Hey guys! I have just purchased a crossfire as my new project car and I was wondering, If I make a custom turbo for the car can upsolute, karmann, and all those ecu tuning companies tune for that? OR can they only tune when the car is n/a?

Also, which one is the cheapest of them? (to make the ecu reflash).

Thanks!
Tito @ TR
www.tr-performance.com

 

Yes you can get a custom ECU.

It will be easier if you are near a tuner.

 

You'll need a custom remap that will require running the car on a dyno under different load conditions... Don't expect to pay anything less than $1,500 to get it done right... The OEM map will not have the latitude to handle the boost, I would start looking into installing the fueling / timing maps from the SRT6 and adjusting from there...

Either way, you'll be hard pressed to find someone with the expertise and resources to be able to do this job for you...

The only people I have found that can do this type of custom remap are Bosch Motorsports ECU techs. And even they don't have access to the OEM programs, so everything must be programmed from scratch...

 

Hm.

I talked to some guys (i think it was hammann or upsolute) and they told me that all they needed was a dyno with the air/fuel maps and the ecu. With that, they could reprogram the ecu (pull timing out, adjust air/fuel etc).

Does that sound about right? I mean, in I know that in other cars that is all you really need the air/fuel ratio to adjust everything...

 

Yes, but ! How are you going to dyno the car and get AFR after you install a turbo kit that will cause the engine to not run properly without ECU reprogramming ? All of these things are tied together...

Think about it !

 

Some cars can be reflashed, for example my Mini Cooper S was reflashed when I increased the boost, but this car was boosted to start with. I am not an expert but I think some stock ECU run into problems dealing with boost when they are only programmed only to see vacuum. I know that people who add turbo's to non turbo'd cars usually add a piggy back system that works with the stock ECU to adjust A/F under boost conditions.

 

Correct sir... A piggyback system is the most cost effective way to do this... And that may not even work properly... That's why we experiment.

 

Hm, I know the first runs will have to be without a tune on the dyno but that's what you do on any car anyway (even if you have a piggyback because you don't know how much fuel you have to put in).

OR, I could swap in the srt6 ecu and start from there (since that ecu is programmed to see boost)... ? (is it the same ecu as the slk32?

I WILL TRY THIS, so i need to know what's going on with these german cars (trust me, i know imports; A LOT easier to work with!)...


SO... opinions comments?

 

Here's what's going on with these German MB cars ! Everything, I mean EVERYTHING is kept like some national secret... You cannot find any information or aftermarket support from any of the systems software or engine management...

All I can say is proceed at your own risk !

 

ALRIGHT! Here is the plan!

As far as engine tuning, I DO NOT NEED AN EXPENSIVE ECU REFLASH!

Here's why...

I can simply buy an FMU (Fuel Management Unit) which regulates and adds fuel during boost (and the stock FPR (Fuel Pressure Regulator) should be sufficient... right?). SO, it would keep the a/f where it needs to be (at about 12.5 on a boosted engine (13.5 a/f is normally best for n/a engines).

SO, FMU is the way and cheap way to go! (Only about $80, and YES it is safe for a low boost set up a.k.a. 6 psi).

So there, I dont even have to worry about sending the ECU out or anything. (BTW, I still have to keep track of the a/f ratio with a wideband! I can't just expect for a FMU to do magic; I will get the FMU at 12:1 ratio and go lower (to 10:1) if it runs to rich.

I am still debating if I want to implement an adjustable FPR... anyone want to chime in and explain why I should or shouldn't get one? (an FPR that is).

 

A Piggy Back FMU is all fine and dandy if you can adjust your timing dwell past the limits of the OEM software...

Perhaps you don't understand the workings of the Bosch Motronic 2.8 ECU and all the associated sensors... Let me explain as quickly and simply as possible in real terms with hypothetical values.

Your NA ECU is designed to adjust fueling and timing from -10 to +10 based on your MAP values, 02 sensor values, Load Calculations, Throttle Position, Knock Sensor, etc. These are given parameters that are written into your ECU software.

The forced induction ECU is designed to adjust fueling and timing from -20 to +20 based on MAP values, 02 sensor values, Load Calculations, Throttle Position, etc. These are given parameters that are written into that ECU software.

If you introduce more AIR + FUEL into your engine, say +15, the ECU will only be able to adjust timing to +10, thus KAPUT on your potential HP gain and goodbye smooth running engine...

So, if you want to be a stubborn semi educated DIY Hot Rodder, by all means install a forced induction system and a piggyback fueling system... Let me know when you throw it all in the trash after you can't get your engine running properly because the timing is far too retarded...

 

That is exactly what I was talking about.

 

^^^ Yes sorry for that. ^^^

Anyway, as far as timing that will not be a problem. First off, the ECU can pull or put in timing (but I KNOW, it can only do it to a certain degree). Now, a way to help with the timing (and add hp) is to add water injection.

Not only will it "appear" to raise the octane rating, but it will also contribute to colder egt's (exhaust gas temps), less fuel being added, and timing will not have to be pulled out as much (this is why this yields to more hp as well as a safer mixture).

Not only this, but water injection can also be used with tuning. If the air/fuel is to rich (lets say, 13:1 instead of the optimal 12.5:1) Then you could add a little more water and the a/f ratio will decrease.

I will start this project soon as I already ordered the turbo (a t3/t4 that will be mounted STS style).

I will keep you posted!

Tito @ TR

 

With all due respect, you are delusional if you think just adding a piggyback FMU and a water injection system will allow the ECU to adjust the timing on an aftermarket supercharger install and properly operate the engine...

 

There are piggyback units out there that will allow timing adjustments. But, simply using an FMU is not going to help in Closed Loop operation since the O2 sensors will simply tell the PCM to pull fuel from the injectors putting you back up at a 14.7 AFR.

Most piggyback systems rely on bigger injectors at a stock pressure, then fool the PCM into thinking it is under less load than actual by skewing the MAP or MAF sensor readings. By the way, you wind up advancing timing through the factory program when doing this, and generally not when you want it to.

Using an FMU along with a unit that can alter the O2 readings when in part throttle boost (closed loop operation) to get richer fuel mixture, then rely on the FMU to get your fuel mixture in Wide Open Throttle (WOT) conditions is about the cheapest method. Not perfect, but it can be done, and get some decent gains from a moderate amount of boost.

In theory, a SRT-6 PCM and injectors would work with a Turbo running similar boost levels, but, the SRT-6 uses an electric clutch on the supercharger, so it only comes on under certain conditions.

If those conditions are related to throttle position (I have not checked the operational parameters) versus sensing positive pressure in the intake, you could have some serious part throttle boost issues with a turbo running lean on the SRT-6 program.

Mr MoPar

 

OK! NEW WAY.

Using an FMU and FPR, I can also tune by adding those cheap ebay "chips". (which all they do is a resistor which makes it inject more fuel... but isnt that what we want anyway for a turbo car? That would bring the afr closer to the much needed 12:5.1 in closed and open loop operation.... HMM!