just swapped my cluster

[aaron325ix]

got a M3 cluster in and I swapped over my old tach face plate onto the M3 tach (and coding plug).

In addition the M3 tach was inop, so I actually used the old tach mechanism from the iX on the M3 one after seperating it from the econogauge by simply cutting the ribbon cables that connect it and cutting 4 of the unused prong plugs.

I am still just not sure if the tach is correct or not. Idle seems the same, around 700-800. But today I got on it and it reved way past 7k and into the oil temp area. I was on the highway later doing 80mph on a flat section and the tach was showing a shade under 5k. Does that seem right? Can someone simulate that next time you are on the freeway so I can get a comparison? Thanks.

[aaron325ix]

ne1?

[accident]

might want to mention what diff you're running.

[aaron325ix]

diff doesnt have anything to do with it

[James Crivellone]

If you used the IX 7K Tach AND coding plug then it is correct, the tachometer will not properly without it.

Now if you used the 8K face with an I / 6Cly 7K Tach coding plug then it would be incorrect.

Also not that it really matters, but as a point the speedometer calibration is set via resistors on the back of the speedomter, not the coding plug. You can create an E30 M3 160mph speedo easily but soldering 3 resistors and printing a gauge face. Thats more of an FYI thing :p

[accident]

diff doesnt have anything to do with it

Uh, yes it does. The final drive ratio dictates what RPM the engine would be at at 80mph.

[aaron325ix]

Uh, yes it does. The final drive ratio dictates what RPM the engine would be at at 80mph.

the diff ratio has nothing to do with the speed reading. the sensor wheel is attached to the output flange, which spins at the same speed regardless of gear ratio. you don't have to recalibrate anything from using a different diff. That was basically back in the days of mechanical speedometers.

[accident]

the diff ratio has nothing to do with the speed reading. the sensor wheel is attached to the output flange, which spins at the same speed regardless of gear ratio. you don't have to recalibrate anything from using a different diff. That was basically back in the days of mechanical speedometers.

But the RPM your engine is spinning at does. If you want to know if 5k is normal at 80mph then we need to know what fucking diff you're running.