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SUPER-CHARGERS FOR FJ'S: Explanation w/ pics

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I want to verify this, supercharging my fj would not benefit me in mud ridding even though it would be nice to have the power to push the 35s
A TRD type supercharger requires higher RPM than a URD type in order to generate power to overcome the parasitic loss of the belt/gear and screw/fan it needs to spin, and to be able to compress enough air to give you good performance.

Short answer - probably not very much benefit. Read the centrifugal supercharger writeup below.

'Roots' supercharger (TRD)

Twin screw supercharger

Centrifugal supercharger (URD)

More supercharger information.

Basic - Supercharger Basics

Advanced - Part 1 - Superchargers A-Z (Part 1 of 3)

Advanced - Part 2 - Superchargers A-Z (Part 2 of 3)

Advanced - Part 3 - Superchargers A-Z (Part 3 of 3)

More info on centrifugal (URD type) supercharger - The Centrifugal Supercharger Explained

Superchargers (these days) are quite reliable and resilient.

There are a couple places where the type of supercharger needed for our off road activities would cause some problems.

A gear driven twin screw supercharger (Whipple for those of you who are familiar with them) would need some way to blow off back-pressure when you rev the engine to get out when stuck. The URD (and I presume TRD) one, since it is centrifugal and a fan type, will allow this pressure to flow back over the fan without a problem. As far as the engine goes, very high rpm is what causes problems and so no worries there.

I *might* suggest very closely logging your engine specs without the supercharger and seeing what kind of use you are putting your truck to. Then, after getting the supercharger installed I would see about getting a custom PCM tune made for it. (Note: URD might offer this I do not know.)

Check into an upgraded fuel rail. Not a lot of use to have more air in there if you can't feed in enough fuel.

ABSOLUTELY check into beefing up the following things:
transmission mounts
engine mounts

Optional but advised
As Air2Air mentioned, you probably want to upgrade the transmission itself
if you are using this for highway and more speed, brakes, BIGGER ONES!
spark plugs - I always advised getting a 1 range colder as you are pushing denser, colder air into the system and as such your combustion chamber temp will be a little lower, plus it helps a little to control any tendencies to pre-combustion. (this is a BAD THING*)
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