Solid motor mount concerns

[GrimJack]

As for the high horsepower cars, they have issues. Upgradedsupra has cracked all the paint on his firewall from twisting the body due to high torque with regular mounts - and his body is stiffer than usual from the cage. Now he has moved to solid mounts as well, we'll see if this stiffens up the front end enough to prevent stress cracking in the paint.

Once upon a time I read (damnifIcanremember where now) about a fellow with a moderate amount of power, 500+ IIRC, who was tearing the stock mounts in half about every 9 months, and these were brand new.

Handling is not an issue, as Soup can now attest to - my car goes where you point it, speed and bumps appear to have zero effect on this.

As for extra stress on the subframe, I've been running mine for just over a year, and plan on pulling the motor again soonish, when I do I'll inspect the subframe. If it's showing signs of abuse, I may switch back - or I may get another subframe fabbed that can handle the abuse.

I am absolutely planning on getting a solid tranny mount as well. If this turns out to be too noisy, I'll deal with it - either by buying another Supra as a daily driver and turning this one into a track only car, or by switching back.

 

[Halsupramk3]

I bet you could hook chains into the motor mount locations and pull the car up into the air just by the mounts. I dont think you could strip the mounts out of the car subframe. But the aluminum mounts on the engine would give first i would think.

The only reason toyota put the oem liquid filled mounts on the car is to absorb vibrations from the engine to please your ass and not to avoid damage to the subframe or any other part. The car fills smoother inside the cabin with the soft mounts.

Any performance engine will vibrate more readilly than a stocker. I have had every rotating part balanced on my engine and you can feel it at idle but down the highway I just feel the engine doing its job. Orin B made my mounts 3 years ago and i can still feel the engine even after it is balanced.

 

[chevyeater]

Have you owned a car with solid mounts? and not just a bodgy engine mount only job im talking about transmission aswell the noise is PAINFULL from the drivetrain acceptable for a race car maybe but never on a road car again

Allan

I used a solid trans mount on my Camaro. The noise factor wasn't rediculous. It was certianly better than breaking trans mounts on a regular basis. My Supra has the solid engine mounts and stock trans mount ATM. Again, not unbearable by any means, even with no radio in the car.

Since up and down movement of the transmission is basically nill even with the stock trans mount in the Supra, it doesn't concern me at all (with a hand on the shifter, you can feel how much it moves). The Camaro with the torque arm was another story.

As far as handling, I'd rather have my engine move with the rest of the chassis than bounce around in a completely independent manner. That will make for more predictable (read better) handling.

 

[boostedj]

I second that, better handling all the way. When you go into a hard turn with the rubber mounts doing as allan said earlier, that would indicate that the engine is still heaving itself to the left while you are trying to turn right and every other possible rediculous direction that you dont want that much weight going uncontrolled. I have had solid mounts in almost all of my previous cars (performance oriented cars) and never was bothered by them once. Just my .02$ though.

 

[thesupraman]

Maybe try a torque strap? Kind of a compromise. Keep the engine from moving enough to tear the mounts, but keep the cushy rubber vibration isolation. As for handling, I would think that the 350-400lb engine moving maybe .5" would have a hard time upsetting the 4000lb girth of the mk3.

 

[drunk_medic]

I was going to get solid or semi-solid mounts and an engine brace that would terminate at the strut tower. I already have a strut tower brace, so I think that all of these things together would really do a good job.
Unfortunately, I haven't seen a genuine 7M/MA70 engine brace. Gotta go custom, I guess.

 

[soup]

FYI there are some North American MKiiis that have the stock engine brace. It looks like a small hood strut and mounts near the starter. Grim can vouche, we hunted a long time for one. I don't recall what year or model the car was, but I think it was a pre 89

 

[GrimJack]

It was pre-89 for sure. I think it was actually an '87.

Our theory was that they removed this as soon as they switched to the round liquid filled mounts with the idea that the new mounts should absorb more of the vibration themselves. Most people seem to toss this part when re-installing their engine.

 

[supaflyride]

Very interesting thread. As i am building up my sons 89 when I pulled the motor I too found a busted mount. Was into drag racing lots and we use a lot of solid mounts. I even ran an ashphalt drag sled (snowmibile) with solid mounts because of the flex with rubber.(caused clutching issues)
Anyway My thought is a bit of a compromise, What I plan on doing is building the soild motor mounts, shorter them, then find some high density oil resistant rubber (similar to a hockey puck) and use it as spacers between the upper and lower mounting points. I'll just make sure the total measurement is what is recomended. Then run a bolt throught the whole unit. Clamps around the rubber portion would prevent and cracking or disintegration of the rubber pieces.
Anyone think this is plausible or have i been standing too close to the exhaust pipe.

 

[MRSUPRA]

Slightly modified motormounts from a 98 MK4 supra will work. Thats what I'm running and they are much stronger than the 89-92 MK3 motormounts. You will have some extra vibration, but its not too bad.

 

[GrimJack]

Very interesting thread. As i am building up my sons 89 when I pulled the motor I too found a busted mount. Was into drag racing lots and we use a lot of solid mounts. I even ran an ashphalt drag sled (snowmibile) with solid mounts because of the flex with rubber.(caused clutching issues)
Anyway My thought is a bit of a compromise, What I plan on doing is building the soild motor mounts, shorter them, then find some high density oil resistant rubber (similar to a hockey puck) and use it as spacers between the upper and lower mounting points. I'll just make sure the total measurement is what is recomended. Then run a bolt throught the whole unit. Clamps around the rubber portion would prevent and cracking or disintegration of the rubber pieces.
Anyone think this is plausible or have i been standing too close to the exhaust pipe.

That will work fine, there was a vendor selling these for a while... I don't recall who, and I think they vanished.