Just a little review of the BDE motor mounts since no one has created one. I do own a G37xS so vibrations may vary from the RWD AT, and RWD 6MT.

The installation was fairly easy since it is the AWD model, and the motor mounts sit a lot closer to the front which makes accessing the bolts a lot easier. The only drivetrain upgrade I have is a diff brace. I will be replacing the diff bushing soon.

NVH:
You will experience the same amount of vibrations that some owners with the Z1 motor mounts do when idling. The vibration is a lot more during the cold start but smoothens out once the car is up to temp. When you initially start the car you will feel the starter kicking on, which is something I actually liked please don't ask me why lol. When at a stop sign or light and get on the gas you will feel the 1st gear vibration but that is basically it (might vary from the AT and 6MT). But when cruising you will have little to no vibrations which is a great part for people that do long commutes. When you go to "manual mode" and shift the gears yourself you will feel a bit more vibrations than when in "Drive mode". The only thing that I hate the most is reverse. The car vibrates like crazy and it could just be from being an AWD since I did not really read on anyone else complaining about it. No matter if the car is up to temp or not it will vibrate in reverse the most.

Cool Factors:
The front end of the car feels way better. When going over bumps the front does not dive down as much, and the ride is a lot smoother. The cornering has also improved. Overall the front end just feels more dialed and that is one of the main things that I enjoyed about this mod. The car also just sounds a lot meaner. It is harder to explain but from the inside of the car it sounds a bit different, and it could also be due to hearing the transmission. This brings me to my next point if you love mechanical noise then you will enjoy the transmission noise when rowing through the gears. You will mainly hear the transmission when in "manual mode" but won't hear it when driving normally. The gas pedal is a lot more responsive and you do not have that delay of waiting for the car to start moving, it just goes. The transmission has also smoothened out when rowing through the gears and no more clunks when you are on and off the pedal.

I did not take any pictures of the install since it was late in the day, but if y'all want to see any pics of the mounts in the engine bay or any videos let me know.

 

Photos please!!!!!

 

Excellent review! Moved this to the Drivetrain forum as a Review thread.

Aftermarket motor mounts are a fantastic modification, for all the subtle reasons you described. The parts are relatively inexpensive, but shop time can really add up to big $$$. Just adding that comment to the mix.

Also, one of the things I noticed a few years back when pursuing this mod with Z1 poly mounts (on a 6MT Sedan), is that the engine was actually lowered. I was able to observe this because of my FSTB, which was 1/4" off the engine cover before the install. After the install, that gap increased to 3/4", give or take a little. Now I'm no engineer, but I suspect lowering the engine a smidge contributes to the changes perceived when driving the car.

 

This is from the driver side view.

It is a bit bend backward not sure if that is how it is supposed to be or not?? I guess we will never know.

For the AWD owners, you have to bend these pinch welds outwards towards you in order to take the OEM motor mounts out. It does not have to be a lot just a small amount and you can wiggle it out of there.

Just a little comparison.

 

Tbh I am not too sure if it dropped it by much. When I took the OEM mounts out I compared them next to each other and they looked about the same. However, the RWD OEM motor mount is a bit short than the AWD from the images that I have seen. Since we do have the front diff to account for.

And yes, if you do not do this job yourself which I heard is a lot more painful for the RWD owners it can cost a pretty penny to get them installed. It took me about 2hr to take them out majority of the time I was trying to figure out how to get the mounts out since there is little to no room until I realized I can bend the pinched welds a bit and sneak them out from the corners.

Also a little bit more detail I emailed Brett and he informed me that these are 88A poly, unlike the Z1 which is 70A. I am not sure how much of a difference it is between the two since you will still feel vibrations during idle regardless (AT Owners). These might give you more of a "Sport" feel compared to the Z1.

 

How much do you need to remove the front lower control arm, just the 1 bolt to gain access to the lower engine mount bolt?

 

Driver side:
For the top bolt, you will need assistance. I got a long extension bar, swivel head, and then a 14mm socket. I snaked it from the top (engine bay) and my friend basically maneuvered the 14mm socket onto the nut from down below. There is an A/C line just have to move it a little bit to the side and then have the socket seated on the nut. For the bottom motor mount nut, I loosened only that one bolt on the control arm that is below the engine mount. Once you remove that bolt you can move the control arm fairly easily forward. I pushed the control arm away from the engine mount and put a pry bar in the hole, where the bolt will originally go. Just so I don't have to fight the control arm when taking out the bottom motor mount nut. The drive side is the most time-consuming tbh.

