I've got some fairly simple questions - I've searched and read and I just want to confirm some things

The black engine mounts are steel and better (easily upgradable with polyurethane)?
The grey engine mounts are aluminum and are worse (and need machining/replacing for upgrade)?

The USDM passenger side mount is the mount that takes the strain on engine load, and therefore it is more important to upgrade that side to polyurethane?

Thanks

 

driver side mount was aluminum from the factory, mazda upgraded it to steel for both sides. yes the steel mounts are more easy to work with for replaceable mounts like urethane. the aluminum driver's side mount is also usually is first to fail by a large margin.

and urethane mounts suck for vibration by the way. not sure why everyone wants them.

 

I'm considering picking up one poly mount for the USDM passengers side... if that is the "compression" side, and also the side with the steel mount, it seems like a no brainer to just do the one

 

compression isn't the issue though, it is tension which is why the driver's side often rips. seems odd mismatching mounts though but i suppose it will last longer, if you swap the sides you were thinking of.

 

I just replaced my mounts with the IR Performance "street" urethane mounts and I don't notice any more vibrations than before. Also replaced the aluminum arm with a steel one while I was at it.

 

I had some that vibrated but they have been replaced softer urethane and it's almost like stock.

 

Yeah same here, got very little vibration even with them fully compressed, and then only from a dead stop. They're also cheaper and easier to work with getting the engine out of the car, for me at least.

 

Banzai Racing motor mounts http://banzai-racing.com/store/FD_po...or_mounts.html

Steel and aluminum



Steel only



This is the condition of the majority of the drivers side aluminium mounts that we remove from vehicles.

 

My car has very low mileage, so I don't think my driver's side mount would be torn up like that one... however I get some wheel hop when launching and shifter movement with loading/unloading the engine
I'm definitely replacing the diff bushings, and I was hoping I could replace the engine mount bushings without removing either of the mounts. But alas, it sounds like I'll need to take things further apart than I had hoped so that I can do it properly
What else is winter for?

 

Yep.

I would revise this to say: I'm not sure why ANYONE would want them!

They vibrate ..... PERIOD!!! Those who say they are not so bad have just gotten used to them. They suck, and there is no reason to use them unless you have a dedicated track car, and don't care about vibration.

To the OP: Start your engine, and open the hood. Rev the engine and watch to see if the engine lifts. If it doesn't lift, your mounts are probably fine.

 

If you are just upgrading to polyurethane mounts then it might not matter if you use a steel or aluminum mount.

The aluminum mounts in the stock configuration fail because the rubber mount is just "glued" to the almuminum. The rubber will tear away from the aluminum and thats that. The steel mount has a bolt that goes all the way through it and holds the mount together.

When you install polyurethane mounts you need to drill a hole through the aluminum mount if you use it. Of course the aluminum side will require machining or a special mount because it has a hump in it and is not flat like the steel mount.

I installed the Himini Racing mounts and I dig them. Yes they vibrate a lot. But hey, my car is a bridgeport and not very pedestrian to begin with. I think the mounts make the car easier to shift and launch because of less movement in the drivetrain.

 

I think it's in the design as well as material. NOLTECS DO NOT vibrate (NVH). No difference from OEM and I would notice. I'm a very sensitive guy.
They DO control movement much better than OEM and do require both arms be steel. Unfortunately they're hard to find here but some other designs from Garfinkle and others look promising. I just don't have personal experience with them.

 

Really? I like mine... Are you guys talking about the Banzai style urethane or the sandwich kind (link)? I made a set of the sandwich style mounts for my car and yes there is a little bit more vibration, but it's really not bad with the sandwich style mounts.

The problem without using the bottom sandwich piece is the thru-bolt transmits vibration straight to the subframe, therefore the rest of the car.

If I did it again, I would use 60 durometer urethane instead of 80 because of the slight vibes. Buuut, my shifts are always positive and the drivetrain feels solid as a rock. Love it.

 

Our mounts are poly and they do not vibrate. Some other mounts on the market are too stiff and may vibrate so it is important to chose the correct mount for your application. Its all in the selection of materials and design. If the car is mostly track driven then you may not care about the vibration. Most of my customers don't want any vibration so I designed these to eliminate it. The stock aluminum driver's mount I find broken on 90% of the cars I see. Take a prybay and lift up under it and you will see how much it moves.

