driving a un-tuned auto with a gear

[91frppgt]

I'm going to have to drive my car un-tuned with a gear for a while now, until i can get it tuned again. I have a 3.73, and the car is a auto. Besides the speedo reading to fast, should it hurt anything else?

 

[AlloyGT]

The tune tells your auto at what mph to shift into each gear. If you can't use the tuner to tell your car what gears you have, I wouldn't drive it until you get a new tune.

 

[Five Oh Brian]

Your upshifts and downshifts are going to be out of whack. I wouldn't drive it far with the tune not updated for the new gears, and definitely don't drive the car at wide open throttle with the shift points all messed up.

 

[NastyStang113]

Your upshifts and downshifts are going to be out of whack. I wouldn't drive it far with the tune not updated for the new gears, and definitely don't drive the car at wide open throttle with the shift points all messed up.

+1

 

[TBrad]

If you had a manual tranny you'd be ok.

 

[StonePony]

BS - You will be just fine. The tranny shifts are based on RPM so the gear chang behind the transmission won't affect your cars shifting points negatively at all.

I ran 3.73 gears in my car for 6 months without changing the tune. The only negative effect was the extra 1800 miles it put on my odometer. Drive it as hard as you want there will be no issue.

 

[AlloyGT]

Shift points in the tune are controlled by mph, not rpm.

 

[StonePony]

are you talking about the user defined settings or in the AdVantage III SCTsoftware used to create the tune?
I believe the only place you will see shift point in milesper hour (MPH) is when you are making adjustments as an end-user in the hand-held. Shift points are set in MPH in the tune.

Whichever you meant is no matter because driving the car with a gear change and no tune will hurt NOTHING but your odometer.

 

[Five Oh Brian]

Shift points in the tune are controlled by mph, not rpm.

My tune was written to upshift at 6,400 rpm's at WOT. Otherwise, the tune is written with an algorithm that specifies upshifts at a particular MPH based on throttle position (assuming something less than WOT). So, upshifts are controlled by rpm's at WOT and controlled by mph & throttle position at partial throttle.

My tune was also written with new mph threshholds for downshifts so that it wouldn't downshift at too high an rpm after the gear change. Before doing so, the car would downshift at too high of speed and literally bounce the car off the rev limiter instantly. Had to have the tune altered for the lower speeds for each downshift with the shorter 4.10 gearing.