beefhole

iTrader: (29)

Yes i've searched. Let me finish

I've read mixed results about this mod, and I am wondering some things. Some say to put it on the AFM temp wire, but I read that is actually measuring air density. So if it reads colder/more dense air, then it will add MORE fuel. I know of the air intake thermo-sensor, which is located on the manifold. Should the resistor be added to this sensor instead to report "lower" air temps to the ECU? In the FSM it says this sensor reads ~33kOhms @ 77F and ~3.5k @ 185F. Would adding a 10k-20k resistor on the green wire for this sensor be ok to "lower" the temps? Also in the FSM I see that the AFM thermo and air intake thermo seem to tie into eachother and both connect to the ECU at "3C". Is this true?

SureShot

That's like driving a tack with a sledge hammer.

Have you read up on air/fuel converters?

beefhole

iTrader: (29)

LOL, interesting answer. Right now I cannot afford an AFC, but I have thought about it.

jon88se

Don't bother with the resistor mod...you won't see noticeable gains and you don't wanna fool with your engine management in such crude manners. Save some $, get an SAFC (Apexi) or SAFR (HKS) and have it installed/dyno tuned. You WILL get the most power safely this way.

boosted1205

iTrader: (9)

That's a very crude way of adding more fuel.
The rteck chip just came out for FCs and at $100, that's a hell of a deal.
https://www.rx7club.com/forum/showthread.php?t=355514

beefhole

iTrader: (29)

I'm not looking for more power, just anything I can do to gain a little more MPG because I am poor

The RTek is only for S4 TII's (BAH!) But hopefully they will make it for the rest of the 2nd gen models.

Icemark

The temp sensor in the AFM, can be off as much as 3K ohm, so using a resistor just simply makes up for that.

And when the AFM is cold the timing is modified not the fuel.

beefhole

iTrader: (29)

I read in a previous discussion that it's actually measuring air density and the intake sensor measures the temp. Is this true? Also judging by the schematic is looks like the afm and temp sensor are tied together. Is that true?

Icemark

There are two intake temp sensors, one on the AFM that the ECU uses for density and one on the upper intake manifold that the ECU uses for warm start (although it is belived by several members here that on S5 and Turbo models that intake manifold air temp sensor is also used for additional timing changes (but the S4 factory manuals do not make that second correlation).

On the AFM, I have played with extensively with the temp sensor there and make the resistors available at just about cost on my webstore for those who wish to modify the stock AFM temp output.

beefhole

iTrader: (29)

It was the mixed reviews throwing me off. I guess I will just try and experiment and see if I notice anything. Thanks

KompressorLOgic

iTrader: (6)

i am also wondering about this mod. and if it works or does anything?

NZConvertible

I'm going to assume this is just a typo, because we all know the AFM's temp reading is a fundamental part in calculating fuel requirements.

Retarding the ignition timing as intake temps increase is a feature of just about every EFI system I've seen. It is an absolutely critical part of a Turbo EFI system in particular, since the AFM temp reading is obviously useless for measuring post-turbo/IC temps. The reason the S4 FSM doesn't mention this is for the same reason is doesn't mention hundreds of other things the S5 one does: Mazda didn't put it in.

As for the resistor mod, all this will do is make the engine run richer all the time. Why would anyone want that?