Custom tubular motor mounts anyone?
 

Maybe I just have bad luck but my motor mount bracket just broke. So now I'm in the process of trying I designing a tubular 2 peice which creates more room on the left and right side as well as eliminating on the common issues with stock mounts.

Are you talking about the cast aluminum pieces that connect the engine to the top of the rubber engine mount? If so, in the process of putting in RX8Performance mount/dampers, it was discovered that at least the LHS aluminum piece was strengthened mid-year 2006. The obvious difference from 04/05 is that the tab thru which the arm bolts to the rubber mount is thicker. There may be other areas that were altered as well.

if you're going all out, i would like to see someone do straight engine & power steering tubular mounts to the frame and take out the oem subframe...

Get a used OE one and be done with it

That's a good one stick because but a that's a bigger project I'm going to get the mount done first then I'll look into that next.

Yea thats what I did 15 minutes and $50 I was back up and running...

Saucey your trends appear to be making life difficult for yourself.

what is going on with this profound, supportive yet still slightly antagonistic Shady?

Charles encouraged me to start being more supportive and helpful.

is this a ploy to become troll moderator?

i did replace it but the difference that i have that most cant address is that i have my block tapped for the loop oil mod which means i have to modify the stock mount to fit. by doing so it creates more stress on the drivers side mount, plus i need more space.

The maint point if this is to create more space for turbo users and people who have there blocked tapped and by giving the engine more support. Dont get me wrong can say this is not needed but and stock mounts work just fine but im just putting a more of an alternative setup

That is my ploy.

i know it been a while but here is sneak sneak peak of the drivers side.

take your shades off an look again

I see it now. My neck hurts. What is the point of this mount?

https://www.rx8club.com/attachments/...one-photo3-jpg

to replace the stop mount plus i broken the drivers side twice and just wanted to go with something different that wasnt offerd, everyone there own version so i have mine, its more of a soild mount with a bushing get rid of the whole jerky feeling of stock mount.

No offense, but I pray you are not an engineer.

edit: i am leaving work and i know that you are going to ask but consider that what you have essentially created (based on what i see from this image) is somewhat of a "control arm" style mount. Not sure where you got the idea that this would work, but I assume you took a look at suspension components and said "hey they work there" .... except you missed one fatal point of execution and that is the law that everything has an equal but opposite reaction. As a suspension control arm articulates the opposite stresses are relieved through camber and various other deflections caused by the other interlinking arms ...

Also take note that any motor mount accounts for these types of deflections, either through the nature of the metals used, or some sort of filler, like the OEM mineral oil (which makes it act like a float), or poly filled (which still absorbs and deflects stresses).

I would absolutely hate to be there when you hit a solid bump in the road ....

I could go into more detail ... but then again, you are the one designing this...

im no engineer i do better in designing the parts, i have someone else do all the welding work.

see above for a very brief comment that should hopefully get you thinking

I see what your saying and such but the mount does have a bushing to absorb the some of the vibration like I have in the picture it's a 2peice just a lot more affective than a stock mount. I know a lot of people on here criticize like why? what for? Well I felt that what wasnt anything on the market that worked for me this does.

What I like
engine feels more solid.
Gets rid of the stock engine mounts
Extra room and clearance for a turbo.
And Reliability this shit is not going to break or go

Not a bad idea, just the wrong location and implementation

I'm not criticizing and I applaud your initiative, I am just trying to get you to look at the design more from a physical point of view.

One example is this: A mount must compensate for the entire axis of travel, either by having a force against the plane of travel, or having a medium for dampening. During driving, the engine faces a lot of travel along the Y axis (vertical plane). This is due to the inertia placed on the chassis as the suspension components articulate.

On the stock oem mounts, the mount brackets act as a brace that helps guide the load outwards to the motor mounts by absorbing stresses at multiple points. The motor mounts thereby absorb this force. Also take note that the OEM brackets have both an upper and lower mount, and that is to evenly distribute the reactive forces along the X axis.

What you have is a good thought, but doesn't fully compensate for these active stresses. What is going to want to happen on your design is that when the engine travels in the vertical axis, it will want to distribute the stresses outward towards the chasis mount of your design. The first point of contact and stress is that plate that is connected to the engine. Now I see that you implemented gussets, which did a good job of taking angular stress off of the engine mounting plate, but as a side effect, this placed all the stresses on the bolt heads themselves.

In a perfect world the bolt heads would have the tinsel strength to compensate for these loads, and the forces would then travel back along their path outwards towards the chassis mount. So what am I saying here? The "weak" point of your design right now is the bolts...

Again, I am getting far too much into the nitty gritty of design, and don't mean to deter you from your ultimate goal. I just want to make sure that you are prepared for these random gremlins that may pop up as the mounts get some use.

thats good advice and a good post.
I am sure that with a little redesign the op will have a long term solid mount.
Good thought about the mount and kudos to ya for the work etc. 1st designs are usually not the best in the real world so progress on dude!

Mounts like OP made here are commonly used in high power applications both on road and the track. I think its a good concept and haven't heard of any issues with this type of mount. I actually think its better than having a bolt suffering tension/compression. This mount works in "shear" which is usually better than tension imo. Of course you could argue that the bolts holding the mount to the sub frame and engine will be in tension but unless you weld it in this can't be eliminated.

Kudos to the op.

Chris

I don't mind the comments at all. Since this just the first time of me doing something of this kind I just thought of making some better. I will show more angles of it when I have time.

Over all the mount is similar to the stock mount is that us just built different and stronger. And also made to be able to pull the engine out with by only removing two bolts. I understand that I'm no way am perfect the some of us may have pulled out your own motors before or even talked about making room for a low mount turbo. Well I was thinking giving it a go testing these first then making some about of billet aluminum. Bet over all u get my concept.