AlwaysBroken

I'm thinking of swapping out my mounts since I'm going to be under the car soon. I didn't swap them out during the recent rebuild because I didn't think I'd need to. I was wrong.

From what I can tell, Fab9 and 949 are both selling the 70 dur AWR poly engine mounts with their own branding. I'm just going by their sites, which seem to depict products that are identical in every way. Am I wrong?

I'm already running the mazdacomp mounts for a while now and I've never really been blown away by them. Small increase in vibration, small increase in firmness, meh.

My car is plenty loud, so I'm pretty tolerant of NVH (I think). I'm not sure of how accurate my perceptions are. I want a bunch more stiffness, but I don't want to feel like I'm riding in a rock tumbler. I also don't want to have to deal with all my gauges going haywire, cracked windows, detached retinas or what have you. I am ok with some noise/vibration but I don't want **** to actually break.

Hammerhead

I went with the hybrid combo of 70 DURO SuperMiata race mount and the 70 DURO MazdaSpeed Comp mount on the project 93LE. I can't wait to get her on the road so see the result.

patsmx5

iTrader: (16)

I run the 70 dur AWR mounts in my daily. It shaked, was pretty noticeable, but I could tolerate it. Then I built a new motor and paid to have it well balanced. Huge difference. Now if shakes about 10-20% more than a 100% stock car with brand new stock motor mounts. It's not even noticeable, probably 10x smoother.

psyber_0ptix

iTrader: (4)

I had switched to the 949 Hybrid mounts after running Mazda Comps, and it felt pretty good without noticeable NVH (partly because my exhaust is ridiculously loud in cabin) but then switched to the full Low NVH Blackbird Fabworkx drop mounts and noticed a lot more initial harshness, but they've loosened up and still feel awesome. Just another data point.

The Australian

I've instated 949 Racing mounts to both sides + poly diff mounts.

It's not worse than my diesel pickup.

AlwaysBroken

Balance means just weighing the rods plus pistons or does it mean adjusting the weight distribution of the crank as well?

concealer404

iTrader: (3)

I run AWR 70s and Delrin diff mounts. It's fine. Would daily drive.

mmmjesse

mine shakes like mad at idle but is very smooth once you come up off idle. love the way they help transmit power.

patsmx5

iTrader: (16)

Shop did it, not me, but they did adjust the crank too.

dleavitt

iTrader: (1)

After this weekend I should be able to give a report on the Blackbird Fabworx "Low NVH" drop mounts. There was a fair bit of vibration at idle when they were first installed (with my old motor) but that could have also been my piston rings convulsing as they died. New short block is balanced, which should help.

AlwaysBroken

The Blackbird street mounts are oversized poly? How do the Blackbird mounts compare to the AWR 70 durometer stuff? If the track one or the street one closer?

dleavitt

iTrader: (1)

Yes, oversized poly bushings compared to most other mounts. The Street/Low-NVH is supposed to transmit less NVH than other poly mounts such as AWR and V8R. Their normal ones should be equivalent I would think.

This is just based off my reading though, I haven't ridden in a car with AWR mounts. I'm going from (torn) stock mounts and stock diff bushings to BBFW Low-NVH drop mounts and delrin diff bushings. Picking up the car from the shop tomorrow evening and going on a drive with the local Miata group on Saturday.

AlwaysBroken

What I've gathered from googling and watching testimonial/review vids is that:
-awr mounts significantly cut down movement of the entire drivetrain from engine back to transmission- things wiggle instead of swaying and they vibrate instead of bouncing
-the awr mounts don't seem to be completely horrible on the street, certainly no worse than my exhaust and worn mazdacomp mounts, which are tolerable at idle and not really noticeable cruising around
-there was a delrin based mount (not awr) that was slightly better from a performance standpoint but the vibration was so bad it damaged everything in the car- since Emilio hated those and uses and sells the AWR stuff, presumably this means AWR won't shatter my bones or anything
-the 949 hyrbid and the street blackbirds seem to be most of the way towards the mazdacomp on NVH and maybe halfway towards AWR on removing drivetrain wiggle. I think if I had a more stockish noise exhaust and less power, I would probably go this route.

In conclusion, I think the street/hybrid approach is just another half measure on the way to going full poly, for me at least. My personal experience is that mazdacomp mounts (40 PERCENT BETTER THAN STOCK SO HARDCORE) were a barely noticeable upgrade to me with pretty much zero noticeable increase in NVH. And they wore out again after a few years. The youtube vid (CarPassionChannel is run by a guy with a turbo miata) I saw of the engine movement with the AWR mounts (he stuck a camera under the hood while driving around) convinced me to go AWR. It's what I wanted from the mazcomp mounts in the first place.

Blackbird

There's going to be fair bit of NVH until they are broken in, typically within a few hundreds of miles.

AlwaysBroken

What does breakin do on poly motor mounts? Does the urethane soften or something?

concealer404

iTrader: (3)

Mostly letting things settle.

Not everyone's subframe is 100% perfect. Until the poly "wears in" a little bit, it'll be loaded up a bit more than designed.

JoshEE

I have a couple thousand miles on the blackbird low NVH stock height mounts and poly diff mounts. There is significantly more NVH transmitted with this setup than with my worn stock mounts. At idle, especially when the A/C compressor kicks on and the idle speed goes up, you get a pretty good massage through the seat and lots of rattles inside the cabin. It smooths out with speed but I do still notice quite a bit more noise on the highway, but I have done other stuff to the car that contributes to that so it's hard to tell how much is the mounts themselves. I'd hesitate to recommend this setup for a DD. I have not tried mazda comp mounts.

With that said, I love the setup and there's no way I'd go back to stock. The shifter feel and accuracy (5 speed w/ the miata roadster kit) is amazing, and gives a lot of confidence you're going to hit the gear you want. The blackbird pieces are also very nicely designed and built, I've had a few miata guys comment/ask about them at track days when they're looking around the engine bay.

Blackbird

We actually shot a video in the shop just a few days ago to show the difference between the OEM mounts and our Competition mounts (NOT the Street Performance lower NVH version), I still need to edit it before I post it, but it's stunning how huge the difference is in engine motion... hence the reason missed shifts are so common when driving hard.

AlwaysBroken

I ended up ordering the awr 70 durometer from Fab9, should be arriving later this afternoon. Going to get started in the garage now, will update after I've driven on them a bit.

Thanks to everyone for the advice.

ryansmoneypit

iTrader: (6)

People still buying stuff from fab 9? Amazing.