Looking to swap out the OEM motor mounts when installing new momentum headers? anyone currently using these, how is the vibration and noise in the Cabin, * I have an automatic.

I'm currently using a Motordyne Exhaust and Test Pipes so curious if the vibration will be noticeable when at Idle,

 

Someone did those and the trans mount. Apparently the engine ones weren't horrible but the trans mount in urethane was too much.

 

 

They definitely add a bit of vibration and harshness but I don't think it feels TOO harsh, they feel amazing on a 6MT and I have no regrets about using them. I have engine and transmission.

 

You might also look into Brett Dempsey Engineering (BDE) engine mounts - they seem pretty cool but I have not tried them myself.

I actually worked with the guy for a while before he left to run BDE full time - incredibly smart, nicest guy you'll ever meet plus he has a stable full of Z cars haha

 

 

 

If you don't mind the possibility of added vibration than get them. I'm still on stock mounts but I'll be getting a set of these poly ones soon.

 

On an AUTO, I would definitely stick with rubbers. The biggest advantages are shifter feel and clutch engagement, and the auto's throttle transition is already smoothed out by the torque converter. The extra vibes are pretty minimal after a 500 mile break in period, on my car nothing rattles at idle after I cleaned out my throttle body to keep the revs from dropping. I do get a slight vibration at 2000 RPM but I'm pretty sure that's just the mounts magnifying a separate issue.

IMO (for 6MTs)
If you're a street driver who doesn't beat on their car often, get the rubbers.
If this will be used as a track car at any point or you like to speed, the polys are worth it for both the added durability and improved shifting and throttle transition feel.

I'm happy I installed mine!

 

 

rubber = OEM

 

I've got an Innovative urethane side mount on my Accord (motor mounts are a real sore spot on 7th gen Accords and 3rd gen TL's) and if there was an increase in vibration, I didn't notice it. Ran solid engine mounts on my Chevelle, engine was balanced so that helped but vibration was less than expected. What might work well on a G35 if vibration is a concern is going with a urethane mount on the passenger side since that's the side that torques up when you get on it and rubber on the driver's side.