Custom Upper Spring Seat

[IdahoZ]

I am playing with the idea of having a custom upper spring seat fabricated out of mild steel for my 240Z. I am running coil overs and want to maintain the maximum amount of suspension travel that I can. I tried modifying my stock seat with the 2-1/2" muffler tubing, but was not able to get the tubing exactly centered and I am afraid the spring will rub on the threaded sleeve. I think this seat or something similar would work great and it would look good also. It is a hybrid of the stock seat and the custom aluminum seat from my coil over kit. I would use the aluminum seat from the kit, but I will loose another 1/2" of travel. Are there any machinists that would be interested in making something like this and if so how much it would cost to make two of them?

 

Thanks.

[JMortensen]

I'm not sure what you're trying to eliminate or make shorter. Apparently you're trying to make the upper spring seat shorter to lower the car without losing travel. That's a great idea and camber plates do the same thing. The one thing that concerns me is that I don't see the original rubber part of the hat there. The rubber is the obvious thing to eliminate, but it is also the part that lets the strut move. If you eliminate the rubber, you MUST MUST MUST put in a monoball or some other pivoting joint in there so that the strut can change its angle as the suspension goes through its travel. Otherwise you'll be buying new struts a lot because you'll introduce a hellacious bind in the suspension. Maybe you already know that, but I didn't see it in the pictures.

[IdahoZ]

My seat design would use the original insulator and bearing (not shown in the photos) and would be the same height as the origianl but it would have a seat designed to fit the smaller diameter coil over spring. The upper tapered portion of the seat is the same shape as the original so that it would fit up inside the insulator without having to modify it like you would need to do with a flate aluminum seat. The thickness of the seat between the bumpstop and the bearing is what I am trying to keep to a minimum along with a seat that will center the spring on the strut tube using the bearing as a guide. On the stock seat and with my seat design, this thickness is only 0.10" vs 0.60" if I use the aluminum seat and washer that came with my kit. The drawing actually shows the seat upside down, but you probably noticed that.

[blueovalz]

I did something similar to this. What I used for the spring seat (remember, this is now a street car) , and rubber insulator, for the upper part of the spring was a Honda spring seat. The seat, and the rubber insert fit perfectly. I pried the rubber piece out of the steel cup (or housing), welded the cup onto the modified Datsun piece, and then pushed the rubber back in place. I can't remember what year Honda I used, but the springs were very narrow.

[BlackBeaut]

Sound pretty much like one I made up:

 

 

Mine are designed for 2.25ID springs though so the inner part is a bit smaller. Granted I'm probably never going to install them as I'm thinking camber plates now but it kept me quiet for a bit making them

 

Cheers,

Rob

[IdahoZ]

BlackBeaut;

 

Your design is almost exactly what I am trying to do, but I would add a small 1.15" outside dia X 0.25" long extention piece on the top so that the seat can center itself inside the bearing. I also like the idea of using aluminum. Do you mind if I pattern mine after your design? Now I just need to find someone that is willing to make a couple of these for me.

 

Thanks

[BlackBeaut]

Hey Brett,

Feel free to copy/improve my design, it's pretty much the same as yours anyway. I didn't put the little lip on the top edge as once it's stuffed in to the isolator it doesn't move, and also the bump stop is a tight fit in to it which helps keep things centralised on the shock shaft.

 

Aluminiums a good choice, I was going to use stainless steel but it's silly expensive and a bit of a git to machine. You shouldn't have any problems finding a local machine shop to turn them up for you, especially if you present them with a design drawing like you attached earlier! Most of the places I've used have never turned down a little extra after hours cash in hand work!

 

Cheers,

Rob