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-   -   solid mounts: lets see them! (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/solid-mounts-lets-see-them-830051/)

fidelity101 04-01-09 03:07 PM

solid mounts: lets see them!
 
Who here is using solid motor/trans mounts? I want to see what yours looks like, I may be making my own out of aluminum and I want to see how yours differs from stock.

I've seen some motor mounts on ebay and some semi solid ones (which looks like they are asking to break) and yes I know solid mounts will give more vibration but its not a daily driver and there is no stereo in it so I don't really care.

but what have you guys used/use? non plastic/poly mount wise.

:icon_tup:

87 t-66 04-01-09 03:13 PM

i have the himni solid mounts... they are just solid pieces of metal with a hole in the middle of them. probably not the best design but my car also isn't a daily driver. i do notice some vibration >4000 RPM.

http://himni-racing.com/images/FC%20...ounts%2011.JPG

fidelity101 04-01-09 03:19 PM

so you don't need to keep the stock diameter for the motor mount? when going to metal because they all look smaller or you just don't use the 2 piece motor mount system anymore?

I got access to a machine shop and I can get the hole straight and precise with a boring bar then just use grade 8 fasteners.

87 t-66 04-01-09 03:28 PM

those are the tranny mounts, i couldnt find the motor mounts on their site. i'm not sure of their diameter.

jgrewe 04-01-09 03:41 PM

You're correct on not needing to keep the stock dia. I grabbed a hunk 1.25 square tube and welded plates on the them to make them into little cubes. Then I drilled some holes through them. Actually having the holes a little off center helps because of how the stock parts line up. Through bolt them with Gr8 and washers and nyloc nuts and you're all set.

jake1191 04-01-09 04:13 PM

himni mounts come in 2 and 3 inch diameters although 3 inch i cant find

fidelity101 04-01-09 06:45 PM

I took measurements of the stock motor/trans mounts and the motor mount diameter is only a couple thousands of an inch away from 3" dead on.

jake1191 04-01-09 06:51 PM

yea the ones i have are the 2 inch diameter for motor mounts and they work fine. not exactly sure of the advantages/disadvantages if any of the 3 inch vs 2 inch

fidelity101 04-01-09 06:57 PM


Originally Posted by jfpimp91elkland (Post 9091971)
yea the ones i have are the 2 inch diameter for motor mounts and they work fine. not exactly sure of the advantages/disadvantages if any of the 3 inch vs 2 inch

2" weighs less and I imagine that 3" can handle more stress.

I'm gonna be going 3" circumference for motor mounts and matching the trans mounts size wise but I will probably go from a rectangle shape to a cylindrical for even stress all around the part.

jgrewe 04-01-09 07:05 PM

Keep in mind you are replacing a couple hunks of rubber, how strong do you think those are? You just need something to keep the driveline in phase so keep them close to the stock height. 2" aluminum would be plenty strong. I've even had 1.5" ODx.25" wall aluminum tube with a recess cut in the top and bottom to keep a washer centered on one of my old race cars.

fidelity101 04-01-09 07:11 PM


Originally Posted by jgrewe (Post 9092015)
Keep in mind you are replacing a couple hunks of rubber, how strong do you think those are? You just need something to keep the driveline in phase so keep them close to the stock height. 2" aluminum would be plenty strong. I've even had 1.5" ODx.25" wall aluminum tube with a recess cut in the top and bottom to keep a washer centered on one of my old race cars.

They are going to be the accuracy of .00X" to stock height and I may have my pick of what kind of aluminum for these too, but we'll see.

jgrewe 04-01-09 07:22 PM

To the .00X is probably a little overkill. These buggers sag as they get older and don't cause trouble with phase. I always found the worst one I could find to measure when rules said I couldn't relocate the engine. That way I installed it, measured it, and ended up lowering my engine within the rules. I'd say within a 1/4" is as close as you need to get.

fidelity101 04-02-09 11:51 AM

I'll post up pics of them when they are done but it may be a week or two.

Davidov 04-02-09 11:27 PM

I have solid engine and trans mounts. It makes starting off in first gear a little more of a pain, since there is no slack in the driveline.

