Go Back   986 Forum - The Community for Porsche Boxster & Cayman Owners > Porsche Boxster & Cayman Forums > Performance and Technical Chat

 
 
LinkBack Thread Tools Display Modes
Prev Previous Post   Next Post Next
Old 05-13-2009, 06:07 AM   #21
Registered User
 
Join Date: Jan 2006
Location: Glen Allen, ON
Posts: 314
I'll add my $0.02.

1) These types of crank failures were seen with the M64 (aircooled 964/993) when people pulled off the front (harmonic balancer) pulley and added a single mass pulley when ditching the AC, like the RS versions of these cars came with from the factory. Guess what, with track use, the cranks snapped.

2) The M97 3.8 engines come with a different front pulley that incorporates a harmonic balancer, might be worth looking into if you have a LWF.

3) I'm not sure of the cars Jake is referring to, but most people doing LWF swaps on the M96 platform are not doing them correctly. They simply swap the DMF for the SMF and use a stock unsprung clutch disk. Well Porsche and other manufactures have used SMF for sometime, and guess what, they use a sprung disk. Why? Because driveline vibration and shock has to be taken up somewhere. If there is no sprung component (either DMF or sprung disk) guess where all that shock is transmitted? Right to the crank. So using a single mass flywheel with an unsprung disk is going to make the harmonic vibration issues even more of a problem.

Even if you read the LUK site (the manufacturer of the DMF) they state this was simply done for noise and making cars easier to drive. And yes my car has an Aasco LWF with a sprung disk.

-Todd
__________________
Current Cars:
1989 911 Targa
1984 944 Original Owner
1971 911T
tholyoak is offline   Reply With Quote
 



Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -8. The time now is 10:43 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0
Copyright 2025 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page