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View Full Version : Just intalled: Urethane Engine Mounts


thinair
08-13-2005, 01:22 AM
I just installed a pair of Ireland Engineering urethane engine mounts. A couple of people told me not to install them on a street car, but oh well, I tried it anyway. I figured it's an easy install and I could just remove them if I don't like them.

Well, I bolted everything up, lowered the car and started it up. The engine doesn't move in the engine bay, not even when revving it. I took it out for a spirited drive, the shifter knob doesn't move under sudden hard acceleration or when full getting off the accelerator. I was really worried about noise/viberation/harshness (NVH), but I honestly don't really notice much. As far as added noise I don't hear a difference. The only thing I really notice more is a slight rumble in the steering wheel, but then again the engine and steering rack are both mounted to the subframe.

So now I have the engine and transmission suspended by urethane mounts, again, no issues, and the engine and tranny doesn't move at all. This is of most benefit to reduce the chance of misshifting under power, or under hard cornering.

Justin e36
08-13-2005, 01:39 AM
good stuff... I have a set of Ireland Engineering engine mounts waiting to go on as well. :(

Miguel
08-13-2005, 09:01 AM
Isn't the point of a mount to absorb the vibration as opposed to "locking" the engine in place?

thinair
08-13-2005, 12:47 PM
Isn't the point of a mount to absorb the vibration as opposed to "locking" the engine in place?

No, the point of a mount is to hold the engine, aka to mount the engine to the chassis.

And the urethane seems to absorb the engines viberation, it's not like BMW engines are that lumpy anyway, they're known for their smoothness anyway.

My main reason for doing the enigne mount swap is to prevent misshifts, plus it reduces wear on various hoses that run from the chassis to the motor (power steering and coolant are the main ones that like to leak.)

Miguel
08-13-2005, 10:56 PM
No, the point of a mount is to hold the engine, aka to mount the engine to the chassis.

And the urethane seems to absorb the engines viberation, it's not like BMW engines are that lumpy anyway, they're known for their smoothness anyway.

My main reason for doing the enigne mount swap is to prevent misshifts, plus it reduces wear on various hoses that run from the chassis to the motor (power steering and coolant are the main ones that like to leak.)
So why don't BMW's come stock with solid mounts?

hioctane
08-14-2005, 12:01 AM
I would suspect due to ride quality (and maybe cost) - compromise of comfort and smoothness is most likely a greater negative then sport/race quality for most BMW buyers.

EMPOWERD
08-14-2005, 12:09 AM
When using the NOS 75HP shot on my old M20 2.7i motor, I ripped the stock motor mounts monthly. I replaced them with custom solid aluminum billet mounts I fab'd up. The vibration through the dash was insane during clutch engagement (no matter how smooth I was). Had to remove them within days, but the increase in "torque" feel was great, plus the engine noise through the chassis was great.

thinair
08-14-2005, 08:07 AM
So why don't BMW's come stock with solid mounts?

Well, many did, solid rubber anyway. Then they went to fluid filled mounts to absorb more viberation. These urethane mounts I have are closer to stock mounts then they are to solid aluminium or steel mounts, they still absorb viberation, just like my UUC urethane mounts still absorb tranny noise. Just at hard cornering on stock mounts, the engine and tranny do shift a lot in the engine bay, enough to cause misshifting.

That's like saying why don't all BMW's come with coilovers, or with weight reduction, sure it's better performance wise..... but they're not for everyone.