SPEEDO and Idleing?

[gldean]

I've used a couple speedo numbers and am at least half of a tenth off.

Currently speedo is set at 3248 or 107% of the original 3037. Thoughts?

Running 70 at about 3K+, was 70 at 2800.

Also, the popping has reall decreased, but my idle is a little rough. Actually sound likes it's trying to pulse, like one cylinder is getting more fuel that the others or it's searching for the correct RPM.

Currently setting at 850RPM. I think I'll move it back to 820.

Any suggestions would be helpful.

Thanks
Gary

 

[Dobieman]

How are you figuring its off a half of a tenth :?: Just curious :?
Wayne usually corrects the speedo error off the dyno and its accurate.

I havent used tuneboy on the Rock yet but on my S3 the 107% was good.

Also on the S3 we changed the prime pulse rate to make faster starting.
Is the idle surging only when cold or continue after warm up?

 

[gldean]

It's about and .5 of the tenth off. It's a best guess based on resetting trip at mile markers, driving the mile and then watching the mile click over about a .5 tenth past the marker.

I reset my speedo to the way Wayne had it set on one of his corrected tunes and will check it again next time on the highway.

This method is not the most accurate, but in real world driving . . . it's not to bad either when you don't have a dyno or a GPS.

We used to check speedo's this way back in the 70's and 80's to correct for error by changing speedo gears. Not perfect, but you can get pretty close. Usually within a couple MPH.