Max Boost The Standard R33 Turbo Can Deliver?

[Torques]

Hi there,

I was wondering how much boost the R33S2 turbo can actually deliver if being maxed out?

As an experiment I set my boost controller to 1.2 bar, but the boost would never go over .9 - 1 bar.

Could it be that the turbine has reached it's mechanical capacity at this level and is actually maxing out?

And yes ... I know the turbine is not going to last long with this kind of boost. (it was just a test)

Cheers,

Andrew

Edited July 5, 2010 by Torques

[Pal]

wont go much over 14 psi / 1 bar.

[paulos]

so my r33 series 2 with gready profec spec 2 b with fmic, cat back 3inch can handle 14psi??

what about series 1's

[R31Nismoid]

Anymore than 12psi is well known to do major damage to the turbo.

So why try?

[JonnoHR31]

but to answer your question, they can go a lot more than 1 bar. personally seen around 20psi from a 25 turbo. definately cant reccomend it tho

[The Dan]

Shut the gate completely and watch them go over 40psi

[SargeRX8]

Shut the gate completely and watch them go over 40psi

exactly this. As long as nothing is limiting the turbo, it will boost til it blows. What the max is and what the same threshold is are two very different figures.

[Rolls]

What is the point of failure when overspeeding a stock turbo? Is it the bearings? Or do the impellers become unbalanced and just eat housing and explode?

[Torques]

Hi guys,

Thanks for all the answers ...

I was thinking that the turbo was maxing out since I could not get the boost over 14PSI / 1 BAR (around 7+ on the internal boost meter)

Background:

I am running this turbo on 13PSI (in High Mode of my boost controller)

Yesterday I was at this event here in England where you can do the quarter mile.

Some pictures if you like -> Santa Pod

Just for the fun of it I tried setting the boost to 1.2BAR, but the boost would never go any higher than roughly 13-14PSI, no matter what.

My conclusion was that the turbo was maxing out.

Very strange ..

Edited July 5, 2010 by Torques

[Rolls]

Sounds like the boost controller is faulty. Get a cheapo ball bearing bleed valve, they always work.

[bubba]

so my r33 series 2 with gready profec spec 2 b with fmic, cat back 3inch can handle 14psi??

what about series 1's

series 1 33 turbos can handle 14-15psi aslong as you have a nice free flowing exhaust, any restrictions (blocked cat, stock dump/front etc) will heat it up too much and destroy the exhaust wheel.

series 2 33 turbos (with the nylon compressor wheel) are notorious for the compressor wheel delaminating much over 12psi, hence I prefer the steel compressor wheeled s1 turbos.

[SlowSkyline]

The nylon compressor wheel isnt the problem, its the exhaust ceramic wheel, which are the same on S1 & 2 turbos. They usually blow over prolonged use over 12psi.

[paulr33]

i think your question is two

I was wondering how much boost the R33S2 turbo can actually deliver?

I was wondering how much boost the R33S2 turbo can actually deliver efficiently?

i suspect they are two different answers as well

what good is 37 PSI at the compressor outlet if its inefficient and the intake temp is well past 80deg?

efficiency of the std GTST turbos is something that is debated to death over and over

some people say 14psi is the limit, some say 12psi and so on

its upto you if you think the risk is worth the gain

ive had mine on 0.85kgcm2 for about 6 years now and still std unit and 227,000

i wouldnt dare run it at 14psi, i dont think it would be efficienct, and i thinik it would blow the exhaust wheel and risk the motor

[STATUS]

What is the point of failure when overspeeding a stock turbo? Is it the bearings? Or do the impellers become unbalanced and just eat housing and explode?

the rear turbine separates from the shaft.

[The Dan]

+1 they are glued on. So the heat generated and the turbine speed cause them to spin right off

[bubba]

The nylon compressor wheel isnt the problem, its the exhaust ceramic wheel, which are the same on S1 & 2 turbos. They usually blow over prolonged use over 12psi.

Tell that to the people that have had their nylon compressor wheels delaminate.

[The Dan]

Tell that to the people that have had their nylon compressor wheels delaminate.

Have you got their contact details?

[mad082]

Tell that to the people that have had their nylon compressor wheels delaminate.

i was running my s2 turbo at 14/15psi and had no issues. as people said, it's the exhaust wheel that packs up it's bat and ball and goes home (which evidently is the cat converter) that causes 99.9% of actual failures on the rb turbos (not counting oil seal leaking as a failure) (whether it be rb20, 25 - r33 s1, s2 or r34, and even the gtr's of each model). this the results in the nylon compressor wheel doing it's impression of a watermelon hitting the ground after being dropped from the top of the empire state building, while the steel wheel just does an impression of an old fighter plane prop that thinks it's a drill bit.

[mad082]

oh and to answer the original question, the turbo should boost higher than what you are trying to boost it to. the issue you are having could be caused by a few things.

1: faulty boost controller

2: vaccum/boost leak

3: blocked cat (however if this was the case it would boost up then drop back as it got higher in the revs)

[bubba]

Have you got their contact details?

I don't care enough to keep contact details, if you search you will find threads and I have seen one with my own eyes that came in to the workshop, exhaust wheel was still intact.

By all means guys, wind your stock turbos up, I'm not the one that will be crying when they let go