Under pulleys
 

Are underdrive pulleys worth the money? The go for about $220 ta $250 for pulleys and I want to know if they are worth the money. What exactly do they do besides give you a little rwhp increase....?

RE: Under pulleys
 

Underdrive pulleys divert some of the power from your engine accessories (Power steering pump, water pump, alternator, and A/C compressor) back to the drivetrain.

For most people they are a safe means of gaining about 10 RWHP. Beware that they are not a good idea if you are installing a huge aftermarket stereo system, or if you live in a really extreme climate.

RE: Under pulleys
 

I am assuming they would be safe for an aftermarket head unit and speakers (in other words, no amps, subs, etc), and an aftermarket alarm system?

RE: Under pulleys
 

Sure, that's fine.

You wouldonly have a problem if you install a bunch of huge subs and big sub amps.

RE: Under pulleys
 

you will not get 10 rwhp. Maybe 2-3 rwhp.

RE: Under pulleys
 

For every mod, there are always doubters. The again, has anyone really seen a before and after dyno? And it would be hard to tell if you really got 10, because some of that could just be other differences (like weather or variation from run to run)? 2-3 is the lowest I have seen, but I have heard estimates as low as 5.

RE: Under pulleys
 

I have a 2006 saleen n/a.(until monday when I pick it up with a turbo on there) but anyway, it comes with UDP and we did a baseline on a land sea dyno and my base was only 250 rwp. Saleen rates it at 330 at the crank. I highly doubt it gets 10 rwhp, 5 would be tops.

RE: Under pulleys
 

If you get a blower, do you have to go back to the factory pulley?

RE: Under pulleys
 

I have the pullys and they have impressed this customer very much. I say it is good for 10 rear horsepower[sm=icon_rock.gif]. Furthermore I live in the dreaded heat here in the south and they haven't made my life

miserable yet? 41,000 miles and counting.

RE: Under pulleys
 

Again, not to doubt your claim of 10 rwhp, untill I see a dyno sheet of before and after I will not belive it when I see it.

Again it amazes me how people claim, 300+ rwnp with CAI,Tune,UDP. Again I am rated at 330 at the crank and only put down a 250 rwhp on a 5 speed salee, now you can add 10-15 rwhp because I was running 20 inch rims, so that will lose more Hp than 17 or 18 inch. So I was right at 260-265, which is what every other GT claims stock. I suppose most people must use a DYno jet for there numbers. Those numbers are just not true street hp.

If you use a S/C I am almost 100% sure you will need to remove the UDP. Now if you have a turbo set up, you do not need to remove.