Poll for Stage 3/homebrew folks
05-19-2005, 01:35 PM
#1
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Poll for Stage 3/homebrew folks
What is your MAF size and MAF reading @ boost level (Temperature too if ya know it)?
I'm running an 85mm MAF (Hitachi) and see around 250g/s in 60F weather at ~15psi.
I'm running an 85mm MAF (Hitachi) and see around 250g/s in 60F weather at ~15psi.
05-19-2005, 01:45 PM
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You're going to get responses all over the place on this one, not very consistent.
With that said, your MAF readings based on the boost levels, MAF housing size, and temperature seem very healthy.
05-19-2005, 07:20 PM
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85mm like you, but not an ASP. TC is complicated to describe on his setup, but here it goes....
He is running XR with MBC only and TCD. Without reducing SEL, you'll get a negative deviation code, which results in no limp/TC with MBC only and TCD, because XR requests a really high initial spike yet the ECU is only seeing ~1bar of actual boost with the TCD. He and Mike Moore tuned his car and while tuning it they decided to try and eliminate the negative deviation code by reducing SEL. What they forgot to take into account was that while this eliminates the negative deviation code upon intial spool-up/spike, this creates a postiive deviation at ~5500-6000 RPM because the entire requested boost curve moves down with a reduced SEL while the TCD still tells the ECU that it is making ~1bar. This positive deviation does not throw a code, but results in TC. It is hard to feel a lot of the time so they didn't realize it. He actually dyno'd his car this way and wasn't too unhappy with the results. I asked him to send me some logs and the first thing I noticed was TC in the 5500-6000 range....yet his car was still pretty quick. When I asked for a print screen of his lemmi settings, I knew right away what it was from. He changed his SEL scaling back to 100% and BAM it was much faster. I still haven't seen logs since he fixed the problem and AFAIK he plans to redyno his car.
As for how much boost he is running, you'll have to wait for his response.
Oh, and GO PISTONS!
As for how much boost he is running, you'll have to wait for his response.
Oh, and GO PISTONS!
05-19-2005, 09:16 PM
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83mm 330g/s 1,5bar to 1,25bar
The thing with the rs4 sensor puzzles me. It gave me with stock injectors 240g/s while the s4 sensor gave 310g/s with the same rs4 housing and boost.
same have said the sensors are the same (didn't check part# when I installed the s4 in the rs4 housing) but some say its different. Maybe there are two or more different rs4 sensors. I'll need to test the rs4 sensor again to see if it handles well with so much lower maf numbers. I need lower numbers but I dont need screwed readings just scaled.
same have said the sensors are the same (didn't check part# when I installed the s4 in the rs4 housing) but some say its different. Maybe there are two or more different rs4 sensors. I'll need to test the rs4 sensor again to see if it handles well with so much lower maf numbers. I need lower numbers but I dont need screwed readings just scaled.
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05-19-2005, 09:56 PM
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Thanks JD. You do know my car well. I am running 22psi. Before I changed this problem my fats time
with full tank of gas was 3.8. I haven't had a chance to test yet since my car is in the body shop getting some work done.
