OK, I admit that I'm old school, and, back then we didn't ask for help. I'm trying to go hi-tech, even got a Superchips for my Denali for when I ran my 22's. Now, I hear that I need a programer because I'm going to go to 373 gears and a torque coverter, and somewhere, I've read that you have to change the shift points? Is this true and could you please make an old (older) guy understand why?? To me, if a car shifts at 6000RPM's and you put 373's from the 315's, won't it still shift at 6000 RPM's? And, is there any other reason to get the programer? I want one, I just want to know if I need one and why....Thanks guys....bob.

 

true, you will need to get a programmer so your speedo will not be off. it may help with your shift points also. If you go into the tuner section a man called Charlie is tunning pcms for 100.00. He just did mine. If you pm him he will answer your questions.

 

I thought that somebody on here said that you don't have to do the speedo because of how it works. I had to do my Denali's speedo when I switched tires........bob.

 

incorrect

there's a lot of reasons to reprog after a rear axle swap in a C5 A4, but speedo calibration is not one of them. There is no speedo error on any C5 when changing rear axle ratio.

 

give it to me straight Mike, I can take it. I don't know if I can pay for it though...........bob.

 

As Mike said, the speedometer is not effected for C5's. You will need to reprogram, though. Your example of 6000rpm's is with regard to WOT. Usually WOT shifts are controlled by RPM's. However, the part throttle shifts are based on MPH and require programming. Also, the PCM reads the extra RPM's vs trans revolutions as slipping. It will throw codes and go into safe mode. Safe mode shifts very hard in order to protect the trans from further slippage damage. You will not like it. Correct programming eliminates this problem in most cases, but sometimes high stall converters require changing the slip test parameters. It's all worth it. The car will come to life.

 

this was from Gojo...thanks....
As Mike said, the speedometer is not effected for C5's. You will need to reprogram, though. Your example of 6000rpm's is with regard to WOT. Usually WOT shifts are controlled by RPM's. However, the part throttle shifts are based on MPH and require programming. Also, the PCM reads the extra RPM's vs trans revolutions as slipping. It will throw codes and go into safe mode. Safe mode shifts very hard in order to protect the trans from further slippage damage. You will not like it. Correct programming eliminates this problem in most cases, but sometimes high stall converters require changing the slip test parameters. It's all worth it. The car will come to life.

will the Predator programmer do this?? I'm still kinda confused on how to adjust part throttle shifting. On the Superchips, (for my Denali with 22's) I adjusted for firmer or smoother shifts and at what RPM's, when the 373's and 3200 stall converter (in Vette) is installed, what do I do next and will the Predator do it, my friend suggested this from a shop that he works at but he does motors and doesn't know why they prefer to use the Predator... any tuners, vendors or anybody use this stuff that can help??? thanks in advance....bob.

 

 

OK... don't know what this stuff is just yet, torque management and slip test parameters but, will the Predator programmer do this? please guys, more info....thanks ....bob....(and I'll try to let you Z06 guys know when to trade up to the Z08!....coming soon.)

 

yes. The Predator will alter the "TCC Slip Table" so that the PCM won't throw a P1870 error code.

The A4 PCM WOT shifts are commanded when two parameters are met... MPH and RPM. When you change rear axle ratio, the MPH @ 6000rpm will be lowered. The PCM won't command a WOT shift until both the MPH figure and RPM figure are reached. It it's attempt to reach ther MPH value, the engine continues to accelerate until you hit the rev limiter (although the RPM setting had been reached, the MPH figure hadn't - yet).

It's all (or mostly) here:

1. Did I have to get my PCM reprogrammed for the new rear axle ratio?
http://mikemercury.home.att.net/342.htm

.

 

thanks Mike, you're always helpful...bob.

 

true, but only 6-speeds i believe

 

incorrect.