Ok, So You Think You Can Burn A Custom Chip For Your S4 - Cause U Got Skillz - Check This Out
AudiWorld Member
Joined: Jun 2004
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Don't need assembler skills - you need a memory map or
Dissassembler skills to decode the assembler solely for the purpose of identifying the location and purpose of the various maps. This is a totally different skillset to writing assembler.
I'd be amazed if any of the above companies do this.
They spend big bucks and buy real time emulators for the ECU that allow the tuner to change the various maps and values. This code is then downloaded and either programmed to a chip or written to the ECU via the OBD port.
As someone else pointed out, none of these companies are going to post the memory map (very few probably even know the map locations) otherwise we would all reprogram our own ECUs and put the established tuners out of business.
Andy sells ECUfix which can check (for free) or fix (paid for) your code once you have modified it.
ECU has several (3 I think) checksum routines it runs against the code to make sure the code good before excuting it.
He is also a nice guy, spoken to him a couple of times.
I'd be amazed if any of the above companies do this.
They spend big bucks and buy real time emulators for the ECU that allow the tuner to change the various maps and values. This code is then downloaded and either programmed to a chip or written to the ECU via the OBD port.
As someone else pointed out, none of these companies are going to post the memory map (very few probably even know the map locations) otherwise we would all reprogram our own ECUs and put the established tuners out of business.
Andy sells ECUfix which can check (for free) or fix (paid for) your code once you have modified it.
ECU has several (3 I think) checksum routines it runs against the code to make sure the code good before excuting it.
He is also a nice guy, spoken to him a couple of times.
Thread Starter
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Joined: May 2003
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From: East Cast Rollin'
You Speak "Da Troof"...Without Code Comments (Docs)...The Best One Can Do Is Massage The MAF/ECU
voltage with "Jiggy" (Piggy) back computers, or go with a stand alone EMS. "Jiggy" (Piggy) back computers are the cheapest solution to get (as close as possible to) proper fueling/AFR when significantly modding ANY turbo car.
Add Lemmiwinks (to control timing) to the "Jiggy" (Piggy) back solution (for an S4), and that's the CHEAPEST solution. In my opinion, Lemmiwinks alone can't pinpoint those specific areas in the fuel curve which are excessively rich, or lean.
It just makes BLANKET increases/decreases in the overall curve. Lemmiwinks is like having a B52 bomber perform a bombing sortie that is better suited for an F18. They both drop bombs, one just does it with more PRECISION than the other.
OBVIOUSLY, stand alone and EMS, or the ability to BURN your own custom chip is the BEST solution for ANY stage 3, or higher S4 (in my opinion).
You are not alone, the guys on the 951 boards complain about the same issues with their stage 3 cars too. One 951 tuner (Vitesse) has come out with a new motronic motherboard for the 951. I don't think that something so radical is necessary for the S4, but I think more stage 3 guys should be looking at "Jiggy" (Piggy)back or stand alone EMS solutions. Their cars will run better and produce more POWAH through more precise tuning.
Add Lemmiwinks (to control timing) to the "Jiggy" (Piggy) back solution (for an S4), and that's the CHEAPEST solution. In my opinion, Lemmiwinks alone can't pinpoint those specific areas in the fuel curve which are excessively rich, or lean.
It just makes BLANKET increases/decreases in the overall curve. Lemmiwinks is like having a B52 bomber perform a bombing sortie that is better suited for an F18. They both drop bombs, one just does it with more PRECISION than the other.
OBVIOUSLY, stand alone and EMS, or the ability to BURN your own custom chip is the BEST solution for ANY stage 3, or higher S4 (in my opinion).
You are not alone, the guys on the 951 boards complain about the same issues with their stage 3 cars too. One 951 tuner (Vitesse) has come out with a new motronic motherboard for the 951. I don't think that something so radical is necessary for the S4, but I think more stage 3 guys should be looking at "Jiggy" (Piggy)back or stand alone EMS solutions. Their cars will run better and produce more POWAH through more precise tuning.
Thread Starter
Junior Member
Joined: May 2003
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From: East Cast Rollin'
With A System Like MAFterburner...You Don't Need A Pre-defined MAF..You Scale The MAF Voltage So
the ECU thinks that airflow is more, or less than what the OEM MAF is telling it. Note, this only pretains to Bosch MAF units. If the Hitachi MAF is of Bosch design and scales 0-5v (which I believe it does), then maybe MAFterburner can be adapted to those MAFs too. This would have to be confirmed by the vendor.
From my reading (from other web sources)on Audi motronic AFR, the S4 MAF/ECU also works on a 0-5v AFR voltage set-up. Thus, you should be able to manipulate the MAF voltage (via MAFterburner, or some other software) to an S4 ECM just like a Porsche 951, and the (S4) ECM will adjust fueling (by RPMs) accordingly.
I'm currently scaling the MAF voltage signal to the ECU on my Porsche 951. It appears that negative voltage scales lean and positive voltage scales rich (confirmed through my wideband 02 sensor).
Scaling the MAF is a GROSS change (like Lemmiwinks fueling adjustments). After I complete MAF scaling, I will re-define the fuel curve on my 951.
I recently had the timing belt replaced/adjusted and changed the FQS (fuel quality switch) in the DME (ECM)to increase fuel by 3%(to accomadate larger 55# injectors versus the previous 37# stock injectors).
Prior to these MAFterburner changes, my previous fuel curve (which I posted on this board) became hosed because of the timing belt adjustment and FQS change. It was very evident when I drove the car and eye-balled my wideband 02 sensor.
Without a wideband 02 sensor and software like MAFterburner, you are just lucky if your fueling/AFR is close to optimal (in my opinion).
From my reading (from other web sources)on Audi motronic AFR, the S4 MAF/ECU also works on a 0-5v AFR voltage set-up. Thus, you should be able to manipulate the MAF voltage (via MAFterburner, or some other software) to an S4 ECM just like a Porsche 951, and the (S4) ECM will adjust fueling (by RPMs) accordingly.
I'm currently scaling the MAF voltage signal to the ECU on my Porsche 951. It appears that negative voltage scales lean and positive voltage scales rich (confirmed through my wideband 02 sensor).
Scaling the MAF is a GROSS change (like Lemmiwinks fueling adjustments). After I complete MAF scaling, I will re-define the fuel curve on my 951.
I recently had the timing belt replaced/adjusted and changed the FQS (fuel quality switch) in the DME (ECM)to increase fuel by 3%(to accomadate larger 55# injectors versus the previous 37# stock injectors).
Prior to these MAFterburner changes, my previous fuel curve (which I posted on this board) became hosed because of the timing belt adjustment and FQS change. It was very evident when I drove the car and eye-balled my wideband 02 sensor.
Without a wideband 02 sensor and software like MAFterburner, you are just lucky if your fueling/AFR is close to optimal (in my opinion).
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