Speedo calibration; biggerr tires

kinkyllama · Post by **kinkyllama** » Thu Dec 21, 2006 6:50 pm

I'm thinking about moving from the 215/40/17 track tires to 235-255/40/17 or just 215/45/17 If I dont make the time to do a crap load of fender work. I'd like to raise the car a bit while still keeping the tires in the fenders, and get a bit taller gearing. I think then I'd even move up to 18s for the street if I come across a good set used. But can you recalibrate the speedo so its correct with different sized tires?

Danny

exist3nce · Post by **exist3nce** » Thu Dec 21, 2006 8:36 pm

I've often wondered about this same question, but it doesn't seem like it would be easy to recalibrate the ecu for the VSS.

kinkyllama · Post by **kinkyllama** » Wed Dec 27, 2006 10:34 pm

No one knows?

MMamdouh · Post by **MMamdouh** » Fri Dec 29, 2006 11:26 am

i don't think this is possible.

MMamdouh

kinkyllama · Post by **kinkyllama** » Fri Dec 29, 2006 7:34 pm

MMamdouh wrote:i don't think this is possible.

MMamdouh

There has gotta be a way. Think of the 4x4s that add bigger tires...I mean, they add so much bigger tires the speed probably readys 20mph when they're doing 40. Plus I know my friend got off a ticket cuz she said her speedo was off and had to get it tested.

Audacity Racing · Post by **Audacity Racing** » Fri Dec 29, 2006 7:58 pm

Buy the Daewoo programmer on ebay and scale the voltage from the sensor

Audacity Racing · Post by **Audacity Racing** » Fri Dec 29, 2006 7:59 pm

OK, Jackassery aside, you could buiild a voltage scaler to change the output from the speedo sensor in the transmission to meet the new value.

Scale would need to be deterimined based on current wheel size and new wheel size.

kinkyllama · Post by **kinkyllama** » Fri Dec 29, 2006 9:29 pm

Audacityracing wrote:OK, Jackassery aside, you could buiild a voltage scaler to change the output from the speedo sensor in the transmission to meet the new value.

Scale would need to be deterimined based on current wheel size and new wheel size.

Dang. Is there an easyier way?

I'm not so good with or figuring out electronics...I'm not sure this is something I'd wanna tackle