Ahmet airflow sensor
 

Ahmet, how are the flap mods coming?

drew1

That's been on hold, since the complete exaust assy. has been out of the car (and head too at some point)...

I talked to a few specialists, and here's what I came up with:

It seems that the best thing to do is either try and make a true MAF work (hot wire), or don't mess with the flap ressistance too much. Problem arises from the fact that with less resistance at the flap, less air will make the flap open more. Even after calibrations, the flap will open at a rate that's not linear to the air flow (increase/decrease). Although many others don't think this is the case. The flap on the MAF is the single most important input for the DME, so I don't want to mess with this too much.

However, if I did not need to have good power, OR fuel economy at part throttle (then it could be tuned for wide open throttle), I could mess with it.

With much less ressistance at the exaust end, I'd like to do something about the air flow sensor. This is easily THE biggest restriction in the system, but altering spring ressistance is not a good way to get rid of it.

Hot wire systems keep the wire at a given temp, and the air passing through has cooling effect. The more dense the air is, the more it'll (try to) cool the wire. The faster it's flowing, etc. Well, this is a much better way to guess exactly how much air is going in, than simply a flap openning, and it definately introduces MUCH less restriction in the intake system.

I wouldn't be surprised if gains at full throttle were up to 10hp, this is quite (surprisingly so) a strong spring, trying to keep the engine from breathing. Part throttle response would be improved lots, but not part throttle power (maybe 3-5hp).

More than worth it for $200 (ford MAF unit), but should I keep the car stock? (if so, it wasn't too smart to swap to a stock head)I guess external tuning, via removal of restrictions is acceptable, specially if I start doing track events. A more efficient engine can't hurt! If the car comes back together, I'll be at VIR on april 14th +15th. Still got to do rod bearings, swap subframe, get alignment, replace a-arms, etc. That reminds me, check the A-arm post if you can!

I'll try to type up my findings, when I actually get something to work, but I've really been busy lately. The only time I get is a couple of hours during school 2-3 days out of the week. (Dropped a class, I usually stay in the library, do research/check the boards).
Ahmet

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It's all the driver...