Motor mounts
 

Hey guys,
Have a jackson racing kit, and have had a lot of movement in my drive train. I replaced all of my bushings, and diff bushing with poli bushing. Car turns great, but still the car will yank to the right when I accelerate.

Anyways, today I got around to replacing my motor mounts and found the problem. Have any of you actually seen any mounts completely split? My mounts had nothing holding them together. Pictures below.

Kind of scary, when I think about how hard I have been driving the car. Surprisingly enough, the car didnt ideal rough or have any obvious signs the mounts were bad.

https://www.miataturbo.net/attachmen...ine=1395547544

https://www.miataturbo.net/attachmen...ine=1395547544

Yup, completely normal and common problem when you ignore a maintenance item like motor mounts.

Well, still trying to go through everything since I purchased the car. Seems to be a lot of items neglected.

To be fair, it's only really a maintenance item on the NA/NB MX5. If you're not in the know that they're prone to failing then you're not going to know to check/change them.

Motor mounts fail on pretty much any and all cars.

Hydraulic ones leak or collapse, rubber ones tear and disintegrate. There may be one or two that are beautifully engineered that last a long time, but for the most part no car is spared from the laws of physics, heat, vibration, and time.

My posts are very dry and bitter in this thread. The canadian in me would like to apologize for that.

Mazda was also sneaky and hid the motor mount behind a metal cover.

https://www.miataturbo.net/attachmen...ine=1395591805
https://www.miataturbo.net/attachmen...ine=1395591805
https://www.miataturbo.net/attachmen...ine=1395591805
https://www.miataturbo.net/attachmen...ine=1395591805

What did you guys replace your mounts with? I went with the Mazdaspeed ones. I found it a pretty mediocre compromise, at least for a daily driver.

They were just hard enough to add a little more NVH on a daily driver. At speed they're fine, but just driving around town, it can get a little fatiguing. It could be exaggerated by the stiffer suspension and bracing through.

Some of the transmission "yank" is reduced, but not enough to make 2-3 shifting more confident/faster. 11psi on a hotside, 6-rib MP62, if that makes any difference. Maybe I need one of those MiataRoadster short shifters, dunno.

Instead of getting a little of the best of both worlds, I feel I got neither. If my shifts still have to be slower, I might as well have gone with the OEM ones again and at least got some "quiet" back. Sorry for bringing up some "wine and cheese" complaints up in here... :greddy2:

I recently had my Mazdaspeed mounts (out of my MSM with ~50k) on it and they were not broken but cracked already.

Luckily I had Mazdacomp mounts kicking around from my last engine build I could use. Symbolized by the white bar on the side of the mount. My Mazdaspeed mount looked like any other miata mount.

I used Mazdacomp mounts to replace my stockers. I immediately noticed NVH when I started the car versus worn (not torn) stock, but I also have poly diff bushings. My shifts feel great, even with a touchy 3rd synchro. Have you rebuilt your shifter yet? Running FMCFSMTF/Redline MTF?

And on general motor mounts, if they have rubber they need to be replaced eventually. Period. We had a RWD Caprice come in to work one day that "was making a clunking noise." Both left and right motor mount inserts were *gone*, and the engine was clunking the intake manifold on the hood. Big dent.

Thanks, I'll try to find a Miata owner who has MazdaComps for a test ride before I take the plunge. From Preluding's experience, seems like that day will come pretty fast anyway.

If you're put off by the NVH of mazdaspeed or mazda comp mounts, you probably don't belong on this forum.

Try Miata.net.

If you're put off by the horrible performance compromise of Mazda comp mounts, you probably DO belong on this forum.

Man i hate those fucking mounts.

I'm not put off. I just said I noticed it immediately vs. stock.

Don't think I'd like the poly mounts on my DD, although I might try putting one on one side like is suggested here just to see how it feels.

I'm going to leave this right here(this is how it should have come from the factory):
SuperMiata Race Motor Mounts 90-05 Miata

Note to self: Call Emilio to see what he has in development before spending money on ANYTHING. I bought my Mazdacomps probably six months before those came out.

Those style of mounts have been available for years and years. AWR first, probably.

LOL

"NOTES:
We do not recommend these mounts for street use. The increased NVH will be too much for just about any driver."

