Engine Mounts

pdsman53 · Postby **pdsman53** » Mon Mar 15, 2021 10:30 pm

Hi guys,

For those newby's, that are contemplating replacing engine mounts....due to the frustration of missed gear selection on track, when another car is up your klacker.

I just fitted an AWR hot side and an MX5 Mania Competition Engine Mount, on road registered Track day 1999 NB8A.
Our existing 180k km, OEM mounts were still in reasonable condition, but substantial engine wobble.
.....a sh#tty, sh#tty job, but very much well worth the trouble.

The existing mounts came out via the wheel well, with a lot of fiddling (patience reqd)....contrary to lot of blogs I've read, like:-

..."remove the intake manifold support bracket"
..."remove plastic shroud under engine"
etc...

The AWR went back in the same way....no walkers!!

However the Comp. Mount (which was 5mm thicker)...needed a little metal grinding on the bottom flange, so it would clear the Brake lines on re-entry.

Also fitted an MX5 Mania short shifter...to confirm the 2nd to 3rd shift.
The result was extraordinarily good!!!...much better than expected.

No engine wobble....but more vibration/noise (open the window).

Do it...if you can't fit an engine damper.

rascal · Postby **rascal** » Tue Mar 16, 2021 6:56 am

pdsman53 wrote:Hi guys,

For those newby's, that are contemplating replacing engine mounts....due to the frustration of missed gear selection on track, when another car is up your klacker.

I just fitted an AWR hot side and an MX5 Mania Competition Engine Mount, on road registered Track day 1999 NB8A.
Our existing 180k km, OEM mounts were still in reasonable condition, but substantial engine wobble.
.....a sh#tty, sh#tty job, but very much well worth the trouble.

The existing mounts came out via the wheel well, with a lot of fiddling (patience reqd)....contrary to lot of blogs I've read, like:-

..."remove the intake manifold support bracket"
..."remove plastic shroud under engine"
etc...

The AWR went back in the same way....no walkers!!

However the Comp. Mount (which was 5mm thicker)...needed a little metal grinding on the bottom flange, so it would clear the Brake lines on re-entry..

I fitted the exact same combo mounts to my nb8a a few months ago.
Just fitted them from above, jacking the motor to fit. A fairly simple job, did the comp mount first and awr one last which was dead easy.
Also I didn’t have to grind anything on the comp mount? It just slotted straight in..

Roadrunner · Postby **Roadrunner** » Tue Mar 16, 2021 8:49 am

It's amazing how much difference it makes. I put a NitroDann hotside mount in mine a couple years ago (stock cold side). Mount was a bit tired but I didn't think the motor moved that much and didn't miss gears etc, but comparing videos afterwards the gear stick now moves significantly less!
Very happy.
Do you get extra vibration at idle with the AWR and Comp combo? I do but only at certain ilde RPM, if it goes up slightly, say 50rpm from normal I get a subtle back massage and the bonnet dances water droplets a bit

ManiacLachy · Postby **ManiacLachy** » Tue Mar 16, 2021 8:57 am

I've been running the Supermiata version of the Mania solution. Mania do it better by putting the poly mount on the other side to Supermiata. Supermiata's setup pulls on the rubber mount and compresses the poly mount as the engine twists, which will eventually tear the rubber more easily than if it were on the compression side as Mania have it. I did find a bit of NVH just above idle, but once running it's not noticeable and the performance is definitely worth it with either setup.

I've now got a crank damper on the snout, but haven't been able to put it to the test on the road to see what the combined result is. My hope is that it brings the NVH back down to near OEM levels, but that might be a bit optimistic.

AWR now do softer durometer poly mounts, with bigger bushes. I've been considering running them on both sides, this should give a really solid mounting, but disperse the vibrations much better than would be with the regular old AWR polys. I think I'll go this way when I rebuild the motor,.

The American · Postby **The American** » Tue Mar 16, 2021 5:44 pm

I have the supermiata mounts on both sides (coupled with energy suspension diff bushings). It was quite buzzy at first, but seems to have settled down now.

I really did not like the experience of changing 2-3 without the stiffer arrangement. Too often it felt like a journey into the unknown with no known destination. Now, the shifting experience is much more predictable.

StillIC · Postby **StillIC** » Thu Mar 18, 2021 7:49 pm

Regarding pulling versus pushing on mounts:

I have the Mazdaspeed rubber engine mounts. I built and installed a little 'tell-tale' movement monitor: a piece of thick straight wire attached to the front of the engine passing through a hole in a panel fixed to the chassis, with little plastic discs on the wire on each side of the panel with the hole.

