6G Celicas Forums

i have heard a few ppl rattling on about them but someone one said to me that the safc will send your timing up the spout when it changes the afr ratio....??? can anyone explain a little to me as i dont know a lot about them and three ppl have just bought them in my area but im not so sure they work well and reliably

???

i dont see how it can affect timing and quite a few reputable companies have told me that it shouldnt make and difference to the timing unless the ecu senses a knock situation....

yes it does change your timing..... when you add or take away fuel, your ecu thinks that the car in under different load conditions and advances or retards the timing. this could lead to major engine damage if you dont know how to use it correctly

the Emanage is bettter in every way. it allows you to control fuel and timing at the same time. the only reson why its not as popular, is because it dosnt have a cool display like the safc. you have to hook up a laptop to it to tune it.

but if you set a correct afr ratio what need would the ecu have for changing timing???? surely it only changes timing when it senses somehting amiss?

not doubting you lagos jus trying to get my head round it

Yes... but there is no real effective way to tune your afr without a wideband o2... and I should also add... just because the afr is tuned doesn't mean the engine will make more power.

what do you want to use this on? your NA motor, or with a turbo kit?

the correct air to fuel ratio is already set by your ecu, a piggy back only tries to trick the ecu into doing what you want to do. if you have a turbo kit, your are tricking and fighting your stock ecu to add or take away fuel. the ecu sees that the car is running less/more fuel, and starts to act differently because it thinks the car in under different load conditions.

remember, this is a piggy back, not a full stand alone ecu where u can just change the fuel ,and it wont affect antyhing. any change you make, will alwasy affect the timing of the motor.

yes i know i meant if you tuned it to the correct afr ratio using wideband o2 why would the ecu decide to change anything?

using the correct afr ratio will not slow your car and will contribute to reliability tho.....

This post has been edited by dan4: Jan 19, 2006 - 4:34 PM

I beg to differ... "correct" is also not a very good word choice...

This post has been edited by Kwanza26: Jan 19, 2006 - 4:36 PM

its an st205 gt four. the ecu will operate within its parameters yes....but it gets to the point sometimes where it cannot rectifiy a situation i.e. running too lean am i right? so if you help the ecu and correct the afr ratio it will use the usual timing as it senses no problems no?

this is a little confusing as you can see!

The only time an ECU leans a car out... is when there's something wrong or you're fuel system isn't up to par. a piggyback isn't gonna fix that.

This post has been edited by Kwanza26: Jan 19, 2006 - 4:38 PM

why not? run too lean or rich and damage will occur either way

I assume the reason you want to piggyback the ecu is to make power right? There is no real "correctness" between afr and making power, besides keeping the engine sufficiently fueled. There are too many variables to consider when tuning the fuel for power... so there is no standard or "correct" afr you need to be at to make power. Each engine is different. I'll say this... running lean can blow you to bits... running rich won't blow the engine... but will chew apart your cat.

so you would be sure that if i connected a wideband to my car and run 17psi instead of a standard 13.8 the afr would be perfect without changing it?


.....if you run too rich you will bore wash

the object of this is not a power gain its more of a peace of mind issue

get youself a wideband o2 gauge. then you will know if you have anything to worry about. if you have an st205, then running 17psi on the stock ecu and stock 550cc injectors shouldnt be a problem.

another thing you can do, is take your car to a dyno. they will plot out and air to fuel ratio and your hp out on a chart. then you will see if the car is running lean in any way.

the worst thing to do, would be to just buy an safc and start messing around with it. there is a strong chance that you can damage the motor by doing something that you think will help it. put your car on a dyno 1st, then you will know if you have a fueling issue that needs to be taken care of. dont just buy an safc because it looks cool in the car. thats a big mistake a lot of peole make.

im not interested in a dyno run, you are checking more dynamically while on the road no?

i wil test the car at 17psi then cause i dont believe that it will be perfect