When is 949 going to release the engine mount equivalent of tecan coilovers? I'm all about that smoooooooth ride.

For me it is all about what you expect from your car and how much power you are putting out.

My Miata had comp mounts and full poly and it rode very smooth. Then again, in my head, I didn't need it to be a perfect daily driver comfort level of smooth so I wasn't in the mindset to notice it.

Now in my Jetta, if it had been bad, I would have noticed straight away. I want the Jetta to be luxury levels of smooth because highway bitch.

Gotta pick comfort vs performance, you always compromise if you are looking for both.

Putting a poly mount on one side accomplishes NOTHING. I could HARDLY tell the difference between one mount and two. Either be a moron and run two poly mounts or be smart and run two mazda comp mounts.

Hmm... thinking about this made me wonder if anyone has come up with a variable durometer mount using something like a magneto-rheological fluid. Sure enough, a quick hit on goggle turned up this: BWIGroup - Suspension - MAGNETO-RHEOLOGICAL MOUNTS

So apparently, you don't necessarily have to pick comfort or performance, but I'd bet you'd sure have to bring the money.

They might. I suggested to AWR that they look into making an even softer version than the 70 duro mount. Its not that the 70 duro mounts really make the car or interior vibrate too badly, they're just loud. If you put them on a car with stock exhaust the car is much louder sitting in the drivers seat or sticking your head over the cockpit than standing 1 foot behind the rear of the car. If I was 18 I could probably daily drive them without complaining. Fuck it, I could probably still now since I pretty much only street drive with ear plugs in to cut down the wind noise so I can hear important things like the radio and sirens (yes with ear plugs in on the highway its easier to hear sirens than without the ear plugs).

For soft street cars are the Mazda comp units too much? Preliminary research is split -- half the people say, "Yeah, I barely noticed some extra NVH at idle, but otherwise it's fine" and the other half say, "It's a bad compromise, I'm not getting enough benefit for the increase in NVH."

Is it worth trying a 50/50 solution, say Mazdacomp on the driver's side, stock on the passenger side? Or is this just a dumbass setup that will put all the stress on the stock unit and cause it to fail earlier?

I'm going with "dumbass setup."

The Mazdacomps offered no more NVH than the stocks mounts on the MSM.

And as far as i could tell, offered no more stiffness/drivetrain control, either.

They're a little buzzier than stock on the 95 we have now, but the whole thing still feels like it's attached with silly putty. I will never ever ever do mounts on one of these cars again without just jumping to the 70a SuperMiata mounts at a minimum.

So what i am getting there are no good motor mounts besides these 949 ones?

The MSM already had stiffer mounts than the regular Miatas, though, didn't it?

I mean, I'm running what I'm assuming are original 127k mile mounts. I'd be surprised if both mounts aren't basically torn in two. I don't need 70a mounts, just something that keeps the motor in place and the shifter from waving around.

Depends on your preferences/goals.

basically. The stock mount design is terrible no matter what material you put in it. I would really like if AWR did make a version with maybe a larger and softer bushing for the "big" power street driven guys that just rip the stock bushings out in a couple hundred miles. The poly stock style mounts only constrain movement a little more but transmit as much or more NHV than the same stiffness awr.

The shifter will still wave around with brand new Mazdacomp motor mounts and ES poly diff mounts.


Been there, done that, was thoroughly shitty that i spent the time and money doing that job for barely measurable improvement.

I don't think the mazda comp mounts are that harsh, but I haven't installed the polly diff mounts yet.

Before i post i'd like to acknowledge that i know i'm going to piss everyone off with this.

I actually like my revshift mounts.

I will note that i did have my engine completely balanced when it was built.

My revshift mounts are not at all harsh, do not vibrate one bit, at cruising or hard driving. They are are very nice material.
I've been in vehicles with a typical "hard poly" mount system it was absolutely terrible.
I've yet to destroy the mounts i put on, but with a lifetime warranty i'm not worried about it.

The MSM mounts are nearly identical to stock non-MSM mounts. The Mazda Comp mounts are 35-40% stiffer.

I love my comp mounts. my dash rattles a bit when it's below 40 out now, but when it's warm, I can't tell NVH increased at all. This combined with stiffening up my diff mounts has made shifting great. I'm only running 7psi, though.