Help, MSD-Tach issue,,

[Wade95]

We installed a tach tonight in my car. Hooked it directly to the MSD box. Zero's out when you turn the key and suprisingly it's pretty spot on w/the tach in the dash. HOWEVER, I had an issue tonight and wanted to bounce it off a couple of ya. Little history first.

Tach supposedly came out of Kenny Schraders race car when he drove for Hendrick (circa '88)
Have a separate shift light hooked up and it comes on when supposed to.

Now, on the way home tonight I stayed in the gas just to see what would happen. I have the 6400 chip in the MSD box. Looking at the tach I stayed in it and when I started to hit fuel cut off of stock Ford the tach was nowhere near 6250. Wanna say it was like 52-5500. I'll have a passenger ride w/me just to see if Im right. Ideas?:

 

[86bluecobra]

Are you a automatic car? I thought the auto's shut fuel off sooner.

 

[Wade95]

5spd. When I looked down at the Ford tach I had that thing tach'd out further than I ever have. For some reason the 5" monster tach was not reading the same. ???????????????

 

[Mike92GT]

The factory tachs are notoriously inaccurate, especially up in the higher RPM ranges. Chances are the Monster Tach reading is correct

 

[95GTAODE]

Also, the MSD pills aren't exactly accurate either... My 6000 RPM chip cut out at 5400.

 

[Wade95]

The factory tachs are notoriously inaccurate, especially up in the higher RPM ranges. Chances are the Monster Tach reading is correct

And Mike, you are correct. Found a 3K pill from a buddy of mine. Put it in the box, matted the gas and monster tach held at 3k. In dash tach said 3300. Wow!