RSR Rear Shock Reinforcements

[abisel]

This subject has been discussed before, but I cannot find recommendations for the thickness of metal used.

I have asked a couple Pelicanphiles, but got no response. Maybe some of you could chime in.

For the gussets that are welded to the sides of the rear shock mounts, what would be the recommended metal thickness?

For the boxed areas where the rear shock cross brace meets up with the longitudinals, what gauge/thickness is recommended?

[RBY]

I have seen a few pic's of various re-inforcements in the auto-X forum. There is a good picture of the RSR setup in Bruce Anderson's 911 Performance handbook that I remember seeing also.

[1980 911 sc]

i just did mine with 16 ga. take the time to look at that book he mentions, note the bends in the triangular braces. this is what make the thin ga material acceptable, like an I-Beam.

[barney911rs]

I need to do this soon myself, anyone have pictures of what they did as a visual reference. I have to go find my BA book to look that up.

[boba]

Not a great pic, but hope it helps. By the way this is a original RSR.

Bob

[RBY]

Here is another picture that shows the reinforcements a little more.

[RBY]

One last pic that I had from a do it your self job. This pic was posted on Pelican a while back.

[barney911rs]

While looking for examples, I found another pic in a forum somewhere very similar to the example above. Is this a better idea then just the gussets on both sides? Is it overkill? I was thinking this is what I was going to do.

Here is the other version of this I found.

[randywebb]

The BA book pic shows a folded over piece of sheet metal - should be much stronger than the "single pane" ones.

[DW SD]

I used 1/8" plate for the gussets and plates. I used 1" square tubing for other reinforcements.

[911teo]

Some more pics of the blue one above (before re-paint), plate reinforcement.

[eimkeith]

we use Keebler Elvin magic.


- or a little torch and hammer work.

[DW SD]

Originally posted by Noah
The thing I've never understood is, how do you shape the metal plating to conform perfectly over the shape of the engine compartment frame rails and crossmember?

I don't even use heat. I used a hammer and a large, secure, bench vice. It takes trial and error. I used cardboard templates, so I start with the right size piece of material.

The big demo hammer, maybe some vice grips, offer the persuasion.

Doug

[abisel]

So it looks like the gussets are 1/8" plate and the boxed areas can be something thinner. Maybe 12 gauge? The square or round tube between the shock mounts can be thin wall DOM.

All this sounds like a plan. Now to get out the tin and make some templates and then the real stuff.

What about the front? The reinforcements that are added to the inner fenders to beef up the mountings for the sway bars. What thickness sheet metal should we use here?

[DW SD]

I used 1/8" on all of the reinforced areas.

For the front I would use 1/8" again and use the sway bar bearing block as the template for drilling the holes. Also, have the sway bar installed and attached to the reinforcements before welding them in. Making sure they are colinear is important. Same for the rear swaybar mounts.

I have pictures of my reinforced mounts somewhere on this board. You can always buy the WEVO ones and weld those in instead.

Finally, another idea of reinforcing is to weld the torsion tube to the body to tie that together, better.

Doug

[efhughes3]

Has anybody done this as a stand-alone project? Or was it done (as I'd assume) as part of a larger suspension upgrade? I'd be curious to know how this would "feel" if added to a car that has all of the other suspension components in the rear replaced or upgraded as far as they'll be going. Or, is this something that really only is needed if converting to coilovers?

As I've got my engine out for the build right now, it's a great time to consider this. My car has polybronze bushings, monoballs, Bilstein sports and 29mm t-bars in the rear-would I gain any appreciable stiffness with the reinforcements?

[barney911rs]

Ed,

As I understand it, the main reason things need to be strengthened is because with coil overs, you are changing where the weight of the car is being supported. With torsion bars it's in the torsion tube, and with coil overs it's now the shock towers. It can't hurt to add the re-enforcement, but I'm not sure how much benefit it will provide.

If I'm way off base here, someone please educate me.

Is the front really needed? I was not planning to do that. I have a bar welded between the two towers already, if I need to add some steel plate to the towers to make them stronger, I'll add that to the every growing list of things to do.

[efhughes3]

Thanks John, that makes sense to me.

[Jeff Alton]

John has it pretty much the way I understand it. I did the rears with 1/8 plate on my car. I have not done the front but if I need to I will. I have an itch to seam weld the front tub next fall/winter......

I ran my car with the coil overs for 1.5 years with out any bracing and there was no evidence of cracking or stress in the rear. I should say no visisble evidence....

Ed, in your case, it you feel like welding it is a pretty easy project and it would be a good point of reference for torsion bar cars.

I would send you my welder but.....

Cheers

[efhughes3]

Thanks Jeff-I've got a welder! I may get bored and do a little something on mine.