Rear Motor Mount Bang Common?

[SkyeSI]

My 2019 SI Coupe is bone stock.
Note: This is my first Honda.

First noticed it when I left a traffic light under heavy-moderate acceleration in wet/damp conditions. Wheel hop combined with traction control caused an osilation under power that caused a rapid bang-bang-bang before I let off the go pedal. It freaked me out. Then another time with a dry road I hit second kinda hard and felt/heard a hard bang which seemed simiar. I hate taking my car to the dealer and I'm no stanger to forums with my other cars so I started searching. I only found one other post which seemed simiar to my condition that reference "soft as marshmellow" motor mounts on our cars. So after some more research I've ordered the boomba rear motor mount. I'm out of town with work so I haven't installed it yet.

The more I read this forum I see modded SI's and I do not see a lot of cars with aftermarket motor mounts. It makes me wonder if it's a common problem that I have a remedy for, or if mine has a specific problem.

Please help by sharing your experience with "shift bang" or lack there of. Thanks!

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[Curtman]

Yeah I can feel it. I plan on upgrading the rear motor mount.

 

[Vincent@27WON]

You just described wheel hop. That's a byproduct of a FWD car under power. An upgraded RMM is one of the best ways to mitigate the problem. Tires, and suspension tweaks also help. you will see it as you start to modify and make more power.

 

[SkyeSI]

You just described torque steer. That's a byproduct of a FWD car under power. An upgraded RMM is one of the best ways to mitigate the problem. Tires, and suspension tweaks also help. you will see it as you start to modify and make more power.

This was a hard bang at the floorboard. There was no effects felt in the steering during these conditions.
Torque steer is caused by twisting in the axle shafts from what I understand.

 

[Gotch]

That's not torque steer he is describing it is wheel hop. Road surface traction, drivetrain lash (from soft mounts) and severe, sudden loading (dumping the clutch) are all contributors. It can be reduced with a stiffer rear mount or by driving it a way not to shock the drivetrain.

 

[SkyeSI]

That's not torque steer he is describing it is wheel hop. Road surface traction, drivetrain lash (from soft mounts) and severe, sudden loading (dumping the clutch) are all contributors. It can be reduced with a stiffer rear mount or by driving it a way not to shock the drivetrain.

Exactly. My wife said "just don't drive like an a-hole". lol

I can make it bang without dumping the clutch. I put it in 2nd, let out the clutch fully, coast down in speed then punch it and it will bang if I'm going the right speed (in it's power band). Mostly I hate the bang-bang-bang when trying to accelerate hard in wet conditions. It scares me and passengers. Wheel hop is manageable, but the banging is not accepable.

 

[Gotch]

I believe that it is “normal “, not that it is right...new rear mount would be a start. I’m thinking of getting one this summer. I’ve hammered it in second and had wheel hop too.

 

[Vincent@27WON]

You just described wheel hop. That's a byproduct of a FWD car under power. An upgraded RMM is one of the best ways to mitigate the problem. Tires, and suspension tweaks also help. you will see it as you start to modify and make more power.

 

[Vincent@27WON]

This was a hard bang at the floorboard. There was no effects felt in the steering during these conditions.
Torque steer is caused by twisting in the axle shafts from what I understand.

the wrong language on my part. corrected to wheel hop.

 

[DarkLight]

I completely cured my wheel hop/drivetrain slop by filling in the rear bushing of the motor mount with a $7 tube of high torque/high temp silicone. Feels like stock except tighter with no wheel hop, and my car is not a rattle trap.

Aftermarket mounts are completely unnecessary unless serious power is being made, like that guy with the CTR who was pushing 400 whp and snapped his stock mount in half.

 

[SkyeSI]

I completely cured my wheel hop/drivetrain slop by filling in the rear bushing of the motor mount with a $7 tube of high torque/high temp silicone. Feels like stock except tighter with no wheel hop, and my car is not a rattle trap.

Aftermarket mounts are completely unnecessary unless serious power is being made, like that guy with the CTR who was pushing 400 whp and snapped his stock mount in half.

What brand type silicone did you use? I'll go ahead and do that to the stock mount as a back up in case there is too much induced vibrations.

 

[joshhjackson2112]

My 2019 SI Coupe is bone stock.
Note: This is my first Honda.

First noticed it when I left a traffic light under heavy-moderate acceleration in wet/damp conditions. Wheel hop combined with traction control caused an osilation under power that caused a rapid bang-bang-bang before I let off the go pedal. It freaked me out. Then another time with a dry road I hit second kinda hard and felt/heard a hard bang which seemed simiar. I hate taking my car to the dealer and I'm no stanger to forums with my other cars so I started searching. I only found one other post which seemed simiar to my condition that reference "soft as marshmellow" motor mounts on our cars. So after some more research I've ordered the boomba rear motor mount. I'm out of town with work so I haven't installed it yet.

The more I read this forum I see modded SI's and I do not see a lot of cars with aftermarket motor mounts. It makes me wonder if it's a common problem that I have a remedy for, or if mine has a specific problem.

Please help by sharing your experience with "shift bang" or lack there of. Thanks!

Yeah man. I have experienced this same deal with my SI. When I get on it in second gear, it almost sounds like I am running over a full grown possum. I just purchased the 271 RMM. I have not installed it yet. I am changing out my front pipe soon so I am waiting to do all the work at same time. (You dont need to take off front pipe to install RMM, I am waiting for convenience) I hope the banging stops with the install. I am fairly confident it will. Like you said, it is hell for passengers. It is very loud and jarring.

 

[DarkLight]

What brand type silicone did you use? I'll go ahead and do that to the stock mount as a back up in case there is too much induced vibrations.

I used Permatex “high torque” in the gray tube. You can get it from most any auto parts store for about $7. Cure time is about a day.

After 50 miles or so it is broken in, and during normal driving is not noticeable. The only time I notice vibration is when the AC is on full blast during gridlock traffic and ambient temps are above *90.

I also experimented with a solid CVT mount, thinking that polymer will have less NVH than aluminum, and it does work for comfort. However the stock aluminum mount is slightly stiffer.

After 30k miles of ab(use):

There is some discoloration from the heat, but performance is unaffected. Better than window weld IMO.

The only time I ever lose traction is in 1st when it’s wet and I’m pushing close to 200 whp with 225 width summer tires.

 

[reesee175]

I plan on upgrading the RMM as well. I had an srt4 before and the stock mounts broken several times. I installed dogbone motors and no more issues, but some vibrations that I didn't care about. You don't want to be left on the side of the road , then get one of the aftermarket RMM.

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