engine mount request - from 964 forum
04-10-2021, 04:55 PM
#1
Three Wheelin'
Thread Starter
engine mount request - from 964 forum
Hi 991'ers,
I've been wondering if 991 engine mounts can be adapted to the 964/993. Specifically, to take advantage of the active/dynamic PDEM/PADM mounts (reliability being a separate topic).
Would anyway have a dead engine mount lying around before I invest in a good pair of active mounts? Either active or not, I want to see how the 991 mounts physically match up. I'm near Boston and am happy to pay for shipping, and some donuts on your way to the post office
Hoping to add some contribution to the 991 forum, I've teased out a little about the electrics:
Connector wiring
pin1 empty
pin2 br pressure sensor supply +5v
pin3 re/wt “mounting high side”
pin4 re/bk pressure sensor signal
pin5 br “mounting low side”
pin6 ye pressure sensor ground
There is a 5v internal pressure sensor (for PASM feedback?) that uses pins 2,4,6. Potentially, that sensor is what goes bad necessitating mount replacement. The magnetorheoligical fluid is controlled by pins 3 & 5. PASM sends a current through these pins, which flows through an internal field coil to magnetize the liquid. That increases the viscosity of the fluid and ends up stiffening the mount. It seems unlikely that the field coil would go bad. For my use, I can easily add a manual circuit to control the fluid viscosity if I can make them physically fit.
Thanks!
I've been wondering if 991 engine mounts can be adapted to the 964/993. Specifically, to take advantage of the active/dynamic PDEM/PADM mounts (reliability being a separate topic).
Would anyway have a dead engine mount lying around before I invest in a good pair of active mounts? Either active or not, I want to see how the 991 mounts physically match up. I'm near Boston and am happy to pay for shipping, and some donuts on your way to the post office
Hoping to add some contribution to the 991 forum, I've teased out a little about the electrics:
Connector wiring
pin1 empty
pin2 br pressure sensor supply +5v
pin3 re/wt “mounting high side”
pin4 re/bk pressure sensor signal
pin5 br “mounting low side”
pin6 ye pressure sensor ground
There is a 5v internal pressure sensor (for PASM feedback?) that uses pins 2,4,6. Potentially, that sensor is what goes bad necessitating mount replacement. The magnetorheoligical fluid is controlled by pins 3 & 5. PASM sends a current through these pins, which flows through an internal field coil to magnetize the liquid. That increases the viscosity of the fluid and ends up stiffening the mount. It seems unlikely that the field coil would go bad. For my use, I can easily add a manual circuit to control the fluid viscosity if I can make them physically fit.
Thanks!
Last edited by -nick; 04-10-2021 at 04:56 PM.
04-13-2021, 01:06 AM
#3
RL Community Team
Rennlist Member
Rennlist Member
And now I run away before they come after me with pitchforks!
.. or, rather, their employees do.
On a serious note though, call your local porsche indy shop (and maybe even the dealer, who knows) and ask if you could get one of the failed parts that they would otherwise throw away.
04-13-2021, 09:51 AM
#4
Three Wheelin'
Thread Starter
Ha! Point taken. Problem with doing your own wrenching is not having strong relationships with any shops. Sounds like I need to find a dealer connection if these are still generally warranty work. I missed an ebay pair of padm mounts for $200, which I could just resell if needed. Appreciate the feedback.
04-13-2021, 12:05 PM
#6
RL Community Team
Rennlist Member
Rennlist Member
04-13-2021, 02:07 PM
#7
Rennlist Member
LOL 
Most of us who have had engine mount failures have been under warranty when they happen, or have an indy shop do them. 991 owners are a completely different animal when compared to 964 owners. Suits versus jeans, soft hands versus first hand knowledge of what a wrench looks like.
And now I run away before they come after me with pitchforks!
.. or, rather, their employees do.
On a serious note though, call your local porsche indy shop (and maybe even the dealer, who knows) and ask if you could get one of the failed parts that they would otherwise throw away.
And now I run away before they come after me with pitchforks!
.. or, rather, their employees do.
On a serious note though, call your local porsche indy shop (and maybe even the dealer, who knows) and ask if you could get one of the failed parts that they would otherwise throw away.
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04-13-2021, 04:13 PM
#8
Rennlist Member
I don't think the view is worth the climb for any performance gains.
I know if the active mounts go out in my car they will not be replaced with like units.
I can't tell when they are on or off so it's lost on me.
I know if the active mounts go out in my car they will not be replaced with like units.
I can't tell when they are on or off so it's lost on me.