RS Motor Mounts – My Turn
08-05-2003, 04:48 PM
#1
RS Motor Mounts – My Turn
Many thanks to JohnM for his post RS engine mounts - WOW! and informative answers to all my questions. That post is what got me started looking into RS motor mounts. After some careful thought, I finally decided to go for it even though I never got a ride in a car with these mounts (I wanted to experience the noise increase first hand). I was pretty sure my original mounts were dead, and I was right.
The DIY was about as easy as it gets. It only took 45 minutes. I followed the very helpful RS Motor Mount DIY on Robin’s site. It’s easier than changing the oil, and far easier than changing the mufflers. A couple notes on the DIY:
1) George couldn’t remember if the nuts were 18 or 19mm. The bottom nut is 18mm, and the long bolt that goes through the RS mount is 19mm.
2) I didn’t bother with jack stands. I jacked the engine up until the rear wheels just left the ground. I never crawled under the car, so even if it came off the jack, I’d be safe. I just stuck my arm and the wrench under the bumper.
3) I didn’t have to raise and lower the engine to loosen the old mounts. Once I removed the bolts, they came right out.
4) The A/C lines on my ’95 did not have to be moved. I think this is due to lack of varioram. I think the varioram cars route the A/C lines like the DIY shows.
5) I used a thread locker on all fasteners, thank you very much, after reading about a car that almost lost an engine on the track.
6) I didn’t need assistance. I put a 19mm box wrench on the top bolt. When I turned the nut with my torque wrench, the 19mm box turned until it hit something, which held it in place.
Now for the improvements.
Clutch engagement is much better. I was having clutch “issues,” either not giving enough gas and bogging the engine, or giving it too much and slipping the clutch. I had previously attributed this to my light weight flywheel, and even mentioned this on a thread about the pros and cons of LWF’s. I retract that statement. The problem was due to the mounts. Like JohnM says, the engine was rotating, compressing one mount and expanding the other. I felt this when I engaged the clutch. With the RS mounts, engaging the clutch feels like it should. The engagement is so much better now, my left foot needs to be “re-educated.”
There is a big improvement in road feel. It feels like I got new shocks. The whole car feels stiffer. With the old mounts, going over a rough road made the whole car feel like different parts were going in different directions. Now, it feels solid. It feels much more planted to the ground. I have a lot more confidence in corners. It’s a lot more predictable.
There is a bit more engine sound. I expected this. It’s not bothersome, at least at cruising RPM’s, but it’s pretty loud in the upper RPM ranges. I’ll probably get used to it quickly. What surprised me is the quality of the sound. The quality has greatly improved. I think I’m hearing a lot more high frequency sounds and/or harmonics. The sound is crisper and sharper. It sounds like there was a thick blanket over the engine before, muffling these sounds. Turn the treble up and down on your stereo for the same effect. There seems to be a barely perceptible increase in vibration.
One very interesting data point in regards to the increase in noise and vibration: My wife did not know I installed these. I had them delivered to work and I installed them when she wasn’t home. She has not made any comments at all like “your car seems louder” or “why is your car vibrating more.” I don’t think she noticed a thing. On the other hand, I don’t see >5,000 revs with her in the car very often.
Lastly, the low speed smoothness issue that JohnM speaks of has improved, but it’s still not perfect. I still get some fuel cutoff bucking in first and second gear. I’ll have to re-learn what triggers this and avoid it. It seems to happen most in the 2000 to 2400 RPM range, and it’s worse when the engine is cold (different ECU maps). I think the ‘95’s (OBDI) are worse that the OBD II cars in this regard. Throttle response has also improved.
One interesting thing that I haven’t quite figured out. It took a couple of drive cycles for these improvements to really sink in. Almost like the ECU had to adapt. Makes no sense, I know. When I first started the engine after installing the mounts, I felt a lot of vibration in my seat and legs. I think perhaps the suspension hadn’t settled after lowering the car off the jacks. I was worried there for a while, but the vibration is mostly gone now. Now I can’t remember what it felt like before the mounts. I’m guessing that maybe the rubber was hard from sitting on a shelf for so long, and after it got stressed, it softened up a bit. It also took a couple drive cycles for the low speed smoothness issue to get better, but the clutch improvement came right away. I can’t explain that. Perhaps it took a little bouncing around for the new mounts to settle down.
I would definitely recommend this upgrade. I would certainly recommend replacing failed stock mounts. I wonder how much improvement I would have seen if I had replaced my failed mounts with equivalent stock mounts, or how much improvement would be seen if good stock mounts were upgraded to RS mounts. I also wonder how much better solid mounts would be, and how much louder and more vibration comes from them as well. I really wonder if solid mounts will improve the low speed smoothness issue even more. The noise increase might be worth it (I doubt it). This issue is the thing that bugs me most about this car. It makes my daily commute (in traffic) and in-town driving a little bit of a PIA. I don’t know why aftermarket chips can’t resolve this. I can’t answer all these questions, but I can say that replacing dead stock mounts with RS mounts is well worth it!
