Good-Win Urethane motor mount illegal in ST?!?

[Richard_rsp]

AWR Lower Dogbone Urethane motor mount illegal in ST?!? (EDIT: it is LEGAL)

UPDATED: This mount was found to be LEGAL in STF according to another member's calculations.

v LOOK HERE v

Finally got around to doing some measuring and installing the AWR mount.

In short, it is legal. Not even close. Plenty of metal.

Read the note here to see the pics and calcs.

Original Message:

PLEASE NOTE: This is an AWR mount, not made by Good-Win. Corrected in title.

Oh CRAP! I just re-read the rules regarding the motormounts (could have sworn that I read this sooner!)

Here is the 2011 Rule from Page 90 regarding ST class :

J. Engine mounts may be replaced, but must attach in the factory
location(s) without additional modification or changes. Engine position may not be changed.
The volume of metal in a replacement
mount may not be increased relative to the volume of metal found
in a stock mount for the particular application. Solid metal mounts
are specifically prohibited. Any non-metallic inserts may be used.
All components between the engine and the mounting structure are
considered to be part of the motor mount assembly and therefore
comprise the motor mount.

Our stock rear mount mostly rubber...
I just installed the AWR urethane motor mount on my Mazda2. Its mostly metal!

So unless I am reading this wrong, that means its illegal! CRAP! :'( And I just got it!

Anybody know of anyone making a non-metal Urethane mount? Is that even a possibility??

 

[DaleNixon]

I'll give you half of what you paid for it

 

[Richard_rsp]

Lol... I MIGHT be selling it at somepoint.

 

[zps2004]

You could use the same bushings, but machine a mount out of a hard plastic. That's what I would do. If you made it pretty solid it would be strong enough. Just would weigh more. Fiberglass might work with a plastic insert to protect the bushing.

 

[CorkSport]

Here is the verification on the mount

http://store.awrracing.com/engine-mount-mazda2-lower-dog-bone/

-Derrick

 

[DaleNixon]

Hmm... hey Corksport, have you thought about some M2 motor mount bushings? I loved the ones you made for the MS3! lol

 

[Richard_rsp]

zps2004 - I had considered that, but wasnt sure if fiberglass would be hard enough. I have also thought about making a slightly larger copy of the stock mount out of higher durometer urethane.... Im gonna have to do something. I already love the way my car feels with this mount.

Derrick - Yeah, I had seen that. Even though they look the same, i didnt really want to assume. But thanks anyway! If you guys do end up making mounts for the M2, please keep this "problem" in mind. The Mazda2 is a great car for ST class, and this rule is a limitation since the stock (weak) rear mount is almost solid rubber. EDIT: Yes it is the AWR mount. Dug the shipping box out of the recycling bin. Shipped from AWR.

 

[zps2004]

Also it might be worth it to just fill in the open area in the stock one with window sealant (urathane). That would make it a good bit stiffer.

 

[XCLR8TN]

This is why I don't autocross

I'll buy it if you sell it!

 

[zps2004]

Well I mainly autocross with the Clemson Sports Car Club and we use the NASA autocross rules, which are basically the same as their TT rules. You car starts out in a base class. Different mods have different points values. Every 20 points you move up a class. Easy and it lets you mod the car how you want to.

 

[Richard_rsp]

Also it might be worth it to just fill in the open area in the stock one with window sealant (urathane). That would make it a good bit stiffer.

After re-examining the stock mount, this was also my thought. I was thinking that the stock mount was solid rubber, but it appears to have a metal lining that is covered in rubber. I plan on trying this next unless someone (*cough* Corksport *cough*) comes out with a mount that will work with ST class...

 

[Slow Paul]

Interesting news about the mount and the ST rules, I was going to be buying this too...

 

[Richard_rsp]

Ok, here is my solution (hopefully): I ordered some liquid Urethane Casting Compound (80A) this morning. I plan on filling the area around the bolt sleeve (where the arrows are pointing). This way I am able to have a stiffer mount than stock, but still retain my legality in Street Touring. EDIT: Decided to go with 60A since its my daily driver...

I will be starting a new thread in the Engine, Transmission & Drivetrain Section regarding this.

Thanks all!

 

[MazdaTwo]

Ok, here is my solution (hopefully): I ordered some liquid Urethane Casting Compound (80A) this morning. I plan on filling the area around the bolt sleeve (where the arrows are pointing). This way I am able to have a stiffer mount than stock, but still retain my legality in Street Touring.

I will be starting a new thread in the Engine, Transmission & Drivetrain Section regarding this.

Thanks all!

That's definitely a good solution. My motor mount on my GTI had a similar design (although it was oriented on the X-axis as opposed to the Y-axis) and the solution for a stiffer mount was a PU insert that filled the gaps just as you're describing.

 

[rchrist364]

So with your motor mount, can you tell a difference at all?

 

[Richard_rsp]

I will be starting a new thread in the Engine, Transmission & Drivetrain Section regarding this.

Thanks all!

So with your motor mount, can you tell a difference at all?

Yes, quite a difference! Here is the follow up thread I referenced above:
http://www.mazdas247.com/forum/showthread.php?123804180-I-ve-filled-my-rear-motor-mount!

 

[Andy Hollis]

PLEASE NOTE: This is an AWR mount, not made by Good-Win. Corrected in title.

Oh CRAP! I just re-read the rules regarding the motormounts (could have sworn that I read this sooner!)

Here is the 2011 Rule from Page 90 regarding ST class :


Our stock rear mount mostly rubber...
I just installed the AWR urethane motor mount on my Mazda2. Its mostly metal!

So unless I am reading this wrong, that means its illegal! CRAP! :'( And I just got it!

Back from the dead...

I believe you are incorrect in your conclusion here. I've looked carefully at the mount in question and the AWR mount. The OE has quite a bit of metal in it that is covered in rubber. Each of the larger sleeves that surround the smaller mounting bolt sleeve are only slightly smaller than the AWR ones. And the outer surround of metal has as much surface area as the AWR tube that connects the two other sleeves. Worst case, you could drill a couple of holes in the AWR sleeves to reduce surface area w/o reducing strength. That's my plan.

 

[Andres3165]

Back from the dead...

I believe you are incorrect in your conclusion here. I've looked carefully at the mount in question and the AWR mount. The OE has quite a bit of metal in it that is covered in rubber. Each of the larger sleeves that surround the smaller mounting bolt sleeve are only slightly smaller than the AWR ones. And the outer surround of metal has as much surface area as the AWR tube that connects the two other sleeves. Worst case, you could drill a couple of holes in the AWR sleeves to reduce surface area w/o reducing strength. That's my plan.

It will be nice to see that,

thanks Andy

Andres

 

[Andres3165]

Back from the dead...

I believe you are incorrect in your conclusion here. I've looked carefully at the mount in question and the AWR mount. The OE has quite a bit of metal in it that is covered in rubber. Each of the larger sleeves that surround the smaller mounting bolt sleeve are only slightly smaller than the AWR ones. And the outer surround of metal has as much surface area as the AWR tube that connects the two other sleeves. Worst case, you could drill a couple of holes in the AWR sleeves to reduce surface area w/o reducing strength. That's my plan.

What durometer hardness do you recommend? 70 , 88 0r 95?

Getting it today

Thanks

Andres

 

[Andy Hollis]

What durometer hardness do you recommend? 70 , 88 0r 95?

Getting it today

Thanks

Andres

70

Anything harder will rattle your teeth out. As an example, I have 70 in my K-swapped CRX track car (Hasport mounts) and that vibrates quite a bit already. And the AWR mounts don't have a ton of bushing material, so there's little room for compliance.