Underpullies

[Oldtimer]

I'm looking at Summit Racing's underpully kit for the '07 4.6 which consists of a new balancer (ribbed) and water pump pulley. Total under pull is 25%. It doesn't tell you but I'm guessing that the balancer reduces everything 25% and then the water pump pulley ups the water pump back up to normal. Does anyone know what HP gain I can expect at the rear wheel with this mod.?



Thanks,



jimmyboy

 

[Dingo]

The crank pulley reduces everything 25%. The water pump pulley slows the water pump down even more.

 

[Oldtimer]

Thanks Dingo for correcting me on the water pump pulley. Do you by chance know what the HP gain would be at the rear wheels? Base HP was 292, added CAI, dual 50 series flowmasters & Todd Z's over-bored TB.



Thanks,



jimmyboy

 

[Dingo]

I'm not sure on the Summit ones, but the ones I have were just over 10 hp.

 

[Dingo]

Here's a pic of my stock crank pulley and my new one. New one's in the front and stock is in the back.



<img src="http://www.zjstech.net/~library/22354/Aug10_0001%20(Small).jpg">