Tom
’95 993
The DIY was about as easy as it gets. It only took 45 minutes. I followed the very helpful RS Motor Mount DIY on Robin’s site. It’s easier than changing the oil, and far easier than changing the mufflers. A couple notes on the DIY:
1) George couldn’t remember if the nuts were 18 or 19mm. The bottom nut is 18mm, and the long bolt that goes through the RS mount is 19mm.
2) I didn’t bother with jack stands. I jacked the engine up until the rear wheels just left the ground. I never crawled under the car, so even if it came off the jack, I’d be safe. I just stuck my arm and the wrench under the bumper.
3) I didn’t have to raise and lower the engine to loosen the old mounts. Once I removed the bolts, they came right out.
4) The A/C lines on my ’95 did not have to be moved. I think this is due to lack of varioram. I think the varioram cars route the A/C lines like the DIY shows.
5) I used a thread locker on all fasteners, thank you very much, after reading about a car that almost lost an engine on the track.
6) I didn’t need assistance. I put a 19mm box wrench on the top bolt. When I turned the nut with my torque wrench, the 19mm box turned until it hit something, which held it in place.
Now for the improvements.
Clutch engagement is much better. I was having clutch “issues,” either not giving enough gas and bogging the engine, or giving it too much and slipping the clutch. I had previously attributed this to my light weight flywheel, and even mentioned this on a thread about the pros and cons of LWF’s. I retract that statement. The problem was due to the mounts. Like JohnM says, the engine was rotating, compressing one mount and expanding the other. I felt this when I engaged the clutch. With the RS mounts, engaging the clutch feels like it should. The engagement is so much better now, my left foot needs to be “re-educated.”
There is a big improvement in road feel. It feels like I got new shocks. The whole car feels stiffer. With the old mounts, going over a rough road made the whole car feel like different parts were going in different directions. Now, it feels solid. It feels much more planted to the ground. I have a lot more confidence in corners. It’s a lot more predictable.
There is a bit more engine sound. I expected this. It’s not bothersome, at least at cruising RPM’s, but it’s pretty loud in the upper RPM ranges. I’ll probably get used to it quickly. What surprised me is the quality of the sound. The quality has greatly improved. I think I’m hearing a lot more high frequency sounds and/or harmonics. The sound is crisper and sharper. It sounds like there was a thick blanket over the engine before, muffling these sounds. Turn the treble up and down on your stereo for the same effect. There seems to be a barely perceptible increase in vibration.
One very interesting data point in regards to the increase in noise and vibration: My wife did not know I installed these. I had them delivered to work and I installed them when she wasn’t home. She has not made any comments at all like “your car seems louder” or “why is your car vibrating more.” I don’t think she noticed a thing. On the other hand, I don’t see >5,000 revs with her in the car very often.
Lastly, the low speed smoothness issue that JohnM speaks of has improved, but it’s still not perfect. I still get some fuel cutoff bucking in first and second gear. I’ll have to re-learn what triggers this and avoid it. It seems to happen most in the 2000 to 2400 RPM range, and it’s worse when the engine is cold (different ECU maps). I think the ‘95’s (OBDI) are worse that the OBD II cars in this regard. Throttle response has also improved.
One interesting thing that I haven’t quite figured out. It took a couple of drive cycles for these improvements to really sink in. Almost like the ECU had to adapt. Makes no sense, I know. When I first started the engine after installing the mounts, I felt a lot of vibration in my seat and legs. I think perhaps the suspension hadn’t settled after lowering the car off the jacks. I was worried there for a while, but the vibration is mostly gone now. Now I can’t remember what it felt like before the mounts. I’m guessing that maybe the rubber was hard from sitting on a shelf for so long, and after it got stressed, it softened up a bit. It also took a couple drive cycles for the low speed smoothness issue to get better, but the clutch improvement came right away. I can’t explain that. Perhaps it took a little bouncing around for the new mounts to settle down.
I would definitely recommend this upgrade. I would certainly recommend replacing failed stock mounts. I wonder how much improvement I would have seen if I had replaced my failed mounts with equivalent stock mounts, or how much improvement would be seen if good stock mounts were upgraded to RS mounts. I also wonder how much better solid mounts would be, and how much louder and more vibration comes from them as well. I really wonder if solid mounts will improve the low speed smoothness issue even more. The noise increase might be worth it (I doubt it). This issue is the thing that bugs me most about this car. It makes my daily commute (in traffic) and in-town driving a little bit of a PIA. I don’t know why aftermarket chips can’t resolve this. I can’t answer all these questions, but I can say that replacing dead stock mounts with RS mounts is well worth it!
