My hptuner is telling me I idle at around 800 rpm and my tach is reading 1000 rpm...
I fixed my speedometer for the 4.10 gear I put in there a few days ago and I'm certain it didn't change my tach, which is good. However, the scanner says my rpm AND mph is slower than what appears on my tach/speedometer.
Is there something else I need to change other than the speedo calibration shown on the demo page? Thanks!
98' Z28 Camaro M6 / 111,000mi / Cats / Headers / 4.10 / Tremec Performance T56 Rebuild
SLP Ultra-Z Hood / Functional SLP intake /
The F-body tachs are notoriously bad about being off - especially at the lower end of things. Just about every one you will ever see will show 150-200rpms more than what the motor is actually turning...
The speedometer may be a bit slow keeping up under acceleration, but it should be good when you are at a constant speed. If it isn't, double check your math on the calibration.
Kevin Conway
2002 Camaro SS M6
...402 LS2, and a lot of other wasted money...
My experience with F-Body tachs has been bad no matter the year, and I've owned 1 - 79 1 - 86, 3 - 89's, 1 - 98, 1 - 02. Thirdgens being the least accurate, Forthgens being the slowest.
But as far as speedos I've used HP Tuners to scan my 2002 Trans Am and currently owned 2003 Silverado. Comparing the speedo on both to 2 different GPS receivers, both of my vehicles have been 2-3 mph fast compared to GPS.
89 Camaro RS Vert
03 Silverado 5.3
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