Recently I installed a TSI/powermod engine management system. It is really easy to work with and I'm learning with my S/C setup before I install a turbo kit in a few weeks.
The fuel map is a matrix of either TPS % and RPM or it could also be set for tuning with boost and rpm readings.
My question is: how should my A/F ratio be at differnt engine load and RPM.
I know that 14.7 is good at iddle and 12 at WOT, but how long shoud 14.7 afr's be under hard acceleration before decreasing to be at 12 at wot regarding engine load.
I hope my question makes sense the way I explained it. If not I could post a pic of the fuel map screen so it would be easier to understand my question.

Thanks for any help

Recently I installed a TSI/powermod engine management system. It is really easy to work with and I'm learning with my S/C setup before I install a turbo kit in a few weeks.
The fuel map is a matrix of either TPS % and RPM or it could also be set for tuning with boost and rpm readings.
My question is: how should my A/F ratio be at differnt engine load and RPM.
I know that 14.7 is good at iddle and 12 at WOT, but how long shoud 14.7 afr's be under hard acceleration before decreasing to be at 12 at wot regarding engine load.
I hope my question makes sense the way I explained it. If not I could post a pic of the fuel map screen so it would be easier to understand my question.

Thanks for any help


In an ideal world, the 14.7 should drop to low 12's high 11's within moments after going WOT. Your wideband sensor, depending on the age and where it is in the exhaust, may take slightly longer. If you're talking like 3....4 seconds of WOT in 5th, i'd say you have a little issue.

In an ideal world, the 14.7 should drop to low 12's high 11's within moments after going WOT. Your wideband sensor, depending on the age and where it is in the exhaust, may take slightly longer. If you're talking like 3....4 seconds of WOT in 5th, i'd say you have a little issue.

I'm not talking about wot in 5th. I'm interested in 2nd 3rd or 4th gear.
I' having 12 or lower AFR before reaching WOT, Wideband PLX 300 is brand new.
I can see the place where the engine is geting the fuel on the fuel map, and when I'm cruising in 3rd gear let say at 3000 rpm AFR are 14,7, and throthle possition sensor(TPS) is at 12%....if I step on the gas until TPS is at 80% should the afr still be 14.7 on a moderatelly hard accelration, but not reaching WOT ???
12:1 afr should be only when the TB is at WOT?

here's the screen of the fuel map and the correction values for each load and rpm pickup point.

http://i8.photobucket.com/albums/a39/BlackMamba325/91be4ac3.jpg

If Mert supplied you the TSI unit, why not get him to advise you?

In an ideal world, the 14.7 should drop to low 12's high 11's within moments after going WOT. Your wideband sensor, depending on the age and where it is in the exhaust, may take slightly longer. If you're talking like 3....4 seconds of WOT in 5th, i'd say you have a little issue.


Can you define 'moments'? In looking at what Nick has done with my afrs, I see that he doesnt let them drop into the low 12s until it hits about 4200 rpms, after starting a wot run at 2000 rpms, up around stoichio.

If Mert supplied you the TSI unit, why not get him to advise you?

As I'm still using AA software, the TSI unit came with no fuel map or ignition maps, even myself that have no problem admiting that I know a lot less than you know about FI, know that it would be dificult to provide a map for a car with a modified and encrypted software and injectors that came with the #codes erased.
I think that my car is the 1st 325i that Mert is working with, I rather have him work on my turbo kit than waste time in tuning a fuel and ignition map for the OEM software, knowing that it would be replaced in a few weeks when the turbo is installed.
Besides I prefer to learn how to use the TSI unit, so I can fine tune the turbo if needed to the type of gas I have here and for the fact that I like to do things for myself......doesn't most of the forum members like to do their own stuff.

On the other hand I did asked the same question to Mert when I posted this question. Do I did wrong in trying to have othe people advice.

I will not get into the issue some of the forum members have with Mert, that was not my intention when I posted my question.

If you had the time to find out that Mert provided me the TSI unit, was it to much of a waste of your time to provide me the answer I was looking. On the other hand...if you had no intention in asnwering my question, or you just did not understand what I was asking, or you just dont know the answer, which I doubt.....just keep your comments for yourself.

If you think you could help me with my original post, you are most wellcome to tell me, if not....please dont make me waste my time answering your questions.

Can you define 'moments'? In looking at what Nick has done with my afrs, I see that he doesnt let them drop into the low 12s until it hits about 4200 rpms, after starting a wot run at 2000 rpms, up around stoichio.

This is the kind of info I was looking for, Thanks.

Good luck.

Good luck.

"I believe in luck: how else can you explain the success of those you dislike?" ~Jean Cocteau
You must be a hell of a believer....:D

In my case, I only need luck when I go to the Casino....$$$$

Not sure how helpful this will be....but I'll throw in my two cents

The AFR for a particular engine, at a particular load, is mostly designed to manage heat. If you take your car to the Dyno you'll find a large range of AFR's providing the same torque.

That said, there are rules of thumb as I understand them:

> 14 psig: 10.3 - 11.8
< 14 psig - NA: 12.5 - 13.2

Figures are for WOT

If you're able to tap into your DME, seeing at what AFR it starts to pull timing will let you know that the engine is starting to knock and your running lean.

A good tool to use is a EGT gauge, for what your looking for and just a great tuning aid.

Hope that helps.

Not sure how helpful this will be....but I'll throw in my two cents

The AFR for a particular engine, at a particular load, is mostly designed to manage heat. If you take your car to the Dyno you'll find a large range of AFR's providing the same torque.

That said, there are rules of thumb as I understand them:

> 14 psig: 10.3 - 11.8
< 14 psig - NA: 12.5 - 13.2

Figures are for WOT

If you're able to tap into your DME, seeing at what AFR it starts to pull timing will let you know that the engine is starting to knock and your running lean.

A good tool to use is a EGT gauge, for what your looking for and just a great tuning aid.

Hope that helps.

Thanks alot,
The thing is my car came with no O2 sensor from the factory, so I think the DME has no way to know how the AFR, pull timing could be done using only knock sensor??? Diagnose tool at the dealer showed a fault for the O2 sensor but they were the ones that told me my car had no O2 sensors from the factory???

The DME uses the knock sensor to monitor detonation.

"AutoTap" has a software package and interface cable to monitor DME function. This will allow you to monitor the timing.