Passenger Side:
This side is really easy. For the top bolt, I had the same set up long extension bar, swivel head, and a 14mm socket. Just put the 14mm socket on the nut and unbolt it. Fairly straightforward and has plenty of space to work around. For the bottom bolt, you will notice that the end of the control arm bolt is covering the motor mount nut. What I did is just loosen that control arm bolt until I was able to put my 17mm socket on to the motor mount nut. You do not have to take the control arm bolt out, but just loosen in.

Also, you need an adjustable wrench or something similar to bend those pinched welds a bit upwards in order to get some room to take out the motor mounts. It does not require a lot, you can see above on my images that I bent them outwards a bit.

 

Good info, I think engine mounts are in my near future, been dreading it hearing the AWD is way more work than RWD but this helps put my mind at ease.

Did you jack up the engine at all for clearance or put a jack on it to support it while the mount was out?

 

The AWD motor mounts are way easier than the RWD actually. For the RWD watching videos, many have to take out the headers in order to get to the top bolts.

Yes, I jacked up the motor from the oil pan with the use of 2x4 wood to distribute the weight evenly. Before jacking it up just to be on the safe side I loosened the y pipe bolts that connect to my test pipes, so I do not put too much stress on the flex pipes. Also when jacking it up make sure to watch your coolant hoses because they will be at their limit of being stretched. It is best to have a friend so they can jack it up slowly while you try to take out the motor mounts. You do not want to raise it more than it really needs or you can damage other components.

 

With all due respect, the above statement makes no technical sense to me:
• How does a stiffer engine mount change the amount os suspension travel going over a bump?
• How does a stiffer engine mount improve cornering?

Based on the last time I dynoed my car with a camera pointed to the engine bay, the factory mounts are quite stiff and the engine might of moved 1/8" from idle to full load at wide open throttle.

 

How could it not? Everything you do to button down the drivetrain to the chassis improves performance while adding NVH.

If the weight of the car is more balanced when cornering, then the tires can do their thing more efficiently.

 

A stiffer mounted engine or transmission will not increase the measured lateral acceleration or change the suspension travel when going over a bump.
Watch a video of a G37 on the dyno with the camera on the engine... The amount of engine movement with the stock engine mounts at full load to zero load is very small, about 1/8"
If the aftermarket mounts prevent all movement, can you see that making a difference in handling? I can't.

It can be difficult to separate "feel" from measured data.
Does my car feel faster/smoother after I wash it? Yep, but I know is isn't.

I started and deleted this reply 3 times... I'm not trying to poop on the guy's review... If he is happy, that's great.
However, I don't want someone to read this thinking they found the "secret" mod to better handling.

 

The operative phrase there is "when going over a bump". A stiff suspension and solid drivetrain will totally suck when going over a bump, but will reward you in the curves.

Everything is a compromise.

The #1 secret to better handling with any car is high performance, 3-season tires. That's no secret.
The #2 secret that's not a secret for this particular car is any brand aftermarket swaybars.
The #3... performance dampers and springs.

Everything else is incremental at best. Very real, but incremental, and not at all the placebo effect you get cleaning your car.

 

I guess I should have listed it, in the beginning, my car is a 2011 with 142K miles. I have done a countless amount of launches and back road sprints. The OEM motor mounts have been put through work. Once I got my tune the throttle response was very crisp initially, but as time went I noticed that I was lagging that small kick. Did the motor mount test by pressing the gas pedal and brake and noticed my driver side is lifting up almost 0.5inch.

How does a stiffer engine mount change the amount of suspension travel going over a bump?
- Might be a placebo effect, but before replacing the motor mounts when going over bumps on the highway you will feel the front end of the car dive down a good amount. Which could be the result of the worn-out motor mounts, and the weight of the motor getting pushed more forward (physics). Also have to consider I have a G37x and have a front diff, and my motor mounts sit closer to the front. I know it is hard to believe, trust me I was in shock myself and did not realize how much of a difference it really makes.

How does a stiffer engine mount improve cornering?
-Rochester basically covered it really well. The motor becomes part of the chassis plus any other drivetrain mounts you change to poly or solid. Which results in less movement side to side, and up and down. It is honestly something that you have to do yourself or drive someone's car that has upgraded motor mounts. My friend drove my car and he was even confused about how much of a difference it really made.

Now, as I listed in my other comment the Z1 and BDE could vary since the Z1 uses 70A poly, while BDE uses 88A poly. As well as it being an AWD, RWD (7AT), or RWD (6MT).

 

I'm glad you are happy with the mounts, but we will have to agree to disagree.