va122

I'm trying to decide how necessary changing the motor mounts to 993RS or Wevo is. I have Motons and monoballs , dog bones and toe links, for those that don't know me. Do you think i should swap out the motor mounts? Porsche parts quoted me like a grand for the 993RS parts. Any rational input appreciated.

DavidNR

I did, Wevo solids. JRZ's, monoballs and Wevo toe links also. Need all the help I can get...
Great parts, had to change the bolt and washers to update on the older set I purchased. Minimal increase in vibration, noticable decrease in dirveline compliance and second momentum. Great tradeoff IMO.

CWay27

Unless the parts at Porsche have gone up, I had gotten mine from TRG for about 400$ (mounts and hardware). 993 RS are stiffer but not really noticeable for over 400$, I would go with Wevo semi-solid.

LVDell

You do NOT need to change the motor mounts. There is nowhere near the deflection that people seem to think caused by the solid mounts.

Take a look at my build sheet in my for sale thread. You will notice that mounts were not listed. With the money invested in my car that should be telling.

Minoclan

I have heard a million opinions on this. I put the Euro Rs mounts in my car on the advice of Joel Reiser, who works on my car. Among a lot of other things Joel owned Reiser-Callas, with David Murry as a driver. They speak, I listen.

LVDell

DM drives for MANY race shops and races for Robertson Racing in the Ford GT. Just an FYI.

As far as there being varied opinions, there is no discounting that. Put them in if it makes you feel better and more confident as a driver but if you have not changed out all the stock rubber filled parts then you have done the mounts for nothing. Trust me, you will NOT feel any benefit to them if your suspension components are still stock. You may think you do, but that is nothing more than a self-serving bias.

P.J.S.

I talked to the guys at GMG a few months back about this... they said not to...

I didn't.

Rob in VA

Originally it was thought that the mounts were causing problems with the car shifting under high loads. That was all part of the R&D. Later it was determined that wasn't the problem.

Austin

fyi Cup Car has solid Motor and trans mounts. Those engines and transaxles move around more than you may think. There's a huge load on the transmission rubber bushing (which is enormous) and the stiffer engine mounts help control that. RS mounts have more resolve than stock, and Wevo semi-solids have even more, but they don't absorb vibration much at all. If you're upgrading the car to monoball elsewhere and doing suspension mods, engine mounts should go on the list.

Would be nice if someone made an upgraded trans bushing.

LVDell

The only mounts I considered were the cup mounts but they are NOT needed. Austin, there is NOWHERE near the deflection you seem to think there is. I have engineering data to support this. I'm sure you know Greg Jones. Feel free to give him a call.

I'd have to say that if my car is setup the way it is and the "only" thing not done was motor mounts yet I feel ZERO deflection and can turn times at VIR in a 3250# street GT3 with driver on used tires commensurate with times put up by 996Cups, I would say you tell me if it's worth the $600???

joyride5

cars like e36 bmw's had very sold tranny mounts and engine mounts.. which caused some drivers to money shift due to the tranny tunnel twisting during high lateral loads. I changed mine out immediately in my M Coupe when I started tracking the car b/c you can def feel the tranny notch positions change!
But I did not experience such deflection in the 996tt.

so spend the money in solid suspension bushings instead... or toe links w/ bump steer.

Austin

Great thing about this sport are the variances in recipes and findings, it's true that the same thing may not be best for everyone. There are lots of credible engineers out there, I know you've had excellent exposure. My co-conspirators (read race team cronies) and I tested stock GT3 and regular 996 and 997 bushings and found movement that ought to be controled, maybe we were too hard on the cars via standing starts and simulating birms and getting light? Maybe we didn't need to stress the engine support carriers enough to break them?

You're very lucky to have hired an engineer to work with you and your car. We were calculating for everyone (a ton of drivers) and multiple conditions though, with endurance abuse in mind.


At $325 with shipping and hardware and an install you can DIY, it's worth it in my book, for sure and for more than just flex. If the RS mounts are now up to more than $400 and the existing mounts aren't yet worn out from heat, oil exposure, and stress then I'd pass on replacement or use Wevo.
Wevo Mounts

LVDell

Austin, let me caveat my statement with the fact that if you have to replace out your worn stock mounts then by all means replace them with SS mounts like Wevo (even though they are NOT made for the GT3) or solid mounts like the PMNA mounts.

va122

Thanks guys, Austin we have talked about this at lenghth, turns out the shocks were too short (cup length) so Lex at Moton re-built them properly. I have no rubber in my suspension anymore except for the motor mounts. I have left nothing stock. Upper and lower links, motorsport Motons, cargraphic 411 kit etc etc. The only thing untouched is the gears. The car is literally being taken apart and being re-built due to many mistakes by the various shops that have worked on the car. Does anyone have pride in workmanship in this industry? No offense intended to those honorable shops but the amount of errors is appalling.

We looked at the motor mounts and they look fine, no wear so I'll just keep an eye on them, my dealer quoted me like 900 for the RS mounts which is crazy.