Tach Accuracy question please help!

[Spidey]

Heres my prolem:

I just installed an Apexi AVC-R on my car. While at idle my stock tachometer will read 800 rpm and the tach on the AVC-R reads aout 5600 rpm. Now I am confused as to which one to believe.

Plese Help

Thanks

[SpeedRacer1]

Did you splice into the right wire??!?!? There is a red wire with yellow stripe (coilpack output) right next to the yellow wire with red stripe (tach signal).

It should be fairly obvious if you are at idle and not touching the gas that the RPM reading would be 800 and not 5600. I doubt you are idling at 5600 RPM's.

[Spidey]

sorry I ment to type 600 rpm. I double checked and I spliced into the yellow wire with the red stripe.

thanks for the reply.

[SpeedRacer1]

Usually electronics can be slightly off. 600 sounds less healthy than 800 so if the car sounds fine like it always has just go with the 800.

[Spidey]

car sounds as healthy as ever. Is there any way to get the AvC-r and stock tack to read the same thing?

But then again the AVC-R will only be used to set my boost level, So if you can help, great. If not no biggie.

thanks.

Your help is greatly appreciated.

[RobDET]

The AVC-R should be more acurate. Stock tachs are notoriously bad. Get a volt meter with a tach imput (they are very common) and check it. That's how i set my idle all the time. My tach is about 250 RPM off at idle.

[1991 S13]

I had a problem like this, I have an safcII, there is a setting for how many cylinders your car is, I drove around for like 2 days before setting it to 4 cylinders...maybe thats it?