Polyurethane motor mounts?

[muslhed]

Who offers polyurethane motor mounts for our cars? I've been searching with little results. Any help would be great!

[TripleTransAm]

The question is... do you need them? And why?

[muslhed]

Do I need them? Who doesn't enjoy putting their cars power to the ground quicker? Does our car come with polyurethane or rubber mounts stock? If rubber, then which type of motor mount is harder and more resistant to rotational force? I've always thought that polyurethane ones were, and they've certainly always made a difference in all of my other vehicles. I put polyurethane mounts in my wife's 2003 VW GTI turbo, and it made a bigger seat of the pants difference than any of the other mods we had already performed combined! I stand on the go pedal, and the torque is right there. So, do I need it? Probably not, but I want it. Who needs a supercharged Marauder? Nobody needs it, but I bet they'd like it too.

[dailydriver]

I agree with you that these mounts can make a difference in some cars. Particularly front wheel drive where there is a lot of movement by the motor. I put them on my 2003 GTI Turbo as well along with a beefier dogbone and there was a decent improvement. I have also used solid mounts in some of my race cars with mixed results. I wonder if there would be an advantage in the MM?

[Ross]

This is news to me, but then, I am always learning from this site. So a polyurethane motor mount, because it doesn't twist or "give" as much as rubber, will mount the engine more firmly, and therefore deliver power more quickly? Come on folks, chime in on this one. I'm anxious to hear some opinions. BTW, Muslhed, I'll be up in Marshall for a few days toward the end of next week.

[muslhed]

Originally posted by Ross
This is news to me, but then, I am always learning from this site. So a polyurethane motor mount, because it doesn't twist or "give" as much as rubber, will mount the engine more firmly, and therefore deliver power more quickly? Come on folks, chime in on this one. I'm anxious to hear some opinions. BTW, Muslhed, I'll be up in Marshall for a few days toward the end of next week.

Cool! I work in Marshall sometimes as well, so maybe we can do lunch!

As far as motor mounts are concerned, yes, a more rigid motor mount well help transmit torque to the drive tires faster then spongy, rubber ones. The only tradeoff is that any vibration there is in your motor, will be transferred to the body of the vehicle, because of the rigid mount. Personally I've never minded the increased vibration...what little there is, for the increased torque response. In my '92 4x4 4.3 V6 powered Sonoma, I actually chain down the driver side of the motor, because 4.3 S-10's come with weak motor mounts from the factory, and nobody makes a polyurethane mount for it. In my Sonoma, just like my wife's '03 VW GTI Turbo, it made a huge difference in the initial torque delivery.

I am just having trouble locating a pair for my MM. A polyurethane tranny mount would be a great compliment to the motor mounts as well!

[Lidio]

Their is a company called "Energy Suspension" thats been making bolt-in Polyurethane motor mounts for the 5.0L Mustangs for a few years now... none yet for the 4.6L Mustangs. Most poeple who I've installed these for end up removing them after a very short period of time.
They are simply to noticable from the cockpit.
Its one of those bolt-ons where you gain an inch but sacrifice a mile.

Solidifying the motor mounts is typically reserved for mostly track or track only cars.


Thanks

[TripleTransAm]

Originally posted by Lidio
Most poeple who I've installed these for end up removing them after a very short period of time.
They are simply to noticable from the cockpit.
Its one of those bolt-ons where you gain an inch but sacrifice a mile.


That was pretty much my point, sorry I wasn't clear.

When one thinks about it, the engine will torque to one side (against the limits of the engine mounts) as it twists the whole collection of driveline parts (tranny gears/bands/clutches, U joint slop, diff gear slop, tire sidewall wrinkle... all twisted by the engine through this fluid interface called the torque converter). So with harder mounts, the engine 'rocking' is limited... perhaps a half-inch of travel? Pop the hood open and have someone watch the engine as you torque it up against the brakes, in Drive, as if you were going to do a burnout.

But once this 1/2 inch or whatever travel is soaked up, then what? No reason why that torque isn't delivered 100% to the driveline. If you've got a modified engine that'll tear up a motor mount on a hard launch (or a fairly worn set of mounts to begin with), the harder ones will become a necessity, for longevity reasons. But is it worth transmitting all that vibration directly to the car's frame, now that the engine is pushing against the frame through a semi-solid mount, not a softer one?

Yes, you'll get a 'bang' when the engine reaches it's maximum travel... definitely makes the launch more dramatic. But performance-wise, I can't see it helping any, on a stock (or even mildly-modified) MM...

But if you do intend on going this route to the full extent, you should consider doing the tranny mount as well, there's a LOT of flex soaked up there as well.

[muslhed]

What was it that was so noticable in the cockpit? Were the 5.0 motors that rough? Are the 4.6's any smoother? Mine seems to run like glass! I can't imagine it being remotely unbearable in the cockpit of a 4200 lb car versus a lightweight Mustang. Since we're comparing the Mustang chassis to a Marauder chassis, isn't the Mustang a unibody and the Marauder built on a true frame? If this is in fact true, then I wouldn't think that much vibration would be transferred to the seats and steering wheel on a Marauder chassis versus a Mustang chassis. Your thoughts?

[BillyGman]

in this thread. Maybe it will help, maybe it won't:

My Vette (which BTW, has more torque than my Marauder does) blew a motor mount. In a V8 engine it will always be the passenger side mount that will go first since that one has more stress on it because of the direction of the crankshaft rotation. So when you hit the gas, the motor will tend to rotate on a horizontal axis towards the driver's side of the car which can really tax the passenger side mount.So I replaced both the stock rubber motor mounts as well as the transmission mount w/the Polyureathane mounts from "Energy Suspension" simply because they will hold up longer, and they won't get deteriorated by oil like the stock rubber ones can. Furthermore the poly mounts while being stiffer than the stock rubber ones, they still aren't like the steel ones used for the track, and therefore will NOT transmit the level of vibration that the steel ones do.
Since then I've been happy w/them and I haven't ever noticed any additional vibration from them either. But I will say that unless you're going to supercharge your Marauder, I really don't think you'll need the Poly mounts nor do I think it will help your acceleration. The non S/C'd Marauder simply doesn't have that much Torque (especially low RPM Torque) and therefore you won't gain much if anything at all in the way of actual acceleration. It's like putting slicks on a non-S/C'd Marauder at the track. There's nothing to be gained by that. Drag radials? Yes, perhaps, if you happen to have 4.56 gears in the rear like I have, but you don't have the power off the line to have a need for slicks w/the MM, unless you're S/C'd. Likewise w/the motor mounts IMO.

[muslhed]

That's interesting! Thanks for all the feedback! I would still like to know where I can find a set of polyurethane motor and trany mounts for our car. If somebody could offer a little information on that, I sure would appreciate it. Thanks!

[BillyGman]

that I'd check is www.summitracing.com and if they didn't have em, then I'd try to contact "Energy Suspension". If you don't already have their contact info then you can just use www.dogpile.com which is a search engine that's very specific and only gives you what it is that you were looking for according to what you've typed in. I hope that helps.

[muslhed]

Cool! Thanks! I'll check it out!