Your cable may need to be lubricated. Or theres moisture in the speedo and its
affecting the magentic pickup for the spinning cable or something.

usually when your speedo is on its way out the needle bounces. that gets annoying quick.. im going 60- no wait, 30, 80? wtf

when in doubt, go the same speed as everyone else lol

Lol, i use gps for my speed 80% of the time. Although, i do use cruise alot, and if tue cable dies im screwed in that mannor.

I have the opposite problem, mine reads high when cold and makes this obnoxious squealing/grinding/whining sound (you almost have to hear it). After the interior warms up, it becomes quiet and semi-accurate.

ReTED, I am jealous that you have a functional speedometer on the dyno, mine apparently only reads up to about 80MPH (even though I was pulling to 165 MPH). The VSS to the ECU is accurate, but the needle on the gauge is not.

Obviously I wouldn't have any way of figuring this out on the street...

Guess I'm lucky?
But I did replace my original speedo cable soon after I got this car back in '97 or so...
I've maybe put on 30k miles on it since - it doesn't get driven that often.

It is kinda unnerving to put down a 4th gear run though as you see the speedo sweep past 100mph, and you're sitting inside going no where on the dyno runs... :eek:


-Ted

Hmm, I am assuming this is the original cable, at 140k now, and it consistently reads 5 higher than I am actually going. Consistent is enough for me. I am following the key rule, If it works at all, don't touch it.