So I believe I'm going to build my own connectors (because I'm cheap, I have the material, and I can). I was hoping I could get some good pictures of other people's connectors, bolt-in or weld-in. Or, even better, I'd love to talk to someone who has made their own.
What I specifically want to know is:

1. Where/how exactly do bolt-ins mount? weld-in?
2. What dimensions of steel is acceptable?

Thanks in advance,
Steel

 

There are tons of pics on here showing where the bolt / weld on to. There are typically two different styles of connectors for these cars.. Inner and outer.

Inners: Attach to the underside of the frame in the front beside the transmission crossmember mount point to the back by the lower control arm body mount point.

Outers: Attach to the side of the frame in the front beside the transmission crossmember mount point, but instead of directly connecting to the back LCA mount point, it runs along the rocker and can be welded all along for extra bracing.

I personally run both styles on my car for the ultimate in chassis stiffness. If you are making your own you can probably make really good ones that don't hang as low as mine do and/or allow for a better exhaust routing. I would also run bars diagonally across the chassis as well if possible. There are so many things you could do to improve chassis stiffness. Good luck.

 

Thank you hellz_wings. Are yours weld-in or bolt?

Can anyone tell me what size of steel I should be looking at?

 

 

one of the first suspension mods that i did were alston/bmr subframe connectors... both are welded in... the alstons i have scrapped VERY few times on the road.. they hang lower than the bmr frame connectors.... other than that i love them...



2frame2.jpg?t=1280852007

 

the tubular ones are the alstons? I might end up doing that too for more stiffness in the car.

 

Yes, they are. I have a set waiting to go on my Firebird.

 

yes they are the alstons... the bmr connectors are heavier...... overall it added about 50 pounds to the car...

 

I have UMI's now. The alston's will work with those it looks like to me...?

 

YEs UMI's are the outer frame rail type and Alston's connect the frame via the inner rails, so they don't come into contact with each other.

 

But don't both types attach to the rear LCA? It looks like the Alstons have a full U-shaped saddle & the UMI ones have a flat bracket that only attaches to one side. Which means they would come in contact & both would fit one side. The UMI one would have to sit over the Alston one. Not that they'll interfere. Just end up with a double wall on one side. Or cut the flat plate off the UMI one & weld it to the Alston U-shaped one.

 

You could be right. I was thinking of how Spohn's and MAC's connect together. They don't interfere, but then again Spohn and UMI aren't the same style (tubular vs square design).

 

So I looked at Competition Engineering's connectors, and they are made of 2"x2"x0.083" stock (.083 is a teeny-tiny bit smaller than 13gauge), so I think that's what I'll do with mine. I'll try to keep y'all posted.

-Steel

 

I see where I was wrong in my understanding of the Alstons & other LCAs (UMI/Spohn) coming into contact with each other.

I thought the Alstons connected to the rear LCA mount, but they don't. They attach to the rear "subframe" right beside it. So no...The 2 different SFCs types will not come into contact with each other.

 

Ah. Cool.. It's true I had forgotten that the inner style attached the front subframe to the beefy rear subframe rather than the LCA mount.

 

yup that is what I saw. Cool stuff.

 

What's the difference with the one's for convertibles

 

i have the alstons on my convert.

 

they are the Alstons. The verts have factory bracing under the rockers that will interfere with most of the perimeter style SFC's.

 

Guys, I scored some free steel stock, 14' of 3"x1" rectangle tubing, 1/8" wall. Think this would be good enough to make some SFC's out of?


I'd do something similar to sofakingdom's pic earlier in the thread..



Thanks

 

IMHO, 1/8" wall sounds pretty heavy compared to the sheet metal that they will be attached to.

 

No not really, the rear lca mounts are quite thick, and everwhere else the tubing would be welded.to plates.that are welded.to .large sections of the floor and chassis. Its fine and that's the wall thickness most companies use for subframe parts.and.suspension components.

As for the question of the 1x3. It can work but its not ideal. 3" is a bit .much and 1" is .not. quite enough. 1.5x2 to 2.5 is the norm for square tubing

 

Cool, thanks.


It's pretty low on my priority list right now but if i do end up using it i'll post pictures.

 

So OP, did you get the job done or not yet? I weld for a living and can get 1 1/2"X1 1/2"x 1/8" thick angle iron all day, and access to other metal too so i think i may do the same. But i need to know exactly where to attach the connectors to and how to bend the metal.

 

For your SFC did you cut the frame on the outer front side or form the tube to flow over the frame?

 

Do a search for Kenny bell double diamond ones... If your building your own ones like those are best they tie inner and outer + room for exhaust...

 

Inner SFC's do nothing in longitudinal form when it pertains to chassis twist.

What boxes a chassis? 3d cage boxing with triangular bracing.

So WITHOUT a cage, how are we best stiffening the frame? We look at the unibody contruction points of strength. The lateral/vetical strong points of the chassis are the firewall (for the front half), and the rear seat backrest panel(for the back half) These are the points that longitudinal bracing ties into to prevent twist. Inner connectors meet these points with far less leverage then outer perimeter SFC's do. However, in order to prevent the span of the SFC's (either outer OR inner design regardless) from twisting and thus yielding a little bend is to ladder construct some inner lateral links welded to each side .

inner SFC's do nothing other than add weight and help with only longitudinal stiffness in forces to lift the left front wheel in drag racing. The chassis will still twist with inner SFC's- they are dead weight.

Now as a side effect, they actually add to sprung weight being low and centered in the car which is the best typoe of weight to add to a car if you need to add for minum weight requirements. They will counter the roll axis in lateral roll forces- it is why I added some heavy dynamat to my floorboards of my car between the wheels for ride comfort, noise reduction, and roll benefits. Lightness for speed was not as much an issue as was ride comfort and cornering characteristics in the car I built. I would never do that to a race car where weight reduction was unlimited.