What I found was that movement in both directions was equal within a millimetre at about 10mm maximum in both directions at the bottom of the cam cover. Of note, I have a high powered 1.6 atmo engine. But from this I assume that there is as much pulling on each mount as there is pushing on each mount. Therefore it probably doesn't matter which side the poly bush is placed on (in my case). Drive torque or engine braking or just vibrating, each mount will always feel some pull some of the time.

The only question is the temporal distribution of pull on one mount versus the other mount (how much time one is pulling versus the other), and this will vary between different cars, different use cases and different driving styles.

Bauer · Postby **Bauer** » Tue Jul 27, 2021 10:49 am

pdsman53 wrote:I just fitted an AWR hot side and an MX5 Mania Competition Engine Mount, on road registered Track day 1999 NB8A..

Glad I came here and searched rather than ask on FB.

Coming down the pecking order to a daily or even a ‘spirited’ weekend car where I would assume the above would be overkill, is there merit in putting a competition mount on the hot side and oem style on the other? Or just do the comp on both sides? Or don’t bother at all and just do oem on both sides?

rascal · Postby **rascal** » Tue Jul 27, 2021 11:07 am

imo, you don't need the extra stiffness of the non OEM options unless you have significantly more than factory power. My 270km stock NB8B still has OEM mounts and doesn't have any extra movement.

Having said that, if it was me I'd just put the Mazda Motorsport (competition rubber ones) on both sides and be done with it.

I originally swapped in the the comp ones into my NB8A and didn't notice any extra NVH compared to the factory originals.
In fact if I didn't put them in myself, I wouldn't have known they were different....

When I went to the rotrex, I swapped to the awr hybrid mounts to cater for the extra torques, and you def notice the NVH change with these...

StanTheMan · Postby **StanTheMan** » Tue Jul 27, 2021 4:07 pm

Bauer wrote:
pdsman53 wrote:I just fitted an AWR hot side and an MX5 Mania Competition Engine Mount, on road registered Track day 1999 NB8A..

Glad I came here and searched rather than ask on FB.

Coming down the pecking order to a daily or even a ‘spirited’ weekend car where I would assume the above would be overkill, is there merit in putting a competition mount on the hot side and oem style on the other? Or just do the comp on both sides? Or don’t bother at all and just do oem on both sides?

I did this combo on a 1.8 conversion. also got the short shifter. OMG I fell in love with the car all over. wouldn't have anything else now. My car is a daily.
yes it is a little noisier, yes some bolts came loose initially.....but I'm a boy racer in my 50's . The car is exciting to drive. The gates for gearbox on an old 350k km gearbox are precise and will make you smile from ear to ear.

Ned Loh · Postby **Ned Loh** » Wed Jul 28, 2021 5:45 am

Has anyone noticed any nuts or bolts coming loose from the increased vibrations? I don’t mind the extra NVH, but don’t really want parts coming off!

StanTheMan · Postby **StanTheMan** » Wed Jul 28, 2021 6:45 am

Ned Loh wrote:Has anyone noticed any nuts or bolts coming loose from the increased vibrations? I don’t mind the extra NVH, but don’t really want parts coming off!

yes in my case the were some. in my case it was the drive shaft & brakes .... whiche were both undone during an engine chagnge .they were perhaps not tightened correctly in the first place.

PaulF · Postby **PaulF** » Wed Jul 28, 2021 8:47 am

I've been running competition mounts for years in a street/track car and never had bolts coming loose from vibration.

rascal · Postby **rascal** » Wed Jul 28, 2021 9:33 am

Similar to PaulF's experience, I ran the comp mounts for 9 years and never had any loose bolts.

I have now swapped to the AWR mounts, which are another level of NVH, and do notice the bolts on the exhaust heat shield backing out somewhat regularly.

RS2000 · Postby **RS2000** » Wed Jul 28, 2021 10:58 am

Bauer wrote:Coming down the pecking order to a daily or even a ‘spirited’ weekend car where I would assume the above would be overkill, is there merit in putting a competition mount on the hot side and oem style on the other? Or just do the comp on both sides? Or don’t bother at all and just do oem on both sides?

Like rascal, I'd recommend the genuine Mazda Motorsport mounts, which are rubber, but a bit stiffer than the original. I use them in my NB8A track car.
Part no. NAY1-39-040. Would be able to get them from Amayama.

Roadrunner · Postby **Roadrunner** » Wed Jul 28, 2021 1:50 pm

StanTheMan wrote: yes in my case the were some. in my case it was the drive shaft & brakes .... whiche were both undone during an engine chagnge .they were perhaps not tightened correctly in the first place.

Oh wow, I’ve had my NitroDann hot side in for a while now. I have developed a small rattle in the centre of the dash near the windscreen but have not noticed brake bolts etc loose when changing pads.
Maybe I should swing a spanner off everything in the engine bay just to double check though!