The best part is, you never have to worry about shitty rubber mounts falling apart.

fidelity101 04-02-09 11:45 PM


Originally Posted by Davidov (Post 9095956)
I have solid engine and trans mounts. It makes starting off in first gear a little more of a pain, since there is no slack in the driveline.

The best part is, you never have to worry about shitty rubber mounts falling apart.

do you have a lightweight flywheel or do you have a stock one?

gkarmadi 04-03-09 06:32 AM

I have polyurethane engine, tranny and diff mount (front and rear). Sorry i dont have any pics... i didnt take it. I think its from an mmr and the front diff mount is a mazdaspeed. I am using a polyurethane master bushing kit aswell... and a liteweight flywheel. I was hard in the beginning, but i am getting used to it now. Only some vibration (below 3000rpm on 1stgear) if you are going uphill and didnt put ur foot enough on the gas pedal.

Davidov 04-04-09 12:36 AM


Originally Posted by fidelity101 (Post 9096026)
do you have a lightweight flywheel or do you have a stock one?

I have a stock flywheel, but it's like driving with a light flywheel. It was hard to make it not jerk at low speeds, but I learned to adapt.

jake1191 04-04-09 09:00 AM

ive ran my solid mounts with a 6 puck clutch on stock flywheel and they actually stopped me from bucking and stalling. Now i have a TII stock flywheel trans and all that and still pretty easy to drive. Beleive it or not ive only driven with them for about 100 miles since ive had them too.

95PGTTech 04-04-09 08:40 PM

I guess I'm getting old, I'd kill myself with solid mounts.

rotorkid 04-04-09 10:32 PM

I had just made mine about 2 months ago, out of 6061 aluminum they are 3" diameter and 2" height. and i got real anal with them to the point there are within .001 of each other. and i did mine on a old school lath. but they work good and are actually lighter then the stock mounts.

fidelity101 04-05-09 12:38 AM


Originally Posted by Davidov (Post 9098963)
I have a stock flywheel, but it's like driving with a light flywheel. It was hard to make it not jerk at low speeds, but I learned to adapt.

I got used to my AL flywheel with that but porting/polishing the throttle body and doing the TB mod helped that too. granted my trans mounts were/are cracked and slightly twisted lol. not to mention when i pulled the motor out the P side mount fell into 2 pieces, it was just resting on the mount arm.

fidelity101 04-08-09 08:39 PM

Alright a friend of mine just finished them I will post pics, however they are not aluminum :(

but free mounts are free mounts! granted I did pick up his tab later that night lol.

levelzero 04-08-09 09:04 PM

http://www.levelzeromotorsports.com/...es/10121_1.jpg

I run these in my FC for obvious reasons. I have solid inserts to replace the rubber during race season, but for winter or long trips I run the thin rubber bushing for a bit of extra comfort.

As far as making your own you don't have to worry about the diameter. Metal has astounding compressive strength. To give you an idea of how much ... a 3" round steel tube with a 1/8" wall, will support 36,000lbs. You can make mounts our of what ever is convenient, although I wouldn't go under 2" in diameter. You'd literally tear the bolt out of either the bracket or the subframe before you could stretch/crush a block of aluminum a significant amount.

When installing your mounts make sure to install them with the nut on the bottom, and I personally would use a locknut and some locktite.

If you're going to also make solid diff mounts you will really want a rubber bushing of some sort. even a 1/8" rubber bushing drastically reduces the noise transmitted into the cabin while only adding a small amount of play.

fidelity101 04-09-09 02:34 PM

I would post up pics but my laptop is being a douche right now but I should have some up this weekend hopefully, my trans mounts are 1.5" OD and the motor mounts are 3" OD both made out of A2 tool steel, it was just what was laying around for tube material. I'll be sure to have the nut on the bottom, I'm looking to drop my motor/trans back in the car tomorrow so we shall see how it runs :D

I don't plan on going solid diff mounts...yet.

were you talking about the front diff mount? or the ones that are circular and are in the diff "arms" that bolt to the chassis?

levelzero 04-10-09 12:41 AM

The round ones in the mustache bar (diff arms).


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