flatlander937
Member
- :
- '11 Mazda2 Sport
Been waiting a few weeks to post this here, I wanted to make sure it all worked out fine, basically I built a rear motor mount using some poly bushings and some DOM tubing.
Some of the welding slag cleaned off, painted and drying:
And installed:
First impressions: Holy crap I need to remove this thing. It vibrates like holy hell for the first 10-20 miles or so. Then it has gradually smoothed out over the following week and it's been about the same since then. I've had it in for roughly 2 weeks now. You get some minor vibrations at certain speeds/rpms cruising, nothing downright horrible. And you feel it a bit when letting out the clutch taking off in first gear. This is by far the biggest difference though: You can actually smoothly feather the clutch to take off, since the whole engine/trans isn't moving 3 nautical miles before it starts applying force to the wheels.
The only thing I was a bit unsure about was the inner bolt sleeves... we have 10mm bolts holding our torque mounts in, finding tubing with a 10mm ID(0.394 IIRC) and an OD of 0.75"(needed to fit the poly bushings properly) is nothing short of impossible. So I did what some OEM manufacturers do and just used oversized bolt sleeves, they are 0.50" ID... so there is about 1/8" of play in each bolt sleeve, which doesn't matter once it's bolted together tight. It's just critical that the sleeve ends are flat and square, and they are very close in OAL compared to the original mounts so as to not stress the brackets, especially the aluminum transmission side bracket. DSMs, many Hyundais, a lot of Chrysler vehicles are all set up with huge holes in the mount brackets and smaller bolts. This can also be an advantage in preloading the engine/trans so it does not vibrate as badly at idle. With 1/8" of play in each bolt hole, you can shift the engine forward/back by about 1/4" to mess with preload. I haven't gotten to the point of playing with that yet, as my vibrations settled down considerably so I'm not too worried about it at this point. Mine is the same length as the stock mount and can be pushed forward/back 1/8" or so, set with the engine pushed forward as far as possible(because when accellerating that's the way it will move, so this eliminates as much possiblity of slipping. May fiddle with it more in the future.
Next up I have a few feet of Acetal Delrin which I'm going to play around with for making some basically solid mounts. Probably won't be bearable for daily driving, but great if you track your car or are srs bzns about autocross.
Some of the welding slag cleaned off, painted and drying:
And installed:
First impressions: Holy crap I need to remove this thing. It vibrates like holy hell for the first 10-20 miles or so. Then it has gradually smoothed out over the following week and it's been about the same since then. I've had it in for roughly 2 weeks now. You get some minor vibrations at certain speeds/rpms cruising, nothing downright horrible. And you feel it a bit when letting out the clutch taking off in first gear. This is by far the biggest difference though: You can actually smoothly feather the clutch to take off, since the whole engine/trans isn't moving 3 nautical miles before it starts applying force to the wheels.
The only thing I was a bit unsure about was the inner bolt sleeves... we have 10mm bolts holding our torque mounts in, finding tubing with a 10mm ID(0.394 IIRC) and an OD of 0.75"(needed to fit the poly bushings properly) is nothing short of impossible. So I did what some OEM manufacturers do and just used oversized bolt sleeves, they are 0.50" ID... so there is about 1/8" of play in each bolt sleeve, which doesn't matter once it's bolted together tight. It's just critical that the sleeve ends are flat and square, and they are very close in OAL compared to the original mounts so as to not stress the brackets, especially the aluminum transmission side bracket. DSMs, many Hyundais, a lot of Chrysler vehicles are all set up with huge holes in the mount brackets and smaller bolts. This can also be an advantage in preloading the engine/trans so it does not vibrate as badly at idle. With 1/8" of play in each bolt hole, you can shift the engine forward/back by about 1/4" to mess with preload. I haven't gotten to the point of playing with that yet, as my vibrations settled down considerably so I'm not too worried about it at this point. Mine is the same length as the stock mount and can be pushed forward/back 1/8" or so, set with the engine pushed forward as far as possible(because when accellerating that's the way it will move, so this eliminates as much possiblity of slipping. May fiddle with it more in the future.
Next up I have a few feet of Acetal Delrin which I'm going to play around with for making some basically solid mounts. Probably won't be bearable for daily driving, but great if you track your car or are srs bzns about autocross.
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