I know old thread, but I wanted to share my experience.

In December 2019 I put a Nitron R3 suspension in the car (996 GT3) along with RSS engine mounts. Around April 2021 when the car was in for a pre-season check the mechanic noticed that the engine mounts were loose and were "jumping around" in the back.. The car had done about 6k km and 2 trackdays.. at the moment I'm considering what the best options could be.. are the 993 RS mounts any better than the OEM 996 GT3 ones?

 

I've just bought a pair of 997 GT2 Motorsport items which are supposedly firmer but retain a level of civility (obviously as OEM fitment) (99737504991)

My original mounts are 993 part numbered and I have the usual passenger seat shake. I did briefly have a pair of solid mounts on there (about 100 miles) - as amazing as the car felt with them, it really was just too much for anything other than when you were at WOT. Too much noise. I'm hoping the GT2 items are a good middle ground

 

someone installed them wrong...

 

I thought about that.. but is that even possible?

And based on this, would you recommend getting new RSS ones or go for the 993 RS route?

 

Square nut does not look like it was seated properly in the engine carrier

 

Anything is possible. With that said, I wouldn't use the RSS mounts. You're not the first the have problems with those. The OEM 964RS ones are excellent I've never heard of anyone have any problems with those. Good luck..

 

Updating this now the new mounts are in -

Part number of item removed - 993 375 049 06
Part number of item fitted - 997 375 049 91

Old mounts had elongated by ~1/2 inch & passenger seat was vibrating at idle. The new mounts raised the tips back up to the correct position on the valance, idle is (much) smoother, and vibration in passenger seat has gone. One thing that has also improved is the elimination of what I would consider "toe steer" - the back end being now much more firmly mounted means it doesn't tramline/track bumps in the road as much.

I'd go so far as to say that the "91" mounts have reduced/improved NVH. Not cheap but VERY pleased with these items.

 

sorry just seeing this now... you have to clock the square locator stud into the receiving hole on the carrier- someone didn't align it and just jammed it 'together'
I've had my TorqueSolutions ones now for about 9 years and 120k km's without issue. They're all decent mounts including oem RS mounts

 

Can you elaborate on the toe steer issue you were experiencing with the worn mounts? I recently started a thread about this and lots of people told me my LSD was likely worn, however my first thought was engine mounts. Are the mounts you ended up going the 964 RS version?

 

Easiest way to describe it is this -

In the UK, we have various forms of traffic control. One form is a type of "bump" in the road -

I never put my wheels either side of these, as I do not want to strike anything underneath, so I take them at an angle, slowly, raising one side only.

What I was finding is that when REAR wheel was going over, my steering would pull one side or the other - I can only imagine the old engine mounts were causing enough movement to "pull" the drivetrain out of alignment. Obviously, this is a very extreme use case but it highlighted the issue well.

In terms of the mounts I fitted - no, I did not fit 964 RS mounts. The mounts on my GT3 were 993 375 049 06 with (what I think) was the "White" sticker. Quite what that means, I don't know - and the date code was 2003, so I know they were original to the car.

The 996 GT3 mounts now offered, according to the catalogue I reference from, are 996 375 049 91 (91 being the motorsport designation, I'm told?)

Curiously, I also looked at the other 996 & 997 GT2/GT3 offerings, and noted that the 997 GT2 appeared to use a superseded number - 997 375 049 91 - and those were the ones I bought. Perhaps also, given the GT2/Turbo engine is heavier, the mounts may be stiffer...? But time will tell. Overall though, I am VERY happy with the improvement.

I did not want to fit any poly/aftermarket mounts, or any that required additional effort to install. I also purchased 4-Off bolts to secure the mount to the body & 2-Off nuts to secure the mount to the engine carrier as I consider these single use items.

As said, they were not cheap, but they were an OEM solution.

 

Thanks for the explanation Phil

 

Sorry for not being active here.. just found this old thread. As a reply to your question: I will most propably replace with 964RS mounts. Perhaps with URO manufactured ones as they are cheap.. Replacements I got from RSS have developed similar play as the earlier ones did. I have a Manthey/M&M exhaust so maybe it puts more heat into mounts than stock exhaust would.

 

The play seems to be right out of the box with the gap on them. I had an issue on my 997 as the engine carrier is different than the 996 using a rectangular hole that caused a similar issue of edges getting rolled over. I was getting some "knock" readings when logging with Kevin on this from the play. Put in the 964RS mounts and all issue solved.

 

Especially the motorsport material....

 

I have use solid ounts on the motor for some time. The transmission still has the OEM. The NVH is not bad, but the car is a bit loud and usually on a track...

Ray