Ok, some of you may have seen my other post about my air bags. I'm working on the rear...and I don't know which way is the best redesign of the top strut mount. My concerns are:
*The strut needs to pivot, more so with the adjustable suspension
*I'm sure there is some fore/aft movement to take into consideration
*And of course, it has to hold up to up and down movement
(making it air tight is figured out with any of the below designs, btw)

If you are a suspension expert, please feel free to donate some remarks.

Here are the ideas I've come up with and some concerns....

A. Pretty much 2 large bushings(red) with a heavy plate sandwiched in the middle. Very much like sway bar end links. Alows some pivoting in any direction. Don't see any durability issues with heavy enough steel in between. Will have to machine the bushings.

B. Strut has a heavy rod pivot(yellow)-Rod with a hole in the middle. Urethane bushed on both ends(red). Allows nice pivoting in/outboard. Doesn't allow any movement front/back...which I suppose there shouldn't be any of, but I can see something possibly breaking because of that.

C. Duplicate stock setup. One issue is that I have to use rubber since poly won't allow pivoting(flexing). My thought was to get lucky and use a control arm bushing that fits the strut. Then I have to find the right size pipe so I can press the bushing/sleeve into. Probably will work itself loose unless I secure the bushing somehow. Unfortunately I can't use a stock one because I have to weld to it(rubber will melt)

I suppose the easy way is the best way(A) and I believe it's the safest also, but I would like to know your thoughts, concerns, and any other ideas.
Thanks in advance!

[This message has been edited by Joe Torma (edited 07-03-2005).]

How about a heim joint at the top? Make a 1/4" plate that covers the factory strut upper plate with pieces to accept the heim joint that is mounted to the shock. That way you have flex

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88GT 3.4SC
88GT T-TOP
87GT VERT (build in progress)

The OE design already allows enough motion to accomodate the entire range of wheel travel. If your replacement for the struts is using the same atachment points it should be just fine. There actually isn't a huge amount of swing at the base of the strut. It would however be a good idea to buy new top plates. You should be able to order them thru most parts stores.

If you are going to try to hop the car with airbags or hydraulics... then you'd want something stronger and you'd probably need to reinforce the strut tower itself. You'll also want to use high grade hardware.

I'm not quite sure what you are doing... If your new system is focusing the entire suspension load on the strut mount bushing... Yes, you'd likely need to build something else. The OE bushing is made with the expectation the spring load will be placed on the strut tower not the strut bushing. The strut itself also expects the suspension load to go to the tower either directly or thru a bearing plate like FWD cars have.

If you wanted to be certain of the range of motion... you could mount the strut with no spring on it and then you can easily move the wheel thru the full range and measure the strut diflection. I would do this before you try to build a new top mount and then again to test the new top mount to make sure you aren't binding anything.

If you have to rebuild... I don't see why A wouldn't work. simple is best with such things. Assuming you can get some hard plate and bushings that fit on the strut. You may not be able to use a simple flat plate due to clearance with the deck lid.

C as drawn could be a punch thru problem. I don't know that you could easily punch out the bushing but you'd pick up vertical play. Depending on your bushing choice it could be significant. This can be reduced by using larger washers.

Something else to watch out for... I don't think there is much clearance between the tip of the strut and the bottom of the deck lid. You might want to use a wad of clay and mash it with the lid ala Plastigauge to see how much room you have for any change you make.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurasic Park)

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quote Originally posted by theogre: ....I'm not quite sure what you are doing... If your new system is focusing the entire suspension load on the strut mount bushing... Yes, you'd likely need to build something else. The OE bushing is made with the expectation the spring load will be placed on the strut tower not the strut bushing. The strut itself also expects the suspension load to go to the tower either directly or thru a bearing plate like FWD cars have.... If you have to rebuild... I don't see why A wouldn't work. simple is best with such things. Assuming you can get some hard plate and bushings that fit on the strut. You may not be able to use a simple flat plate due to clearance with the deck lid. ... Something else to watch out for... I don't think there is much clearance between the tip of the strut and the bottom of the deck lid. You might want to use a wad of clay and mash it with the lid ala Plastigauge to see how much room you have for any change you make.

Thanks for the suggestions Ogre. I've had the decklid off for so long I convinced myself there was more room than there is! I checked and like you said, there is barely any pivoting at the top.

The new system is attempting to put the load where it's supposed to go, like you said the strut tower, and unlike what is available for purchase.

Thanks again, knowing it doesn't pivot, A is my choice.