 

this is false actually. the stock steel side removable mount is glued to each side of the pad as well. if you're curious, dissect just about any stock mount from any manufacturer, it is standard procedure to make mounts completely isolated.

in fact, through bolt style mounts are a poor design as they offer no flexibility AT ALL when tension is applied and act like solid mounts, which is where vibration mainly comes into play. this tension also has a tendency to shear even grade 8.8 bolts, of which i have seen several from vendors on this site. i won't name names but i'm sure they already know that it is also an issue but still produce them anyways. if you want a through bolt design they should have an additional puck above the mount to absorb the tension portion of the mount as well to hopefully save the bolt.

in all honesty the stock mounts are really not that bad, they have a stainless strap that holds the mount when the mount does eventually fail. the main reason that the mounts fail is due to oil impregnation which softens the rubber and allows it to debond. FC mounts were horrible because they have no strap to hold the mount in the case of rubber fatigue. OE FD mounts would last much longer if they had an umbrella cover to keep oil off them from oil changes or leaky oil pans.

 

So in my situation, where I have a low mileage car (25-26k kms) that doesn't have any seeping/weeping of grease or oil, but I have more drivetrain movement than I would like (shifter movement/wheel hop), what would you suggest?

I was thinking diff mount bushings and engine mount bushings, but now I'm not so sure

 

wheel hop actually isn't that common in FDs unless you have crappy tires or blown rear struts.

but regardless of mileage, if the mounts are original i'm sure the almost 20 years of sitting has done one or both of them in. the IRP mounts do look ok, just keep in mind the rigidity of the materials used when going with a material like delrin/poly mounts. as well keep in mind you may wind up shearing the motor mount bolts with those type of mounts.

just about every mount i have seen out there will work but each has it's own pros and cons, the stock mounts just aren't as horrible as many people make them sound aside from their price..

 

Install a differential brace to reduce wheel hop and shifter movement http://banzai-racing.com/store/Banza...ial_brace.html

 

Can't use a diff brace in my autocross class
Apparently they're worse than aftermarket diff mounts when it comes to vibrations anyway

 

Not trying to say that the bolt goes all the way through the rubber and steel mount - of course it doesn't or what would be the point of having the rubber mount? However, there is a bolt attaching the rubber to the steel mount and just "glue" attaching it to the aluminum mount. The glue on the aluminum fails before the other mount just splits internally.

Moving forward - one thing that the polyurethane bushings have done is amplify - or rather make the slop in the rest of the drivetrain more noticeable. Particularly there is more noticeable movement in the rear end now. Not much but to the extent that I'm looking at using polyurethane mounts on the diff or adding a brace to the front of the diff. I think the diff brace is the better option.

I don't mean to blame the engine mounts for the rear end woes but - hey, the car is almost 20 years old and stuff wears out.

 

Whoever is telling you that has no clue what they are talking about. Fact is the diff brace actually reduces the amount of vibration that could be caused by the installation of poly mounts. The FD only has 4 mounts for the entire drivetrain, 2 motor mounts and 2 diff mounts, this leave the potential for a lot of movement. The diff brace prevents the nose of the LSD from climbing during acceleration, this pretty much eliminates the trans movement you previously complained of. Additionally is stops the engine from rocking front to back, which prolongs motor mount life (both stock and poly). Obviously if your motor mounts, diff mounts, or PPF are already shot you cannot rely on only one component to fix all that ails a vehicle.

I am exceedingly picky when it comes to annoying noises in my cars. I have our poly mounts and our diff brace in my 600+ whp 20B street FD, there is not a single vibration of any kind. Yet the drivetrain is just about as movement-free as it can get. I also have Powerflex poly bushings for everything else in the car. Everyone that has ever riden in this car has commented of how smooth and quiet it is for such a high HP FD.

Anyway good luck with your quest for stiffening your drivetrain.

 

MY 2 CENTS ......gonna agree with Banzai....i have poly motor mounts (fortunate enough to have steel on both sides) and have much less movement than stock mounts (referring to shifter) and i will upgrade to poly everything in the not too distant future because of how smooth it is.

 

 

the puck. twist it and notice there is no interference from one side to the other. take most aftermarket mounts with a through bolt and notice the bolt passes all the way through and takes all the tension from the engine forces.

IRP has an isolator on the tension side to allow it to have some breathing room.

 

I have tried and installed a few of the aftermarket motoWpr mounts and in my personal opinion (for me) I like stock motor mounts much better, too bad they are so expensive..