Stock Pulleys > Underdrive

[phoonTy]

Long story short:

Bought my truck with underdrive pulleys on it. Crank pulley and alternator pulley. As far as I was concerned, it ran pretty good, though sometimes the idle left a lot to be desired.

Alternator went bad, mental lapse, lost the underdrive alternator pulley with the core. Then came voltage problems, because the crank pulley couldn't spin the stock alternator pulley fast enough.

Instead of spending $78 or more for a new pulley, I just decided to go back to stock (previous owner gave me all the stock parts with the truck).

After putting the stock crank pulley back on, and having a stock alternator pulley, I think my truck runs better, and is more responsive. Mind you, this is only the butt-dyno talking, but it seemed to build boost immediately compared to before. I need to drive it some more to be sure, but that's my first diagnosis.

Moral: If you're thinking of running underdrive pulleys on a Ty, Don't! It's not worth the electrical headaches and it even seemed to create lag and bad idle situations.

 

[redty]

I second your opinion, been there done that.

I second your opinion, been there done that.

Bought my Typhoon in 1998, had the underdrive pulleys on it also, when I installed the Fluid Damper, everything came off and back to stock. Smoother idle, better cooling in the summer, (later added one of the HD water pumps with the empeller plate another big bonus) so verdict was, ain't going back.

I truly feel our ECM has all types of issues if the voltage is not on the money, this is not a scientific study, but one that does seem to merit some oveall investigation one day.

Sincerely,
Steve N.
RedTy 8)

 

[phoonTy]

that "better cooling" in the summer sounds good. i noticed it last summer cruising up the interstate at 85mph with the AC on, didn't get hot per say, but it warmed up more than I thought it would.

 

[0966Sy]

I can agree with the idle voltage problems, at night i can see my Ty's headlights slightly dim when i come to a stop. I have the stock alternator pulley also, my Ty came with the underdrive pulley but when i get my hands on a stock pulley i will change.

 

[Sy769]

I really don't think that most of us turn enough RPM to warrant underdrive pulleys.

Now if you want to shift at very high RPM (6500+ IMO) you might consider them but expect the drawbacks i.e. lower voltage at idle and less flow through the water pump.

 

[TyGuyJeff]

Would the fuel pump be included? I dunno how many amps the fuel pump takes, but at idle I could see it coming *just* short of stock voltage/amps with an underdrive pulley at idle.