[GasPasser]

I just got my custom tunes and they are really nice. Bill definitely knows what he is doing. But it's time for the next upgrade to the truck. First on the list is a set of underdrive pulleys from Troyer, I just have a few questions.

I've read a little about adding them to the truck and most say you don't need to do anything other than maybe increase the idle RPMs by about 50 or so if the battery voltages drop at all. I've read that with a custom tune this probably wont happen because the tunes have already most likely increased this. Is there anything else I should be concerned with needing to have changed in the tune?

How much benefit will I get out of them? Basically are they worth the money?

Did you guys notice any difference in pick up when you throttle it? Low RPM or High RPM differences?

At the very least I'm going to pick up a higher quality serpentine because to get rid of the belt squeal when I'm pushing it, but I'd like to go all out if it is worth it.

Thanks.

[JackandJanet]

88Racing would be the one to answer your question definitively, since he's recently installed a set. I think, though, they WILL give you increased power and possibly slightly better gas mileage since they reduce the work the engine has to do to power the accessories a bit. And, those accessories might just last a wee bit longer, since they aren't spinning quite as fast.

You may not need to increase your idle speed, but if you do, probably by only about 50 rpms.

- Jack

[Punisher]

I've had the TP underdrives for about 3 months now. When I swapped the pulleys I also installed the TP eFans so my opinion is going to be of the upgrades combined. I've noticed that the engine is much more responsive. As for mpg's... not so much. I've not noticed any mpg gains but that may have more to do with my foot than anything else.

Pics of stock and the TP underdrives below:

[88Racing]

Mpg's increases? Not really.
Added power? Some not much.
Engine/throttle response? Better.
Custom tunes problems? Some: due to dropped rpms and that I had to add some through the custom options menu.
When you first get them installed watch your voltage for everything you do with the truck. You don't want the voltage below 12.7 for to long it's hard on the electrical system.

Good belts? Gatorback by goodyear.