i am in need of new motor mounts. I am considering 3 options.

a. go with stock motor mounts, I can get a new set for $280

b. go with rotor motorsports urethane mounts. approximately $340 after core

c. make my own. under $100
has anyone ever made their own for a FD? how did they work, what did they look like, what material did you use, etc.????
I (or my personal machinist, a.k.a. my brother ) could probably make some decent ones, so whether we can do it is not really much of an issue.

any suggestions?
i'm not really concerned with vibration as long as it's within reason and not shaking my teeth out

in my eyes, all three are basically a wash in terms of money and time input. just want some opinions on what you guys might do in my situation.

Thanks,
Ryan

 

if you can get the stock set for $280 i would just go for that. that sounds like a good deal. having sat in a friend's car who has had the rotormotorsports mounts in the car i have to say that the vibration is substantially greater than the stock mounts. in fact you can feel the vibration from the passenger seat. of course ymmv. good luck.

 

hahahahhahahaha
yeap vibrations.....between 1000 to 1800 rpm
all the time.

i don't know why some people here said no vibration after a while...

reza

 

get the stock ones or some used ones with low miles and then get a really nice engine brace so you never have to get mounts again

 

My mechanic makes a nice engine torque brace . If you need info just PM me

 

Get stock ones or MS

 

I'd love to know where you found a set of stock mounts for 280. Cheapest I found for ONE was 238....

 

process for getting good deals on stock parts:
A. join some sort of racing club (ie. SCCA Solo2)
B. get an account with mazda motorsports
C. order parts (has to be non-body related if you only race Solo2)
D. Save money

I am a little bit off, it'll be a little under around $295 for a pair from mazda motorsports

 

I was gonna ask where you could get new ones for $280.

Drivers side mount is $148.xx from Mazda Motorsports.

Jeff

 

looks like stock it is. thanks everybody.

btw, jeff, i should just use 2 drivers side mounts, right?

 

Hmmm. I don't know if you can use 2 drivers side mounts. Why would you do that?

Oh and my post above should say pass side mount. I just ordered a drivers mount about 30 min ago and it is also in the $148 range. Pass side mount has a big heat sheild on it, probably should keep that since it is right near the turbos.

 

Whats the website to mazda motorsports?

R.K.

 

http://www.mazdamotorsports.com/weba...0001&langId=-1

also jeff, i had read somewhere that you should use the passenger(?) side mount for both since it was a heavier duty mount. plus i could only find the part number for one of the sides. called mazda motorsports and got it all figured out though

for future referance for any one looking for the parts numbers:
Left engine mount: FD01-39-050A
Right engine mount: FD01-39-040D

 

deleted

 

I installed a set of the rotorsports mounts, but hockey-pucked the bottom of them. They feel totally solid, and don't vibrate one bit. Much better than my stock mounts w/ torque brace. If you want, I can try to dig up pics of the pucking.

 

newbernd

, pics please....I want the urathane mounts but dont want vibration...your method solved it huh?

 

I've got the urethane mounts, and the vibration isn't a big deal... Especially considering the comfort concessions most people make with suspension upgrades.

However, if this 'hockey puck'ing gets rid of all the vibration, it's worth understanding. Please explain, thanks.

 

New Stock mounts with Rx7 Store Engine Torque Brace

 

*edit: I seem to have trouble uploading images to the forum, so I'll have to host them from home. Patience is key.. *

I didn't do anything complicated.. but let me first explain where I believe the vibration was coming from.

Any stock style engine mount, or most any vibration dampener for that matter has a certain aspect to its design. The dampening agent (rubber, urethane, hydraulic piston, etc...) is either "floating" between what it's dampening and a solid surface, or is sandwiched around either of the surfaces and firmly attached to the other.

The Stock mounts are of the first variety. They consist of a solid arm that firmly mounts to the engine. Rubber is bonded in between that arm and a flange with a bolt used to attach it to the frame, in essence making a rubber sandwich. What's important here is that it absorbs vibration in either direction. (A pull or a push)

Why does this suck? Because someone's always launching harder than the strength of the bond can hold, and we always break mounts at this bond.. (setting aside the fluid leakage problems..)

Broken Mount

What Brian at RotorSports has done is to eliminate this possibility of splitting. He's basically drilled a hole through the arm of the mount and passed a long bolt all of the way through it, through a block of urethane (dampening agent) and through the frame.

Urethane Mounts

What's the difference? His mount only dampens upon compression. It's basically a solid mount going in the other direction. Now you can say that if forces are exerted in the other direction, then the other mount would compress. Sure. But not without exerting some stress on the bolt. Which vibrates. For a competition style mount, this goes unnoticed because on the track you're not looking for comfort, you're focused on performance. On the street, we like to be pampered.

Mounts installed

What I did was to put another dampening agent on the opposite side of the frame. This has converted the mount into the second style of mount, where the frame of the car now floats between two dampening agents. I didn't have any urethane rod, and wasn't about to shell out McMaster $$ for any when I had a couple of $0.99 hockey pucks available. With a hole saw I trimmed then down to something that would fit, and cut about a third off of the width. This and a big-assed steel washer from the Depot fit perfectly on the generously sized bolts that Brian used. Lock-tighted it up, and viola.. no vibrations.

Mounts Pucked

Actually, that's not 100% true. I had a little to begin with, but it went away with about a week of driving. I believe that the urethane does loosen up a little.

Sorry if that was long winded..

 

Hmm.. My post aborted 1/2 way through (go forum!), and didn't update the last post ID, or trip the subscriptions. Here's a bump to those subscribed.

 

Pettit says the driver side mount is always the one to go bad, but the passenger side should be fine

 

nice write up. i'm about half tempted to just make my own now luckily i haven't ordered the stockers yet. probably should make my mind up, huh?

 

Pass goes bad to just not as often. Oil leaks ruin the rubber of motor mounts and cause them to fail pre-maturely.

Jeff

 

I would just like to clear up the name of the company that sells the urethane mounts. They are www.rotorsportsracing.com
Not the now defunct r o t o r m o t o r s p o r t s. I'm not sure if the name-band is off or not so I typed the name of the company in encryption.

Garrett

 

newbernd, great info and great mount type explaination

i wonder if we can get bryan to make a version with this kind of fix included