When I ran the Mallory mag I could not get the tach to read correctly anywhere but at idle. It had a playback and after the run it said over 10,000 rpms! I knew that was wrong! I tried the MSD mag converter box and when that didn't work I found a tach with the "loop" on the end of the signal wire....that didn't work either. Both set ups the idle was fine.
I have a rpm data recorder on the car and had to put a crank trigger on it just for the rpm recording. That works perfect.
If you don't have a data recorder...maybe the crank trigger could be made to work with the tach you have? 4 magnets on the degree wheel might give enough clean signal to make the tach work?
Anyone try this before?
I'm running a MSD 20 now......same problem as the Mallory with the "loop" style tach pickuo wire.