If you want underdrive pullies for the power steering and water pump, then contact ruslow on the NLOC board, very good quality. If you want to overdrive your blower then like JB said, 4# or 6# lower crank pullies are the most common. I think 4 pound pulley is the best all around pulley.
My friend, who is an engineer at Roush in Detroit tells me that if you upsize the crank pully then you will increase the belt speed accordingly. Depending on what rpm you will be maxing out at you could exceed the belt rpm limit and have premature failure or wear of your belt. He suggests changing the blower pully to the smaller lightning version (2.93 or 2.80) and then play with a 8" crank pully if you want more boost. If you change the blower pully the belt will spin at the same speed but the blower rpm will increase yielding the increased boost you may want. All you should need would be a belt for a Lightning to make up the difference from the 3.25 to 2.93 pully swap.
I'm gonna try this inthe next 2 weeks so i can let you know how it goes then.
With as many lightning owners running upwards of 20psi of boost, I don't think I have heard of anybody blowing a belt. The problem with going to a smaller blower pulley is belt slippage due to less wrap, also the smaller upper only gains maybe 1.5 psi (depending on the size).
And think about it, the crank pulley is turning at the same speed as the engine regardless of the size. The blower pulley is what would be turning faster due to the pulley ratio. I don't see how turning it faster exceeds a speed rating of a belt. I could maybe see that it exceeded the load rating though because it takes a lot more power to create boost at those high pressures.
I agree with you about potential belt slippage with the smaller pulley on the blower. Typically when people add this smaller pulley they add an additional idler pulley and bracket on the left side of the belt or they upsize the 90mm idler pullies to 100mm diameter to wrap the belt for about 88% contact with the upper pulley. Is this what you have seen as well?
However, the belt will definitely travel faster with an increased lower pulley change due to the belt having to travel a further distance around the larger circumference of the increased lower pulley diameter. I would hope the Gatorback belt would stand up to a little extra speed.
Perhaps the ideal situation would be a 2.93 (Lightning)blower pulley and either a 4# or 6# lower crank pully setup. This would likely give you about 7 to 8#'s extra boost from stock. Keep in mind the lower end on these beasts are still only forged pistons and casted rods. Not like the Manley/ARP equipped Cobras.
Remember I am talking about replacing the stock HD 3.25 blower pulley to bring it in line with the Lightning and the pump it up with the lower pulley.
0neFstLightning, Looks like it's been a month or two since you posted this. But I'll give you an answer just incase you or anybody else runs accross this.
Since you have a stock 99 you'll want to do several things when *overdriving* the blower to make more boost.
*on a stock truck* Don't go bigger than a "4lb lower" pulley. The stock belt will work if you break the tensioner tab off the idler arm housing. Or get a 1" longer smooth type belt. (stay away from the ribbed versions like a gatorback)
Step the plugs down one range colder and gap them to 0.036 max. (torque them to 13ft lbs) (I like ngk TR6s)
Now... a custom tune via chip or programmer will seriously wake this thing up when running a overdrive pulley. And that's not a opinion.. that's a steer with the rear fact.
btw: I know this is my first post and ya'll don't know me from a hole in the ground. Lets just say I have an unhealthy amount of knowledge about the 5.4L S/C motors. Now, I don't have a friend who's an engineer in motown...? It's just that I are one. Not only that, I was one of the engineers on the belt drive system of this particular modular motor.
Last edited by wydopnthrtl; 11-23-2005 at 03:36 PM.
I have no pulley setup installed yet but I would like to know your opinion since I want to get going on this soon. I was thinking of an interchangable pulley for the blower (2.76") and leaving the stock lower alone. They claim on the Harley truck a 4-5lb boost increase with this combo. I would also add an additional idler bracket and idler pulley (100mm) on the left side of the blower axis to wrap the belt further around the smaller upper. I have an SCT Xcal2 tuner already and I have access to a chassis dyno to tune the beast. By adding the extra idler pulley and downsizing the blower pulley i figure the stock belt should work ???
