Boost pattern with 3071

[th.b.w.]

Hy,

what max. boost from 4000 - 7200 is possible with the 3071/ar82 ?

I run now 1.9bar at 3800 to 1,6bar at 7000 RPM.

Is it possible to get 2,1 to 1,8 redline ?

Is it durable and without to damage it, or is it short lifetime...


Thanks Thomas

[220bhp]

Very short

[A80Avant]

I dont think the turbo is that off it's comp. map running those boost levels

i was running 2bar to 2.1bar overboost and 1.7 to the red line on 3071 and .63AR and that is it's limit really. Lamda was .80 to .77 and had no issues keeping that boost till 6800-7000rpm.I was dropping it thereafter anyway to lower level as the backpressure was too high i believe and it was struggling.

So i suppose that the .82ar should handle 0.1bar more towards the red line. It might only keep it till 7000rpm rather than 7500 or 7800 depending where the limiter is, but the turbo is already not very effective on those rpm levels, so you may not need to keep 1.8 till 7800.

[Bram]

What spark plugs are you running Thomas?

[Jamo]

With a .82 should be fine with a 3" exhaust system.

[th.b.w.]

Hy, i run the Bosch F5DPOR...

My exhaust is 76mm from turbo to cats, than 70mm BN-Pipes...
Ported head with oversize Supertech valves, short IM, big IC, Wagner ExM, ....

I have an error in the RPM it drops in the range of 6200-6500 sometines about 200 RPM an shoot in the exhaust ???

But only at this RPM range, can it be a trigger or fail RPM sensor error be ???


Thomas

[th.b.w.]

I forgett this,

The redline is set at 7.300 RPM, because the turbo is not so efficient after 6.500 RPM...


Thomas

[Bram]

Hy, i run the Bosch F5DPOR...

My exhaust is 76mm from turbo to cats, than 70mm BN-Pipes...
Ported head with oversize Supertech valves, short IM, big IC, Wagner ExM, ....

I have an error in the RPM it drops in the range of 6200-6500 sometines about 200 RPM an shoot in the exhaust ???

But only at this RPM range, can it be a trigger or fail RPM sensor error be ???


Thomas

What is your lambda reading between 6200-6500? Maybe it's too rich....

70mm for that turbo is quite on the limit I would say. I got the advise to run full 76mm for my old GT3071R 0.63AR setup. Your setup should flow even more.

[Jamo]

Twin 70mm pipes is o.k as long as they join back into a single 76mm at the middle or back box

Of more importance is what size are the cats? are they both 100 cell?

[A80Avant]

is it ok if you have twin 70mm all the way?

[Jamo]

is it ok if you have twin 70mm all the way?

If the egt's and backpressure are fine then can't see why not.

[A80Avant]

cause i have been told that 2x63 or bigger was even better than one 76mm tube. BN pipes used to do that for cat backs.quite loud though

[Jamo]

cause i have been told that 2x63 or bigger was even better than one 76mm tube. BN pipes used to do that for cat backs.quite loud though

When I had my exhaust done in single 76mm pipe at Pipewerx I asked this question of the professionals.

They said the reason why manufacturers use dual pipes is twofold

a) Space, smaller pipes mount close to the body
b) Noise, less chance of drone with twin pipes.

There are no performance benefit of running twin pipes, the reason to fit single if possible is that there is no change of diameter in the system and you get a better flowing system which is the ultimate aim of the exhaust.

[A80Avant]

ah i see. good to know

[Bram]

Twin 70mm pipes is o.k as long as they join back into a single 76mm at the middle or back box

Of more importance is what size are the cats? are they both 100 cell?

Aha, I forgot BN-pipes use twin 70mm pipes. Then it should be fine I guess.