FLYWHEEL is it dual mass or not?

[Blameless]

How did the clutch/flywheel swap go??? I'm dying to know what your impressions are???

[black318i]

I went with a SMFW and an Exedy stage 1. I didn't notice much of a difference with smoothness, or performance (acceleration) and nothing as far as noise. I personally prefer the SMFW.

[define]

SMFW is less expensive. That's the only reason to use it - if you are looking for an OEM setup, that is. I noticed no perceptible change in pedal feel, engagement or fuel economy when I swapped in the SMFW 10k miles ago. I did notice it is a bit louder, but quickly just fades into the road/wind noise as the car picks up speed.

 

AND they weigh a heap more, like around 8KG MORE. Which slows your car down when accelerating.

 

Both flywheels are heavy as #%^!, but I have trouble believing the DM was almost 18lbs (yes, I'm an imperial bastard) heavier.

[LegacyDan]

I replaced my stock clutch and dual mass flywheel in my jdm Legacy with an Exedy kit with a single mass flywheel when it died on me. So much better clutch pedal feel over standard and a lot cheaper than local Subaru dealer wanted for the clutch alone. It actually came from Exedy in New Zealand aswell!

 

Also have the Teins on Bilsteins on mine. A lot firmer than standard springs, i think those plastic sleeves have moved on me too as there is a bit of knocking sound coming from the rear when i go over speed ramps too quickly

[black318i]

Both flywheels are heavy as #%^!, but I have trouble believing the DM was almost 18lbs (yes, I'm an imperial bastard) heavier.

 

I didn't weigh my flywheels, but I can say after handling both there is nowhere near a 18lb difference between the two. Someone here weighed DMFW clutch and PP and a SMFW clutch and PP and it was just under a 5lb difference.

[B-BGTLimited]

flywheel to flywheel there may be that much of a difference, but whole assy may only varry by 5lbs... I'm not sure how much changes between the disc and PP for the two flywheels.

[Blameless]

Ah sorry I was assuming people would put light weight flywheels in with the swap out. I know I sure would! SMFW it is for me, just gotta wait till I got a bit more coin first ;-)

[SBT]

LWFW too hard to much "fuss" to drive daily. You get used to it, but you just have to shift into a lower gear more often, where previously you just kept moving.

[NZGT]

I cancelled my new SMFW clutch setup. Decided there is too much to do to my car to bring it up to a standard I would be happy with, so I'm going to drive it for another year as it is then upgrade to a newer car

[Blameless]

LWFW too hard to much "fuss" to drive daily. You get used to it, but you just have to shift into a lower gear more often, where previously you just kept moving.

 

I just dont get this sorry???

 

I have built a WRX race car and had lighter flywheels on all my rides (all subaru's) but didnt have to change down "more often" to keep moving. The car doesnt loose power when you lighten something in the drive train... all that happens is it allows the flywheel to speed up more quickly (not more slowly) basic physics.

[SBT]

^Mass in motion will stay in motion until reacted upon by an equal or greater force. The more mass, the more energy it carries while in motion.

 

I've driven a LWFW LGT (lightest) and a SMFW (heavier) and a DMFW (heaviest) and by far the easiest to drive "slower" in a higher gear is the DMFW. Reason, the DMFW carries more energy and will keep the drivetrain "turning" when the SMFW and especially the LWFW, will have given up it's energy. I noticed this immediately when I stepped down to a WRX SMFW on my LGT, that I had to downshift to keep the car moving at a given speed on a surface street or I'd lug the engine. And, even more so with a LWFW - the DMFW would not lug, nor require a downshift.

 

Granted, the LWFW will spin up much quicker, but it will also slow down much quicker too. Not requiring as much input to overcome the inertia of a heavier FW, nor having to release energy stored in a heavier FW has it's advantages, i.e., on a track, but I restate my previous comment, a DMFW is easier to drive as a daily driver.

 

And did you reduce the weight of your WRX race cars? That might very well offset the mass reductions at the crank

[B-BGTLimited]

but I restate my previous comment, a DMFW is easier to drive as a daily driver.

 

I think this is only true for some, unless they changed something else in 07 to make this issue you speak of no longer an issue. (only thing that comes to mind is the VF40/VF46 change but I don't think that should matter much) With the 07+ coming factory with the SMFW then they found some benefit to using it again over the DMFW... Not sure what it is or if you could ever get a straight answer as to why they switched back, but they did, and I have no issues driving my car daily. As for the LWFW yes, that will make daily driving a bit more of a bear for the reasons described above. I hear that from people who switched to a LWFW on other cars as well.

[rtbrjason]

I mentioned this in another thread but, I went with the HDSS Clutch and Streetlight flywheel in my Spec B. At first I was regretting it, but between breaking it in, getting used to it, and upping my requested torque tables a bit, it is no longer any harder to drive than it was stock.

