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i'm fighting the last part of my tune -- the speedometer scan tool scalar. i've calibrated with tunercat's built in speed calibration
it's an M6. 3.42 gears (confirmed by marking/turning driveshaft/wheels). tires are about a half inch taller than stock now, but i calibrated with stock tire sizes. i dont care about small speedo innacuracies at all.
my speedo reads correctly, or close enough, judging by usual traffic speeds im sticking with.
pcm speed is grossly innacurate, though.
for example, i did a datalog on the way to work today. cruising @ 50kph in the city, datamaster reads 14-16kph. smoking the tires on a back road, where the speedo touched 100kph, it reads 32kph.
now, my speedo scalar is @ 45.258 divisor. some rough calculations based on the formula in the manual (tire rev per mile x rear end ratio / 60) yeild a value pretty damn close to that.
so why is it so damn far out?
i know i can just screw with the divisor until it's closer.. but that's a huge pain in the ass
one other side question; i thought for sure there was a constant in the bin somewhere, where you can disable fan turn-on over a certain speed. now i can't find it..
it's an M6. 3.42 gears (confirmed by marking/turning driveshaft/wheels). tires are about a half inch taller than stock now, but i calibrated with stock tire sizes. i dont care about small speedo innacuracies at all.
my speedo reads correctly, or close enough, judging by usual traffic speeds im sticking with.
pcm speed is grossly innacurate, though.
for example, i did a datalog on the way to work today. cruising @ 50kph in the city, datamaster reads 14-16kph. smoking the tires on a back road, where the speedo touched 100kph, it reads 32kph.
now, my speedo scalar is @ 45.258 divisor. some rough calculations based on the formula in the manual (tire rev per mile x rear end ratio / 60) yeild a value pretty damn close to that.
so why is it so damn far out?
i know i can just screw with the divisor until it's closer.. but that's a huge pain in the ass
one other side question; i thought for sure there was a constant in the bin somewhere, where you can disable fan turn-on over a certain speed. now i can't find it..