#5 Pulley

[2002DSG]

Can I run a #5 pulley on a stock engine with NO chip?

What kinda Hp gain would I expect to see?

Thanks!

[Ayrton]

You might be able to get away with a #5, but I know you can run a 4.

Always have eveything dyno'd to make sure.

[CajunCobra]

Ayrton: Which 4# pulley, the 4# Lightning pulley that supposedly makes 2# on a HD or the 6# Lightning that supposedly makes 4# on a HD??? I sure wish that these folks would use the diameter instead of an arbitrary number!!!!
DT

[2002DSG]

Can I run a #5 pulley on a stock engine with NO chip?

What kinda Hp gain would I expect to see?

[RiceKicker]

I would NOT recommend running a 5# pulley without a chip. I personally think 4# is pushing it. Unless you want to see problems in the future --- you should definately get a chip. ----

Horsepower numbers -
JDM says " 50 lbs.-ft. and HP by 18 " for a 6# so you should be getting a little less than that - Maybe 43lbs/15HP

[Ayrton]

Originally posted by CajunCobra
Ayrton: Which 4# pulley, the 4# Lightning pulley that supposedly makes 2# on a HD or the 6# Lightning that supposedly makes 4# on a HD??? I sure wish that these folks would use the diameter instead of an arbitrary number!!!!
DT

Let me rephrase my answer to be clear, as the pulley numbers can be confusing between the HD and the Lightning.

You can run a 2# pulley on a Lightning without a chip, and this results in the truck having 10#’s of boost, so you can run 10#’s of boost with no chip. Having said that, I see no real point in upping the boost beyond 8#’s without running a chip, and I have heard all the excuses about warranty, and in my opinion you should just leave well enough alone if you are that concerned about voiding your engine warranty. 8 out ten people would not even know the difference between 6 and 8 pounds of boost in a 5000-pound truck.

[CajunCobra]

How well I know St. Louis. I am the poor fool that Ford attempted to screw when the engine blew at 5400 miles, turned out the main bolts were not tightened at the factory. Will not play the hide and seek game with a chip just yet.
DT