TS

Hello,
I've a 89 C4 with 160'000km bought two years ago. The previous owner changed the clutch at 80-90'000km with the original clutch.
My mechanic told me to install a RS clutch because it is better and cheaper.
Has anyone installed a RS clutch on a C4, is it really better?
A porsche mechanic told me that with a RS clutch the C4 make a strange sound... is it right?

Thanks in advance
TS

johnfm

If you want a performance improvemnt look into the lightened flywhell/clutch assembly.

For theory behind light flywheels, looks here
<a href="http://www.pumaracing.co.uk" target="_blank">Puma Racing</a>

Go to the main menu and look for the lightened flywheel article.

DaveK

... But beware that lightened flywheel / clutch can cause idle / stalling ptroblems.

GT9111

My 90 C4 has the RS flywheel and clutch system intalled about two years ago. I have nothing but praise regarding the car's performance after the conversion. However, it does stall occasionally when I come to a stop during initial driving with A/C on. So, I usually drive for 5 to 10 minutes before I turn on the A/C.

A rattling sound from the transmission does occur when the rpm is below the gear's proper rpm range and you apply gas, i.e, 3rd gear and below 2000rpm.

Overall, the positive outweight the negative.

Roygarth

</font><blockquote><font size="1" face="Verdana,Tahoma,Arial,Helvetica,Geneva">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Originally posted by GT9111:
<strong>My 90 C4 has the RS flywheel and clutch system intalled about two years ago. I have nothing but praise regarding the car's performance after the conversion. However, it does stall occasionally when I come to a stop during initial driving with A/C on. So, I usually drive for 5 to 10 minutes before I turn on the A/C.

A rattling sound from the transmission does occur when the rpm is below the gear's proper rpm range and you apply gas, i.e, 3rd gear and below 2000rpm.

Overall, the positive outweight the negative.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">In what way is performance improved?

Thanks
Piers
1990 C4 Coupe

BrokeAss

Performance is improved by lightening the rotating mass of the engine. The RPM's spool up much faster when it doesn't have to twist that big hunk of metal. Blip the throttle on a car with a lightened flywheel and the engine is "there" right now!

It's a lot of fun, but like GT9111 said. I make sure the engine is fully warmed up before switching on the air or I'll wind up stalling the motor at traffic lights and suffering a major loss of "cool points".

mark_in_maine

1991 C2 Cab with Tiptronic bought 3 years ago from the original owner with 97,000 miles. The car is completely stock and now has 110,000 smile filled miles. No enhancements planned for the future other than gas, oil, and top down fun.

Since purchasing I have had an upper engine rebuild along with oil line replacements and oil leaks repaired. The PO had brakes replaced including rotors, the cab top replaced including the cab top motors, and the tiptronic was replaced all within the last 5,000 miles of ownership. In addition, the PO had all major service intervals performed by the dealer from which it was purchased.

Thanks,

Roygarth

</font><blockquote><font size="1" face="Verdana,Tahoma,Arial,Helvetica,Geneva">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Originally posted by mark_in_maine:
<strong>1991 C2 Cab with Tiptronic bought 3 years ago from the original owner with 97,000 miles. The car is completely stock and now has 110,000 smile filled miles. No enhancements planned for the future other than gas, oil, and top down fun.

Since purchasing I have had an upper engine rebuild along with oil line replacements and oil leaks repaired. The PO had brakes replaced including rotors, the cab top replaced including the cab top motors, and the tiptronic was replaced all within the last 5,000 miles of ownership. In addition, the PO had all major service intervals performed by the dealer from which it was purchased.

Thanks,</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Mark, I think you're lost!
BR
Piers

Adrian

Dear TS,
The 1989 C4 is fitted with a single mass flywheel and standard clutch. The stalling problem certainly affects the 1990 and up C4s and Porsche do not recommend you do it because they have double mass flywheels and th rpm changes are not mapped and the originals do not match properly.
However you have an 89 C4 (check the 10th digit of the VIN is a K). The 89 C4 is much less affected by the stalling problem.
A RS clutch on its own will not cause you any problems anyway.
If you install a RS lightweight flywheel make sure they install your original motronic timing ring. Do not use the RS motronic timing ring.
Ciao,
Adrian
911C4

TS

Thanks everybody for suggestions, links and explications.

Adrian, I confirm you my C4 is a '89 model. I'm pleased to read another good news about 89 C4.
I'll not forget your motronic suggestion, thanks a lot.

Ciao
TS
911C4