Sure hope this is a race-only application.... your teeth are gonna be hatin' life otherwise. I ran high durometer poly in race applications and a street car way back..... and that was enough to blur my vision.

Not to mention the additional stress it places on the transmission case itself. I've seen a few split cases on race trannys.... not conclusive that it was caused by solid mounts but how they looked makes it likely.

 

Z1 has some don't they?

Yeah....I also have heard solid only for track. ALTHOUGH, I have solid motor mounts and love them.

 

I'd be most worried about this ... the stress has to go somewhere...

 

Yup. Bushings are usually soft for a reason.

This is going to be a mistake but hey, it's OP's car

 

The Z sees most of its days on the track. Thanks again gentlemen for your input. Z1 had solid one back when momentum was around. ISR states theirs are derlin, Z1 uthrene, and torque solutions 75a durometer urethane bushings. Which is of harder material?

 

Delrin (trade name for polyoxymethylene - why I remember that is unknown.... just weird) is about the "hardest" of the ones mentioned with a durometer rating in the 80s somewhere.

Again, I've used Delrin suspension bushings and there's no slop in them to speak of. Not streetable, IMO, where urethane is a slightly better choice. Another thing to keep in mind is that hard isn't always better, even for track application. There's a certain amount of "give" in certain parts and on certain cars that is desirable, depending on the state of the REST of the car. I do NOT know what works best in a track oriented 33, this is just based on my previous use.

You have to ask yourself and answer honestly, "Is a solid or otherwise unforgiving transmission mount being use to SOLVE A PROBLEM you're having or is it just "I need a new mount so I might as well use solid."? Because honestly, don't believe there's too many problems using a more forgiving material that *need* to be fixed with a solid unit.

But, as someone else said, "Hey, your car, not mine."

 

Awesome! Thanks again gentlemen for your feedback. MicVelo, that’s exactly what I thought “might as well go solid”. Didn’t take inconsideration of the higher stress levels not being absorbed through a softer material and the transmission taking the abuse, definitely not in my budget of replacing a transmission from a poor choice. Will go with Z1.

 

going to hijack this thread since its on topic.

But I've been thinking about upgrading but going with OEM tranny mount. But i'm skeptical because the OEM tranny mount will be a 15 year old rubber mount. Thats 15 year of rubber sitting somewhere with no stress on it. I don't think they make a fresh batch every few years or so? Might go polyurethane but I'm just worried about that vibration and noise. Anyone replaced with OEM rubber mount?

 

You can buy a new or used transmission mount from Z1. I wouldn't bother with oem, since it would wear out anyways. But it does appear to be a slightly cheaper option than aftermarket.

https://www.z1motorsports.com/engine...nt-p-3194.html

 

oh , the reason I was thinking OEM is because, even the softest polyurethane that is offered still produces a lot of cabin noise (from most reviews I've read).

 

What if you're running solid engine mounts with a solid trans mount? Will it still cause stress to the trans case? My whole rear end is solid and am considering poly motor/trans mounts but also considering running solid. It is a street/future track car and I don't mind vibrations and would love to hear some transmission whines heh. I apologize in advance if this is a stupid question, trying my best to do some research.

 

You will be fine. It is usually recommended to run either solid motor and solid trans, or solid motor and poly trans, or poly motor and poly trans, but never poly motor and solid trans. At least that it what I have gathered from my research. Your rear won't affect everything as much or cause the other two as much stress as they will cause each other.

 

Why anyone would want to roll around in a mobile drum is beyond me.

 

Not everyone has those results. It is usually pretty annoying until the mounts are broken in (if running poly, not solid), then they are not much worse than OEM. Plus, it's knowing you can beat on the car and never have to worry about thrashing the mounts

 

Solid will always have that result, some poli aren't terrible but nothing like OEM. You aren't going to destroy OEM if you drive like a normal person, if it's a race car then by all means. But most people that say they have a "street/track" car probably only track it once or twice a year lol. Maybe I'm getting old but I'm sound deadening and getting rid of rattles in my car, stiffer mounts do the opposite.

 

alrighty, so solid motor/trans should be good?
thanks for the replies!

and yea haha I've only went to the track once to and auto X event and it was great! probably only 10 minutes of seat time in the 4 hours I was there but I had a blast so I definitely plan on attending more events since its inexpensive.
I plan on attending drift events too since i'm itching to get into it and would like to keep it off the streets, lately have been doing donuts around the light pole next door from my shop lol.

 

Yes, solid motor and solid trans and you will be fine!

Keep it safe!