I think the issue here is the blower rpms and NOT the boost, because like Krummer said himself the higher pulleys do increase the wear on the bearings and blower rotors..thats a given. And like Highroller and Sal said the 4# power is incredible throughout the power range and is a bit lower than the 6 on the top. To me those are great reasons to buy the 4#. As far as performance, Blackjack kinda hit it on the head.Its your" total package" combo that makes it...not one part. Timburntire has a 12.2 second daily driver L with no Nitrous and a 2# pulley. Yes, he has other mods but I'll bet he has no engine issues.Think about it.

 

I think we have reached the limits with the stock Eaton. I have seen gains, yet with diminishing returns by changing pulley size. I currently run a 1.5 upper and 6 lower and that's about all I can squeeze out of the stock blower. I don't drive my Lightning as a daily driver and I am very conservative on the street. I would run a 4/5lb lower and stock upper if I used it as a daily driver.

 

Blackjack,

When did this new JDM pulley come out? I didn't realize they had a new design??

 

Weedo,

JDM just received these new pulleys in the last few weeks...The goal is sell the cage/pulley as a unit. His source is a little delayed in getting the cages. They had to machine my cage on a lathe a bit...took 3 mins. So he is selling 4 , 2 and stock size right now. If he ever comes out with 5 or 6 lb pulleys, it would be a VERY easy upgrade. I have no idea if the other Tuners(Sal or JL) have this..you might wanna call.

Scott

 

Weedo,

Personally I think you should stick with a 4lb lower and try that out first.

Once you think you need more power I would get the interchangable upper pulley system. It takes 5 mines to swap out a pulley and that way you can run more boost att eh track is you want.

You keep on thinking about dollars and cents, but look at it this way brother. I would be scared running a 6lb pulley in a daily driver all the time, especially since I know the way I drive my turck (WOT all the time). The 01 motors don't have to good of a track record right now with reliability so I would think 4lb's of boost cause a new motor nto covered under warrenty isn't going to be no dollars and cents, more like thousands!

Like black jack said, get the 4lb pulley and then get the long tube headers and exhaust! With that and a chip & filter you'll be well over 400 rear wheel HP! You'll never hook up on the street!

thats another thing you need to consider, traction. My trucks got so much power now that I turn a corner and just barely get on it and the rear tires are spinning! On the street my trucks pretty much useless for racing purposes cause I'll spin the tire everytime. That is unless you invest in some nitto drag radials (I wich they made some 20 inch version for us too!).

 

Those Long Tube Headers actually relieve the load in the motor so much that you lose 1lb of boost...they add life to your motor.

 

So if i get a 6#, then long tubes, i'll be at 5#. Sounds like a compromise.

 

For real?! You lose a pound of boost with the long tubes?

 

Weedo,

After a lot of consideration of how my truck is driven and used for pulling my boat around. I chose to only go with a 4# set up. I have been discussing every detail, on how my truck is driven and used, several possible filter, chip, pulley combinations, and I think it all depends on what you want to spend and how you want to spend it. Things to definitely consider when you either go to 4# over or to 6# over is spark plugs, different belts, and stuff like whether or not the stock pulley cage is still used. There is a lot more to consider when you pass the 4# mark. Personally, I think for the all the headaches the 6# pulley would cause me, I will stick to 4#'s.
Just my .02!!!

 

Exhaust really has nothing to do with boost.Your intake valves are closed during the exhaust stroke. The reason the L.T.'s work is because they create a better "scavaging effect" thereby creating less "work" for the pistons on the exhaust stroke which equates to more ponies!!

 

Doh!! why didn't I think of that?!

 

RTKILLA

How much do thos 20in nitto drag radials run $$$ wise

 

Weedo, Go with the 6lb lower and 2lb upper and no chip! Because if you don't understand what this is doing to your motor you shouldn't screw with it. It should last you a couple days like this before you hear a BANG!!
Seriously, not to be a jerk, be very conservitive if you can't afford to break stuff. I work on 12,000-60,000 hp marine diesels. I understand how boost, compresion ratios, and injection timing and duration effect firing pressure. Instead of worrying about a lean condition, I would be worried about early timing, whcih causes premature combustion or "knock" a lean condition creates heat and can blow you rods but more likely will burn up a piston. KNock is what blows rods. The comment about the headers and the 6 pounder only giving you 5 pounds is correct, but, that is a good thing, not a bad thing. Just like a more efficiant intake, or head or valve, may reduce boost, it is doing that because there is less restriction, again, a good thing. I would start with a four pounder and a good chip. If you are upset with the gains of that, I'm sure you can sell it for close to what you paid, and use that towards the six pounder. But by that time, you really should think about what is happening to your rods bro! Again, sorry if I started this out being a ****, but you have to think about what is happening inside that box too!!!!

 

I've read your post three or four times whip and none of it makes sense and I still don't know what you were trying to say.

 

Whip,
Yeah, you did start out being a ****, but some people like to sound tough.

Seriously though...
Believe me, i understand all of this, and how a motor works. I've owned 37 cars and blown 3 motors. I didn't realize that my question lead you to believe that i had no clue what i was asking.

I've decided to go with the 4# pulley so you 4# advocates can settle down now.

Thanks for the constructive advice that some of you gave, and appreciating that sometimes we don't all know the best answer to every question before it's asked (thus the question).

Thanks Sal for your answer too, nice to hear a Tuners opinion given the variables.