i thought id ask here maybe for a simple answer rather than call...but i thought sct x3's had an option to where you can change tire size ? if so , where do i change it at? to be honest im not sure how much i went up or down in tire diameter or if changed at all ,i had the stock 17's on before with the stock pirelli's, and i now have 18's with wheel/tires measuring at 26.5 " tall ....the only thing i see on the tuner is tire revs/mph?? is there a chart to convert this or something? am i stupid and dont see it lol?

 

I would call Brenspeed and ask them

 

tirerack.com has a calc u can enter your info into

 

http://www.gordon-glasgow.org/tirecalc.html

use this link for your tire size to figure out your revs

 

There are a few choices to obtain your tire RPM's. Tirerack.com lists most tire specs, you could try the manufacturer's website OR try this: http://www.1010tires.com/tiresizecalculator.asp

You'll probably come up with a few different numbers for the same tire but no worry. The SCT allows you adjust it to the nearest "10" RPM's (i.e, 740, 750, 760). If you have a GPS you can fine tune it from there.

 

I would first check it with a GPS and make tweaks from there. you will see the options pop up when you start the flashing process. If you don't see them, then your tuner didn't enable them.

 

lol excellent yall thanks for the responses! ill try those links first

 

thanks to the gordon glasgow link for tire calc , i was able to figure out the revs.....and the funny thing is it actually didnt change at all ! from the stock 17's with 235 /55 /17 to my 255/45/18 front 275/40/18s in the back! i didnt feel like it needed calibaration, but hell 2-3 mph off is 2-3 mph off lol !