I recently picked up a set of full solid RSS engine mounts for my TT. Obviously I was concerned about the NVH I'd end up with bolting the mezger directly to the chassis. I brought my most expensive and sensitive NVH test kit with me on a back road drive to find out the results. While I can confirm there are some minor rattles at a couple spots in the rpm range I think the results speak for themselves on the noise level.



Though the Fabspeed MaxFlo might be over shadowing it somewhat haha


Professional noise and vibration test kit.

 

Nice writeup !!!! Just installed them in my TT.

 

Good stuff!

Just a word on those sensors, having two in back myself. They can sometimes be finicky, and may even shutdown with high NVH readings.

 

Be aware it's possible for added vibration to trigger the knock sensors.

 

Nice! How do you like the engine mounts overall? Big change to the feel of the car?

I plan on installing semi-solid mounts in the next week or so. Solids are a little too hardcore for me.

 

So far the knock sensors has been a non-issue. I read it might be a concern but it was all based on vapor from what I could find. No dobut it has come up, but chances are it's rare and more due to the sensors than the mounts. But, we'll see.

As far as the noise etc, is it louder? Yeah. Very mechanical, you can hear the character of the engine which I like. I decided sports cars should be loud so long as it's tolerable and I find the noise to be marginal so I'm happy. This was a concern and now I can cross it off as a concern. I do hear some vibration at various points but again it's a light buzz then it goes away.

Now for the handling, I've just done a bit of light back road stuff. You can tell the engine is part of the chassis and the end follows the front nicely. I imagine where it really shines is when you pick up the pace.

Taking my wife on the PCA driver intro track event the end of April. It'll be interesting to see where the engine is at on the slalom.

 

semi's ( i run wevo's ) will utterly transform the car if you've been running the original OEM stuff at this late date. there will be NO more slop and that tautness of the shifting under lateral stress will exceed anything the old OEM stuff provided. it's all about the tightening up of the weak links and the three connecting points ( t-mount & 2 MM's are primarily "it" ). the aded NVH is noticeable but a good balance for a dual duty car. you guys installing Solid Motor mounts on a street car are brave souls and clearly have dental insurance.

semi's mm's work just fine for me. but all is a trade off when eliminating rubber for added connectivity. but there is OFTEN a point of no return that is crossed when trading out solids when you you usually have THREE choices. middle is good lol and you won't be sorry with semis. GL.

ya pick your poison and elimination of components that make the car drivable on the "street" should be changed with much aforethought. it's real easy to cross that invisible line.

people rarely UNDER mod their cars, and overkill is all too common. caveat emptor.

 

I'm not sure why dental coverage would be required, we're talking about solid engine mounts not suspension lol. The road my daughter was sleeping on was a pot hole filled back road. Could you hear the bumps a bit more? Maybe? But it was surprisingly compliant. Zero regrets, let's not make it sound like they are something they're not.

 

It's always nice to see scientific testing around here...lol I used the same type of equipment but mine is a little older!! (she's 9) when I installed my exhaust I dropped her at school in the morning with stock exhaust and picked her up in the afternoon with full exhaust...not a peep or comment so it passed the test

BTW, did you go from stock motor mounts to the solids?? I'm planning to go with either semis or the 964RS mounts.

 

no, of course, good point. perhaps i overestimated the potential impact of having the majority of your connecting points going from rubber to bits of hard poly/plastic.

i think my general admonition or warning has more to do with going from stock to all racing bits. most particularly the three main points of engagement of motor to frame. e.g. mm's and the t-mount.

i know anecdotally of guys that have taken a stock floating mildly modded 996 turbo and with the addition of solid motor mounts, solid rear sub frame bushings along with cup cables and and and all manner of what trackers add out out necessity, only to find their once genteel dual duty car is all but undriveable for long distances on the street. you aren't there yet, thankfully.

of course, the key as i noted above is a happy medium and a measured series of component add on ons until one find their own sweet spot. you may have found yours!? and i salute you. many more have found that by removing vast amounts of components that once were encased in rubber, they began to regret the added NVH immediately. that this isn't you, is a good thing!

enjoy the tautness of the solids. the semis as I've said still offer *some* semblance of the cushioning the oems did, while eliminating all that awful and instantly noticeable lateral slop that a worn t=mount and old motor mounts will manifest to anyone paying attention.

but enjoy your setup. just remember, though it's only ONE mod that take a street car over the arbitrary "edge' of comfortable street drivability and its usually suspension related as you say.

 

I have the engine out of the car now, is there anyway to check if the mounts are bad?

 

I went from the original oem mounts to solids but I did the install while it was parked over the winter so it's hard to do a real direct comparison. But it is noticeable as the engine just follows the chassis.

As for the engine out and checking the mounts question, it should be really easy. It's an easy job to pull them with the engine in the car so now it would a snap. Pull them out and see how much play there is. It should very limited.

 

I could move the stud around by hand on my old mounts once they were removed. Definitely could not move the stud on the semi solid.

 

I personally don't know, but I'm trying to find an objective way to measure 'wear'.

This doesn't help you with the engine out, but I've seen some people comment on the droop visible with the exhaust tips relative to the bumper. A bit subjective for me.

I measured my motor mount to engine cradle gap as being 22mm's. This is on my '03 w/ 45k miles.

Hoping someone with fresh mounts can give us a dimension.

 

I have to agree with you and it's a slippery slope that's easy to go past without realizing until the car is no longer pleasurable for it's intended purpose.

I just recently went from my Fabspeed Maxflo, to stock for a couple mths, then back to Maxflo. NVH is dramatically different, and I enjoyed my car enough to do some long distance drives. But I really enjoy it with the Maxflo to wake me up on my morning commutes too. It sure would be great to have a push button jerkyll / hyde selector.

Does someone know which brand of semi mount allows for the most isolation. Something firmer than stock, but less than most semi's?