Benefits of stiffer trans/motor mounts???

[rkuhn]

I have been looking up transmission and motor mounts looking forward and making plans in my 84 GT Turbo build. My question is what are the benefits, if any, are there in installing stiffer, prothane, urethane, type transmission and motor mounts? Are they worth the extra $$$ ?

[86GTFoxBody]

I may be 100% wrong but I believe the thought behind it is if you put stiffer motor mounts in its less energy/power wasted in the twisting of the motor. Under hard acceleration or launch the motor won't twist and that more energy would put to the wheels. Like I said may be wrong but I think it's in the right direction.

[86GTFoxBody]

Along the same line back in the day how weekend drag racers chained their bock to the frame to reduce engine twist.

[rkuhn]

I may be 100% wrong but I believe the thought behind it is if you put stiffer motor mounts in its less energy/power wasted in the twisting of the motor. Under hard acceleration or launch the motor won't twist and that more energy would put to the wheels. Like I said may be wrong but I think it's in the right direction.

Along the same line back in the day how weekend drag racers chained their bock to the frame to reduce engine twist.

Sounds logical to me!

[cottonbear]

I welded the motor mounts solid on my 79 formula, with a polyurathane transmission mount. I noticed the tires chirped a lot more frequently!

[Bruce Mohacsy]

A guy in my area did a complete tear down and rebuild of a Pantera. It was the most stunning bit of craftsmanship I have ever seen! He told me that he used poly bushings on everything when he put the car back together and it rendered the the car almost un drivable on the street. He said "never again"! My understanding is that there are reasons why rubber is used on the street and poly or metal is used on the track and with some exceptions the two don't mix. That said I have no personal experience with switching.

[82MustGT]

Everything has pros and cons. Polys have their place and it all depends on what you are going to do with the car. If you are going to mainly use the car for street use then use oem bushings, mounts,etc. IMHO. If you are going to build a performance oriented car then use poly, but where becomes the question? On the engine is good, but you get vibrations. On the rear suspension you'll get binding of the axle on a Mustang...Not good. On the front control arms you should be fine. To Bruce, On a Pantera the main problem with polys is sqeeking. I know because I used them on a Pantera and the car drives and rides good, but I should have used grease fittings. The ride has to do with the shock and spring package, like all cars. The car can ride like crap or ride smooth. Learn from other peoples experiences. Back to the original question... Use polys and you'll be fine for the motor mounts. Just remember the vibrations will be there and all depends on your engine build to how much vibration it will have.

[qtrracer]

I installed poly motor and transmission mounts on my 86 when I installed the K-member. As noted above, much more NVH was transmitted into the cabin; I could also feel it in the steering and at the shifter. I also experienced the motor being raised almost 1" from the previous position (I used Prothane motor mounts which are NOT like the vert mounts that came out). After a couple of weeks, I took all of the poly mounts out and installed stock rubber including the vert motor mount. Engine was back in the original position and much less NVH.

Just to be clear, I have quite a few poly and rod-ended suspension pieces but the addition of the poly motor/tranny mounts created the proverbial NVH "straw", so I took them out.

[TWR2003]

I have been looking up transmission and motor mounts looking forward and making plans in my 84 GT Turbo build. My question is what are the benefits, if any, are there in installing stiffer, prothane, urethane, type transmission and motor mounts? Are they worth the extra $$$ ?

Unless you are RACING the answer is no. For a street car save your $$ and use stock style mounts.

[rkuhn]

Thanks guys for all the info. I wont be racing my car I just want it to be fun to drive. I have put polly bushings in the front suspension and rubber in the back. After reading all the advice I think I will stick with rubber motor mounts as well. My car will mostly be a cruiser so I want to enjoy the ride. lol

[Tracer]

Using poly for motor and trans mounts is very close to having solid mounts. I placed pieces of steel with my rubber mounts and welded them solid. I don't notice any vibrations.

[ryanws6]

I bought the eng mounts and already had the trans. I hop they don't shake my teath. I've been in a couple cars so stiff if you run over a penny you feel it. Bottom line though a good mix is best for a street car.

[86fiveoh]

I have poly engine and trans mounts, I don't think there bad at all.

[Ourobos]

I do too and can hardly tell the difference