Hey guys, im pretty new to fordmods, a mate of mine hooked me up to this site, its quite sweet!

I own a BA XT with a few mods so far, i have begun the never ending road of modifying my ride. So far it has SS Inductions air intake, K&N panel air filter, pacemaker extractors, 2.5" exhaust, high flow cat and redback end with dual tips. Sounds throaty and mean and goes a whole heap harder than when it was stock. Ive also thrown on some 20" chrome Verde's to help out the aesthetics dept. Still plenty more work to go, lowering, brakes and plenty of engine work. I'll try posting a couple pics, hope it works, lemme kno what you all think!!

I have a question about aftermarket resized underdrive pulleys, they claim to reduce the amount of power used from the fan belt circle and free off Kw that would of been other wise used by the aircon etc etc. Claim between an increase of 7-14 KW. Is this really true? And whats the technical basis that it works on??

The technical basis is, as far as I understand, it uses a different harmonic balancer (I imagine it would be smaller and lighter) that basically gives less power to all your accessories i.e. air con, power steering, alternator, etc, but leaves enough to power them. The energy saved by not giving it to the acc has to go somewhere, and thats to the wheels! Im about to get one in a group buy on another forum for a great price, pm me if you want details! I wont say on here in case its against any rules

Ive seen dyno sheets where the rwkw have gone up by about 8-10 kW, and people have nothing but good things to say about them, and that they let your engine rev more freely.

there is a big thread in v8 workshop about the b.p.t. kits, might find some info in there.

All accessories are a parasitic loss to the engine power. The slower you turn your accessories (less effort required to turn them slower) the more power is available to the engine.

hey, just while on this subject, would having a smaller alternator wheel be bad for having a decent sound system ie. with subs?

You have a smaller crank pulley and larger accessorie pulleys.

No the under drives are still within safe operating limits for all accessories. It does pay however to have a good condition alternator other it may not be charging at idle in which case it would be bad for having a decent sound system with subs.

can you get the underdrive pulleys an s**t for e series 4 liters?

I wouldn't really bother.. yes you will get results which may or may not be noticable without a dyno, but I personally think they offer poor value for money. I'd rather put the money towards a diff ratio swap or even better a supercharger conversion.

well if the gains are about 10kw its not to bad, was just reading the thread in the v8 workshop and value for money is about the same as getting some extractors.

also found out that apparently the e series 6 cyl engines already have them, well close enough to them anyway