Rb25 Det Neo Safe Boost Presure

[Rolls]

Any boost is safe if temperature and detonation is kept under control.

Max the turbo out at 18-22 and make sure ignition is safe and AFRs are under control keeping the motor cool and it will last forever.

[Lithium]

I don't know for sure, but I'd be pretty suss of pushing a little GT2871R to around 20psi on a 2.5litre - I'd have thought that would be well and truly maxing the turbo out and doing some nasty things to exhaust pressure/temps?

[simpletool]

I don't know for sure, but I'd be pretty suss of pushing a little GT2871R to around 20psi on a 2.5litre - I'd have thought that would be well and truly maxing the turbo out and doing some nasty things to exhaust pressure/temps?

+1

The science is with you on this one.

Not sure about ANY boost level being acceptable, as there are a few design limitations you need to consider. Like valve spring pressure, rod strength, chamber design, etc. Depends on what you call safe and reliable. I personally would think 1.1bar, but if you have a fat tune, no pinging and aren't pushing the turbo too hard I'm sure 1.4 bar could be considered safe - if given a large enough margin to cope with varying fuel, temperature, filter blockages.

But...a 2871 at over 1.1bar on a 2.5L would be running into choke (unless you taper the boost down as the revs rise ala Evo-style)

Edited June 2, 2011 by simpletool

[Rolls]

I don't know for sure, but I'd be pretty suss of pushing a little GT2871R to around 20psi on a 2.5litre - I'd have thought that would be well and truly maxing the turbo out and doing some nasty things to exhaust pressure/temps?

Maybe not to redline, but in the midrange it will do 20psi, probably drop to around 15-16 by redline.

my highflow is built to similar specs and would peak to around ~19 at 3-4k then slowly drop down to 15 by 7500rpm.

Edited June 2, 2011 by Rolls

[PM-R33]

I pushed mine to 263rwkw on 20psi dropping off to around 17-18psi by redline (tuner didn't really do anyting with the boost controller so perhaps may have been able to hold 20 if setup right). Only reason I could't try to run a little bit more was that the old Microtech had a 20psi MAP sensor.

But yeah 18psi is about the sweet spot of the GTRS. Above that the only gains are in the midrange (because if setup nicely it will be on 20psi before 4000rpm), but not peak.

[Rolls]

If you max out a turbo throughout the entire rev range it will always be able to flow more in the midrange (more psi) as more revs = more airflow needed.

So really if you want to get the most out of your engine and outright torque won't break it (build motor) then you should always be able to run x% more boost in the midrange than the top end.

[Addicted2BoostR34]

i owuld be happy with 15 i just want it so i can drive it how i like and dont have to think about it giveing up !

[Rolls]

i owuld be happy with 15 i just want it so i can drive it how i like and dont have to think about it giveing up !

If tuned poorly you could very easily destroy it on just 15, might as well spend the extra getting it tuned properly and run 18+ and reap the rewards.

[Addicted2BoostR34]

If tuned poorly you could very easily destroy it on just 15, might as well spend the extra getting it tuned properly and run 18+ and reap the rewards.

true true !! the plan was wen the ecu gets done run 17 on high and 12 low on a switch as the ipec has its on boost controller ? ..anyways as i said i would be happy on 15 ..

[Rolls]

high and low is just a gimmick, after a week you'll never run it on low trust me hehe

[DVS JEZ]

Run low boost on hot days

[Rolls]

Run low boost on hot days

Or just tune it with a coolant temp trim table, even a plain old nistune lets you do that. If it is going to ping on hot days then something is wrong.

Obviously within limits eg a 40c day, but you shouldn't be revving it out more than once in that weather no matter what the boost settings is imo.

Edited June 3, 2011 by Rolls

[DVS JEZ]

Need more than coolant temp dude. Air Temp is a MAJOR factor. An once the cooler is heat soaked than ur up shit creek.

[femno]

The tune should be away from the max limits influencing knock anyway??????

[Addicted2BoostR34]

Or just tune it with a coolant temp trim table, even a plain old nistune lets you do that. If it is going to ping on hot days then something is wrong.

Obviously within limits eg a 40c day, but you shouldn't be revving it out more than once in that weather no matter what the boost settings is imo.

im in tas soo its always cold our best day may be 20c at night its around 7 to 12

[simpletool]

Need more than coolant temp dude. Air Temp is a MAJOR factor. An once the cooler is heat soaked than ur up shit creek.

You could adjust the MAP sensor temp calibration table above 70°c intake or whatever was deemed abnormally high. I have no practical experience with this, but I don't see why it wouldn't work.