I am working out some suspension issues for next season and I have a quick question. What is the bore I.D. on a stock FC front strut?

I am trying to see if I can make it work with some other 3 Way adjustable strut setups that I have. They are designed for a Cougar and they just need the spindle mount ears fabbed up or adapted on. I am trying to keep it low buck and if the stock strut bore is a 2" I.D., that would be awesome. I have the same issue in the rear as I have to change from a slide in and clamp to an eyebolt setup, but I can have a can fabbed up with a bearing inside it to replace the eyebolt.

Any ideas about a quick and inexpensive way to do this would be great. Don't say sell the struts, as there are about 3 full race Cougars in the world and I happen to own one that came with 3 sets of 2 and 3 way adjustables and these are brand new. The other set in the Cougar work fantastically well and I can hardly wait to get them in the RX7, so advice would be great. I can always take a stock strut and a new strut and tell a machinist to make them the same, but I expect that would be pricey.

Regards,

Eric

 

Not sure if this will help you. I use AD double adjustable insert type struts. I used a pair of Volvo 240 front strut/knuckle assembly. I cut the knuckle off and then trimmed tube to length. Trimmed the "ears" off the stock strut and welded to the new tube. Hope this helps!

 

those are like ones i have, but we just started with thickwall tube, no volvo's were harmed...

 

The Volvo tubes are much thicker than the stock ones. Not sure what the standard for thick wall strut tubing is. Next time I have one out I will measure the wall.

 

I found my notes from building the tubes.

The stock tubes are OD-50.8 ID-45.15mm
The Volvo tubes are OD-52.75mm ID-46.2mm

The shock is 44.6mm

 

Thanks for the shots and these are like the ones I have currently in the car. I am using Koni inserts in one set and Bilsteins in another. The question that I really have is that the RX7 spindle ears are longer than the available area to clamp on to the new strut. If you look at the drawing I put at the top of the thread, the available area for clamping the ears on to, either welded on to steel or machined out of billet, is only 58 mm or just about 2".

What I was thinking of doing is using a steel sleeve up on the 58 mm clamping area, then extending it lower to where it is long enough for the RX7 ears to be welded on to. Then supporting the open end of the tube with a thick washer to prevent load collapse or stretch of the tube. The struts are aluminum now, so I may need to have this machined out of aluminium to make it work. I dont know for sure......

Eric

 

I sat and thought about this a bit more this morning and I think I know what to do. I am uncomfortable with having the spindle mounting ears cantilevered off the bottom of the strut. So what I am going to do is get some thick walled tubing and have a step machined in the tubing part way down. This will allow the tube to slip on from the bottom and have part of it slide over the the step in the tube to come in to contact with the strut body above it. The step in the tube will create the positive stop for the slip on tube part.

I will then need to cut a slot out of the tube part way to allow the retaining ear to slide through it and a notch for the side body damping adjuster, but it will work.

All I need are some spindle mounting ears.......... hmmm.......... LOL.

Eric