Motor/ Trans mounts

[Doc Bro]

Are motor mounts free? I don't have my GCR handy. BMW uses a fluid filled motor mount which isn't particularly strong in a hit....suffice it to say one of mine is not healthy . I was wondering what my options were.

Thanks

R

[JLawton]

Mounts are not free. Must be stock.

[Doc Bro]

Thanks Jeff....are you sure your not just saying that?

R

[benspeed]

I just was wondering the same thing since I'm about to put the motor backin the car. Motor mounts must be stock but trans mounts are free - my understanding from others and my review of the GCR. But if I'm wrong please correct me before it's to late....

Cheers,

Ben

[Matt Rowe]

The way I read the rules I would have to agree with Jeff also, we are stuck with stock engine/trans mounts.

But I'm curious how many other vehicles have issues with "relatively "fragile" mounts? I know I have to treat them as a consumable, even with the allowed additional stay rod. It seems odd that we can add a stay rod and we can replace suspension bushing but the motor mounts are off limits. So does anyone else have any thoughts one way or the other?

[ddewhurst]

***So does anyone else have any thoughts one way or the other?***

You could call the flexible motor/trans material bushings. Then you could use Spherical bearings as your material. (Yes I understand bushings are tubular.)

We ALL have options when we don't like the IT rules. Why should the IT rules be changed closer & closer to Production rules? Why don't people who need more free rules move to a class with more free rules ?

The fun part IMHJ of the original glossary definition of Bushing is that the word had NOTHING to do with suspension bushings. The rule had to do with installing a sleeve or tubular insert as a linear bearing or to salvage a worn part.

GCR Glossary

Bushing/Bush - A sleeve or tubular insert , whose PURPOSE is to reduce the dimension(s) of an existing hole.

The friken rubber suspension things are to reduce noise & make up for irregularites of lack of perfection. Not to reduce the dimensions of an existing hole.

Have Fun
David

[Andy Bettencourt]

Ben and I talked about engine/tranny mounts. Engine obviously stock - tranny I say stock too. Can't find any allowance in the GCR for alternate material.

If vibration is an issue, you can always go to a stayrod.

[jlucas]

The friken rubber suspension things are to reduce noise & make up for irregularites of lack of perfection. Not to reduce the dimensions of an existing hole.[/b]

I'll have to disagree with you there. Suspension bushings do indeed reduce the diameter of an existing hole. At the 25hour in 2005, I had a rear trailing arm front bushing disintegrate during my stint due to the exhaust getting too close (from someone's prior off road excrusion).

Can you say 1" of dynamic toe adjustment? Turning was not a problem, going straight was! The high speed kink at on the back part of the course was especially hairy. When it came time to pit, I was very much looking for something to reduce the diameter of the hole. :P

[mlytle]

Are motor mounts free? I don't have my GCR handy. BMW uses a fluid filled motor mount which isn't particularly strong in a hit....suffice it to say one of mine is not healthy . I was wondering what my options were.

Thanks

R
[/b]

only one? if you hit something hard enough to break one, i bet the other is toast too. and the tranny mounts would now be suspect. both my stock bmw engine mounts and both of my uuc tranny mounts sheared off in my front end "incident" on labor day. entire drive train moved forward several inches since is wasn't connected to anything anymore.. system basically worked as designed to absorb the energy of the impact.

marshall

[ddewhurst]

***The friken rubber suspension things are to reduce noise & make up for irregularites of lack of perfection. Not to reduce the dimensions of an existing hole.***

***I'll have to disagree with you there.***

Jerremy, do ya think that the OEM intent of the rubber suspension thing was to reduce the existing hole?

Second question:

Do ya think the ORIGINAL Glossary definition of the word Bushing/Bush had any reference to the rubber suspension things that reduce noise & make up for irregularites of lack of perfection?

Have Fun
David

ps: Sometimes it's good to stay some what grounded when reading the rules/glossary.

[bldn10]

David, I don't think we'd have SBs today if that had been the operative definition. But there is a separate one for "Suspension Bushing" and it uses the word "bearing" so, of course, that opened the door to things that were never envisioned by anyone as being a bushing.

[ddewhurst]

Bill, thanks for grounding me.

[benspeed]

Y'all think I should stay stock on the trans mounts? Anybody running anything but stock? The ones I want to put in are urethane.

[Greg Amy]

Ya know, those engine mounts are "suspending" the engine and transmission...hmmm, looking through the GCR for the legal-to-the-letter definition of "suspension"...strange...none found...

It's amazing how one silly little "clarification" of a rule can be so wide-reaching...what a surprise...

[Matt Rowe]

I like the way you think Greg. Here I've been replacing stock rubber mounts with more stock rubber mounts like some kind of sucker when all I had to do was squint really hard while reading the rulebook.

I'm still just curious how many people have to treat motor mounts as common maintainence items, or maybe I should ask how many people AREN'T using stock mounts?

[RSTPerformance]

We have stock bushings in the Audi's and yes, they can be a problem and need to be replaced every years or so... more frequently if we are involved in an "incident."

Raymond

[lateapex911]

...., or maybe I should ask how many people AREN'T using stock mounts? [/b]

Uhh...yea...

My informal eavesdropping in post race inpound yeilded this quote from the owner of a blue honda this summer at Lime Rock..., " Those? aluminum..... Illegal? Sure! (laughing), but what do I care? I make 'em for guys....need a set?"

Uhhh yea....your question might be the one to ask....

[benspeed]

So what happens if I do the trans mounts - Do I become a cheater? (I bought these but they aren't installed yet.)

The aluminum motor mounts for this car is supposed to be a top handling enhancement - do I become a double weezle if I use those?

Not looking to put myself into a world of pain by doing this stuff.

I guess the big question is what are guys doing in the NE? Stock everything? If so, then I will to. But if folks are running solid mounts, so will I.

Reaching out to the experienced ITA folks and rules folks for direction. I do not want to be pulling these out after buying and installing.

Thanks

[RacerBill]

I'm still just curious how many people have to treat motor mounts as common maintainence items, or maybe I should ask how many people AREN'T using stock mounts?
[/b]

I'm using stock motor/transmission mounts, but I would sure like to go to polys.

[Z3_GoCar]

only one? if you hit something hard enough to break one, i bet the other is toast too. and the tranny mounts would now be suspect. both my stock bmw engine mounts and both of my uuc tranny mounts sheared off in my front end "incident" on labor day. entire drive train moved forward several inches since is wasn't connected to anything anymore.. system basically worked as designed to absorb the energy of the impact.

marshall
[/b]

Another point is that UUC also makes what they call The Enforcer. Basically an aluminium sleave that goes over a stock transmission mount that stiffens it up. I know IIDSYCYC, but you're still using the stock mount and the moving transmission does cause shift linkage bind which this helps as it stiffens up the mount.

James