For those that have installed the solid light weight flywheel can you describe the additional noise you get at idle? or any RPMS I suppose. It's my understanding the transmission sounds like marbles gurgling around in it. Is this heard from outside the car, inside or both?

Any noticeable change in driving the car, rpms wrapping up or perhaps clutch engagement or feel?

And lastly would you do it again over?

I'm installing a clutch in my car and trying to decide if its right for me or not?

Thanks
Malcolm

 

I did it, and would do it again. Noise is there but not that bad. Goes away if you depress the clutch.

 

What benefits did you see from it that you'd do it again? How loud is the noise?

 

faster revving. less "mass", but chatter is there. depends on how far over to the darkside you're taking your car vis a vis nvh + performance VS creature comfort quiet streetability + usually less performance.


by way of example, I'm rwd with a wavetrac LSD at 600 rwhp and a stock clutch with only a gt2 disc, and a new dmfw taken from that guy rogers car that blew up with paul walker


I've driven cars with both but opted for less chatter and mine revs enough with the fast spooling 16/24's etc so it's a choice thing. again, depends on your goals.


what type of clutch are you putting in?


wise move on that BBI slave delete btw

 

I agree less rotating mass will have a quicker RPM wrap up but I'm wondering if its enough of an effect to feel seat of the pants or something you'd only see on a race track when you get an edge on the car next to you?

How far do I want to take it? Well that's a tough one because I love performance. My 03 Cobra was at 700 whp, just wrapping up a new build on it that should be 1000 whp on E85. It's my obnoxious car lol. It's loud and raw. I rather enjoy the 911 been civil but I also want it fast. I just want it all don't I

Supposably my 911 is 650 hp from the prior owner but it felt more like 500 ~ 550 to me and others who see my sig and mods tend to agree that's about what it is. Immediate plans are to get a tune and possibly turn up the boost.
As for the future.... well who knows... I'm sure in a few months I'll be bitten by the HP bug. Or maybe the Cobra satisfies that side of things and I enjoy this as a nice ride.

I picked up the Sachs 2.5 clutch from AWE.

I was just going to have my stock dual mass flywheel turned and re-install but I'm having a heck of a time finding anyone in town who can machine it due to that lip around the edge. So faced with the possibility of having to purchase a new one regardless I started exploring the option of the solid light weight.

 

Maybe you've thought of it, but DO NOT use an unsprung disc with the LWFW. I say that because if you already bought the clutch setup, it might help in your choice.

 

Yeah the Sachs 2.5 kit is basically OEM Porsche pressure plate and disk from a GT2 and 3 I believe. Not entirely sure on the details of where they pieced each part but it's sprung and supposed to drive like stock.

Well after a few phone calls it appears our factory dual mass flywheels are not turnable. So I'm buying a new flywheel either way. Now just have to decide if I want a stock replacement or the solid light weight.

So far from what I gather.
Dual Mass:
Pros: smooth clutch engagement, quiet transaxle
Cons: none really

Light weight solid:
Pros: Engine feel more responsive on initial throttle tip in, quicker RPM changes
Cons: Noisy transaxle when idling

 

oh no, you'd "feel it" no doubt and with your stated power levels and the sachs 2.5 I would think the lwfw would be perfect, also given your used to power/noise, it'll be no problem. but the dmfw isn't gonna impede what your doing either and do it more quietly! especially if you keep your car near the sweet spot ( for the stock internals ) of 600+/-whp. which like you said others have ( rightly I would think? ) estimate where you are.


maybe retune and do the lwfw if you want to spend the bread..i'm not sure I'd got re-machining the older dmfw? have no experience with results from that. I figure once it's a rounded bar of soap, forget it. its toast. I'd opt for a lwfw before I'd buy a NEW dmfw. like I said, I got rogers from his 996tt almost brand new, ( he's dead ( sorry to say ) and wont need it ), and I pd like 75 bucks? maybe.

 

exactly on all points. the sachs 2.5 ( or what they used to call it its a marketing meme lol ) is exactly one step up from my stock oem with gt2 disc. theyre pretty darn close in terms of what they'll take which limits them to 600rwhp safely.


you're on the right track and now ya know you cant refinish a dmfw? don't bother with the dmfw! put in that 2.5 kit with an aasco or something similar and tell us all it was the perfect decision, as you don't mind engine chatter = noise

 

I have the Porsche RS LWFW. The engine revs quite a bit quicker. Your choice in clutch will determine how noisy the the gearbox will be. The sprung OEM 4.0GT3RS clutch disc is very quiet compared to the old style 996GT3 sprung version which was rather noisy. DO NOT us a solid clutch disc in conjunction with a LWFW. I'm not sure what disc is in a Sachs 2.5. That's just vendor jargon but doesn't tell you what you have. In my car, gearbox chatter due to the LWFW is hardly noticeable. The clutch shudder with a LWFW is a myth. If you have the right components, the clutch is just as smooth as stock. You will also want to get a tune that takes the LWFW into consideration to account for it. This will take car of a lot of issues that people have who just throw on a LWFW with their current flash. The OEM LWFWs are good. Stick with those. The 964RS flywheel is 11lbs while the Cup version is about 2 lbs lighter as more material is milled away.

