Let's Talk LW Flywheels Vs Pulleys

[SubyFusion]

What one give more performance? Is it better to go for light weight Pulleys and leave the stock flywheel? or go for a lightweight flywheel and leave the pulleys stock?

Brian

[speedmaxx]

I installed the Perrin light weight pully, it's a noticeable difference, the rpms defiantly climb quick. I'm not sure how a lw flywheel would compare cause my cars a 4'eat

[SubyFusion]

From what I read you either have to one or the other, correct me if i'm wrong lol so my thoughts were ya the lightweight flywheel looks cool but when its installed whose going to see it right, so I figure get the pulleys because they look awesome, and who isn't going to see them when you have your hood up! but I want to know what makes a bigger difference in performance flywheel or pulleys? because if the flywheel is better you can always just paint those old pulleys

[gijonas]

The one gripe i have with LW flywheels is the fact that they are light

Im really not able to accept that it is really better to have your engine be able to "rev quicker" at the expense of removing rotational weight.It seems to me that for a daily driver it would be far better to keep a flywheel that maintains momentum and is harder to stop or slow down.

Imagine a flywheel that weighs 400 punds,you could still burn all 4 even after you turned the engine off

[jefferson]

I found out when I rebuilt my tranny that I had a flywheel that was lighter than stock. It was right around 18lbs. It was in the car when I bought it so can't comment on what it did for the car, but I do feel that the car revs pretty quick when you blip the throttle. I installed an unorthodox underdrive crank pulley and really like what it did for the car. I have both and love the way the car drives and performs.

[kimokalihi]

I have a 9 lb flywheel on my car and it's great. I drove it daily for a while and I love it. Didn't effect driveability or anything. Felt just right.

[Mattheww044]

I was under the impression that you can have a LW flywheel AND pulley, but not an underdrive pulley and LW flywheel. Is this correct?

[jefferson]

I have both on my car and I can see no reason not to. It has been at least a couple of years since doing the underdrive pulley and while my flywheel is not one of the really light ones, it is about 8 lbs. lighter than stock. You will get more results from an underdrive pulley over just a light one.

Jeff

[SubyFusion]

Kimo what brand flywheel do you have the lightest I could find was like 11 and 12lbs!

[Legacy777]

There's really nothing saying you can not have one or the other or even both. However, I do have some comments about them, and suggestions.

Regarding the flywheel, the LW flywheels do improve how quickly the engine revs. I personally feel that the LW flywheels sacrafice a little bit of drivability. It may not be a big deal to some, but on a daily driver in traffic especially, it may not be desirable. I've also found that it takes a little more concentration to drive it smoothly vs. a stock weight flywheel. This is due to the engine revs dropping more quickly. I've got an Exedy WRX LW flywheel, it's 14lbs.

Regarding the pullies, I've used all three types of pullies: stock, LW, and LW under driven. The main issue about the under drive pulley is the fact it decreases the rpm of the alternator and power steering pump at idle. This is more of an annoyance, but might lead to possible issues due to lower voltages at idle and lower PS pump pressures. When I went to a standard sized LW crank pulley from my underdriven LW pulley, I really didn't notice much of a difference. I swapped due to the issues with the alternator. I just got tired of it.

Now the caveat to pullies is that the stock pulley is also a damper. There is a rubber ring between the inner and outer pulley. I have heard of issues on WRX's & STi's that swapped out the stock pulley to a LW pulley. There was a resonance or something going on mid rpms where the crank sensor would pick up noise and cause hesitation. In doing a little more homework, the generally accepted internet lore is to use the stock pulley if you are making decent power 200-250+ range.

The other side of this is that with the more power you make, the less noticable the changes in pullies are. So with that being the case, if you are making decent power, I'd probably suggest sticking with the stock pulley with the damper built in.

FWIW, I'm running the stock pulley.

[gijonas]

^ this.

[kimokalihi]

Kimo what brand flywheel do you have the lightest I could find was like 11 and 12lbs!

It's a clutchmasters WRX flywheel.

[oskar_subaru]

The one gripe i have with LW flywheels is the fact that they are light

Im really not able to accept that it is really better to have your engine be able to "rev quicker" at the expense of removing rotational weight.It seems to me that for a daily driver it would be far better to keep a flywheel that maintains momentum and is harder to stop or slow down.

Imagine a flywheel that weighs 400 punds,you could still burn all 4 even after you turned the engine off

or flip your car over