# Max boost on stock internals?



## Bakes12 (Oct 28, 2007)

Currently running 1.2 Bar. Have all the usual bolt ons with stock internals. Making 400 HP at 4 wheels. Have decat in but am about to put a hi flow cat back in and will need touch up tune. 
Is 1.2 Bar the max safe boost I can run on stock internals RB26DETT??
p.s: I dont want to have to rebuild the thing.


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## icydude (Nov 15, 2006)

I know 1.4 can be done but the turbos do not last too long there and are likely pretty hot. It pulls like a beast non the less. They have lasted me long enough for 500 km of hard driving though as of this post.


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## Daryl TunerLab (Jun 7, 2008)

1.2kg is pretty much the top end of the safe zone. I wouldn't go past that.


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## Bakes12 (Oct 28, 2007)

I have Garrett -5s.
So pretty much leave boost at 1.2 Bar eh?


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## Eaze (Jun 19, 2009)

Can anyone steer me in the right direction as to what bars are in reguards to boost?

I'm not sure if I don't understand the conversion from metric and standard or if it's something entirely different.


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## infamous_t (Jul 9, 2007)

Eaze said:


> Can anyone steer me in the right direction as to what bars are in reguards to boost?
> 
> I'm not sure if I don't understand the conversion from metric and standard or if it's something entirely different.


Bar, PSI, and torr (mmHg) all read the same thing, in this case boost pressure.
Conversions = Pressure units conversions - conversion unit pressure convert unit psi Pa - sengpielaudio Sengpiel Berlin


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## madandy (Jun 6, 2007)

A good tuner will make all the difference. A metal head gasket will be required before any stock internals' limits are realised though I assume you include the gasket in the 'bolt on' category. 1.4 bar is pretty safe but what turbos are you talking about?


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## R.I.P.S NZ (May 7, 2004)

I think your question may be more along the lines of what can my turbos take? 

The stock engine internals (including head gasket) could take 2 bar depending on what turbo/s you have just as you could make 600hp at 1 bar with a large turbo so its not so much how much boost it can take its more what hp and rpm the stock internals are good for.

Most say around 600-650hp/7800rpm is a pretty safe level for a stock motor but its also well known its possible to go alot higher.

The tune is critical end of story.

Rob


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## Kevingo (Feb 21, 2006)

On a customers car, we are running 1.5 bar on 2x gt2860-5s turbos, metal headgasket, hks cams, haltech platinum ecu and stock engine internals.

It's running all day long, dragraced and pushing 530hp. at the wheels. It's all in the tuning.

my 2 cents:thumbsup:

Cheers


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## Eaze (Jun 19, 2009)

infamous_t said:


> Bar, PSI, and torr (mmHg) all read the same thing, in this case boost pressure.
> Conversions = Pressure units conversions - conversion unit pressure convert unit psi Pa - sengpielaudio Sengpiel Berlin


Hell yea thanks alot!


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## dean j (Jan 28, 2007)

I got 2860-5's on mine, and i'll be getting mine tuned with the 'bolt ons' you talk about.

I think theres certain limits of certain parts before you reach safe limits of the internals. The head gasket will be my first restriction, as i've been told 1.2 bar is safe for that.

1.2 bar makes for a quick GTR if tuned right though.


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## ru' (Feb 18, 2007)

head gasket is fine; 1.2bar limit is utter nonsense imho


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## R.I.P.S NZ (May 7, 2004)

ru' said:


> head gasket is fine; 1.2bar limit is utter nonsense imho


Totally agree, we've run 1.7 to 1.8 bar + NOS, low 10s with a stock head gasket, still going strong after 6 or 7 years.

Rob


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## dazman (Mar 9, 2007)

Ive got 2860-5s on mine and am running 1.34 bar with metal head gasket.


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## G40tee (Feb 25, 2008)

i have never heard issues with head gaskets at 1.2 bar, utter rubbish!

i have been told before 1.6 bar is a general limit but as said is all in the tune and depends totally on the turbos and other mods and how they are mapped!


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## Eaze (Jun 19, 2009)

I'm not to sabby on my R32 im picking it up on July 15th from the port so hopefully everything is running right and i can get it home. As far as bars are concerned i was wondering if to low would be a problem as far as 1.1 bar?


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## Mobilcepet (Apr 22, 2009)

How about for the nurs...? what are the basics thing to get it on 400hp? just turn-up the boost to 1.6? or have to change the exhaust etc as well??


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## Dynamix (Nov 1, 2007)

Eaze said:


> I'm not to sabby on my R32 im picking it up on July 15th from the port so hopefully everything is running right and i can get it home. As far as bars are concerned i was wondering if to low would be a problem as far as 1.1 bar?


If your car has the stock ceramic turbo's 1.1 would be a little high, 1.0bar (14psi) is recommmened as the safe level for stock turbos, people have run them higher, but above 1bar you run the risk of breaking the turbine wheels off as they're ceramic and were never meant to take that kind pressure, i've run my r32 gt-r at 1bar on ceramics for 2 years with no problems. The best lesson you can learn is the tune in the most important part in the whole mix.


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## dean j (Jan 28, 2007)

I wasn't saying boost limited to 1.2 coz of the head gasket. I got what i've heard mixed up.

Anything past 1.2 and i was told a hard pipe kit was needed usually. 1.4 was for the head gasket. I'd love to run that sort of boost, but just worried about the head gasket. 

Maybe i just been told horror stories, or maybe good advice considering my engine is a completely standard internal 80k odd motor?

Please advise me too, as i'm looking to go up in boost soon. Wheres my limits?


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## Eaze (Jun 19, 2009)

Dynamix said:


> If your car has the stock ceramic turbo's 1.1 would be a little high, 1.0bar (14psi) is recommmened as the safe level for stock turbos, people have run them higher, but above 1bar you run the risk of breaking the turbine wheels off as they're ceramic and were never meant to take that kind pressure, i've run my r32 gt-r at 1bar on ceramics for 2 years with no problems. The best lesson you can learn is the tune in the most important part in the whole mix.


I highly doubt that it's stock, but for some reason it turns out to be then thanks for the info!


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## KaXXeN (Oct 6, 2008)

great thread this one.

Im going to run about 1.1 bar on a stock engine with r34 gtr turbos, so will stock head gasket and studs will hold for this?

i was recomended to get 1.2mm head gasket and arp head studs as stock wont hold for this boost pressure of 1.1bar. Im running my spec after kingsleys gtr almost except stock camshafts and elbows.


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## R.I.P.S NZ (May 7, 2004)

We regualrly run 1.5 to 1.7 bar + NOS on stock head gaskets and stock head bolts.

Save your money for real a good fuel system and good mapping.

Rob


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## KaXXeN (Oct 6, 2008)

well then 1.1bar feels very small in comparison.

The fuel system will be a Nismo fuelpump and nismo fpr, with power fc and a good company of mapping. They mapped a few skylines that are running impressive specs


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