legacycentral bbs

I've heard lightened and/or underdriven pulleys make quite an
improvement on our cars.
-Does the improvement come mostly from the crank pully or all of them?

-Any reason to not get underdriven ones?
-Could I use pulleys meant for a '02 WRX since its also a EJ motor?

Thanks!

pulleys underpower your alternator, ac, and everything
else running on a pulley.

this means if you crank the radio the headlights dim,
and if you draw too much power (radio and headlights
and a weak battery) you could draw more than the
alternator produces and wind up with a dead battery.
your ac wont be as cold, and who knows how it affects
your fuel, water, and oil pump, you could potentially
overheat, though thats less of a risk. You could
shorten the life of the engine too.

pulleys give better mpg, accel, and reduce the wear on
those spinning accessories slightly. its a trade-off.

if you wanna tinker with your pulleys, id disconnect
the ac pulley first. You dont run any risk, and while
the ac wont work, you can always slip it back on when
it gets hot. Beyond that, be careful and talk to
someone with more experience with legacies and pulleys
than me

scott b

Josh Milne <totalperformance@mrjosh43.com> has just made a batch of
lightened, but not underdriven pulleys. As far as I know, he's got
them in black, blue, and red. Now, these are STOCK SIZE, meaning
they will not cause the previously stated underpowering of your
electrical system like the UR pulley and the like, but they are
still substantially lighter, weighing in at a mere 1.2lbs compared
to the 5lb. stocker. Mine has been ordered, and I'm awaiting
delivery, should be here this week. Josh told me he was gonna be on
vacation this week, so if he doesn't promptly reply, that's why.

I paid $130 shipped, but I think the price may have gone to $150,
not sure, still better than the price for the UR pulley.

If you really want to notice the difference, get a whole lightened
pulley set, or rip out your A/C like I did... one less pulley to
deal with!

-mike

The a/c uses some sort of magnetic clutch to engage so when your a/c
is not running then the pulley is just freewheeling, I would guess
you saw very very little gains by removing your a/c.
Noah

Just did the GFB kit for a WRX on my car last week witht he t-belt and water pump change...ncie gains across the rev range.

Next week goes the intercooler, turbo, HKS downpipe and custom cat back section 92.5 inches) to a Tanabe universal Hyper Medallion muffler

Adam
Z-1 Performance

Nice, this is the feedback I was looking for. Sounds like pullies for
the EJ engines are all the same. I may look into this soon.

Sounds like you've planned a similar upgrade path to what I'm thinking.
I've already got the 02 wrx intercooler, the fit is going to be really
tight though. AC line will have to be moved as will the coolant tank.
Let me know what you're thoughts are on the intercooler install.
-T

well I think I am going to now do a turbo and IC from a '95 STi RA we have coming in...seems to be a much more straightforward swap than '02 stuff

Adam
Z-1 Performance

That is true, Noah, I didn't see much in the way of performance gains
when I removed the A/C, but I removed it for other purposes... my
crazy a/w intercooler setup (to be continued). But really, the
pulley itself on the A/c compressor has a lot of rotational mass,
just spinning it in my hand. I don't know how much exactly, but it
seems pretty heavy. So, although gains were not specifically
noticable, since I did install my AVC-r at the same time, I would bet
that revs are a little quicker under no load (clutch to the floor) as
they would be under the influence of a lightened crank pully. It's
true that it takes very little effort to keep spinning the ball
bearing compressor pulley, but that is not the issue. The real issue
it the force it takes to change the ROTATIONAL SPEED of that pulley,
which, for a heavy pulley, can require a bit of force.

This is why lightened pulleys have more influence on revs and
throttle response than on horsies.

-Mike

Pulleys can help.

The main increase is from a reduction of rotation mass on the crank. Underdriving may help a tad...but not that much.

You can get a pulley kit.....it would probably help. I have just an underdrive pulley on the crank, and noticed quicker revs.

Some of the issues scott brought up.....are sometimes there....but not always. Underdriving can cause lights to dim and such, but not always. The legacy electrical systems are better then the imprezas. I have NO....ZERO dimming with my setup, and I've got a 600 watt stereo system.

I'm not saying it can't happen....but I haven't had any issues.