dragon993

Has anyone installed this on their 987.2 and which options have they gone with and how does everyone like them?

Stock flywheel weighs 11.5kg or 25lbs.

So far I've found 3 brands.

1) Aasco. American. Has a few options, the more hardcore ones prefer to replace the with a Sachs sports clutch as well. Machined from 6061-T6 aluminum. Doesn't give exact weight but assume the three types below are decreasing in weight with the *425 being the lightest.

http://www.aascomotorsports.com/admi...456be5e741.pdf

106422-12 -- looks like a stock replacement, can bolt to stock clutch & pressure placeSTEEL OEM pressure plate.
OE or Sachs pressure plate 883082_000884106423-12* -- uprated lightweight clutch, to be used with SACHS sports clutch only, uses OE type release bearingSachs pressure plate: 883082_999736
Sachs friction plate: 881861_000017
Release bearing: OE type106425-12* -- uprated lightweight clutch, to be used with SACHS sports clutch only, uses an Aasco bearing that's suppliedSachs pressure plate: 883082_999736
Sachs friction plate: 881861_999856
Release bearing: Aasco type (supplied)

2) Cargraphics - does not have a lot of specs or descriptions. Also says its 6061-T6 aluminium. If I was guessing it seems like the similar spec as the 106422 Aasco one as it also says it can use all the stock pressure plates etc so no need to have upgraded ancillaries.

https://www.cargraphicts.com/en/prod...s/porsche/987/


3) FVD - spec says 7.8kg or ~18lbs. - Black in color and also bolts to OEM components.

https://www.fvd.net/us-en/FVD1140120...kg-171lbs.html


would appreciate any information whatsoever as I can't find much indepth reviews of who's tried one.

Has anyone done a lightweight flywheel with negative feedback?

Thanks in advanced.

MidEngineRules

Well since there are no responses... I've done lightweight flywheels in Ducatis. Turns your throttle into a light switch. Definitely more throttle response but equally will make rpms decrease much faster when you take your foot off the pedal. The lighter, the more the effect. Personally I wouldn't do this for a street car unless 1) it's a marginal difference in weight, and 2) I was already having to replace the clutch or something else requiring disassembly to get to it.

DasCayman

I did a review on it here:

harveyf

Research past threads here on Rennlist.
There is documented risk from any non stock flywheel of damage to the drive train due to undampened vibrations.

KrisA

While I don't doubt this is true, I'm curious how Porsche solves this from the factory? Porsche has sold LW single mass flywheel cars, the 911 R and S/T models. Do they just assume that nobody will actually drive them?

I hate the lazy feeling of the engine in my car. Going to tune it this year to see if that makes it appreciably better. If it's still dull feeling I'm feeling like rolling the dice on a sing mass flywheel.

DasCayman

I spoke with several Porsche racing tuning shops and they said that there is no need to add a harmonically damped pulley to my application. Even if I wanted to, no one makes one. I can't offer any guarantees, but my Spyder drives amazing with the LWFH and I don't feel and resonant vibrations. Additionally, a certain RPM would trigger this destructive vibration event known as the "critical speed" of the crankshaft. The thing is, you'd have to be hanging out at that one speed / frequency for an extended period of time to start causing damage to the bearings. To reverse engineer this, you'd need to know the resonant frequency / natural frequency of the crank shaft ω_n.

My advice is to call whoever makes your LWFW and ask them what engineering analysis has been done and if they have determined what RPM range to stay out of for your car and application. In the meantime, don't lug your engine and make sure you don't shock the drivetrain with bad shifting not rev matching.

HP Academy does a video on harmonic balancers and they specifically say that Porsche is the only manufacturer that doesn't need them since the engines come "perfectly" balanced from the factory.

Additionally, any eccentric installation of the flywheel or clutch would significantly increase the harmful effects of crankshaft vibrations and failure. The more off-set the disc, the greater the vibration / harmonic problem you'd have. So I'd wonder if this played a part on these engine failures... poor installation. But we will never know.

harveyf

@DasCayman You probably also know that when you take the damping term out of the equation, the forces go to infinity at the critical speed.
Do we really expect that Porsche, who doesn't readily release any engineering data on their engines, to come forward with the critical frequency?
I think special flywheels are fine for race engines, which have a service life measured in hours, not years. But if you want your street driven car to last 100K miles, I would just be prudent and avoid them.

BTW, I think we tend to lump "perfectly balanced" in with the inherent torsional firing pulses, which cannot be "balanced out" but can be dampened. Ergo the stock dual mass flywheel.

Arione

I had the aasco on my 987.1. We used the sachs/ ZF racing sprung clutch and had no issues for 40k miles before I sold it, still going strong. https://www.fvd.net/us-en/FVD116941/...-material.html