thinking of Xmas - Underdrive Pulleys?

[Mercury]

Hi all

i have a 2003 f250 5.4L gas with 6" lift 37" tires 4.56 gears

I want to squeek out more power but don't want to do anything major

Already did: programmer, E fans, intake, exhaust

Next I think is under drive pulleys - what do you all suggest? I would assume a kit so that it is balanced...?

also do i need a longer belt / shorter belt?

Thanks in advance!

Kenny

[Mercury]

nobody has done this?

just wondering?

[Snake Eyes]

I don't really know nothin' about under drive pulleys but I thought that you'd lose performance of the driven accessories. In other words, your output from your alternator (for example) would be lowered, same for the A/C pump, etc. Seems like an under drive setup is good for cars, Mustangs, Boy Racers and that kind of stuff but it doesn't really seem to fit in the truck world where full output from accessories is more important.

Again, I don't really know nothin' about none of that...just what I've been told.

Not to hijack...but what kind of increase did you see from the programmer? What kind do you have?

Good luck,
John

[Mercury]

I know I will loose performance of the

1. alternator
- but still fine for anything above idle

2. A/C
- but still fine for anything above idle

3. Steering pump
- worries me a little since i have 37" tires to turn - but while rolling I almost don't need power steering at all.

people i know have done it to their trucks, im trying to pick their brains [img]/forums/images/%%GRAEMLIN_URL%%/smile.gif[/img]

As for my programmer

I have a U7153 diablo sport predator

http://diablosport.com/index.php?mod...display&pid=57


I like it, There was one thing I was not happy with on it - and that was that it did not modify my tire size for the larger tires even though it said it would. I used a Speed Wizard to take care of that problem.

Anyway the diablo sport is great - you can log information to review on excel at a later date.

I dotn think any programmer will give you extreme gains on a gas engine. I did get custom tunes done by the diablo sport people and they advanced the timing so much for me that when the bed is loaded I can get the truck to ping - PERFECT for non loaded - The truck has a seat of the pants difference to it (with the custom program)

With the standard program you feel the difference but it is mostly a slight difference in timing and mainly tranny shift pressure - makes it shift much harder.

I already have a Factory tech valve body in there - and that is better then what any programmer will do for shift pressure.

Good luck if questions just ask

kenny