I've seen a lot of posts and peoples opinion but I really like to hear people from this forum and what they think about any underdrive pulleys or kits, from a specific manufacture and company does anybody have any specific pros and cons from their experiences I tend to trust people on this forum more than others…Just my opinion and saying you guys know a lot more than me I'm Still green with A lot of this stuff, I did have one on my Mustang but really couldn't see if it did anything like to try do it on my hemi…Thanks a lot for any info I appreciate it

 

I run a summit 20% underdrive crank pulley. It is a nice piece, simple install and makes a small performance gain. Not going to be a night and day difference but it was noticeable.

 

Cool thanks I appreciate it...are there more percentages? Or is that the "perfect" one that does the job?

 

There is another company that makes a 25.

 

Just remember...Underdrive means that you are under driving(spinning slower) certain components.
What does this mean?

It means that you lose coolant flow from the waterpump because it's spinning slower...
It means that you lose some output from your alternator because it's spinning slower...
It means you lose steering precision from your PS pump because it's spinning slower....
all those are underdriven, i.e.driven slower to reduce drag.

Robbing those areas is why you gain the small amount of power. Personally, if you tow or do anything legitimate with your truck, I would stay away from U/D pullies.

 

This is the typical response your see from people who don't have one. First hand experience has proven out none of those problems are legitimate concerns. And I do a lot of legitimate things with my truck.

 

Typical response you see from people who don't know any better...

How does what I said have anything to do with not having U/D pullies? What I said ifs PURE FACT!
Just because you may not notice the robbed steering, alternator.etc doesn't mean that it isnt true.
Had March 20% U/D pulley's on my 550hp Mustang. It got too hot from the 20% less pulley spin, the lights were very dim at idle from the slower pulley spin, and my steering was very stiff in parking lots(low idle) from the slower pulley spin.
Had same type of pulley's on my 2000 Silverado. My lights were dim, my fan for the heater would drop considerably when sitting at traffic lights. My truck actually stalled a few times when stopping abruptly. I didnt notice any steering issue's in the truck. Everything resumed back to normal once the pulleys were removed.
Because of previous issue's I have had with them(as well as many other I have spoke to and see on a regular basis at car shows) I would never put them on any of my cars ever again!

BTW. I ran dyno comparison with and without on my mustang. 476rwhp/470rwtq w/20% pulley's installed. 473rwhp/468rwtq with stock pulley's. On a car with that much power, 3 measley HP dont mean nothing if you cannot keep the engine cool!

For a truck that is a daily driver and is neded to be dependeant on, under drive pulley's is not the answer for more power. There are much better things to spend your money on.

 

Yes, this right here is a typical response from someone who doesn't know from first hand experience of running one on their truck. I do plenty of legitimate stuff with my truck and have never had an issue and so have thousands of other guys. Maybe you should try putting a mod on your truck before touting that it is a bad choice for people who do legitimate things with their truck.

 

Your arguing nonsense bud.
I think you need to read all of my posts because I DID have them, just because they weren't on this particular truck doesn't mean anything.
Towing..yep, because your limiting tyour cooling efficiency! Alternator, limiting your charge capacity if you have trailer or winch use...

I'm done with this. It's a waste of my time.

 

Is OK man, you drive a truck with no mods so you just go by assumptions. It actually does mean a lot that you never ran one on these trucks. Unless of course you are saying that what is true for one vehicle is true for all vehicles. Is that what you are trying to tell us? That what works on a mustang works on a ram and what doesn't work on a mustang will get the same results on a ram? Is that really what you are trying to get us to believe?