SCT Won't correct speedo.

[DeadLifter]

Just picked up a 99 Cobra with 373 gears and a SCT tuner and I've tried programming it to stock gears and to 373 gears and it doesn't change the speedo at all. I have to run just a hair over 1,900 rpm's to be at 55, but when I'm at 55 the speedo reads around 65 to 67. This is staying with wife's Grand Prix when she's at 55.
Anybody have a clue why it isn't correcting speedo?

 

[midnightdriver]

First, make sure you have 3.73's because I have come across a lot of guy's that claim they did this or that. Jack up the rear of the car, and put it on jack stands. Mark the drive shaft and tires then while someone spins the tire one full rotation count how many rotations the drive shaft makes.

2nd, if it has different sizes tires other than stock it will also throw off the speedo as well.

 

[2002BLGT]

Just picked up a 99 Cobra with 373 gears and a SCT tuner and I've tried programming it to stock gears and to 373 gears and it doesn't change the speedo at all. I have to run just a hair over 1,900 rpm's to be at 55, but when I'm at 55 the speedo reads around 65 to 67. This is staying with wife's Grand Prix when she's at 55.
Anybody have a clue why it isn't correcting speedo?

Have you did an update on the tuner on sctflash.com ? If that doesnt fix it call SCT tech line

 

[DeadLifter]

First, make sure you have 3.73's because I have come across a lot of guy's that claim they did this or that. Jack up the rear of the car, and put it on jack stands. Mark the drive shaft and tires then while someone spins the tire one full rotation count how many rotations the drive shaft makes.

2nd, if it has different sizes tires other than stock it will also throw off the speedo as well.

It has gears. It doesn't change no matter what gear selection I use. SCT said Bren Speeds program is probably overriding it. Bren Speed said they'd fix for $10.

 

[txredgt]

You should be able to do a 'custom' tune as well and change the gears around that way as well..

 

[DeadLifter]

I did the custon tune and changed it, it's just not doing anything. Bren Speed just said to mail it in and they'd take care of it.