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Discussion Starter · #1 ·
Ok, ive seen a few reviews of the CS 70a RMM (softest one i could find) and im not sold. Everyone seems to mention that theres alot of vibration at idle, especially with the a/c on. I understand the point of a stiff RMM but why would anyone want that on their mazda 3, a nice comfortable dd? I hate the wheel hop i get spinning in first and the slight bucking i get downshifting sometimes off throttle (i have a 2.5l 6AT), but i dont want vibrations that drown out my great sound system and annoy passengers.

So, that brings me to the title of the post. Ive been looking around and found that filling the stock mount with some $5 polyurethane from home depot using a caulk gun seems to be the best solution. Anyone tried filling in a rear motor mount before? What did you use? How long did you let it sit? Did it work, is it the happy median i think it will be?

Im pretty sure alot of ppl looking for a rmm have the same concerns, why doesnt someone just make a rmm to fit those needs? Maybe someone from CS or JBR can chime in?

Tldr; want rmm, dont want vibrations, window weld inject stock mount?
 

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70duro is about the softest poly you'd want to to use for a motor mount. It sees a lot of stress and anything much softer wouldn't have the performance upside that the 70 has. 70 is the softest poly I have ever run. That being said, most poly is stiffer the first few months and will eventually settle in and be softer.
 

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One option is the hardrace mount. It used a hardened rubber compound so it woul dbe in between OEM and the poly mounts offered by CS and JBR. I have a 70 duro jbr mount myself, however I have not installed it yet due to #extraworkforawdinstallation. I am considering filling my rear differential mount someway though, that thing moves a lot during wot shifting (I recorded it). I purchased some black sealant from the car part store and will try it out.

~6:50 for wot 1-3
 

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Discussion Starter · #4 ·
That hardrace mount looks interesting, any idea where i can buy? I saw your post on another forum saying "font motorsports," is a dealer, but there isnt a working website atm. Also, i saw your build thread. Thats awesome keep us posted!
 

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Discussion Starter · #5 ·
[email protected] thanks for the insight, but from what i hear its exactly what i dont want. Theres no real way to tell until i try, but vibrations sitting at idle and more with ac on doesnt sound pleasant. Its a dd after all
 

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Discussion Starter · #6 ·
Chris_top_her i found your post about it from like 3 months ago, thank you very much. Will probably order tonight
 

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Discussion Starter · #9 · (Edited)
vv
 

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Discussion Starter · #10 · (Edited)
wow.. I just noticed they added a crapload of new stuff for the CX-5 and mz3.. http://www.hardrace.com/VEHICLE_Search.asp?Car_Make=12&Car_Model=36&Car_Type=207 might actually have a cheaper alternative to the expensive AUTOexe endlink now.. still need to install my hardrace rear camber arm as well.. i'm slackin

Damn, nice. I wonder why they only offer a right side motor mount and not a left, weird. (Theres a rear, right, and left, am i rite?) Btw, thanks for recommending the hardrace rmm, its in and its great. Literally no vibration like i was hoping for. Im gonna do a review soon
 
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2015 Mazda3 S Grand Touring, 6spd Manual, Soul Red
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Just thought I would let you guys know, I got AWR to make a RMM for the 3rd gens. Mine is off to powdercoat right now, but should be getting it soon. Tony alluded to having made multiple, so they may be popping up for sale on his website soon. He sent a picture (pre-powder-coat).
278660
 
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