RS Flywheel rough idle
11-20-2007, 06:12 PM
#1
Rennlist Member
Thread Starter
RS Flywheel rough idle
I was looking get one installed in the car and was told by my Porsche dealer here in San Anotnio that it could cause a rough idle. True?
11-20-2007, 07:17 PM
#2
RL Technical Advisor
Hi Mel:
I don't think the idle is any rougher (unless there are pre-existing issues) but you'll hear some transmission noise (rattle) at idle and up to 1500 RPM.
I don't think the idle is any rougher (unless there are pre-existing issues) but you'll hear some transmission noise (rattle) at idle and up to 1500 RPM.
11-20-2007, 08:09 PM
#5
Rennlist Member
Ryan,
Stalling is not the same thing as a rough idle, at least by my definition. When my car is at a standstill, the idle is fine. Since the OP asked about rough idling, that's what I addressed. My occasional stalling issues occur when the car is moving and I push the clutch in. I think a cleaning of the ISV valve will take care of it since I had not experienced the stalling before.
Stalling is not the same thing as a rough idle, at least by my definition. When my car is at a standstill, the idle is fine. Since the OP asked about rough idling, that's what I addressed. My occasional stalling issues occur when the car is moving and I push the clutch in. I think a cleaning of the ISV valve will take care of it since I had not experienced the stalling before.
11-20-2007, 08:16 PM
#6
Instructor
11-20-2007, 09:01 PM
#7
Noodle Jr.
Rennlist Member
Rennlist Member
Ryan,
Stalling is not the same thing as a rough idle, at least by my definition. When my car is at a standstill, the idle is fine. Since the OP asked about rough idling, that's what I addressed. My occasional stalling issues occur when the car is moving and I push the clutch in. I think a cleaning of the ISV valve will take care of it since I had not experienced the stalling before.
Stalling is not the same thing as a rough idle, at least by my definition. When my car is at a standstill, the idle is fine. Since the OP asked about rough idling, that's what I addressed. My occasional stalling issues occur when the car is moving and I push the clutch in. I think a cleaning of the ISV valve will take care of it since I had not experienced the stalling before.
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11-20-2007, 09:14 PM
#9
Rennlist Member
Thread Starter
Slider. Is it worth the rattle? The dealer told me they could install it for me but that since the the flywheel is not made for the car it has caused problems for customers they have installed them for.
Mark. Will getting it installed by someone who knows what they are doing get rid of the stalling and noise? Want the performance improvement but don't want the car sounding or acting like something is wrong with it.
Steve?
Mark. Will getting it installed by someone who knows what they are doing get rid of the stalling and noise? Want the performance improvement but don't want the car sounding or acting like something is wrong with it.
Steve?
11-20-2007, 09:44 PM
#10
Rennlist Member
As far as the noise is concerned, I think it sounds great. It doesn't sound like there's anything wrong with the LWF, but, rather, emphasizes all of the whirring noises that I associate with a cool piece of machinery that I am not requiring to be whisper quiet.
11-20-2007, 10:07 PM
#11
Rennlist Member
Thread Starter
The noise and stalling are independent of the installation, assuming that all you have the shop do is to install the components. You might even be one of the unlucky few who have problems despite all of the known LWF stalling remedies, but I doubt it.
As far as the noise is concerned, I think it sounds great. It doesn't sound like there's anything wrong with the LWF, but, rather, emphasizes all of the whirring noises that I associate with a cool piece of machinery that I am not requiring to be whisper quiet.
11-20-2007, 11:34 PM
#12
Race Car
Hey Mel,
My buddy recently purchased a 993 with LWF and he has stalling issues. However, I have not ruled out driver error. When I drive his car, the idle dips more than my DMF, but does not stall.
Honestly, I don't notice the performance difference between his non-varioram LWF car and my varioram DMF car. But I don't drive his car much. Oh, and the noise is a non-issue.
If you want to try the LWF, I think Adrienne has one. And if you are in Dallas, my buddy will certainly let you check it out.
Good luck!
My buddy recently purchased a 993 with LWF and he has stalling issues. However, I have not ruled out driver error. When I drive his car, the idle dips more than my DMF, but does not stall.
Honestly, I don't notice the performance difference between his non-varioram LWF car and my varioram DMF car. But I don't drive his car much. Oh, and the noise is a non-issue.
If you want to try the LWF, I think Adrienne has one. And if you are in Dallas, my buddy will certainly let you check it out.
Good luck!
11-21-2007, 12:10 AM
#13
Rennlist Member
Thread Starter
Honestly, I don't notice the performance difference between his non-varioram LWF car and my varioram DMF car. But I don't drive his car much. Oh, and the noise is a non-issue.
11-21-2007, 08:30 AM
#14
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As each cylinder fires at idle, it sends pulses to the crankshaft. A heavy flywheel carries a fair amount of centrifugal force, so it tends to smooth out those pulses. A light-weight flywheel won't carry as much centrifugal force(one of the reasons they are so popular in high-performance applications), so it transfers those pulses straight to the gearbox. During each pulse, the gears that would normally be in contact with each other clack together, then slack off between pulses, then clack together again with the next pulse, ad infinitum.
Sometimes just raising the idle will calm the lash a little, but it would probably not eliminate it.
--Chuck--
11-21-2007, 08:42 AM
#15
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I will throw my 2 cents in here.......I replaced my Dual Mass Flywheel (ie heavy) and standard clutch two and a half years ago and could not be happier.....but mine is a 97 so no stalling issues per se.
Plus:
1. Much quicker spool up in first gear, the lack of weight does make some difference in response. It probably makes no difference in 0-60 times but the car does feel much more responsive
2. I actually like the gear noise, its not meant to be an ultra quiet car - go buy a BMW if you want quiet
Minus:
1. Cost...unless something is wrong (need to replace clutch/flywheel) this is not a must do
2. You do have to be more careful when doing hill starts as you do not have the flywheel momentum to help the engine, so it is possible to stall here, or get very occasional clutch spin.
All in all, would I do it again face with the same choice when I had to replace my DMF....you betcha
Plus:
1. Much quicker spool up in first gear, the lack of weight does make some difference in response. It probably makes no difference in 0-60 times but the car does feel much more responsive
2. I actually like the gear noise, its not meant to be an ultra quiet car - go buy a BMW if you want quiet
Minus:
1. Cost...unless something is wrong (need to replace clutch/flywheel) this is not a must do
2. You do have to be more careful when doing hill starts as you do not have the flywheel momentum to help the engine, so it is possible to stall here, or get very occasional clutch spin.
All in all, would I do it again face with the same choice when I had to replace my DMF....you betcha