[93DLEGT]

K i need to get some straight info, i have done a lot of info and just got more confused.
1. Will a safc2 w/stock gt ecu work on a gtx reliably?
2. Its been said that the safc2 doesnt work at WOT, is it true with a 2nd gen escort gt ecu?
3. Can i tune the motor strictly with the Safc2 (no dyno/wideband o2)?
THANKS!!!

 

[mikeflys1]

The safc is decent for cheap fuel management but using it messes up the ignition timing a little bit. Its fine for low boost but for the same price you could do a megasquirt and have something 10x more reliable.

 

[Jeffescortlx]

Some wide band tunning will be safer and could make more power. You could just street tune it rich.
I'm not sure about the WOT thing, air flow meter's usally still stay used at WOT, but O2 sensor's dont.

 

[93DLEGT]

Ya i think im just gonna stick with me wBo2 and just tune my vaf to make it run decent. Then ill probly get an fpr then get it tuned on a dyno, but i wont be able to dyno tune for like 4 months after I get it all installed.

 

[mikeflys1]

I think the WOT thing you mean is the rumor that mazda computers ignore all the sensors including the vam/maf while at WOT. But with my own car i had the safc and rx7 460cc injectors.....i datalogged a bunch with my wbo2 and everything definately worked.

 

[JohnScort]

When Marclar see's this..There will be one word

MEGASQUIRT

lol :lol:

John

 

[Josh_LX]

no it'll be 5 words (give or take a few)....


"Welcome to my world..... (insert blah blah blah).... MEGASQUIRT!!!"
:lol: :lol: :lol: :lol: :lol: :lol:

 

[Mysta316]

So the SAFC only works on low boost. and it messes with timming?

Have you ever used one? Or is that what you read on the internet from someone else that has not used one?

Because I used one on my car running 19psi and 550cc injectors. And last time i checked that was not low boost. And never had any problem with it changing my timming.

 

[Jeffescortlx]

Mysta, I know your car is'nt a Honda but this artical applies to many car's. Ones that have a distribitor/MAP or pretty much any kind of air flow meter.
Read:
http://www.honda-tech.com/zerothread?id=841443

This is more based on Ford with MAF and distribitor-less ignition, but same thing applies, you trick the air flow meter you trick the timing map with it.
Read:
http://www.mustangworks.com/articles/el ... Blues.html

 

[Jeffescortlx]

I googled "AFC timing advance" and came up with 8010 finds.

From a Nissian forum:
http://www.nissanforums.com/showthread.php?p=478634
FMUs are typically coupled with such devices as Super-AFCs and VPCs , and is a very useful tuning tool. Typical stock ECUs reduce timing after seeing a certain amount of airflow (either lbs/hr or cfm) , but using a S-AFC combined with massive injectors and an FMU can cause the ECU to actually ADVANCE timing , as the S-AFC tricks it into thinking it's seeing LESS airflow than is actually going into the engine , while maintaining fuel flow capacity. I've seen timing advances of better than 40 degrees in DSM applications using the devices listed above.

DSM Forum
http://www.stealth316.com/2-tmo2.htm
One side effect of using an A/F calibrator (such as the ARC2, AFC, or VPC) and larger injectors is that the ECU thinks that less air is flowing (less load right?) so it will keep timing advance a little higher. This is good for performance but also increases the chance of knock. On the other hand, the little bit of retard that results from a small amount of knock still leaves timing on the healthy side of 20.

Yes A AFC can advane timing, Mysta just did'nt get the memo.

 

[mikeflys1]

So the SAFC only works on low boost. and it messes with timming?

Have you ever used one? Or is that what you read on the internet from someone else that has not used one?

Because I used one on my car running 19psi and 550cc injectors. And last time i checked that was not low boost. And never had any problem with it changing my timming.

Dont you also have a gtx ecu? So that computer is already meant to be boosted and isnt exactly the same thing as pushing 19 psi on an n/a computer with more advanced timing already.....

As for it changing the timing......
1. The AFC works by scaling back the maf/vam signal to make the computer think theres less air coming in therefore giving it less fuel and allowing the use of bigger injectors.
2. The most timing advance is in the lower end of the table.
3. So if the afc is scaling the signal back into the lower end of the table then guess what.....Its advancing the timing further than it would normally be.

I think the WOT thing you mean is the rumor that mazda computers ignore all the sensors including the vam/maf while at WOT. But with my own car i had the safc and rx7 460cc injectors.....i datalogged a bunch with my wbo2 and everything definately worked.

oh yeah i guess i do have one.... :roll:

 

[Jeffescortlx]

ECU's with knock sensor's can get away with the screwy AFC advanced timing more then ECU's with out.

Like my 2nd gen lx computer for exsample, no knock sensor. So the computer cant see what's going on, it can ping knock and blow up and wont know the differece. While my friend with a DSM can run a AFC, if the timing get's to be too much, the knock sensor can see that and the computer pulls timing and saves the motor.

 

[fordboy4ever]

mysta doesnt have a knock sensor.