How Light is Your Flywheel+Clutch?
 

Samc asked how much the new Aasco lightweight flywheel tipped the scales at and how it compared to the stock weights, this should offer a comparison:

Lightweight Flywheel only - 13.0 lbs.
Lightweight Flywheel + New Sachs Clutch Assembly - 25.4 lbs. *
Stock Dual Mass Flywheel only - 26.5 lbs.
Stock Dual Mass Flywheel only + New Sachs Clutch Assembly - 38.8 lbs.
Lightweight Flywheel + New Sachs 4 Spring Clutch Assembly - 18.0 lbs. **

All I know is the stock FW and clutch were HEAVY! And my engine has to spin that up. Whereas, the LWFW and clutch…I had to check to make sure the clutch was in there! 13.4* to 20** pounds LESS may not seem like a lot, unless you're the engine! One went CLUNK on the scale and the other made a slight noise. I was even able to control it better!

The total weight for the 4 spring clutch AND housing, Throwout bearing, and spacers is only 6 pounds! And that is shipping weight! The 4 spring ZF Sachs clutch is for sale right now for only $357 - shipped! PM me for details.

So maybe you can have the BEST of BOTH worlds…AND the price is right!

Lighter is better AND the Aasco LWFW offers the ability to resurface (for around $100) instead of replacement, which is good. Anyone want an old flywheel?

Funny how all the HEAVY stuff ends up in my garage - now I have a couple boat anchors - flywheel & stock muffler. Now all I have to do is get my car back together and I'll let you know how it goes!

It will interesting to see how you like it once you drive it ?

Do you have a link to the clutch you're using? It doesn't sound very "street friendly".

Just be careful you don't end up with another "boat anchor, your engine:

http://www.flat6innovations.com/imag...s/dscf4881.jpg http://www.flat6innovations.com/imag...s/dscf4880.jpg

This is out of a factory X51 engine that was switched to a lightweight flywheel, but without fully harmonically balancing the engine (the dual mass flywheel is the only harmonic dampener in the M96/97 engine).

OUCH! You sure KNOW how to hurt a guy!

Exactly why I went looking for a clutch with 4 springs, and to reduce the gear lash. Hopefully this will do it…at $357 - IF it works - it is a steal! And I will be driving it like it was stolen but that is a given.

Stephen, here is a link:

Brand New Genuine ZF Sachs Clutch Kit for Porsche Boxster S | eBay

JD, I will interested in JUST DRIVING it once it is off my garage floor!

Its not the engagement of the clutch (I assume this is the gear lash you are referring to) you should be concerned with.

The dual-mass flywheel is the only balancing device these engines utilize. With out removing the crankshaft and having it sent to a specialty machine shop to be balanced, you risk the crank assembly vibrating apart at the weakest point (a journal and webbing joint).

That being said, these engines rev SOOO FAST with aluminum flywheels. I think you will enjoy the engine response a lot.

Skoot

I think you are mistaking drivability and clutch noise with torsional harmonics. These engines are not particularly well balanced internally, which is why Porsche uses such a heavy two piece flywheel, the elastomer section absorbs those harmonics. Without the dual mass, they are left to their own devices.

We have seen a couple of these failures, Jake has an entire section of his site devoted to them. Porsche even released a TSB about not using single mass flywheels on these engine's, regardless of their weight.

Just food for thought.................

I've had the Aasco lwfw and a Spec stage 3 plus sprung clutch in my car for 18,000 miles including 40+ autocross events. Street driving requires paying attention to things, but isn't that just part of the experience?

Just out of curiusety.
Is there anyone in the forum that runs with a LWFW for segnificant time?
Or suffered a catastrophic failier due to one?

Interesting response j.fro….what do mean by paying attention EXACTLY?

I know it will rev fast. Do you mean like doing a "rental car ram" thing? :eek:

The car now definitely needs to rev a bit more so that it doesn't stall, but I also don't want to launch like a top fuel dragster. When the car was stock, it didn't take nearly as much attention to just drive away "normally".

I've had the LWFW and Sachs sport clutch installed in my car for 33,000 miles and 50+ track days. No problems whatsoever. I'm not an expert, just relaying my personal experience.

And as always, your mileage may vary.

Some seem to get away with it for long periods, others not so much. That said, there have been enougn failures to warrant PCNA making mention of it.

Purely a matter of how risk tolerant you may be.

Any updates on this combination -- thinking about the pros/cons for a
drive to the track car.

Wonder how many of those crank failures were with the original non-sprung clutch?

Mike

I am up to about 62,000 miles and 94 track days and I am on the 2nd clutch (same LWFW) without a problem.

And as always, your mileage may vary.

Maybe I am lucky with clutches and unlucky with valve lifters. :)

The reason for the weight itself in the flywheel is the momentum. it keeps things constant. With a heavy weight flywheel it will tend to stay at its rpm when you let out the clutch. With a light weight flywheel, as soon as you let out the clutch there is no mass to keep the rpms where it was. Thus easier to stall a car with a light weight flywheel. This also allows the engine to change rpm quickly (like accelerating)

I wish someone would come out with a lightweight clutch replacement for the stock Sachs.

The new Cayman GT4 has a "lightweight dual mass flywheel".

Is your Sachs sport clutch spring loaded?

Which model?

I'm having the Ims done on my track S so I'm considering clutch options

Mike

Yes, the clutch disk is spring loaded.

Flywheel: AASCO Lightweight Flywheel PN 106412-11
Clutch disk: Sachs Performance Clutch PN 881861 000 017
Pressure Plate: Sachs Performance Sport Pressure Plate PN 88 3082 999 754

From our forum owner's website;
Pelican Parts.com - Lightweight Flywheels
Pelican Parts.com - Performance Clutches

Not sure if these parts will work on an S-model. Be sure to check before buying any parts!

So how about lightening the stock dual mass flywheel a couple pounds?