Let me know what you think. Always good to hear peoples opinion or facts.
Love this truck. So many people have commented on it. I was lucky to find a beautiful 100th Anniversary edition with 10,000KM on it (approx. 6,500 miles). Two tone black and silver with every option on it too. Really nice to drive.
The high tension side is on the drivers side. Avoid any type belt altering setups on that side. Anything you want to do on the pass side is fine.
I'm not a fan of JDM as a company. But they do have top quality products. Contact them and they'll get you set up with the right belt. With that pulley and a **smooth** belt you should'nt need to increase belt wrap. (the smaller a pulley the less contacting patch you have. Increasing belt wrap does increase contact patch. But it also places higher loads on all the componets/bearings)
Thanks for the suggestion about the lower pulley from JDM. I think it makes more sense to change the lower only and leave the blower pulley alone. Living here in Canada (just across the creek from you I see) Essex, Ontario we have to get emission tested every 2 years, so putting the factory lower back on would be much easier then swapping uppers I think. Plus I agree with you about larger pullies having better contact with the belt. I also thought that adding an additional idler pulley would stress out bearings due to extra loading, but it appears pretty popular out there as a standard mod for blown vehicles. Is it just the look people are after?
I was on your website for your "L" and it looks sweet! You mentioned an "oil sepatator" from REM? Can you send me a link to the place you bought it from? I had bought one from RPM outlet www.rpmoutlet.com and it broke as I was installing it. After looking at it in two pieces, I determined that there is about .010" of plastic holding the threaded part to the main body. What a piece of crap I said to myself. I have been in contact with RPM outlet and we will see what they say about it. Sent them some picture of the broken piece. Snapped off right away as soon as it contacted the "O-ring" surface. !@#$
Well let me know if you can locate the oil separator website
Is the tuner of my choice. The one they have works "ok" but not perfectly. This winter I'm going to make one like the high boost imports use. Just a home made 2-3 times larger one w/more trapping qualities. Don't get me wrong. The REM one works but it does let some oil by. Especially after it's been oil soaked for a while.
After market idler pullies are popular on these trucks because of perception and P&L reports for the retailers. Not because of any functional problems.
Magnum powers has a new style that I like very much. It increases belt wrap on the pass side and looks to function very well.
Since your this close, come check out MiLoc.org We are getting smaller but we do meet up several times a year.
I traded my 01 lightning in for a new 04, it's funny because for some reason the 04 was making 14 to 15 pounds of boost bone stock and I test drove 5 before I took this one out for a ride, I asked the saile's man was there some mods made to it and he said no way that this truck was brand new and with only 22 miles on it I new he was telling the truth, so this is what I put on the motor.
All the add on's I bought from LFP,
#4 lower pully with a gator belt
18" filter and map sensor
Cool air intake to the SBTB
There new intake that is huge inside
A oil seperator that works great
A oil breather filler cap
I took off the clutch fan
and used there electric single fan
and shrowed with a heat sensor
Then came the Diablo sport tunner
and that was it, then took it to a place called
Speed INC in Roselle IL, for a dyno tune
when they got done I had a smile from
ear to ear on 94 octane it made 477 ATRW
and 496 #'s of torque when the weather is cool about 40 or so
I add 2 gallons of 110 race gas and it just loves it
if I diden't live in Chicago I would of went with a 3 way chip
It peged the stock boost guage so they put a larger
one on and let me tell you this thing makes close to #20 of boost with
the right conditions, of course I can't floor it off the line but untill I buy some wider cheater slicks, when I ease into it then floor it BAM!! this lightning moves, those programers truly new
what they were doing, everything else is bone stock, just for the record I blew the doors off that 06 S/S chevy sport truck with it's 6 speed and vette motor hehe, I have about 32k $ in mine and the S/S cost him 48K plus tax, How can I post a pic and another toy of mine on here I'm new and need some help, thanks