cylinders a terrific hone.

2. All you are doing is increasing MAXIMUM boost. It should still cut in at the same point, with the same "kick in the bum".

Link to comment
https://www.sau.com.au/forums/topic/108270-safe-psi/#findComment-1995928
Share on other sites

i don't agree with elk entirely, without a fmic i was only able to run 9psi (in an r33) before engine started pinging, however once i installed that i was able to increase it to 12psi safely, so mods do allow higher boost to be run. Once you get to a certain point though the turbo will become the weakest link in the chain, not sure what that is on an rb20.

With the boost increase you should feel more pull under acceleration but probably won't spool up quicker. Would probably have to look into dump pipe and larger cat amongst other things to help that.

Link to comment
https://www.sau.com.au/forums/topic/108270-safe-psi/#findComment-1996011
Share on other sites

hey guys i have the rb20 in my silvia as far as i know those conversions are pretty spot on as 1.0bar is 14.7 psi so they sound about right. As for the safe boost limit a mate of mine in Darwin was running 14psi through stock turbo for ages still is now i think although when i did it it spun the wheel off the shaft like the other guys on here were saying so they are right about that so i personally would only run 12psi to be safe or better still get a hold of a turbo off the VG30DET 300ZX APPROX $300 and use that it is a direct bolt on other than oil feed lines and they arn't hard to do and they have a steel rear wheel so can handle around 18psi then boost it to 1.0 bar and have fun how ever with these engines i wouldnt over rev them to much they tend to spin big end bearings G.L Let us know wat power figure you end up with

Link to comment
https://www.sau.com.au/forums/topic/108270-safe-psi/#findComment-1996201
Share on other sites

1.) there is no "SAFE" boost limit.

turbo's can break at factory 10 psi or it might not break at 16 psi..

you run it, you risk it.

2.) having an intercooler will not save your turbo from damage. intercoolers are there for your CHARGE air (the air going in to your motor) and doesn't cool the exhaust gasses which is the heat that breaks turbo exhaust wheels.

3.) when you say boost comes on at 3500rpm.. you mean you have full boost (12 psi) at that rpm or starts to come on positive boost at that rpm.

if you want to put the boost up, go right ahead.. stock turbo's cost piss all and an upgrade to an RB25 turbo is not much more.

if you can't afford to have your car off the road (like me) don't risk it.

Link to comment
https://www.sau.com.au/forums/topic/108270-safe-psi/#findComment-1997389
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Latest Posts

    • I've heard the Tomei USA head gaskets are decent if you want to o-ring the heads but otherwise not recommended.
    • The 296mm rotors are the R33 turbo brakes. The 310mm rotors are the R34 turbo brakes. The calipers are nearly the same, but not. They're the same caliper but the R34 caliper has longer legs so that it sits out far enough to go over the rotor. The pads are the same for both. When you say, "I bough tsome EBC"....did you just mean pads? Or rotors? 310mm rotors fit under 17" wheels. There may be some wheels without enough clearance though. I can't fit my fingers between the barrel of my wheel and the "corners" of my R34 calipers, but there is plenty of room behind the spokes. This is on Enkei RPF1. You can fit 324mm rotors inside a 17" wheel, but I'd be willing to bet that it would be close to impossible with the Nissan/Sumitomo caliper (using an adapter, of course), because the Sumitomo caliper is fatter than the Brembo caliper that is supposed to go on the 324mm rotors.
    • Hi. Can someone tell me what brakes(and mainly WHERE) can i buy brakes on R34 GTT? I bought some EBC which SHOULD go on my car(i have GT but it has GTT brakes) but it does not fit, Brakes are "too" small(296mm) Are 310mm be good or? I have 17 inch wheel so no "big boys" but for me driving i just need one that fits and i can get here in EU/Czech.
    • Since winter isn't that harsh anymore in Poland, i will definetely drive it 365 days a year 😉. But if the snow hits i will try it for sure and let U know. Only swap i am planning to do is of course R34 GTR front 😍.
    • Hey. Very valuable information about pitwork, I will pay attention when buying any consumable parts 🙏 As for the carpets - I got a handful of information from nengun, from which it appears that indeed the carpets for the driver's side are OEM. They are not able to show me any pictures due to the long chain of different sales entities but after I place the order, as soon as the goods arrive at the nengun warehouse from which they will send the shipment to me they can send me photos and if my purchase differs from OEM I can immediately return it / cancel the purchase. I think I will give it a try 😉. Of course i'll let you know what's what as soon as i get them P.s. I know the topic is not relevant to the thread, but both nengun and amayama have these SICK 😍 trunk room lamps available. Do you know anyone who ordered them? I need to have one in my car
×
×
  • Create New...