Flywheel confusion and questions

[RJS5689]

My head is spinning with facts and numbers from STI transmission parts and Spec.B transmission parts. I want to make sure I have all of my information correct before I decide to place any orders.

 

I realize I can use the same clutch and pressure plate that would fit an STI, but I learned that our flywheels are actually slightly different.. So far it looks like they are just different weights, but are both single-mass units according to this thread here. According to the Subaru factory service manual I have for the Legacy, it says that turbo models have a dual-mass flywheel, it does not differentiate between GT and SpecB, and Car101 lists it as a dual-mass also. Can anyone tell me for sure what the factory flywheel is? Anyway, I'm assuming I can also use any flywheel intended for the STI?

 

If that's the case, is it worth just going with a factory STI flywheel when I replace my clutch? Or could I have mine resurfaced because it is a single mass unit? I don't think I want to go with a lightweight flywheel, as I have read they're not really worth it in a daily driver. The STI flywheel would lighten things up just a little bit (I think), and also be about $200 less than an aftermarket lightweight unit. Any opinions?

[sirbOOm]

I got the STI flywheel installed when I had my clutch replaced. Previously, my clutch was way to m'fing heavy, especially since I find myself in traffic a lot (Chicago). This new flywheel/clutch combo has reduced the weight of my clutch to perfection. The clutch catches a lot differently though (i.e., fast and within a small window), which makes stop-and-go a little harder, but I expect that to smooth out just a little with (1) break-in and (2) getting used to it.

 

Personally, I believe the stock clutch/flywheel combo on the Legacy GT was a joke. It was ridiculously heavy and made it very hard to rev match, performance shift, and inch about in stop-and-go traffic (without having a tired left leg). I'm very happy with the change that this has made!

[mwiener2]

Dual Mass Flywheels are for 5MT only and I believe in 2007 they went to single mass anyways

[BAC5.2]

Heavy flywheels win drag races.

[sirbOOm]

Drivers win drag races.

[BAC5.2]

Heavy flywheels win drag races.

 

Fixed.

 

The best drivers in the world can't overcome physics.

[sirbOOm]

Fixed.

 

The best drivers in the world can't overcome physics.

 

Regardless, hot shot, I don't drag race. Neither does the majority of Subaru owners. I drive in traffic.

[m sprank]

It is a single mass. I have mine in a box in the garage now. I can take a pic if you want. Should be the same as an STi. The differnce is in the discs. STi has a slightly larger surface area than the SpecB. Both work fine (I use the STi disc). Subaru in their infinite wisdom decided to use a weaker clutch disc in the SpecB and save some cash. They figure the lower HP numbers between the STi and SpecB justify the change.

 

Otherwise disc, pressure plates, flywheels all are interchangeable. Just use your SpecB flywheel and an STI pressure plate.disc if you want. Also realize that for the STi there are different weight LWFW available. I use the ACT HD Xtreme preesure plate and street disc (STi) and the Streetlite Flywheel (14lbs-Sti). There are flywheels as light as 11 pounds available.

[BAC5.2]

Regardless, hot shot, I don't drag race. Neither does the majority of Subaru owners. I drive in traffic.

 

Then why would you contradict what I said?

 

Heavy flywheels help with all aspects of driving, except for making you feel like you are driving a race car. Heavy flywheels mean lower RPM launches from stop lights, and less legwork in traffic. They also mean less NVH, and less jerkiness at low-speed/low-throttle.

 

You lose the ability to pretend to be The Stig with lightning fast downshifts, but that's a small price to pay for most people.

 

The flywheel doesn't change how heavy the pedal is. The pressure plate does.