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What is the maximum boost that people are running on standard internals providing turbos and injectors are fit for the job & mapped correctly.

Thanks in advance.
 

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Did run on std head gasket for quite a while but changed it to a tomei when i had the haed off to fit the valve springs. If the maos good and you have no dat a std gasket will be fine for a very long time.
 

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It all depends on how the turbos boost. If they only produce hot air after 1.6 bar you probally will kill the engine. Biger singles are a bit different as they dont pass the efficency band as quickley. Its all relitive to the mapping.
 

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Robbie is spot on.

Unfortunatley the way the UK tuning scene has always been is "my pistons and head gasket have broken, so i must need stronger ones" but the fact is they dont fix the reason WHY the break, and thats almost always det.

So the stronger parts are just masking the issue, rather than fixing it.

A well mapped car on standard internals will last a lot longer than a badly mapped one on mega internals.

In-cyl pressure are massivley higher when an engine dets than even when the car is at full revs and full boost.

Fix the issue and the parts may well not be needed and you will be suprised how long things can last.

Almost all engine failiures of on tuned engines are oil or det problems, rather than things breaking purely through reaching their strength limit with no det and no lubicaion issues.

Obviously stronger parts ARE needed (hell, ive got uprated pretty much everything barring crank on my car) but not as soon as many people believe (or will have you believe).

Only thing with pushing things to limits are there is a lot less leeway, less margin for error.
But thats a balancing act which has to be decided upon.
 

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2bar on a Gt35R....

2.3bar cracked a ringland, but it was evident that the damage was due to pressure rather than detonation or heat.

The problem is as i see it... 'most' twin turbo set ups for the gtr's are not efficient at high boost levels, so no one really runs the pressure. As long as the turbo/s are efficient at that pressure and the engine is mapped safely at that level you shouldnt really have problems.
Detonation creates massive shock waves and cylinder pressures go through the roof, this pressure can be too great so it either blows the head gasket or cracks pistons etc, extra boost will raise the cylinder pressures but as long as the fuelling is right and the timing is not too advanced you will be less liekly to have problems.

Rob
 

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we ran 2.2 bar on standard pistons - no damage to them what so ever when we stripped the car, but that was due to good mapping and a bit of a test really to see what would happen before the 2.8 stroker was fitted

Bottom end soon went though!! 8 runs!!!
 

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This post is filled with people who do not know what they are talking about. There are some really smart people in here, who must be half-asleep or maybe just not thinking about the big picture.

Boost levels are IRRELEVANT.

Period.

Yes, tuning is important. I am a EFI nut case, and will be first to say this. However, you could have a dozen different setups all with perfect tuning, with a set of det cans on the road at all times, tuned to MBT, however you want to do it, and what the boost gauge says in relation to how reliable the car is going to be, still DOES NOT MATTER AT ALL.

You need to look at the size of the turbo(s) and the efficiency at the pressure ratio they are being used at, and the mass flow of air into the engine. Air intake temps are going to be completely different. Peak cylinder pressures, and overall cylinder pressures (graphed over time per one revolution) with a pair of stock turbos at 1 bar, a pair of GT2530's at one bar, a single GT4088R at 1bar, are going to be completely different.

If you want to discuss, "What is the max boost that I can safely run with a pair of Garrett GT2860-5's on a stock block RB26 with consistent 170psi compression test results and 10psi variance from cylinder to cylinder setup with a pair of Tomei 280° 11.5mm lift cams and a wide open 90mm exhaust when my air intake temps are 65°?" then that is a valid question, and I guarantee that there are less than a half dozen people on this forum qualified to answer it.

This thread should be locked.
 

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If you want to discuss, "What is the max boost that I can safely run with a pair of Garrett GT2860-5's on a stock block RB26 with consistent 170psi compression test results and 10psi variance from cylinder to cylinder setup with a pair of Tomei 280° 11.5mm lift cams and a wide open 90mm exhaust when my air intake temps are 65°?" then that is a valid question, and I guarantee that there are less than a half dozen people on this forum qualified to answer it.
It still goes beyond that though, you can't promise anything - its all about playing the odds when you are chasing more power. You know that running stock boost with stock exhaust and stock ECU and turbos you are going to be pretty safe, and you know that running 40psi on pump gas with a bad tune on stock turbos revving to 9500rpm on a car running oil which has been changed 4 times in its 140,000km life is probably not going to last very long at all.
 
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