rear motor mount mod

Well it's my turn to fix a bum rear M.M.After removing it,on my back, marveling at the absolutely stupid bullshit design of the R.M.M. I decided that I wont ever go through the trouble of replacing the RMM.no way.A royal pain in the ass to remove and the cast steel bracket weighs a f.....n ton!
Here are a few pics of my attempt to lighten the bracket a little.






you get the idea.It was a lot of fun drilling out all those holes.It made a little difference, few ounces,and it looks cool

wish I could do more.I really should replace it with alu,but lack of $ forbids it.

here is a pic of the dogbone steel sleeve that I removed from the OEM rubber mount.I'll resuse later.



and here is a pic of the dog bone sleeve all welded in a 1 3/4 dom tube.nice and solid.the RMM will now be a solid mount.no deflection no squirm.I figure there are 3 more rubber mounted brackets to take up some vibes.1 will not make a difference.

finished part.







finally.All painted.Royal PIA to remove/install.I was crawing all over the floor on my back like a drunk monkey.

Interesting idea. Would you say that the metal you added to replace the rubber insulator results in an even heavier mount, even after drilling holes in the bracket?

Since the filled rubber mount I created resulted in significant vibration levels felt through the wheel, seat, floor, and cabin, I'm guessing your solid steel mount transmits near 100% of the NVH through the car, making it extremely noticeable. Interested in your report after driving the car.

How was that for install? Since even with the rubber or poly filled ones, there is a lot of monkeying around to get the bolt properly lined-up and there would be NO play or give in your design. I'd love to go for a ride in your car to see how it handles after all this custom work. If I'm ever in Vegas I'll look you up.

Either the doors are goin to rattle off,or you may get a BONNER from the seat........LOL Nice work Robo,all kidding aside,i'm sure you will like her that tight!!!

Haha,it's still a little lighter than OEM. the thin wall Dom tube is hollow of course with the dog bone sleeve welded in the middle with 1/8" stel plate.those are the flat plates welded to the bracket in the pic.Coming from a motorcycle background some vibration dont bother me that much. I do have an alternate plan if the vibes are just too much,involving alu channel and a slab of poly.
But I still have to button up the exhaust and tighten up the front mount..so we will see..

I didnt struggle all that much gettin it back in.I really shaved alot of metal away from the OEM bracket, so it went back in alot easier.instead of dropping the cradle I removed the down pipe.after removing the tranny bracket that is attached to the tranny itself, and moved it aside,I then removed the 2 bolts that hold the steering rack to the RMM,I then just pushed up on the rack and was able to wiggle the bracket out.To get it back in was just the reverse. the toughest bolts were the rack bolts.they did not want to go back home!

@Karma.c'mon down! She handles way better now.Just with my RSSA mod,and my adjustable links..Night and Day! no kidding.I dont know if the solid mount will translate into a better handling car.I hope I dont ever have to do this again.Oooff

@flyineagle96,Hey,anything I can do to keep mr.Winkie happy! lol

It's nice to see that you take your vitamins Robo!

Thanks! But vitamins aint gonna help a sick bastard like me.thank God there's beer!&wine&Vodka$Gin

Oh good God! My first impression,driving with a solid rear mount..Yee gads! Now I can imagine a little more what Race cars are all about.Instant torque.instant drive.And a ton of vibes LOL! I have a long trip on Tuesday.Long streches of highway.We'll see how she does.As of right now,She has turned into one angry bitch! Oh man,Just starting her up scares the shit outa ya!
I took a couple exits on the freeway from the house,and before I knew it I was doing at leat 10 to 15 mph more than usual! At speed she is rock solid and all vibrations quiet down some,but youre constantly reminded that in front of you ,you have an engine that is just ready to roar. I'll have to relearn my right foot.I cant believe the difference.Is it still a Riv? not any more.She buzzes and twitches but step on the gas and zoom! she just takes off! Going around corners is a hoot! with my RSSA mod,she feels so raw and savage! Good lord,When I have my sphericals installed front and rear ,and my front coil overs in place,she will just be a nasty bitch! And I love her!

damn that sounds awesome.......lots of envy going on over here right now......
I love it when a car feels like it has a personality....

