I recently replaced my broken motor mounts and am now ready to replace my broken tranny mounts.

I'm trying to decide whether to go with the 911 sport mounts or the solid mounts.

From what I understand, the solid mounts transfer a lot of noise and vibration.

So my question is, as far as performance goes, are the sport mounts almost as good as solid mounts, or, are they just a little improvement over the stock rubber mounts?

I have the billet aluminum 911 mount on my tranny. There is a much better unit out now by WEVO (i think)

It has a very rigid nylon spacer so it is supposed to be easier on the tranny, think it is pretty $$$ though.

Potentially for a full racer a solid mount will provide an adcantage.

But after reading & talking to ex racers, 100% solid mounts are more of a hinderance than a help. Reason being when the motor torques up there's no movement. This causes premature wear on the engine & trans..

For my 0.02c i'll be ditching solid mounts PDQ.

WEVO has a new mount.

It is firmer than the 911 Sport mount, yet it does have the some compliance that the solid mount will not give you....I'm hopeing to pick up my mounts next week

They should have the 914 specific part available right now....

Joseph, Kevin has the solid mounts on his car. I think it's one of the reasons that shit gets loose and falls off his car weekly. Just too much vibration. Just my humble opinion.

I just replaced my tranny mounts with 911 sport mounts. What a difference! I think my tranny mounts may have been original, they were cracked to hell. The shifter no longer bounces around when I'm cruising, shifting seems easier too (that may just be in my head, like the car running better after I wax it!). I did have to oversize the mounting holes of the new mount slightly. No big deal. Otherwise they fit perfectly.

QUOTE (synthesisdv @ Mar 18 2005, 11:47 AM)

think it is pretty $$$ though.

I was talking to Brad a little about them at the GAF and if I remember correctly they were somewhere around $80.00 each.

not the hardest thing in the world to make them up yourself.

Here is what we did.
I actually didn't turn them on the lathe myself, but these are home made from delrin.

And in fact if you ever noticed, on a teener one tranny ear is about 1/4 to 1/2 half inch different than the other side. I think It depends upon how each chassis was made and the normal variation from body to body.

So on our tranny mounts we made them specific to the needed measurement for right and left.

After we got them, and bolted everything together we were still off another 1/4 or so and we ground down the extra magnesium on the tranny ear to make it a better fit.

This way some of the twist and pre-load is taken out of the driveline:

I have the 914/6 trans mounts.
Interestingly enuff, they have an Audi trademark on em', but no part number. The rubber without holes but otherwise identical to the 914/4 mounts. I got em' from AA some time back and they raped me.

I did pretty much the same thing as Brant. I got a schedule 40 aluminum pipe 1 1/2" long welded it to a 3/8" aluminum plate. filled the inside with layers of thick fiber impregnated rubber sheet 3/8" each until the thing was filled
mounted the whole thing to the car looks almost like Brants except heavier gauge aluminum.
2 years of running and that transaxle has NEVER moved. Also use nylon cutting board material for the engine mounts 73 and later style. I don't notice the vibration over the howling 44 IDF's, screaming Bursch, Poly suspension bushings and no sound deadening material on the firewall

Theoretically, the mount pictured is useless in terms of the original (OE) design. Porsche has suspended the trans from a bonded rubber/metal mount, which isolates the trans from the body (that's why you need a ground strap). You have attached a plate to the chassis, and bolted the trans to it, albeit you have a "cushion" in there. That cushion is no more than a plastic spacer, and serves NO purpose whatsoever, other than adjusting the height of the trans relative to the body. If it had any "give" or compliance in it, then you'd be inducing a pretty sharp knock into the trans every time you hit a pot hole or expansion joint (because the bolt length remains fixed while the trans moves up and down). You're introducing a weak point in the equation, one that could result in vibration and loading on the ears of the trans, which are magnesium alloy castings. These ears are already prone to breakage in an accident, and I wouldn't want to subject them to unnecessary daily stress from driving on our roads (which are most often FAR less well maintained than a racetrack)........ The Cap'n

QUOTE (joseph222 @ Mar 18 2005, 11:24 AM)

So my question is, as far as performance goes, are the sport mounts almost as good as solid mounts, or, are they just a little improvement over the stock rubber mounts?

911 sport mounts all the way unless it's a dedicated track car ...

i run 'em and they're much better than the stock rubber ones and much less vibration/noise than solid mounts ...
Andy

QUOTE (Cap'n Krusty @ Mar 18 2005, 01:04 PM)

Theoretically, the mount pictured is useless in terms of the original (OE) design. Porsche has suspended the trans from a bonded rubber/metal mount, which isolates the trans from the body (that's why you need a ground strap). You have attached a plate to the chassis, and bolted the trans to it, albeit you have a "cushion" in there. That cushion is no more than a plastic spacer, and serves NO purpose whatsoever, other than adjusting the height of the trans relative to the body. If it had any "give" or compliance in it, then you'd be inducing a pretty sharp knock into the trans every time you hit a pot hole or expansion joint (because the bolt length remains fixed while the trans moves up and down). You're introducing a weak point in the equation, one that could result in vibration and loading on the ears of the trans, which are magnesium alloy castings. These ears are already prone to breakage in an accident, and I wouldn't want to subject them to unnecessary daily stress from driving on our roads (which are most often FAR less well maintained than a racetrack)........ The Cap'n

Theoretically, I don't care. If it breaks I will fix it better. 9,000 miles on my car this year. with I think 9 autocross events. Don't see no good reason to rubber isolate other than to reduce road noise and vibration.

I had a pair of solid mounts and a pair of sport mounts....neither of which got put on my car.

The solid mounts ...for the reasons the Captn' said...great minds and all.
The sport as the metal is only a bit over half as thick as the -4/-6 mounts.

Youz' pays your money and you takes your chances.

QUOTE (J P Stein @ Mar 18 2005, 03:18 PM)

I  had a pair of solid mounts and a pair of  sport mounts....neither of which got put on my car.

Thanks to each & all - VERY informative.

It looks like the new & "improved" Wevo units are TWICE the price of the Porsche units.

They also look VERY MUCH like the original Porsche engine sport mounts!

I'm thinkin' of going on the CHEAP and just buying the Porsche units!



Interesting note from WEVO on the new mounts:
"Owners of cars with Weber or PMO carburetors will be pleased to know that development of this product was encouraged by Richard Parr at PMO as a way of protecting against carburetor issues related directly to engine vibrations."

JP - do you still have the sport mounts? do you need some extra paint money?

Nope, long gone.

Unless you have specific "issues" with the stock mounts, I can't see using anything else. They held up for 30 years, eh.
If you insist on sport mounts, don't forget to use the concave(convex?) washers that are made to go with em' or your tranny will end up on the ground.