Installed a new MSD alternator and it does not begin to charge until 1400rpm, wanted to know if there is a larger crank pully available then the stock 13B.


The current ratio looks to be 2:1 crank vs alt. pully, wanted to try 2.5:1 or 3:1

Thanks

 

MSD sells a downsized pulley for their alternator now due to this very problem. Check their website. You may also have to make a custom crank pulley also. I did both.

Aaron

 

Got the car started today, something strange is going on with voltage.

I get 13.5-14.2 reading everywhere ie: fuel pumps, alternator, coils, battery, except my ecu is reading 12.0-12.8.

Its at least a full volt lower, Im going to check my ecu power wire tommorow, its the only thing I can think of that would cause a lower reading.

Should have it on the dyno is a day or two and if my fuel pressure holds. will finally try a WOT pull.

 

That sounds more like ground issue to me.

 

Already dealt with any possible grounding issues, one of the first things checked.

The smaller pully from msd should solve the problem.

 

I thought you might be interested in this line from their manual:
"The One-Wire APS models will begin charging between 3,000 - 3,500 pulley rpm (typically 1,500 - 1,750 rpm at the crankshaft.). Once this rpm level is achieved and the alternator begins charging, it will remain ‘on’ at lower rpm as well. "