993Racer2

Monday my 95 993 goes into the shop to replace the clutch. I am getting lots of variation on pricing. Very interesting when you shop around.

Question of whether the DM Flywheel needs to be replaced. That seems to have an impact on costs. I only have 58k on it and it is a daily driver.

Any thoughts on what to look for?

Thanks

GratefulJED

You're in Portland - me I'd take it to ol' Steve Weiner @rennsportsystems.com. Definately a plus to living in Portland - of course if I did live in Portland I would be several thousand dollars poorer!!

DJF1

I second JD's recomendation....although I'm afraid you may end up with an RS clutch and flywheel if you hang around here and ask these kind of questions! Great upgrade by the way!

Flying Finn

I'll second Danny,

Go to Steve and get the RS fluwheel clutch.

Both things now you don't need to think about anymore.

sy308

As you probably know, 1995 cars have a different engine management system than 1996 and later cars. It is going to be necessary for you to discuss the modification addition of a LMF with a professional shop. The 1995 cars reportedly suffer from low speed drivability issues when a LMF is added. Later models run really great with the modification. Get the info from a professional. Replacing the clutch is expensive enough, you don't want to create new problems by going for a modification that you might regret, (maybe not today, maybe not tomorrow, but soon and for the rest of your life).
Good luck.

Tom W

Most "professionals" have no idea what to do with the LWF in a '95 as they have no first-hand experience and may not have correct information. However, as there are many of us on Rennlist that have made this modification good information can be obtained.

The LWF on a '95 can cause stalling if you disengage the clutch at higher rpm (in my case above about 2k rpm). This can be minimized by changing your driving technique a bit and it can be eliminated by tweeking the ISV (Idle Stabilizer Valve). The ISV adjustment takes 30-60 minutes and can completely eliminate the stalling. There are no other drivability issues with this mod (other than you can accelerate faster). I've had mine for over 15k miles now and no issues since the ISV tweek. The transmission does sound more like a cement truck at idle and if you try to accelerate while at low rpm. Some people hate the sound difference. I think the performance benefit far out-weighs the difference in sound.

tom_993

Tom,

Do you have the low-speed bucking problem that these cars are known for? You know, feathering the throttle in first gear, as you drive through a parking lot. It happens to me the most around 2,000 to 2,400 RPM in first. Accelerating sharply doesn't cause it. Just on/off the throttle at those speeds.

I have this problem. I had it before the LWF, but the LWF made it worse. I adjusted the ISV, and that helps. A new chip, a new MAF and new motor mounts also helped. But it's still there... I did all these things after the LWF was installed. Now I don't know if removing the LWF will solve it completely or not.

Tom
'95 993

vjd3

And, I think while you're in there doing the clutch it would be a good idea to replace the rear main seal, too ... it will fail eventually, and it's right there.

Vic
95 C4 (for sale)

Edward

tom_993,

I believe the low-speed "bucking" problem you describe is somewhat inherent to any high-compression engine. I say "somewhat" because the the DME and it's programming also play a part here (the DME is trying to figure out whether you want gas or not at that slow speed). Exacerbating the problem, decreasing flywheel weight (rotational mass) on any engine reduces its smoothness at low speed since it is the rotational mass' inertia that helps keep a slow-turning engine turning. Add high compression to a LWF and you make it even more difficult to keep the engine turning at a constant low speed. The fix is really very simple: drive fast! Barring that (say, in that parking lot you describe), I've just made it a habit to clutch in/out as necessary to avoid the bucking. If you like the feel of the LWF, I wouldn't remove it; just re-learn how to drive it with this little idiosyncracy. Hope this helps

Edward

993Racer2

Thanks Guys,

Most people here in Portland say stay away from the RS. THere are nightmare stories here within the PCA community. I have heard that the adjustment discussed works though. Also mine is a daily driver so I prefer the right blend of smooth shifting and sound versus the improvement in performance/speed. Although I would think differently if wasnt a daily driver.

Thanks for teh cmment on the seals, that is a good one and I will do it...

Glen

The ISV is very easy to adjust and the car will work fine with a LWF. If You have any concern use the ANdial piece which is slightly heavier but much lighter than the DMF. The DMF is a failure waiting to happen especially with the years and miles You have. Many people forget that the Factory Supercup 993 had no VRAM and a LWF with no stalling problem...

Tom W

I have no significant low speed bucking and no difference between dual mass and RS-LWF. I do get the occasional bucking in stop and go traffic, but it's no differnt than what I've experienced with other manual transmissions (most recently a BMW 325).

My car is also a daily driver and I would say there is no significant difference in the "feel" to driving in stop and go traffic or typical puttering along. There is a marked difference once you get the opportunity for spiritied driving. I had about 9 months (9,000 miles) of driving with the dual-mass flywheel before I switched to the LWF about 1.5 years (about 17,000 miles) ago. I get stuck in stop-and-go/bumper-to-bumper traffic almost every day for a mile or two.

tom_993

Hi Edward,

I agree. I think the ECU plays a big role, though. It’s the “trying to figure out whether you want gas or not at that slow speed” part of the ECU. If you lift, the ECU cuts fuel, which induces compression braking and you lunge forward. Touch the throttle, and the braking is replaced with acceleration, and you get shoved back in your seat.

If the ECU were smarter about this particular issue, the bucking would be greatly reduced. As far as I know, the OBD II cars are better in this regard than the OBD I cars. They made improvements in this area.

This is the “low speed drivability issues” that “sy308” refers to. The ’96 and later cars are better.

I do the clutch in/out you mention, but that can be a PIA sometimes.

Tom
’95 993

993Racer2

Hi Guys,

Well it came back wednesday afternoon. Did clutch Kit , seals, one valve cover gasket ad slave cylinder. It works great. Rmoved all oil eaks and everything. Like a new car after strugling with it for 13k miles since I bought it.

I used Stuttgart Autotech in LakeOswego to do the work..

thanks

stinky

Well, nobody asked yet so I will. How much was the clutch kit, valve cover gasket and slave cylider.

I like to put a price on my "upgrades."