JBP Underdrive pulley???

[Akai oni]

i was reading on the shortbuss that they made 5whp on a stock LSJ with this...

http://www.jbodyperformance.com/new/PartDetails.php?partId=706&catId=706&catName=JP0706

The HP gains would be greater with a smaller pulley and other mods wouldn't it?
Im thinking of doing this and thier A/C compressor pulley...

think it's worth it? i may end up getting one.

[Doc]

I'd just say no :lol:

[Akai oni]

I'd just say no :lol:

Perosnaly i think it would be worth it, prolly help create less parasitic drag on the motor to free up some already existing power...

[Doc]

I can give you 5whp other ways....;)

[Doc]

much cheaper too

[Akai oni]

much cheaper too

What ways would those be?

im not just looking at the 5whp number, but the long term bennefits of having less parasitic drag, also, like i mentioned before... wouldn't the gains increase with a smaller pulley size and other mods?

[Doc]

a drop in air filter

[Akai oni]

a drop in air filter

LOL... im guessing this is the attitude that keeps people from making 300whp+ on the stock blower...

I already have a CAI... im looking for somthing to help with the parasitic drag.

[MGM1979]

LOL... im guessing this is the attitude that keeps people from making 300whp+ on the stock blower...

I already have a CAI... im looking for somthing to help with the parasitic drag.


umm...no, this is the attitude of realistic expectations - the cars using underdrive pulleys are already in the 3-4-500 hp range, so they have A LOT more to gain/lose with such a mod...sitting at trying to get to 300, Doc's saying it's just not worth it - think about the hassle involved, as well. Are you pulling the motor anytime soon? I'm doubting the pulley can be changed without that work...

But hey, if you're so inclined - I don't think he's saying DON'T do it...:shrug:

[Doc]

exactly...its more of a pain in the ass to change the pulley than its worth.
If you want something cheap you can do on your own, match the inlet of your supercharger to your throttle body. Don't screw with the V only the inlet.
A cobra heat exchanger is another cheap mod. If you know how to weld aluminum, I'd suggest making your endplate a dual pass.

[Akai oni]

exactly...its more of a pain in the ass to change the pulley than its worth.
If you want something cheap you can do on your own, match the inlet of your supercharger to your throttle body. Don't screw with the V only the inlet.
A cobra heat exchanger is another cheap mod. If you know how to weld aluminum, I'd suggest making your endplate a dual pass.

Ahhh... i see, i just figured getting lighter weight pullies would help the parasitic drag on the motor...

Im thinkin about buying the dual pass from ZZP... $129 isn't much to spend for that mod... i have a Cobra Heat Exchanger waiting for me to pick up in denver for $50... if i install it tho i want it done right and not with some tacky ass angle iron b/s or plastic legs off of a lawn chair like alot of people are doing... i would most likely order the bwoody brackets but between those and the H/E, wouldn't it be much better to get the dual pass first? then get the H/E?

what kind of gains do you see from port matching the S/C to the TB? i was just thinking about pickin up a LS4 TB with the spacer rather than porting the stock parts... granted it costs more but the LS4 TB made 14whp without tuning... i doubt that port matching the S/C to the TB would yield that kind of gain. then again it's free to do and wouldn't hurt untill i get my LS4 TB... Speaking of which... anyone know where i can find one for like $50?

[Doc]

It doesn't matter which order they are done, they will both help. I have B-Woody brackets and I love them.
I don't remember the gains for port matching but it can't hurt :lol:
I have a LS4 TB coming as well, with the 3" piping too. I think you can find them in junkyards, I might have posted it over here, if not, I did on the shortbus.

[Akai oni]

It doesn't matter which order they are done, they will both help. I have B-Woody brackets and I love them.
I don't remember the gains for port matching but it can't hurt :lol:
I have a LS4 TB coming as well, with the 3" piping too. I think you can find them in junkyards, I might have posted it over here, if not, I did on the shortbus.

Ill have to check out some of the local junk yards then... i already have the 3" CAI...

[Cat Ion]

exactly...its more of a pain in the ass to change the pulley than its worth.
If you want something cheap you can do on your own, match the inlet of your supercharger to your throttle body. Don't screw with the V only the inlet.
A cobra heat exchanger is another cheap mod. If you know how to weld aluminum, I'd suggest making your endplate a dual pass.

Can someone esplane the dual pass endplate? I've heard of it. Just not sure what it entails to do it let alone where it goes.

Also I can't find any literature on how to port match the inlet like you mentioned. I'm good at learning new things, so if I had some reference on how to do that, I'd be willing to tackle something like that.

[Doc]

Basically you change the routing of the system. Stock it goes in once and out once. Changing to the dual pass, it goes in once and exits at the top and bottom.

[Cat Ion]

Basically you change the routing of the system. Stock it goes in once and out once. Changing to the dual pass, it goes in once and exits at the top and bottom.

Is this major surgery or simple outpatient surgery with the right parts and tools? I've never done any disassembly on this motor yet. Also elaborate on the inlet port matching if you can, please. I fully understand the logic behind inlet/intake/exhaust port matching but what is the process to knowing how much material to take off and what tools are recommended for doing this?

[Akai oni]

Is this major surgery or simple outpatient surgery with the right parts and tools? I've never done any disassembly on this motor yet. Also elaborate on the inlet port matching if you can, please. I fully understand the logic behind inlet/intake/exhaust port matching but what is the process to knowing how much material to take off and what tools are recommended for doing this?

Yeah... What he said^

[Doc]

Let me look into the port matching.

Simple outpatient surgery for swapping the endplate. There are, I think, 8 bolts that hold the intake manifold on, one of those being a PITA to get to if you don't know about it.

[MGM1979]

yeah, the hardest part about the endplate is pulling the mani - that one bolt under the alternator is retarded.

Once it's out, nothing more than swapping the endplate and reversing two of the cores.

[Cat Ion]

yeah, the hardest part about the endplate is pulling the mani - that one bolt under the alternator is retarded.

Once it's out, nothing more than swapping the endplate and reversing two of the cores.

This said endplate is sold somewhere? What about plumbing? Does the hose routing need to be modified for flow direction?

[Doc]

ZZP sells a dual pass endplate
yes, hose routing needs to be changed...

[csementuh]

I do recommend the ZZP Dual Pass. I installed it a few months ago and it is working great. They even give you the "T" fitting that is need. The only thing you need is 3/4" heater hose and coolant.

But back on track, I to agree that $350 is a lot for 5hp...

[rlinbatonrouge]

These people made the heat shield.

Why would you consider buying anything from them?

I think I've been gone for too long.....

Read the quote in the pic of my sig.

[thoraldshib]

I agree with most the other ppl, I believe it there are many more cost efficient ways to increase that amount of horsepower.

[burntorange]

I agree with most the other ppl, I believe it there are many more cost efficient ways to increase that amount of horsepower.



Good thing I am not worried about cost effective lol

[Tinkles]

Just some info to toss in this post.

A set of lightweight pulley's wouldn't hurt, but an under drive pulley will slow down the S/C and reduce the PSI.


Also JBP are scammers.

[1BadSVT]

Go very small