If you really want to wake up these engines and make them rev even quicker, you will need to install additional lighter rotating components. We swapped the heavy TT crankshaft for a lightweight OEM RSR crank along with lighter pistons and a RS pulley. The difference these items made in how fast the engine revs is quite dramatic and easily greater than the difference was in going from the DMFW to a LWFW on a stock motor. Stock engine with a DMFW feels downright lethargic in comparison. If you like to track your car where you are rowing through the gears a lot, a LWFW is a must in my opinion. The For 60-130 squirts you probably won't see much of a benefit from a LWFW..

As an aside, I would drill/tap the gearbox and add the OEM GT2 components as designed by the factory. I would stay away from any of the aftermarket slave conversion solutions that are being peddled. Porsche got this right and there is no need to go with an aftermarket solution which will never be as good as the factory stuff.

 

I think you've gotten great feedback on pros and cons of LWFW. IMHO, there is a significant difference...I have the GT3RS clutch, LWFW and GT2 slave...best of all worlds.

 

i debated it too...I had a couple clinchers that made up my mind...

1. Was that I am borderline dual + set-up...so I needed the most holding power I could, when i was looking Porsche Motorsports parts and sachs stuff...If I went DMFW with unsprung disc, it was rated a bit higher in terms of torque.

2. was that I got a smoking deal on a new DMFW.

 

I will email them and get specifics.

That's what AWE told me too. Glad to hear a confirmation of this.

Did not know that about the tune. Since I plan on a tune anyways this works out good if I go that route.

This was the flywheel I was planning on going with
http://www.awe-tuning.com/sachs-porsche-stages2-5and3

You mention a 964RS which is 1 lb lighter. Is it 100% bolt in? or do you need to change throwout bearings or anything else to make it work? When searching for one what year 964 would I pick? Exploring my options here.

I hadn't planned on a complete engine tear down yet but if that ever happens then yes stuff like this would be great.

I got the BBi slave ordered because it's supposed to be 100% bolt in, work in a manual manner like the GT2 slave but does not have the engagement issue of the GT2 slave that people say engage towards the top of the clutch pedal travel. Although I'm not sure why you couldn't just shorten the push rod coming out of the slave to address that? Do you then not have enough travel to disengage the clutch?

 

Again, I'm not a fan of any of the aftermarket stuff which is rarely as good as OEM Porsche or what comes out of their race division, PMNA. In my book, most of the aftermarket stuff just devalues the car. If you are going to go with a LWFW, stick with proven OEM. It's direct bolt on, end of story. The 964RS LWFW part number is 964.102.239.31. To do the clutch, you will need the pressure plate (Sachs 764 or the new higher clamp 487), 4.0 clutch disc, 964RS lwfw, flywheel bolts (9x), pilot bearing, throwout bearing, guide tube, guide tube bolts (2x), ring gear, and pressure plate bolts (9x).

The GT2 conversion consists of about $600-700 worth of parts and a few hours of labor if your gearbox is out. Everything about the GT2 set up is spot on. There is no engagement issue whatsoever. The only people that are having engagement issues (high or low) are those that are using aftermarket clutch parts since the stack height may be different. If something were to break, any Porsche dealer can fix it for you since it's OEM. I would not change a thing. Porsche got it right...

Changing the length of the slave pushrod will have no effect as it's hydraulic. You would have to change the piston diameter of the master or alter the clutch pedal fulcrum somehow.

 

Thanks buddy I appreciate all the help. I found that part number cross references to a lot of models including the 2004 GT3.

http://www.pelicanparts.com/cgi-bin/...02-239-31-M894

Assuming that's correct I'll get that ordered. I just know me and performance and I think I'll be sorry if I put a dual mass back in there.

I did not order new clutch or flywheel bolts as the torque numbers on them were low and they seemed re-usable. Is that not true? They did not appear to be TTY (torque to yield) bolts that stretch.

I also didn't order the guide tube that the TB rides on as it showed no signs of wear. I did notice one of the phillips head screws holding it in looked chewed up so I'm sure it was replaced at some point. As cheap as they are though I may just replace it for good measure.

I was not aware the GT2 conversion worked properly on stock(ish) clutch setups. This makes it a lot more appealing. I'll have to see if I can cancel my order with BBi as I really did like the GT2 conversion initially but the whole pedal engagement hight issues I was reading about scared me off.