Wow, I think maybe it's time to put the ol' girl on a diet. Removing interior parts would surely lesson some of those rattles!

robotennis61 wrote:

Oh good God! My first impression,driving with a solid rear mount..Yee gads! Now I can imagine a little more what Race cars are all about.Instant torque.instant drive.And a ton of vibes LOL! I have a long trip on Tuesday.Long streches of highway.We'll see how she does.As of right now,She has turned into one angry bitch! Oh man,Just starting her up scares the shit outa ya!
I took a couple exits on the freeway from the house,and before I knew it I was doing at leat 10 to 15 mph more than usual! At speed she is rock solid and all vibrations quiet down some,but youre constantly reminded that in front of you ,you have an engine that is just ready to roar. I'll have to relearn my right foot.I cant believe the difference.Is it still a Riv? not any more.She buzzes and twitches but step on the gas and zoom! she just takes off! Going around corners is a hoot! with my RSSA mod,she feels so raw and savage! Good lord,When I have my sphericals installed front and rear ,and my front coil overs in place,she will just be a nasty bitch! And I love her!

Hope you don't start breaking axle shafts/splines etc! This is one thing the soft mounts absorbed that is now gone, so easy on the shifts!

-D

Yeah Deek ,I hear ya.I read somewhere that on rear drive cars a hard mounted engine is ok as long as the tranny mount is either poly or rubber. the Riv is a front drive car with the engine mounted sideways I wonder since I have the hockey puck front mount,pretty stiff,that the forces placed on the mounts are Not the same but equal to a rear drive car in the sense that the two main mounts on either side of the wheels suck alot of the shock.right?

After drilling out (weakening) the mount, and removing the shock-absorbing materials, are you concerned at all about the mount fracturing under the added stress and shock?

That mount isn't weak.It.s streses are on the vertical.With the plates welded into the mount the engine torqueing downwards is on solid steel so to speak. as much as a positive mod this is in that power is transfered imediately,I feel that at some point I might add some poly to the spot and do away alltogether with the OEM mount.my plan is a simple one,will be twice as strong as the OEM,be very servicable and shock absorbing without gaining too much NVH.
The buzziness might at some point get annoying so..putting the OEM crap back in is Out of the question.

Did you see what turtle did with hockey pucks loaded into the rear mount bracket? (in the fill thread)

yeah.My idea is a little differant.I'll look into buying a 2" thick sheet of poly and come up with something else.the OEM mount is way overkill for its purpose.
I'm thinking something along these lines.the general idea is there, but I would have to modify of course along with it being a little bigger.

http://www.speedwaymotors.com/Universal-Bolt-Through-Engine-Mount-Cushion-Kit,1199.html

robotennis61 wrote:

Thanks! But vitamins aint gonna help a sick bastard like me.thank God there's beer!&wine&Vodka$Gin

Glad to hear your liking her all stiffened up!!!

yeah it's pretty cool.But I tell ya..it's gettin buzzy on day 2! and no joke.I dont mind the instant response but the buzzines is startin to annoy me.I think I'll do the poly thing.But I wont reinstal the OEM mount.It's just a senseless design.If a 500 hp big block Chevy can run a simple mount like this
http://www.summitracing.com/parts/ENS-3-1108G/?rtype=10
then why cant I? and I can make it work. a longer bottom bracket to line up with the OEM bolt holes and done.

robotennis61 wrote:

yeah it's pretty cool.But I tell ya..it's gettin buzzy on day 2! and no joke.I dont mind the instant response but the buzzines is startin to annoy me.I think I'll do the poly thing.But I wont reinstal the OEM mount.It's just a senseless design.If a 500 hp big block Chevy can run a simple mount like this
http://www.summitracing.com/parts/ENS-3-1108G/?rtype=10
then why cant I? and I can make it work. a longer bottom bracket to line up with the OEM bolt holes and done.

I just saw the racecar rear mount you created - whoa! If you were sticking with that I'd say lightly thread-lock the bolts for the bracket to subframe. What is buzzy about it? Is something vibrating or it just feels really harsh that way? The hockey pucks are terrific so far. It's firm - the engine does not move a c***hair but my teeth aren't rattling out of my face or anything driving it. As long as they last, I couldn't be happier and cheap!

I thought about the thread lock but forgot.Duh.I better do that. More than buzzy,you can feel everything the engine is doing.I can allmost feel the pistons, the valves ,and every thing. There is no doubt that there is an engine just banging away in front of you.There is no isolation at all.With my Front cradle isolators deleted and the cradle hard mounted I can feel every whine and pop.I have the pucks mounted in the front.IMO the engine doesnt move at all.It cant see-saw right to left.the engins torque rocks the engine front to back so...over all it's great.instant drive with no slop at all.
the buzziness comes at me from the dash mainly and the door panels.the body feels ok.I dont get the buzziness at the seat. all quiet there.