 

FWIW the flywheel that came out of my Spec B was about 28lbs and the Streetlight is around 15lbs.

[SBT]

I think this is only true for some, unless they changed something else in 07 to make this issue you speak of no longer an issue. (only thing that comes to mind is the VF40/VF46 change but I don't think that should matter much) With the 07+ coming factory with the SMFW then they found some benefit to using it again over the DMFW... Not sure what it is or if you could ever get a straight answer as to why they switched back, but they did, and I have no issues driving my car daily. As for the LWFW yes, that will make daily driving a bit more of a bear for the reasons described above. I hear that from people who switched to a LWFW on other cars as well.

 

ISTR that they changed gearing too. That would explain some of the dynamic changes. Also, I'm running a VF46 on my 05, originally tuned with the DMFW / stock setup. Should I change something about the tune tables to compensate for the lighter setup?

[Blameless]

^Mass in motion will stay in motion until reacted upon by an equal or greater force. The more mass, the more energy it carries while in motion.

 

My cars were all street and not lightened (except my coupe racer)

 

As for your comment above...

 

scenario 1) your going up a hill and you are in to high a gear where the load/friction/gravity is sufficient to overcome your engine power. In that scenario you will be forced to change down a gear more quickly than with a heavy flywheel. (But in real life this means you are only delaying the inevitable down shift by a few seconds with a weighty disc)

 

Scenario 2) Your going up a hill and you are a capable driver who has chosen the correct gear where the load/fiction/gravity is INSUFFICIENT to overcome your engine power. In that scenario you will be accelerating up the hill faster than with a heavy flywheel.

 

Ultimately the lighter flywheel is only going to cause you to shift down if you are a lazy driver that is in the incorrect gear for the task in the first place.

[SBT]

I've driven every kind of manual transmission in countless vehicles, in nearly every imagineable environment for the past, 45+ years, so I've learned and trained myself to gauge load "changes" on the drivetrain and to anticipatorily shift up and down accordingly. My point above was that, no matter what the load, or driving condition, you'd always have to shift down sooner and likely shift up later with a LWFW...which bears out in my experience with my "lighter" WRX SMFW, and in your scenarios above.

 

FWIW I was referring to driving at a steady state on a reasonably level surface street. But, to your point in scenario 1, a normal driver would have been monitoring speed, load and anticipated the need to downshift, unfortunately sooner in a LWFW-equipped vehicle versus later if at all in a heavier FW-equipped vehicle.

 

In your second scenario, a heavier flywheel would enable the capable driver, to increase fuel slightly to load energy into the FW and crest the hill without downshifting or lugging the engine and thus maintaining a steady state. Something that a capable driver would not be able to do in a LWFW-equipped vehicle, who would have had to downshift to maintain stead state.

[Blameless]

I've driven every kind of manual transmission in countless vehicles, in nearly every imagineable environment for the past, 45+ years, so I've learned and trained myself to gauge load "changes" on the drivetrain and to anticipatorily shift up and down accordingly. My point above was that, no matter what the load, or driving condition, you'd always have to shift down sooner and likely shift up later with a LWFW...which bears out in my experience with my "lighter" WRX SMFW, and in your scenarios above.

 

FWIW I was referring to driving at a steady state on a reasonably level surface street. But, to your point in scenario 1, a normal driver would have been monitoring speed, load and anticipated the need to downshift, unfortunately sooner in a LWFW-equipped vehicle versus later if at all in a heavier FW-equipped vehicle.

 

In your second scenario, a heavier flywheel would enable the capable driver, to increase fuel slightly to load energy into the FW and crest the hill without downshifting or lugging the engine and thus maintaining a steady state. Something that a capable driver would not be able to do in a LWFW-equipped vehicle, who would have had to downshift to maintain stead state.

 

Alrighty then old timer.

 

I'll leave you to cruise in peace with your heavy flywheel while you berate us assumed younger drivers for our supple speedy arms that have to change gear slightly more often

 

While I enjoy the enhanced performance of a light weight SMF you will be slowly inching your way over the cusp of a hill, commenting to whoever will listen to you about the fuel saving benefits of being old and lazy. Hehehe...

 

Please dont take offense I'm just trying to be funny. We obviously have different driving interests.

[SBT]

^ It's all good - knew where you were coming from...

[Blameless]

^^^ me too! I had to postpone it till next week due to work commitments this week

 

So is it in????!!!!! Keen to hear how it went???

[NZGT]

I cancelled it, look at my post end of page 4

[SBT]

^ I only have two pages... you must have your page limit set at a lesser figure in your settings. Will try to spiral backwards and see what I come up with.

[NZGT]

Sorry, post #59

 

I always wondered why my pages were so short!

 

EDIT - it was set to use forum default, now I have it on 40 posts per page which is much better, thanks