Digital tach more accurate than stock tach?!

[Pyr8]

So i finally got my Stuart Warner digital tach installed this week...however i noticed that the tach i installed seems to be off, compared to the cars factory tach by almost exactly 100RPM. Anyone have any thoughts or comments?

[EvanH]

i dont know how accurate my setup is, but my Apex i SAFC II shows a 200rpm difference some times, other times it is dead on. most times it is reading different it is at idle. so dont be scared to much about it, just run by the higher one, you cant go wrong.

[ExExGuy]

While we're on the subject of rpms and gauge accuracy.... my TT seems to idle really low.. its steady, but something like 500 rpm or so... is that normal? im used to cars idling between 1000 to 1500 when warm

[Polygon]

Cold idle should be between 1,300 and 1,500 RPM no higher. The warm idle should be around 750 RPM. If your cold idle is 500 then I would suspect you have a bad IAC or FIAV.

[Pyr8]

Originally Posted by ExExGuy

While we're on the subject of rpms and gauge accuracy.... my TT seems to idle really low.. its steady, but something like 500 rpm or so... is that normal? im used to cars idling between 1000 to 1500 when warm

your idle is WAY to high....search the threads there is allot of info on idle issues...might just need to adjust the idle manually.

[SmoothGT]

can we see pics of ur digital tach?

[ExExGuy]

Originally Posted by Pyr8

your idle is WAY to high....search the threads there is allot of info on idle issues...might just need to adjust the idle manually.

sorry, i said im used to *other* cars idling at like 1000-1500... my 3s sits at like 500 or so, it just seems so low!

i cant think of any cars ive seen with a digital tach added, but i would almost be inclined to think its less accurate if it is just reading out rpm like a clock

[Pyr8]

Originally Posted by SmoothGT

can we see pics of ur digital tach?

Here ya go....sorry but it was taken at night with my CrackBerry!

[TrueblueGTO]

Hook up a data logger and see which one is right you can't get any more accurate than taking it straight from the ECU.

I would think if your digital gauge is reading straight from the ECU it would be pretty close to spot on.

[Pyr8]

Originally Posted by TrueblueGTO

Hook up a data logger and see which one is right you can't get any more accurate than taking it straight from the ECU.

I would think if your digital gauge is reading straight from the ECU it would be pretty close to spot on.

I would have to tend to agree with you there....and actually, my thought is that the needle on the tach in the dash is analog...so that it actually takes time for it to "sweep".