JGA

HI

I was using my Hypertech to change the gear ratio on my 98 Camaro A4. After I selected the new gears and pressed Yes, it took me into the tire size change option. I pressed No, as I have the stock tires, but it then took me back to the gear selection. I was like going around in a loop. I had to select a tire size and press Yes to get past the option.

Questions:

When doing a gear change do I have to enter a tire size every time? Did I do somthing wrong? Can the gear setting be changed without changing the tire size?

I have the stock Eagle GAs which are 26.1" The options were 26 and 26.25. Which should I select?

I tried 26. I whent for a drive and my speedo seems to be reading a little high still. Will the 26.25 work better?

Any help appreciated.

JA

2000TransAmWS6

iTrader: (12)

its been a while since i've used a hypertech, but i seem to remember having to choose EVERY option EVERY TIME. yeah, i know, kinda sucks,... but i believe that after you do it once your previous options will be save the next time you do it and will go alittle faster the next time you use it.
since you're going to have to choose a tire size you're going to have to decide if you want the speedometer to read alittle high or alittle low... personally i'd rather think that i'm going alittle faster than i actually am when i'm crusing.

JGA

Hi

Thanks

Which is which? I think making the tire size bigger in the program will bring the speedo uo slower, or therefore read lower. Does that make sense?

Thanks JA

2000TransAmWS6

iTrader: (12)

i think that the bigger tire size would make the computer think the car was going faster.

2001NBMZ28

Thought stock tire size was actually 25.66? Been a long time since I had one too - speedo is just probably a little off. I always use www.f-body.org/gears/ to double check mine after tuning.

JGA

Hi

Thanks for the link. Very usefull. I am a little confussed. The default of a 98 F Body A4 on the setup table is 25.66. That must be the model with the 17" wheels


I have the stock Eagle GA 235/55/R16. The spec sheet on the Goodyear web site has that size at 26.1.

Any idea which is right?

Thanks JA

2001NBMZ28

Sorry, when you said stock 16's I took it to mean the 245/50-16 on the Z's. That size along with 275/40-17 on the SS's are both 25.7 - that site also assumes the same I guess. You need to go with the 26.1, then change the tire size/gears on the site and have it recalculate so you can doublecheck the speedo.

JGA

Hi

According to the table: with my rear gear ratio and tire size at 1500 RPM in 3rd, the speed is 36 mph. My speedo reads 30 mph at 1500 in 3rd gear. Does this mean it is reading 6 mph low?

Thanks JA

2001NBMZ28

What gears you running now, and what was stock?

JGA

Hi

Stock was 273. I now have 323.

THanks JA