View Full Version : Pro mag 20 Tach converter

outlaw dragster
01-20-2012, 02:20 AM
Hi There
Currently running 430 cui blowen alcohol small block with pro mag 20.Also using MSD tach convertor Part no 8132.Im having problems with data logging showing very short but large spikes on the rpm graphs.Of the tach converter im using pick up for tach in car and rpm pick up for data logging.I have slowed down sample rate which helped.Would i be better to use a RPM pick up using Inductive pick up cable part no8114 straight of the mag.
Also making 36 pounds boost with 17% over with 1071 Hi helix what plug gap would you reccomend
Thanks Paul:001_rolleyes::001_rolleyes:

01-20-2012, 12:51 PM
is it a race pak?

outlaw dragster
01-21-2012, 12:47 AM
No Edelbrock Qwick data 2

01-23-2012, 09:12 AM
well, lets start from basics...

1) do we have the heads grounded together ..then from there to the corner of the points box ....then to chassis ground?

2) what kind of plugs wires do you have?
lets check with a ohm meter ...ohms per foot ..

3) are you using just the generator or with a crank trigger ?

outlaw dragster
01-26-2012, 01:57 AM
Sorry been having log in issues
I have the cylinder heads grounded to top top rail on either side and block has earth strap two.Middle engine plate is steel as well.No i have not earthed the points box so i will do that.Leads are MSD 8.5 Super conductor sorry dont have ohm meter at moment and not using crank trigger just trigger in the mag itself also using a 2 step for staging.I have run the mag kill switch wiring on top rail and all data wiring on bottom to seperate them.All other sensors are logging and graphing fine just having spikes in rpm graph.
Thanks Paul

outlaw dragster
05-01-2012, 04:15 AM
would running a crank trigger help the data logger from interferance?

05-02-2012, 04:10 PM
Sounds like you definitely need to ground the heads to the block as well as ground the points box to the motor as well. You need to check the spark plug wires for resistance as they can be the culprit most times in which a noise issue is suspected. Keep a close eye on the coil wire, since it carries 8x the amount of voltage the other wires do. In other words, if your car has 10 passes on a new set of wires, the coil wire already has 80 passes on it.