MSefi.com read only forum (Jan.15,2018)

Hi, to simplify my tuning, I want to remove the Gair factor from the PW equation. To do this, I will place the Gair curve into the IAT compensation curve. This will negate the Gair effect by making the Gair value always at 100. I know some of you will tell me : Place a x ohms resistor in place of the IAT sensor to "generate" a 100 Gair. My point is that I want to fine tune my fuel and AFR table but I want to know the real IAT too (I'm turboed and intercooled, I want to know the IAT when boosting). To fine tune the fuel and AFR tables, I want as less variables as possible. So, I can easily make Gair always 100 by making a curve in the IAT compensation curve.

So, I need the Gair curve (IAT vs %drop).

Thanks for any inputs!

Sam

bump plz

Thanks a lot lance, that's all I want to know.

Sam

I think I have achieved the same thing by changing IAT Fuel based corrections under "Other tuning" in MSII.

I have GAIR now constantly at 100% as I had heat soak issues on restart.

My table is (in deg C)

IAT Deg % corr
8 0
21 0
33 4
46 8
58 12
70 16

Hope this helps

Wow thanks a lot Linzerl!

This is what I want, exactly. I was gonna find the values with the PV=nRT formula, but I'll use yours. Thanks a lot again, it will simplify my tuning.

Lance, in my understanding of the Gair ratio, it will only make the air-fuel mixture a little richer than normal on normal driving condition i.e. bad fuel consumption... But I can live with that during my tuning.

Anyway, supposing that I set EGO correction factor at "on", it will fight the Gair factor to achieve the target AFR. So, what I'm doing is like having the EGO set to "on", in my mind.

I understand that, because I'm turboed, I shouldn't do that because of the increase of temp during boost. But, I'm confident in my intercooler and I'm not tuning the boost part of the map right now. I'm in the idle part fine tuning.

I may relocate my IAT sensor in the intercooler piping (after intercooler) instead of the manifold, like it is for now. I have a place where my intercooler piping is outside of the engine bay, so, heatsoak will no more happen.

I'll keep you updated with this.

Thanks again

Sam

Linzer my corrections to IAT are very similar to yours. I'm running a turbo Datsun 280 motor with my iat probe mounted in the top intercooler piping that returns to the throttle body. I initially thought that it was heat soak that caused oscillations on hot or warm start but after a few datalogs it appears to be an iat above 100f causing my problems. A correction of about 3 to 5% at 100f ramping up to 15% seems to work better than anything else that I have tried.

Running MSII 2.888a

Thanks for posting niner11!

Plz, post your IAT correction table values like Linzerl did. It will be helpful!

Thanks

Sam