Flywheels

[Sekred]

OEM dual mass flywheel compared to TTV Racing single mass chrome-moly.


OEM, around 11kgs






TTV, 5.1kgs








Static movement shown, OEM flywheel. This is the movement in the flywheel halfs before any spring tension is felt.

 

[GAbOS]

Nice reduction in rotational mass!

 

[airjor13]

Very nice how does it feel?

 

[frankiefiesta]

Wanna hear about the results

 

[Sourskittle]

In for dis !!

 

[Ronbo]

I wonder how forgiving this flywheel is in traffic.

 

[Sekred]

Have not got it running again yet. Will let you guys know what my impression are when that happens.

 

[kjohn09e]

I want in on this.

 

[eleven]

Inbetween up shifts, I've noticed how heavy the stock flywheel is. I'm assuming that the 'rev hang' thing has been turned off on my application (Cobb OTS 93 octane Stage 3 tune) so it's got to be the flywheel, yeah?

 

[pelotonracer2]

In for more feedback. I had an aftermarket lightweight flywheel on my WRX and it really made a big difference!

 

[eleven]

In for more feedback. I had an aftermarket lightweight flywheel on my WRX and it really made a big difference!

I ran a teeny tiny dual disc clutch on my Miata. It revved up and down like a sport bike. It was bliss.

 

[Hypntick]

In for some results on this as well.

 

[Natedogg]

Dear God, a little over 24 lbs for OEM? Wow.

No wonder you can hear that thing clicking around in there with all that play.

With the OEM disc being unsprung, I can see the chatter getting much worse, but I had a 6 puck unsprung on one of my other cars and although it chattered, it was tolerable. I don't ride my clutch enough to really care. It will be interesting the hear the feedback on this SMF with the solid disc.

 

[TheGreenOne]

Won't a lighter flywheel affect torque, fuel economy, and the overall smoothness of the ride?

 

[Natedogg]

A SMF by nature will add more NVH. That's why all of the manufacturers switched to DMF. Even with a sprung disc, a SMF is more harsh, even if the difference is negligible. Being as our stock disc is unsprung, the switch to a SMF will add quite a bit of NVH when using the clutch, but I doubt you would feel it any other time. Maybe a little at idle because of the lack of rotating mass.

The gas mileage change would most likely be negligible as well, unless you enjoy the loss of rotating mass a little too much. The flywheel by itself won't make much difference unless you're a hyper miler and you see a dip in mileage. If you're a hyper miler though, you probably don't care about swapping to a SMF anyway.

There is no torque loss when installing a lightened flywheel. It's a seat of the pants thing because with a lightened flywheel, the torque builds up quicker and holds steady, therefore giving the driver the feel of a "lack of torque" because they don't feel that steady buildup. It happens so fast with a lighter flywheel and is so instant, you get the full effect right away. Keep in mind, we have a DMF and the springs compress as torque builds, lengthening that feeling of torque building.

Hope that makes sense and doesn't sound back asswards from what I'm trying to say.

 

[TheGreenOne]

A SMF by nature will add more NVH. That's why all of the manufacturers switched to DMF. Even with a sprung disc, a SMF is more harsh, even if the difference is negligible. Being as our stock disc is unsprung, the switch to a SMF will add quite a bit of NVH when using the clutch, but I doubt you would feel it any other time. Maybe a little at idle because of the lack of rotating mass.

The gas mileage change would most likely be negligible as well, unless you enjoy the loss of rotating mass a little too much. The flywheel by itself won't make much difference unless you're a hyper miler and you see a dip in mileage. If you're a hyper miler though, you probably don't care about swapping to a SMF anyway.

There is no torque loss when installing a lightened flywheel. It's a seat of the pants thing because with a lightened flywheel, the torque builds up quicker and holds steady, therefore giving the driver the feel of a "lack of torque" because they don't feel that steady buildup. It happens so fast with a lighter flywheel and is so instant, you get the full effect right away. Keep in mind, we have a DMF and the springs compress as torque builds, lengthening that feeling of torque building.

Hope that makes sense and doesn't sound back asswards from what I'm trying to say.

Thank you. I was under the impression that removing that much rotating mass from a flywheel would mean that you would constantly have to be on the gas to maintain the same RPM as before. I.e. when you let off on the stock flywheel, it'll continue to rotate at that RPM for much longer than a lower mass flywheel, so when you get back on the gas, there's less throttle needed to accelerate. That would be where fuel economy and ride comfort take the biggest hit.

 

[rodmoe]

Being as I have had my Lightweight Flywheel for all summer I can say that when i do take it out around town it is really no different than the heavy factory unit for drivability. My milage clutch release and NHV all were a non issue for me as it was not much different than stock. I will say I never drove it with the stock turbo as it went in with the big turbo upgrade and to me that was a little bit of a learning curve with less spool as early but nothing I could not live with. IF I recall the Spec Unit i have took off about the same weight from 24ish to 10ish lbs and pedal feel is the same and grab and release felt the same.. Hope yours works out as good.. Nice looking unit all steel where as the one I have is Aluminum with a steel friction face on the clutch disk area.
In for the Good results too Im sure you will find bliss also ..

 

[Sekred]

I ran a light flywheel on my 99 WRX, it was 3.5kgs if I remember correctly so I have a fair idea what to expect. The benefits were faster response, both rise and fall in the rpm.
Negatives were it stalled easier so you needed a few more revs to get it off the line. The only time I had a serious problem was exiting a underground car park when I was staying at this apartment complex for a few days. It had a very steep ramp leading to the street. I had to stop near the top to wait for the auto gate to open. Getting the car moving with a full load of passengers and luggage was a real struggle. I need least 3500 rpms to get the car to move without stalling and smoked the clutch a couple of times as well as stalling it.

I wouldn't recommend this mod as a daily driver with your family. Having to negotiate heavy traffic and steep grades won't be much fun.

Also, converting from a dual mass flywheel to a single mass, I would definitely not use a solid disc friction plate. I know there are a few clutch suppliers who may say this is ok but you risk damage to the transmission in my opinion. The springs in the friction plate or a dual mass flywheel for that matter, are there to absorb torsional vibration produce by the engine crankshaft.

 

[rodmoe]

I need least 3500 rpms to get the car to move without stalling and smoked the clutch a couple of times as well as stalling it.

LOL this reminds me of most any Honda I have owned.. not bashing just saying they needed to have the clutch soft pedaled sometimes to start on a incline ..

 

[Natedogg]

What you guys are describing is what I hear a lot with the really light flywheels (7.5 lbs or less). I had an 11 lb flywheel on one of my cars and it wasn't any less drivable than it was at the OEM 17 lbs, the RPMs just dropped faster if you weren't quick to shift.
[MENTION=3220]TheGreenOne[/MENTION], you are correct, the RPMs will drop faster because of the lower rotating mass, but only when you push the clutch in. When you're coasting in gear, you don't notice it because it's the forward momentum of the car in relation to the many points of drag (friction) on the car that keeps you coasting, not the rotating mass of the engine (as much). I didn't even notice the difference when coasting in my other 2400 lb car when I went from 17 lbs to 11 lbs.