3.0

 

Ya beat me to it!

 

I've always heard that the stock alternator pulley is 2.60"........Is this chart incorrect?

 

I measured mine......it is 2.60".......whaddya laughing at?!?!?....the alternator pulley you sicko!!!

 

so with an 8lb lower should i go 3.5? or 3.7?

 

so with an 8lb lower should i go 3.5? or 3.7?

By all means, 3.7.

 

A 3.7" on an 8# lower will WAY underspin your alternator relative to OEM.

I use a 3.2" with my 8# lower and am happy. Alt speed is within 2% of OEM.

http://www.modularfords.com/reference-forum/alternator-pulley-combo-reference-35303.html

 

hmmm maybe ill split diff and go 3.5

 

A 3.7" on an 8# lower will WAY underspin your alternator relative to OEM.

I use a 3.2" with my 8# lower and am happy. Alt speed is within 2% of OEM.

http://www.modularfords.com/reference-forum/alternator-pulley-combo-reference-35303.html

It is my understanding that 16000 RPM is the max continuous RPM that the alt. can withstand with 18000 RPM being the max instant RPM it can withstand.

I have now been through one stock unit, and two PA units. The stock unit and 1st PA unit was with a stock alternator pulley. The 2nd PA unit went bad with a 3.2 pulley on it. I'll be putting a 3.5 alt. pulley on the next one...

For mobius, a 3.7 alt. pulley with an 8 pound lower only slows it down 300 RPM at idle compared to stock and keeps it less than 16000 RPM @ 6k RPM...

If I am reading the chart wrong or am misinformed, please enlighten me. I'm on my 4th alternator now, and it's getting old.

 

yeha you are right.... i think i shall order the 3.7... i would rather under spin than over... especially with all the alternators going out.... also i plan to do the power tour this year so dont want to break on the road.....