Speedometer

[ghenny440]

So im probably lifting my sons TB in the spring being i have some suspension work then anyway. And im planning how much we wanna go up with this thing. So question is when i go with bigger tires is there a programmer i can get to correct the speedometer being off or is it just gonna be what it is.
2003 Trailblazer 4.2 4x4

 

[Blckshdw]

Long time man! There was some talk years ago about some kind of add on to trick the speedometer, since we can't correct for tire size via tune, but nothing ever came out of it, so you're kinda stuck.

 

[ghenny440]

Long time man! There was some talk years ago about some kind of add on to trick the speedometer, since we can't correct for tire size via tune, but nothing ever came out of it, so you're kinda stuck.

Deffinately has bro. Hows everything been?!
Ok cool i kinda figured just seein what to really expect.

 

[Blckshdw]

Things are pretty good down here, bought a house, so that's kept the mod bug in check.

I'm running 265/70/17s (31.5"), with a 2.5" front lift and wheel spacers. That works out to be about a 2 mph difference @ 60 mph. It's not too bad, usually for any highway trips, I've got the GPS up and that shows my speed on it too just in case my lead foot gets a little happy.

 

[ghenny440]

Things are pretty good down here, bought a house, so that's kept the mod bug in check.

I'm running 265/70/17s (31.5"), with a 2.5" front lift and wheel spacers. That works out to be about a 2 mph difference @ 60 mph. It's not too bad, usually for any highway trips, I've got the GPS up and that shows my speed on it too just in case my lead foot gets a little happy.

Ok awesome, glad to hear alls well, im thinkin we are gonna do 3 inch suspension and 3 inch body with 33’s so it should be pretty cool. But his fusion is first over the winter.
i kept my old american bass HD 18’s and we are putting them in his back seat in a half wall on 2 rockford t-2500.1’s strapped, 6 rockford pro series 6.5” in the front doors(3 per door) on a t600-4, and 4 rockford t1ts tweeters on a t400-4, and airing it out. Then the TB will get started. This is his baby now. Me and him did all the work so far, he just turned 18 on the 19th and already has 2 vehicles. I got him a job at my the shop i work at, hell hes been goin up and learning since he was about 12. Kids a hustler for sure! We are hoping to make it to slamology next year so long as this covid crap doesnt prevent the show
We

 

[UsernameIsTaken]

I remember seeing a tire size calibration option in my Tech 2. It's under "Chassis" for my '04 Ascender and '04 Rainier. It lets you pick from a list of wheel and tire options from 12" to 24" if I recall correctly. This menu is from a Saab 9-3, but the GMT360 menu looks the same minus the tire brands.