increased boost on JR super

[KingGreg86]

Is it possible to increase the boost on the JR super charger?
and if so what mods to the engine internals would i have to make to make it safe?

[danoonez]

I think you have to buy a different pulley to boost the ...uh boost...on superchargers. Bigger pulley=spinning faster=more boost. Of course I could always be way off. Anybody else know for sure?

EDIT:ignore this post and read down one for the right answer

[oldschoolimport]

a bigger crank pulley, or a smaller s/c pulley will increase the compressor speed. I would think that any pulley off an eaton s/c will work and there are lots of eaton equipped vehicles out there. for example the xterra and frontier have the same engine/supercharger but the xterra top pulley is a 2 psi increase for the frontier (slightly smaller). a little investigation of diameters seems in order. Benz, pontiac, I think jaguar, nissan, ford, all use some eatons.

[danoonez]

a smaller s/c pulley will increase the compressor speed

you sir are absolutely correct, and here's why

v=wr
where v=linear velocity; w=angular velocity (rotational velocity) and r=radius

v is the speed at which the belts are moving over the pulley so the rotational speed w=v/r. Since v is always the same, as r decreases, w increases, and vice versa. Sorry I didnt stop to think before i made my quick and wrong reply.

Good answer Mr. Oldschoolimport
:cool:


Yeah I love physics.:p

[02SilverSiHB]

I heard that the crv crank pulley is slightly larger and might be good for about 2lbs of boost max...I'd think you'd be okay with just 2lbs extra...over that, I wouldn't do it, no way to cool down that charger unless you do some crazy modifications

[Loudpedal]

If you're looking at changing the s/c pulley, you'd need to ensure that it is able to be removed. A buddy with a GTP was looking at reducing the size of the s/c pulley, however, you have to change the whole shaft attahment to the blower as the pulley is "pressed" into place rather than simply bolted on.

[02SilverSiHB]

Originally posted by Loudpedal
If you're looking at changing the s/c pulley, you'd need to ensure that it is able to be removed. A buddy with a GTP was looking at reducing the size of the s/c pulley, however, you have to change the whole shaft attahment to the blower as the pulley is "pressed" into place rather than simply bolted on.
yeap, it's a pain that's for sure.