Hey any of you out there had any problems with underdrive pulleys? I had a set on my truck and did feel an improvement, but always had provlems with the charging system. Any ever experience this?

 

just put one on my truck, seems to be okay I had to change to a six rib belt instead of a seven but it doesn't seen to be a big deal. ASP told me that you need 900 RPM's for a full charge. My truck is a manual with a 318 the lights will barely dim at idle. I don't have any auxillary lights or amplifiers in my truck, that will draw more from your alternator and possibly cause problems. I will say that it took forever to get the pulley from ASP like 4 months after I paid for it. They told me that they don't make them until you order it. I don't know how much truth there is to that, but the truck does seem to rev quicker, not a lot but did just as much as my airraid intake.

 

Underdrive pulleys should never be considered a "bolt on" the need to be used in conjunction with other performance parts and a computer mod.

The big thing is that these trucks roll off the line pre-programed with factory settings and calibrations, which include the balance of all the stock pulleys VS the prime mover (engine and harmonic balancer). I aint saying don't do it I am just saying you should recal your ECM for it or any other MOD.

Good luck

 

How do you recal the ECM? Because I have quite a few mods and haven't got that much performance from them.