see i was always under the impression that underdrive pulley's actually do increase performance & ET's due to the slower rotation and decreased drag on the motor it increased ponies...i could be wrong?

 

they do. . .there are just people that speak for them who have never tried them. . .+1 for ASP UDP

 

This is true and you also have those that say something like, "My grandpa used to put boat motors together and he said to never ever use underdrive pulleys. I asked him this just yesterday after giving him Alzheimer's medicine so underdrive pulleys will make your engine blow up!!!"

 

hahahahaha too funny...IMO they work better on FWD cars though just because you already have like no loss of power from motor to wheels....i think it's more efficient in a FWD car than it is in a truck or camaro...however if you are building something that you plan on running down the track just because well it's an easy way to get more power..and that's always good

 

How do you know if you NEED the alternator pulley? According to the speed engineering site.....just Crank has full charge at 800rpm and Crank with ALternator has full charge at 950.....

Why does that not make sense?

 

i think thats bass akwards! unless you have subs or lights like a semi you should be good without it.

udp also makes a better short belt routing which can gain up to 2 tenths in the 1/4 from what a couple other fellas said on here!

 

I'm not really going to rack myself trying to figure all that out.

but here are my first impressions... there are some people interested in this tiny little bolt on, so i'll say my piece.

I noticed right away (w/o adjusting the idle), that for me it idled better. Before, no matter how good the tune is, it still had a little hot surge, a little drive to reverse surge, etc. But now w/ the ASP's installed... there isnt even a little surge.

Now, i also realized that my e-fans need the idle at 950 or above. 950 is perfect for me and now when the fans turn on, it doesnt pull as much power as before only drops .5 volts according to hpt and it'll jump right back to 13.8-.9.

Driving around, i noticed that the acceleration feels more effortless... like under light to moderate throttle. WOT, no different sotp... but im told this mod is good for maybe a tenth... maybe more since of my mods, but this is just speculation. But if i were told to drive this vehicle w/o udp, and than drive this one w/ udp, i wouldnt be able to tell you the difference at WOT.

Last time it was a solid 13.3 pass on a sub 1.9 60ft. So we'll see how it is, we're going back to the track on the 21st this month... i'll let you guys know how it did.

Im also going to try the short belt conversion and see how much that really helps... in going to get these damn 12s on a n/a 4.8 some way or another, lol.

 

good review!

 

thats good info man. i want to know the difference in the 1/4

 

difference in the 1/4 is usually only like .2 but still for 300$ that's not a bad difference...as many know & i'm sure have done...you could spend more & get less