J.S.J

This is a rough design of a Differential brace using a engine mount stabilizer attached to the diff and a fabricated body mounting bracket. The brace functions perfect. It will be trimmed down in areas of exposure to streamline its foot print. My FD drives much tighter with it installed. It makes a big difference when up shifting under power. The vibration associated with solid braces is like night and day. I also have urethane (94 hardness) diff mounts as well.

http://members.***.net/stdotjohn/Cop...Size%20600.jpg

GoodfellaFD3S

iTrader: (213)

I have Keith's brace and I have no vibration whatsoever.

J.S.J

Vibration was a bad choice of adjectives, solid braces are great but you know they are there. I had one and didn't realize it did transfer road noise until I removed it. My goal is to civilize the feel of the ride but keep the performance. Make the ride quality as good as it can be.

twokrx7

iTrader: (1)

Not critiquing here, you just got me thinking ... how about a PU donut sandwiched between to flat bars, one attached to the diff and the other to the frame, each bar with a ring welded to it, top bar has small diameter ring to fit inside the donut and the bottom bar with a large dia ring to fit the od of the bushing, thru bolted to hold it together!

The drawing I previously attached using dashes etc did not stay formatted right so I deleted it ... gotta use your imagination. Maybe I'll build one.

J.S.J

That surely was a though I spent some time on. I felt since the PPF is built in layers and is designed to work with connections on top and below the diff it might stress the lower half and just twist/bend somewhere else. I am sure it would work with some testing. I was sure this would work If I got the right type of steel and mounting hardware. Send me the drawings if you care to share them. I also thought an independent source would help with the overall security of the rear end. I guess I felt it would stiffen up the flex of the PPF and keep the drive line as a hole from moving forward or back. I think you idea is a good one so let me know how things go. I also have a trans mount on the car and its also set up with a similar mount. I don't have any pictures but its so crude I don't want to show it until I can get a bender to shape the bracket. Now its just a series of 3/8 steel welded together attaching to the factory moorings used for the aluminum strut at the trans tail housing. It too works well to balance the load between the engine mounts, PPF and diff mount. I made my diff bushings, that was the easiest part of this project. I haven't farmed anything out. I also removed all my vacuum/solenoids out from under the intake and placed them on the fender wells. I can inspect the vacuum system, relays etc any time I wish. The coils are out of there as well. The other thing I did is mount a fan on the factory oil cooler. I used a electric fan from a old Supra. Its about 9 inches total and works great.

93BlackFD

i think that urethane chunk is twice the size it should be

J.S.J

Any other suggestions, ideas on the subject are welcomed. I don't have access to a lot of parts. I got the mounts for 11.00 and since this is a process I didn't want to spend to much on a unknown. I think the best size would be a smaller, longer mount like two trans mounts on your basic G.M. turbo 400. I want the mass there its important to the concept I have in mind.

cloud9

iTrader: (4)

I think this sounds like a pretty good idea, having a "civilized" brace would def. be of interest to me and I think a lot of other people. I mean I love modding my car but driving comfort is important too.

rex u.k

I agree the bush is a little tall, you could put it in a sleeve or cut it down.
I like the idea as i'm not too keen on the solid diff. brace looking at it from a point that it allows a little movement rather than none. The vibration issue isn't too much of a problem though.

J.S.J

I will be making my own bushing from 80 shore urethane and redesigning the unit soon. I want to limit the overall exposure for better clearances. I also have a trans mount which should be ready next week or so. I am using the same angel iron and a rubber mount which is a bit smaller than the diff mount. The difference it makes is unreal. The power transfer is so much smoother. My diff mounts are made of 94 shore urethane so the difference is real not just covering up a problem. I do however have the original PPF and it may be a week spot although I don't see any bends in it.

Zyon13B

Looks good, but I agree with the others that the bushing is too big. I don't think you need all that much bushing for it to do it's job there. And maybe make the metal part flat, it would help alot with clearance. Great job other wise, its good to have some creative thinkers around.

moehler

iTrader: (12)

me too... I have ZERO vibration from keith's brace.

MakoDHardie

If that bushing doesn't go through the brace arm and prevent direct contact between the mounting bolt(s) and the brace itself, you're still going to have vibration conduction. If its not like a motor mount bushing, you'll have to put bushings on both sides of the brace arm to allow both directions of vibrational play or else you'll still get some noise from the brace.

cloud9

iTrader: (4)

But can you hear it?

moehler

iTrader: (12)

I could hear the diff at first. After the brace settled in over about a month, I couldn't hear anything. I don't think rubber mounts will stop the noise translation anyways.

MakoDHardie

As long as they prevent any metal to metal contact, they will.

J.S.J

I did a little testing using flat stock a 3/8'' by 3" wide just bent over. The stock is channeled and is real rigid. The mount is a Volvo (new) motor mount. I am going to change the angle's to move it out of the way. Our reaction to noise and vibration is subject-able and often become the "norm" thus are noticed far less over time. The solid mounts are better but with a hard connection theres bound to a frequency transfer. The rubber mounted one I have transmits some just far less. I didn't feel anything the first time I used it. All I felt was a more secure transfer of power.

pinkrx7

iTrader: (2)

yes im bringing this from the dead..

where can you get rubber pieces for a diff cradle or tranny brace?

FD3S2005

iTrader: (11)

wow, 4 years old

pinkrx7

iTrader: (2)

come on i need to know how to reduce vibration thru the braces