Speedometer Correction Help 06 GTO HELP ASAP PLZ

[camaro10]

Having trouble using efilives correction table to adjust for new tires. Ive had no problems with the gm trucks correcting it by entering in the rev/mile and letting it apply the corrections. It wants to change pulses almost triple for stock tires without even changing the tire size. Why is this happening? The car is off 35mph now and obiviously Ill enter the stock values to fix it but how do I correct this problem on this car? Thank you!!

[camaro10]

Nobody has had issues getting the speedo correct after different tires? Are you just using the fine tune method? Should only be off a few mph from stock I'd think anyways..

[joeygc5]

I use the tire adjustment calc utility then verify with gps. Ive never had a problem except on 98 f-bodies when using tge front abs sensor as a speed ref for th350/400 swaps. It just took a little bit of #'s play to correct that scenario.

[camaro10]

I use the tire adjustment calc utility then verify with gps. Ive never had a problem except on 98 f-bodies when using tge front abs sensor as a speed ref for th350/400 swaps. It just took a little bit of #'s play to correct that scenario.

Ive done multiple trucks using the correction calc and entering in the the tire manufactuer rev per mile and letting it do the rest with good luck. Your saying to use the fine tune correction table and altering the vss pulses until its confirmed with gps that it is correct?

[camaro10]

By using the method of the new tire size/pulses, it triples pulses and multiplys the trans output shaft rev/mile by almost 6. Im going to try stock numbers and than alter vss pulses until I can get it correct. Maybe the E40 doesn't work the speed calc Im not sure as this is the first e40 ive tinkered with.