Ecumaster forum

Is it possible to do this?

Is the 'Convert MAF to MAP' function locked to use MAP input, or can whatever signal that is used as load be used?
The reason I'm asking is that I want to replace an air flow meter with a MAF.

Doable wrote:Is it possible to do this?

Is the 'Convert MAF to MAP' function locked to use MAP input, or can whatever signal that is used as load be used?
The reason I'm asking is that I want to replace an air flow meter with a MAF.

excellent thread.. i was going to post the same.

remove afm and replace with hotwire maf...

Replacing AFM with a MAF is an extremely complex operation. Unless you want only drive WOT or idle.
The problem is not only in the air temperature correction that you'd need, but mainly because of transients. Every time pressure changes inside the plenum there is a transient state that can last say 0.1-1 second. During this transient reachness must be modified to cope with wall wetting and injection delays. AFM are much slower than MAF so accel/decel corrections are radically different and this can not be changed with DET3, in fact you need a special ECU for this.

All I'm asking is if DET3 is capable of representing the transfer function from MAF to AFM?

I understand that the transfer function will be "infected" with IAT compensation unless the signal is clamped. Doing a MAF conversion on my car (Porsche 944 turbo) is a pretty common upgrade and I'm not that worried about unhandled transient states, since there are several vendors out there selling MAF-kits that are doing the conversion this way instead of using true MAF code. Besides, not many (none that I'm aware of) have been able to do a satisfying AFM to MAP conversion using stock Motronic ECU on my car, while AFM to MAF has proven to be a successful upgrade.

alpha, thanks for your input!

I made several AMF to MAP conversion (not in Porsche but in BMW, Toyota, mazda cars ) and all of them working up till now. I don't see a reason why it should't work with AFF to MAF using IAT for correction. Precision is most important in conversion.

As I'm using DET3 to trick MAF and ignition advance I did not realize there was a built-in MAF->MAP conversion feature.

I'm really surprised this can work without any accel correction functionality. I'm still sometimes contacted by guys using old Motronics, all of them wanting to convert AFM to MAP or MAF and they always ask same question: how to do that and why a simple table conversion does not work. They all do this on BMW/Porsche/Opel/Peogeot GTI/... , all of them using the same Motronic generation of the end of 80th - mid of 90th.

To me DET3 is missing a 1D accel enrich map for fuel as function of analog_in change. This would also help for not conversion usage because drastic engine mods can need accel enrich modification.