Phil99vette

iTrader: (11)

Finally got my Mustang to the dyno last night and after looking at the info somethings out of sync. The Big stuff has the limiter set to 6800,

On each dyno pull we went to anywhere between 5000-6200 on the Big Stuff logger.

The dynojet software showed the top end RPM around 7500 when the logger showed the RPM at 6100-6200.

What would cause this?

TLewis4095

iTrader: (10)

The sensor clamp that goes on the plug wire to pick up each fire may be failing, could be outside interference, some spike that confuses it to show a momentary spike.....

Jake@EPP

We never had much luck with the inductive clamp on our mustang dyno stuff, went to a crank pick up for older cars and a obd2 pickup for newer stuff.

Phil99vette

iTrader: (11)

Thanks guys, I guess its safe to assume the Big stuff is right on.

Jake@EPP

You can always check it with a timing light that reads rpm.

kp

iTrader: (34)

Unless the dynojet has winpep7 or higher with a high stall auto the RPM will be off, its a calculated value and not displayed directly from the inductive pickup.