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New 1G subframe bushings

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RayPeters

15+ Year Contributor
270
9
Dec 26, 2006
Rogersville, Tennessee
In all my spare time when I'm not slaving away on my twincharger setup, I had some of these made: The tall ones are rear subframe, and the rings go with them. The smaller ones are front subframe. The material is Ultra High Molecular weight Polyethelene.

I've yet to become a supporting vendor here, but Chris has outlined the steps I need to take. If there is enough interest in these I'll go through with that and make these available. I won't discuss prices at this point, as that would be inapropriate until I'm a vendor, so please no pm's etc. Right now I'm just looking for feedback on what people think of the bushings.
 

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They look like really nice pieces. I'd be interested for the point in time when those have to get replaced...which is innevitable.

I think a replacement bushing should also be made for the rear trailing arm on an AWD car. The bushing that controlls rear toe. As far as i know...you can only buy the whole arm from the dealer...and thats a huge PITA for just one eccentric bushing.
 
Chalk me up as interested, although of course it will depend on price. I like the design.
 
Ok, as requested here's photos of the install on a GVR4 rally car today. I'm going to take a look at the toe bushing next, I need a control arm that isn't supporting a car :). Anyone have a bent damaged one they are willing to send me, I'll remember ya when I start making them.
 

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Are you planning all of the bushings under the car? If so I would probably be interested. This means the brace that is behind the rear diff, the bar that the front motor mount it on, all of the front sub-frame, and all of the rear subframe.
 
How tight is the fit of those bushings? It looks like they just slip in. I'd worry about added vibration. Is it press-fit at all?

Question two: why did you leave so much area hollowed out?
 
How tight is the fit of those bushings? It looks like they just slip in. I'd worry about added vibration. Is it press-fit at all?

Question two: why did you leave so much area hollowed out?


No they press in. It is possible to remove them. There is no vibration.

Answer 2, the shape is from Mitsu engineers, there has to be some flexebility in the system for a street car, that hollow area provides this. I did stress analasis on the part, with a 3000 pound side load (ie the wheel hits a curb and the whole car weight is against it) there will be slight permenant deformation to the bushing but no failures. If you are really hard core and want super rigid, I make these from 6061 Aluminum as well, but they transmit gear noise wicked. I've got an option for a polyurathane o-ring on the metal bushings to eliminate this and give it approx .050" of compliance. I'm working on a buch of things for the 1g cars because they are really capable if the parts are all in good condition, but they drive like crap when the suspension is all loose and the subframe won't stay put.
 
No they press in. It is possible to remove them. There is no vibration.

Answer 2, the shape is from Mitsu engineers, there has to be some flexebility in the system for a street car, that hollow area provides this. I did stress analasis on the part, with a 3000 pound side load (ie the wheel hits a curb and the whole car weight is against it) there will be slight permenant deformation to the bushing but no failures. If you are really hard core and want super rigid, I make these from 6061 Aluminum as well, but they transmit gear noise wicked. I've got an option for a polyurathane o-ring on the metal bushings to eliminate this and give it approx .050" of compliance. I'm working on a buch of things for the 1g cars because they are really capable if the parts are all in good condition, but they drive like crap when the suspension is all loose and the subframe won't stay put.

Thanks for the detailed response :) Once you get some prices worked out I might be game. I was looking into solid metal inserts but it sounds like a bad way to go from your description. Is the noise so bad you can hear it over a 3" exhaust? :confused:
 
yeah, it sounds ok in a racecar, a 3" open exhaust would mast a bunch of it. But on a trip or something it get old fast. The whine from the gears is high pitch and load sensitive.
 
First don't take my comments below as super negative, just some things to think about. I think what you've got it pretty cool, an excellent step in the right direction, but further refinement is needed to make it truly a market worthy part.

There is no vibration.

To you, but what about someone else? What conditions were the car driven in? It's vibrating, but to what level? Keep this in mind, you sell this as a fix. People will buy it. The vibration might bother 10%, 50% or higher. Those people likely will be on here, complaining about how horrible the ride is. Reflect badly and hurt your sales? Hard to say.


Answer 2, the shape is from Mitsu engineers, there has to be some flexebility in the system for a street car, that hollow area provides this. I did stress analasis on the part, with a 3000 pound side load (ie the wheel hits a curb and the whole car weight is against it) there will be slight permenant deformation to the bushing but no failures. If you are really hard core and want super rigid, I make these from 6061 Aluminum as well, but they transmit gear noise wicked. I've got an option for a polyurathane o-ring on the metal bushings to eliminate this and give it approx .050" of compliance. I'm working on a buch of things for the 1g cars because they are really capable if the parts are all in good condition, but they drive like crap when the suspension is all loose and the subframe won't stay put.

A permenant deformation in a plastic is a failure. Granted a 3000lb load is decent load, but is that enough? For example, with GM's sunraycer (which weighed well under 1000#) they found when passing over the typical 'cattle pass' found in AU, that the suspension saw spikes of 20G's. Who'd have guessed that? I really couldn't tell you if that load is high enough. You'd have to put a strain gage on that joint and go drive the hell out of the car to see what the peak loading may be getting.

Did you cut a section of the stock unit to get the shape? You realize, that shape is a 'tune', based on the material the bushing is comprised of, right? Just copying it, and calling it equivlent, really doesn't cut it. Simply, that material, is transmitting more vibration. It is dampening differently. I'd suggest throwing an accelerometer on it to get back to back differences in the vibration. Might be worth it to work with a company to get it measured, then have them 'tune' via analysis, using the material you have.

Also, it'd be in your best interest to find 10 people or so, to throw your best design at and get as many miles on them as possible to test durability. On paper it may look good, but it's amazing what time, vibration, and the elements will do.

One last thing, is there a comperession limiter? Looking at your pics, it's not readily shown.
 
im very interested, im actually just about to under-go a complete bushing overhaul, what kind of time frame are you looking at? i'd like to get a set ASAP



Likewise, I know for a fact I need to likely replace all of them seeing as how I have a 90 model AWD TSi.... and as im sure any of you can figure out it's 17yr's old now.
 
What are we looking at in terms of price...?


See what he posted

"I won't discuss prices at this point, as that would be inapropriate until I'm a vendor, so please no pm's etc. Right now I'm just looking for feedback on what people think of the bushings."
 
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