Tom
’95 993
08-05-2003, 05:10 PM
#4
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I absolutely agree with all of the above ! That being said, before there is a rush to get RS mounts, I should point out that the noise is louder but not necessarily better (not like an exhaust mod). It's just a bit louder and more metallic - just want to make this clear... and there is a bit more vibe/noise that can be annoying on long commutes to some people.
Lastly, nobody mentioned the possibility of replacing the old "shot" mounts with the same stock mounts, new and firm... That would probably make the car feel tighter as well and still isolate some of that sound/vibration. Not a bad thing either.
I am definitely happy with the mod, but I would not say it is for everyone as it definitely takes away from the "plush" feeling of the 993. For us would be racers, it's great !
In my case the change in noise/vibe is pretty noticeable (my wife picked up on it immediately when she drove the car, the good and the bad). In conclusion, I think that we see improvement because our mounts were shot... I think 80% of the goodness of RS mounts (better shifting, more solid feel) could be had with brand new standard mounts - let's face it, ours are old and shot in most cases (hell my boxster went thru a set in 15K miles).
Just playing devil's advocate for a minute here ;-)
Aw, screw it, I like'em and they saved weight too !! ;-)
Lastly, nobody mentioned the possibility of replacing the old "shot" mounts with the same stock mounts, new and firm... That would probably make the car feel tighter as well and still isolate some of that sound/vibration. Not a bad thing either.
I am definitely happy with the mod, but I would not say it is for everyone as it definitely takes away from the "plush" feeling of the 993. For us would be racers, it's great !
In my case the change in noise/vibe is pretty noticeable (my wife picked up on it immediately when she drove the car, the good and the bad). In conclusion, I think that we see improvement because our mounts were shot... I think 80% of the goodness of RS mounts (better shifting, more solid feel) could be had with brand new standard mounts - let's face it, ours are old and shot in most cases (hell my boxster went thru a set in 15K miles).
Just playing devil's advocate for a minute here ;-)
Aw, screw it, I like'em and they saved weight too !! ;-)
Last edited by Greg D.; 08-06-2003 at 10:52 AM.
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08-05-2003, 06:11 PM
#8
Burning Brakes
Join Date: Apr 2003
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Hate to disappoint you guys but I e-mailed Gert last week re: a group buy on the motor mounts and here's what he wrote:
"The motor mounts are priced pretty sharp so even a group buy would not
change a lot to the price."
Perhaps if enough of us jump in, maybe Gert might change his mind?
On the flip side, for us on this side of the pond, the USD to Euro exchange rate has been slightly favorable recently so the mounts are a few $ cheaper than they were a week ago.
"The motor mounts are priced pretty sharp so even a group buy would not
change a lot to the price."
Perhaps if enough of us jump in, maybe Gert might change his mind?
On the flip side, for us on this side of the pond, the USD to Euro exchange rate has been slightly favorable recently so the mounts are a few $ cheaper than they were a week ago.
08-05-2003, 06:24 PM
#11
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Boy you guys are quick to pull the trigger! 
Ok lets start looking around for some shop willing to give us a good price. Whoever finds info first please post on a separate thread.
Let's do this!
Ok lets start looking around for some shop willing to give us a good price. Whoever finds info first please post on a separate thread.Let's do this!
08-05-2003, 06:25 PM
#12
Burning Brakes
Join Date: Apr 2003
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Yes.
Here's the link to Robin's webpage that lists the part #s and R&R procedure:
http://p-car.com/diy/motormount/
IIRC, talking to Sunset a few weeks ago, the motormounts have a new part number:
964.375.043.81 (instead of 964.375.043.80)
Here's the link to Robin's webpage that lists the part #s and R&R procedure:
http://p-car.com/diy/motormount/
IIRC, talking to Sunset a few weeks ago, the motormounts have a new part number:
964.375.043.81 (instead of 964.375.043.80)
08-05-2003, 06:52 PM
#14
If you guys do a group buy, be sure to account for my commission!
Just kidding… But I wish… Look what I started!
Greg makes some good points in his reply. I perceived the more metallic sound as better, but I suppose that’s a subjective thing. And like we both said, replacing failed mounts with good standard mounts might give much of the same improvements.
Tom
’95 993
Just kidding… But I wish… Look what I started!
Greg makes some good points in his reply. I perceived the more metallic sound as better, but I suppose that’s a subjective thing. And like we both said, replacing failed mounts with good standard mounts might give much of the same improvements.
Tom
’95 993
