Just to let you all know a freind was working on a charger because it was in limp mode,,, he found that other mech had removed the 282 gear and installed a 362 (not sure of that number) being that he had worked on my car when i had installed the 327 in it ,,and got the limp mode,,, he had a diablo predator for the charger,, he changed the TCM and now the charger is driving around with a 362 rear gears,,, if we could somehow convance Dialbo to make us,,and we need to know what other cars have a similar tcu so maybe they(diablo) will make it ,,i think a lot of mercedes have the same set up in the tcu we just need to prove it, ,jim

ps i would like someone here to draw up a nice request letter to Diablo sport for our predator ( i am not good at letter wrighting )

 

Same issue here had a differential with the 327 differential put in the crossfire and got a transmission limp mode and code to the effect off "3rd gear out of sych".

 

Not to hijack the Diablo Sport thread, but why can we not get one of our current tuners (ie: Eurocharged, Inmotion) to mess with this "header file in the PCM". I can't see how this could be that difficult. I'd much ratherstick with the same tuner instead of having to get a tuner box just to alter the gear ratio, if Diablo will even make one (1000 people?)

 

good point maybe we couls all e mail let and inmotion and see if they are interested,, jim

 

Both of our current tuners watch this site and neither are commenting. Until they do, Diablo may be our only choice for gear changes. Diablo allows for multiple adjustments, it makes a much more convienent way to update the computer then loosing the use of the car and $50 shipping the computer each time a new mod is installed. I have a hand tuner for my Hemi. It's great, has many options for adjustment and can be easily rest to factory any time I need dealer work. The best of both worlds would be for one of the current tuners to sell their knowledge to Diablo.

 

The transmission limps because the computer is measuring a significant diffrence in the rotational speed of the front and back tires.
Do you think it would be simpler to either put taller tires on the back or shorter tires on the front?

 

i think the tranny is measuring the speed of the in and out of the tranny,, as i put 305 50 16 on the rear and the car ran ok (srt 6 rear307) at 80 i was doing 4500 rpm and punch it the tires would let loose,, doing the math this equaled 317 rear ratio, that is when i put the limited 327 ratio rear into the car, the cel says 3 gear transmission ratio incorrect,, don't forget on a dyno the front tires do not move. jim

 

Actually the transmission goes into limp mode because the sum/2 of the rear wheel speed sensors is not within the defined range when compared against the transmission output shaft speed sensor. It has nothing to do with the front and rear tires spinning at different speeds as was proven by Jim when he put on the smaller diameter rear tires.

 

Also, just changing the gear ratio would have absolutly no effect on the rear wheels spinning at a different speed than the front wheels. LOL Unless, the rear wheels are breaking traction.

 

In theory yes. We have smaller tires up front so their rotational speed is actually higher than that of the rears. But then of course as you pointed out, you could be get into it and then the rears would actually be rotating faster. LOL

 

So the taller rear tires will compensate for the 327 gear ratio?

 

I think we are saying the same thing Rudy. A SRT with stock wheels/tires front and back would have the same relational rotation speed regardless of the gear ratio. It is the drive shaft that would be spinning at a different relational speed than the tires based on the gear ratio.

 

No, the rotational speed of the tires (RPM) and the revolutions per mile are two completely different things. Changing the tire diameter will result in a higher or lower revolutions per mile at a static RPM. Think of it this way, if you take a pencil and roll it on your desk one revolution, it will travel approximately an inch. Take a pop can and do the same and it will travel about a foot. Same thing with tires, just not as exaggerated. Now when applied to the rear gear ratio of a car, it would be like taking that pop can and rotating it 3.07 times or 3.27 times and measuring the distance. Now with only one revolution, the difference is quite small but after 50 or so revolutions, the difference becomes quite dramatic.

 

Why can't the signal be intercepted and modified to fool the TCU??

 

There is a reason why Diablo has never made a tuner for Mercedes Benz. It's because they do not have the ability to do it

 

This is something that is being worked on as we speak. Unfortunately I'm playing pin the tail on the *** with my differential so until I get the car back up and running, my test bench is parked next to my work bench.


James, while this is your forte and you would have to be very knowledgeable in this arena to do your particular line of work, I have to respectfully disagree. The LX platform shares many components with their Mercedes counterpart. As far as engine tuning, you may be correct but only because their ability is directly correlated to number of units they expect to sell as a result of their research and development. When it comes to being able to change the characteristics of the transmission, it's the same hardware with ever so slightly modified software. Heck, you can take the EGS2 out of them and swap between the two and get it to run, albeit with a few issues but like anything, you have to work out the bugs.

 

How is that MAXX running, Rudy??

 

The nun-mobile is running like a champ... I don't even have to worry about dash lights and a wing that has a mind of it's own.

 

What about swaping the diff and the TCU from a N/A Crossfire into the SRT? would that work?

My fiance' has an N/A if so she can have my diff and TCU and I'll take hers!

 

How about trying a TCU from a LX?

Les