traxz4000

I'm curious to know if the tire/wheel size for the vette (all types) be reprogrammed. I'd like to get a new set of wheels and tires and I like the 19/20 setup....however I dont want to sacrifice the 35/30 tire profile protection I get from my current 18/19 setup. I've read that the 19/20 wheels with 30/25 will work but thats the limit. I also DONT want any issues with Active handling and/or Traction control. Can this be done? Has anyone done this? Is that parameter accessible to change via tune?

MCSSLT1

The simple answer is yes it can.

The complicated answer is modifying the tune in your car could create problems down the road if you were to place certain warranty claims. Even if you didn't modify anything but the tire/wheel ratio GM would blame something such as an engine failure on you.

There has been many debates on this over the last few years. IMO the safest bet would be using HP tuners but saving the original tune first.

Bill Dearborn

The answer to your question isn't quite that simple. It is both yes and no.

You can do adjustments in the ECM so the speedo and odometer are correct. You can't adjust anything to do with the ABS, Traction Control or Active Handling. Tuning can only be performed on the ECM which allows you to adjust the settings for the odometer/speedometer. The EBCM controls the other three functions and a tuner can't get access to it and wouldn't know what they were doing if they did get access. The EBM gets its data from the Vehicle Speed Sensor (VSS) while the EBCM gets its data from the 4 wheel speed sensors, steering sensor, lateral G sensor, and yaw sensor.

Bill

traxz4000

Thanks for the information Bill. With that said, the ratio between the stock GS tire/wheels is 1.1 (26.67 rear - 25.57 front). Would a 335/30/20 rear (27.91) and 285/35/19 front (26.85) work ... 1.06 difference?

traxz4000

bump for info!!

Bill Dearborn

I get a ratio of 26.67/25.57= 1.043019 for the stock size and a ratio of 27.91/26.85= 1.039479 for your proposed sizes. You are less than 1% off the stock ratio. You could get that just by going to a stock size set of tires from a different company. That should work fine. An industry wide rule of thumb says you should be OK if you stay within 4%.

Bill