"If the car runs 10.5:1 to start with and you go to 11.5:1 you end up with about 10% less fuel, which correlates to a MAF voltage drop of about 10% if under open loop conditions."

This is 1 AFR point. As with all these things though you go in smaller stages and see the results.

[Edited by john banks - 4/1/2002 10:03:55 AM]

 

Hi folks,

I have read a recent thread teling about these, but it doesn't really say what on earth it is supposed to do for the car.
I have just got my second scooby and this has one in. The old style with about 5 twiddly *****. They all came set to zero and the previous owner said that he had no idea what it wasw or what it did, as he had never played with it. Came with the car.

What exactly do I do with it guys????

Thanks,

Nick

P.S, oh, if only the search facility was there....

 

Nick

The AFC allows you to adjust the fueling for the car at different rpm / boost figures in comparison to the standard ECU. In theory it allows you to correct the ECU map for any mods that you have made to the car (revised turbo/exhaust/intake/intercooler etc) without having to go to the expense of a new ECU (link, Unichip etc). In practice it is more limited than these options, but is cheaper. As with anything like this, it is only as good as the person that tuned it to your car.

For more info, check this link for info on the current version on the Apexi USA website.

If you have one fitted in your car, this is a likely sign that your car has been fiddled with in the past.

Duncan

 

Cheers, Looked at the current Apexi ones yesterday, My, how they have changed!
Do you know who can tune these thingies then???

Cheers,

Nick

 

A lot of people take 1 AFR point off the top end subject to no knock and the EGTs being OK, and in so doing liberate up to 15 BHP.

If the car runs 10.5:1 to start with and you go to 11.5:1 you end up with about 10% less fuel, which correlates to a MAF voltage drop of 10% if under open loop conditions.

Some say you gain power all the way down to 12.6:1 which is about 5% CO. But it can be difficult to control the temperatures, and so most put in considerably more fuel than this.

You also have to map in consideration for different conditions - ie. poor fuel, high ambient = higher charge temp = lower knock threshold, high demand on track = the same.

This is not just something you can adjust lightly and needs a lot of thought.

 

'PoP'
Sorry, that was my head exploding!
Thank you for the above info John. I think that I am just going to concentrate on fitting it in properly and looking at the pretty lights change colour!!
Will look into getting it tweaked once the mods are complete.

Thanks again guys,

Nick

 

when you say 'take 1 AFR point off', what do you mean in terms of adjusting the fuel output at different RPM levels? This device allows you to set the fuelling +/-50% at each rpm level.

I have one of these devices and would like to understand how mine is set up.

cheers

 

I had one of those things on my car when I first got it , took it Powerstation got them to put it on the rollers and set it up my STI2 made 279 bhp with it fitted .

 

While of the subject of old apexi gear. I have an super ITC and super AFC which I had fitted to a friends celica a few years back. Does anyone have wiring details, and dip switch settings for these units for a subaru ( 92 legacy turbo....same as early 93+ imprezza ) I have details I think for the AFC, but none for the ITC. The apexi site only seems to cater for the newer stuff now.