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MAF reading for stock?
Posted: Wed Aug 20, 2008 8:25 am
by TurboBeater
Has anyone checked what their MAF voltage or g/s is on a completely stock turbo car? Right now I'm getting 184 g/s max at 11.6 psi. With 9.5-10 psi I get 178 g/s max. This is with a full 3" catless exhaust and stock turbo, no intercooler (no knock yet!).
I never checked when the car was still stock so I'm just wondering where I'm at. Tomorrow I'll bump the boost some more and see what the difference is.
Posted: Wed Aug 20, 2008 2:18 pm
by Legacy777
What voltage is that?
I've come close to 5v with the stock turbo and 3" TBE.
Posted: Wed Aug 20, 2008 9:58 pm
by TurboBeater
Exactly 5V is 200 g/s, the curve is very steep just under that. I think mine is around 4.9ish. I'll check the MAF transfer curve when I get home.
Posted: Thu Aug 21, 2008 6:03 am
by TurboBeater
I should correct myself, the 184 g/s was at 10.5psi.
Ok, here's the conversion.
Code: Select all
Volts g/s
5.00 193.8
4.92 186.6
4.84 179.2
4.77 172.2
4.69 164.8
4.61 157.8
4.53 149.9
4.45 143.4
Now at 13psi I'm over the limit already, going to check for knock next time I drive it. Boost seems kinda spiky, need to check for leaks.
Posted: Fri Aug 22, 2008 2:49 am
by Legacy777
Boost isn't necessarily a measure of the mass flow rate of air through the engine.
Posted: Fri Aug 22, 2008 5:52 am
by TurboBeater
Well, what I'm saying is that is the maximum MAF reading at that boost setting. The MAF sensor is pretty much pegged from 4600 RPM to redline.
Posted: Tue Sep 16, 2008 4:37 am
by tmarcel
TurboBeater wrote:Well, what I'm saying is that is the maximum MAF reading at that boost setting. The MAF sensor is pretty much pegged from 4600 RPM to redline.
On what turbo? Kinda' like comparing, say a TD04 13T vs a GT3076. Do they both flow the same amount of air at xx.xx/psig (kpa, bar or whatever you want to call it)?
Thanks for the info. Aside from the voltages, how did you come up with the g/s data?
Posted: Tue Oct 07, 2008 3:55 am
by TurboBeater
This is on the stock turbo with 3" downpipe and exhaust.
I got the numbers from the MAF calibration table in the chip. Looks like I scaled them wrong, multiply all the g/s values by 0.827. This means the factory MAF maxes out at 160g/s.