Hi everyone,

I recently put on semi-solid engine mounts. While I liked the performance gains (quite drastic improvement in engine response and cornering feel), I didn't like the added NVH. I then decided to replace the semi-solid mounts with new OEM Rein mounts because my originals had 72k miles on them. I was quickly disappointed to find that the new engine mounts had no perceivable difference from my original engine mounts. After trying to find the right blend of performance and comfort, I decided to take matters into my own hands and create my own version of semi-semi-solid engine mounts like the Function First ones.

Since I now had two sets of stock engine mounts, I decided to fill both sets with two different polyurethane sealants to stiffen them up. I purchased Loctite Roof Sealing Polyurethane and 3M Windo Weld. The Loctite is rated at 30A in hardness according to the spec sheet while the 3M Windo Weld is rated at 60A. Here are the steps I took to fill the engine mounts with polyurethane:

• Clean the engine mounts with soap and a brush
• Dry them off completely
• Use a caulking gun to dispense the polyurethane into the void on each engine mount
• After initially filling the engine mount, tap it all around with a rubber mallet to work the air pockets out, and then fill with more polyurethane and repeat

Here's a summary of the results with the two different polyurethanes:

• Loctite Polyurethane
  • It was easy to work with and get a nice, clean finish
  • Drying time took a few days to fully cure
  • This stiffened engine mounts considerably as I could no longer easily deflect the bolt on the engine mount as easily
  • Performance wise, there seemed to be a slight improvement in throttle response
  • Video footage of the engine movement on startup and with light load show it does noticeably reduce engine movement
  • I could not detect any increase in NVH
• 3M Windo Weld
  • It was harder to work with as the 3M had a thicker consistency than the Loctite; results looked messier
  • Drying time only took 1 day to fully cure
  • This stiffened the engine mounts significantly over stock as I could barely deflect the bolt on the engine mount
  • I felt a noticeable improvement in throttle response, but it was not as dramatic as my previous semi solid mounts
  • Video footage also confirms that these filled engine mounts reduced engine movement significantly on startup and under light load
  • I could not detect any increase in NVH under normal conditions, but there is slightly more engine noise when I ring out the engine (I like this!)

Overall, I'm very pleased with the results. For about $20 and some elbow grease, I was able to find the right balance of performance and comfort. I also believe you can restore worn engine mounts with this mod. Here's a video review I did in case anyone is interested in doing this themselves!

Cheers,
DC

 

Nice Job DC
I have Function First Mounts does anyone know what they fill theirs with? What the hardness is?

 

Did you utilize brand new stock engine mounts for both or was one set the original engine mounts you had on the car from new? I assume you're going with the 3M Windo Weld mounts based on your video?

 

Yes, I stuck with the windo weld versions which were done on a set of engine mounts with less than 1k miles on them. The loctite was used on my old mounts. Looking at camera footage of the new oem mounts versus the ones with 70k miles though, they wasnt a discernable difference.

 

de

 

Are you selling the rennline mounts??? :-)

 

I sold them a while back. Sorry.

 

No problem - I thought I'd be cheeky and ask, I like your YouTube tutorials BTW watched a couple of them and found them to be good information and interesting to watch.

Stay safe...

 

Nice DIY. Thanks

 

How have these held up? I'm considering doing this mod with the new OEM mounts I just purchased.

 

I tried semi solid mounts and my .2 ran like crap. I should have listened to Jake Raby. Don't think second guessing Porsche engineers is worth it.
Years ago before computers ran engine systems using stiffer mounts probably worked fine.

 

Bumping this. Got around to doing this mod to my newish engine mounts.
Can confirm, no increase NVH and a more solid feeling rear end. A little messy, but worth it.

 

That's sort of how I feel about just about anything on my car. Seems like there are either negligible gains to be had with [insert your mod here] and/or [insert your day-to-day compromise here] after doing so. The most drastic mod I did was to replace my orange side markers with clear, and even then OEM for the win. If mods are your thing, go for it. I just don't get it.

 

Maybe true for engine stuff, but mounts are a balance between NVH and sportiness. If you want something sportier, there's nothing wrong with changing these out. They're more of a preference thing, to a point.

 

Right. Porsche went as far as dynamic motor mounts (PADM) to offer best of both worlds. Unfortunately that solution is crazy expensive. I've had semi solid mounts and they are too much for me... This solution seems like a decent compromise of $, comfort, and performance.