darkwaveboi

Hey, ive been reading posts lately on how effective the S-AFC is for our cars. How come there is 20 hp worth of gain from using one of these, i mean...why would mazda run these engines so rich that they lose power becuase of it? Maybe it just could be that over time the car tends to run this way.

My car smells REAL rich (like tangy and stingy) and takes literally forever to go from 6k to redline (like 10 seconds in first gear)

Since im on the exhaust topic, whenever im idling i always here 'tit **** tittititit' from underneith the car comin from the exhaust system around where the cat is. Sounds like its not bolted in securely. Anyone know what this may be?

thanks for any imput
Jeff

nashman69g

iTrader: (3)

that 'tit **** tittititit' sound is probably your heat shield vibrating
mine does the same thing

and the problem with your car taking like 10 secs to get from6k to redline... somethings reallly wrong with your car

rx7_turbo2

I can't speak for Mazda but I imagine they set it up to run rich as some insurance against detonation.

Does a S-AFC help? It depends on what you want to do with it. If you have a need to control fuel delivery it works great. If your running completey stock there might be some gains from it I guess, but you will need a device to tune it ie) Air/Fuel, EGT gauges, maybe some dyno time.

For the most part people run a device like a SAFC if they have upgraded to bigger injectors, or pump etc and they need to be able to tune the fuel.

RETed

The stock ECU runs a bit rich in the midrange.&nbsp I've seen +30hp gains in the midrange just by jacking down some of the fuel in the middle.&nbsp This was on an FC running around 230hp to the wheels on a DynoJet.&nbsp This doesn't add to the peak horsepower, but it makes for a much QUICKER car for daily driving.



-Ted

Blake_AE

can you tune it with an a/f gauge or do you really need the EGT as well?

Grimlock

any suggestions as far as numbers? i cant seem to figure out what to my safc at right now i have it climbing at 4000rpm set at 2+ then climbing 2 points every 1000rpms. i figure it would be safe. i was told not to put it in the - numbers by a rotary mechanic. i know a dyno is the best thing to do but i cant do that right now. just wondering what else you might be able to advise?

boostmotorsport

Can I really trust my auto meter AF guage when tuning with my SAFC? I keep it 2 in the green pretty much full time, is it safe to tune it down more?

FoXX

if that "titititittitit" sound is not the heat shield, it could be pre-ignition or detonation as it also sounds like that

Grimlock

nope dont trust it! use the blue wire off your safc and wire it into the o2 sensor wire. then you can get a better reading. i notice on my car that if i turn off the head lights and radio my a/f gauge shifts a light in the lean direction. so when your running all your accesories it could be a false reading. unless my mechanic wired my gauge *** backwards. anyone else have this happening to them?

this tuning off gauges isnt easy!

darkwaveboi

i dont think it is pre-ignition, cuz it started happening when i got my clutch installed and exhaust. I SHOULD have a profile under my name which says what i have done to my car for technical answers..but its not showing up.. I got a stage 3, and i stalled and crunched it a lot when breaking it in cuz it was my first high performance clutch. the exhaust also a single, so the weight offset may causing a momentum in the pipe lower causing it to tap against the chassis. the sound does not come out of the end, + it does not come from anywhere near the engine. Been giong on for at least 6 months.

peejay

A N/A isn't going to detonate unless you do very stupid things with ignition timing (like get your trailing wires mixed up). You can run so lean the car misfires and makes no power, but it's not gonna detonate.

N/A's rule

go_speed_go

An MD Racing ECU on 87 octane on a hot Florida day will detonate an NA FC.

RETed

We usually knock it down 3% - 5% in between 3,000RPM and 4,500RPM.


-Ted

Felix Wankel

My A/F guage does the same thing. It damn sure doesn't like my amp that came with 3 30 amp fuses in it

I have a Walboro rewired with 8 gauge wire, I don't believe the voltage is dropping at the pump THAT much.

von

the 20hp gain was from a n/a car with mild mods that was running really rich.

I have done major crazy **** to my N/A that u would think would blow even a piston engine but NOPE. Shes still going and going and going.. boom boom boom

rx7_turbo2

find a better ground for the gauge. I ground mine right to the battery and there is no longer a drop when the headlights come on.

Bambam7

Going back to the first post- sound like maybe you have a clogged cat??
And yes, I have an N/A, and DAMN did my S-AFC make a difference.
Especially in the midrange, where I have it down by -5-9% between 3,000 and 5,000
I have it down about -3% at 7,000-8000 too, it reallly helped- but not as much as the midrange.

I wouln't tune off of the stock o2 sensor, it's good for crap.


I havn't had my S-AF tuned on a dyno yet, but just by lowering the midrange a little bit it probablyt took 1/2 sec of my 1/4 time EASY!
I can't wait to get it tuned properly... I don't want to lower it any more because I don't know how lean it'll be... I've got a wideband I just have to build and install...

darkwaveboi

thanks for the input, i think i'll have to look into that before i start any fuel or power mods.