lean afr above 8000 rpm after airflow, load and idc drop
May 10, 2012, 11:01 PM
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lean afr above 8000 rpm after airflow, load and idc drop
for those who don't know I'm on the stock ecu/maf and have seen as much as 790awhp at 46psi on the HTA3586 turbo setup. Gary's car is pretty much a clone of mine but now has the PTE 6766. At 30psi everything works fine beyond 8000rpm but at 35psi we're seeing an odd drop in airflow and thus load and IDC which causes a lean condition.
He has an EVO 7 but after noticing this problem we installed an EVO 8 ecu, maf and map sensor and he's running the same ROM as me. Same injectors, same fuel system etc..
He has an EVO 7 but after noticing this problem we installed an EVO 8 ecu, maf and map sensor and he's running the same ROM as me. Same injectors, same fuel system etc..
May 11, 2012, 07:31 AM
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we've tried multiple ecu's, mafs and installed a map sensor without any change. We're going to try a different intake pipe and shield the maf wiring better to see if it's related to interference from the shape, electronics, vibration or noise. I found a log of the previous 3582 turbo @ 42psi making 736awhp and we were able to go to 9000+RPM without a load/idc decrease.
the only difference was the buschur ported stock intake manifold vs current Driven Innovations intake and old FP HTA3582 vs current PTE 6766
the only difference was the buschur ported stock intake manifold vs current Driven Innovations intake and old FP HTA3582 vs current PTE 6766
Code:
TPS RPM WideBandAF LoadMUT2Byte InjDutyCycle 100 7094 11.4 418 45.4 100 7156 11.5 414 45.8 100 7156 11.5 411 46.2 100 7250 11.5 407 44.9 100 7313 11.5 406 45.2 100 7375 11.5 404 45.6 100 7406 11.5 401 45.8 100 7438 11.4 399 46 100 7531 11.4 397 46.6 100 7500 11.5 393 46.6 100 7594 11.5 393 45.2 100 7625 11.3 390 45.5 100 7625 11.3 388 45.5 100 7688 11.3 386 45.9 100 7750 11.4 384 46.3 100 7750 11.4 381 46.5 100 7813 11.3 380 46.7 100 7875 11.3 378 45.4 100 7906 11.3 377 45.5 100 7938 11.3 374 45.7 100 7969 11.2 373 45.9 100 7969 11.2 371 45.9 100 7969 11.2 369 45.9 100 7969 11.2 368 45.9 100 7969 11.2 366 45.9 100 7969 11.2 364 45.9 100 7969 11.1 362 44.2 100 7969 11.1 361 44.2 100 7969 11.2 359 44.2 100 7969 11.2 358 44.2 100 7969 11 357 44.2 96 7969 11 88 44.2 26 7969 11.1 28 5.1
May 11, 2012, 08:20 AM
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good news!
first I want to thank hamish(evoscan), david (tephra) and david (merlin) for looking at the data with us and making great suggestions along the way.
we changed the intake pipe and we're no longer seeing airflow abruptly drop beyond 8000rpm. we do not blame the old intake pipe for this, we've used the same intake pipe on hundreds of cars that never had problems including mine that has seen 9500-10,000RPM with more than enough fuel. It was the turbo and intake manifold that started the problem for us but changing the intake pipe fixed it.
now to the new data on a custom intake pipe gary made.
first I want to thank hamish(evoscan), david (tephra) and david (merlin) for looking at the data with us and making great suggestions along the way.
we changed the intake pipe and we're no longer seeing airflow abruptly drop beyond 8000rpm. we do not blame the old intake pipe for this, we've used the same intake pipe on hundreds of cars that never had problems including mine that has seen 9500-10,000RPM with more than enough fuel. It was the turbo and intake manifold that started the problem for us but changing the intake pipe fixed it.
now to the new data on a custom intake pipe gary made.
Code:
TPS RPMMUT2Byte WideBandAF LoadMUT2Byte InjDutyCycle 100 6410.15625 10.8 376.5625 45.78666667 100 6503.90625 10.8 376.5625 48.3 100 6679.6875 10.8 375.625 49 100 6718.75 10.8 376.25 50.16666667 100 6898.4375 10.7 368.125 50.86666667 100 6984.375 10.7 369.0625 51.56666667 100 7082.03125 10.8 363.4375 52.73333333 100 7246.09375 10.8 359.0625 52.96666667 100 7281.25 10.8 356.875 54.36666667 100 7417.96875 10.8 349.6875 55.06666667 100 7539.0625 10.8 346.875 55.53333333 100 7628.90625 10.5 342.8125 56.46666667 100 7812.5 10.3 338.125 57.63333333 100 7886.71875 10.3 336.25 58.8 100 8003.90625 10.2 331.25 59.26666667 100 8160.15625 10.2 327.1875 57.8 100 8289.0625 10.1 322.1875 56.1 100 8398.4375 10.2 319.6875 56.1 100 8523.4375 10.3 315.625 56.1 100 8609.375 10.2 311.25 54.4
Last edited by Mellon Racing; May 11, 2012 at 08:38 AM.
May 11, 2012, 08:21 AM
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yes, when the airflow drops, the idc and thus load drops, then the AFR goes lean so the car falls flat.
we don't use tephra's NLTS, we do it manually with our feet
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May 11, 2012, 08:40 AM
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FYI
we've always run 3" intake pipes with 4" reducer couplers at the turbo. we've had customers try 4" intake pipes at the turbo that reduce with a coupler to 3" at the maf and it gave them poor drive ability.
we've always run 3" intake pipes with 4" reducer couplers at the turbo. we've had customers try 4" intake pipes at the turbo that reduce with a coupler to 3" at the maf and it gave them poor drive ability.
May 11, 2012, 09:46 AM
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May 11, 2012, 10:21 AM
#15
My experience is that it is super picky, and the same rom with the same mods on a different car will behave differently. There is sometimes a jittery stutter like an injector cutting out with some cars... Then on other cars it is like it was tuned from the factory that way... It has really been hit or miss for me...
One thing I will note, is that all cars that I have tuned on SD with ER's SD programming run nearly flawless, I don't know exactly what Aaron does, but it works...
One thing I will note, is that all cars that I have tuned on SD with ER's SD programming run nearly flawless, I don't know exactly what Aaron does, but it works...