Is it REALLY necessary to load the suspension when installing subframe connectors? I've read it numerous times but I've never seen any fact to support it.
The reason is I'm getting ready to put my car on a rotisserie and it would be a whole lot easier to do it then.

Also, does anybody know of anyone who offers a chromoly steel version of SFC, preferrably a boxed version?
Draino

 

I was wondering the same thing.

Also what if you load it and there is not equal pressure on each wheel??

 

Our cars suffer from pretty bad chassis flex both while driving, and when up on a lift (just try to open or close a door while it's up there. If you install the weld-in SFC's while it is in that state, it's going to stay in that state, and that is not a good thing. Ideally, you wpould want to weld in the SFC's with the car sitting on the tires, but that doesn't give enough room to work. So, whatcha gotta do is, jackt the car up and set jack stands under the front control arms (as close to the ball joint as possible to simulate the car on the tires) and under the rear diff out by the shock mounts. If you are lucky enough to have access to a drive-on lift that is the way to go (or a pit that isn't full of greasy rags and stuff that could catch on fire) but most of us don't have that access. It does make a difference with the weld-in ones, but the bolt-in ones can be installed while on a lift, and adjusted once returned to the ground. As soon as all the car's weight is on the jack stands, the suspension is as evenly loaded as you're gonna get it (which it pretty even).

 

Good idea.

thanks.

I have a set of wheel ramps and 2 jackstands. I'll have to put wood blocks under the diff and I'll try to get it level since I'll be working on a slight incline.

 

Hey mon....

I had a friend with a race car jig do mine. Gotta be the best way - bolt it to something that absolutely holds it perfectly where it's supposed to be, and lock it in place.

 

OK, to be safe I'll do it with the suspension loaded.
Does anybody know of any sfc's made of chromoly...especially a well designed (ie..stout, ground-clearance friendly) square tubing design? Or am I gonna have to make my own?

 

Dang dude...What are you building this thing for.
I give you credit for not takeing any shortcuts, that's for sure!

 

i don't think you would want chromoly, it requires TIG welding and i don't think its as easy to join to mild steel as you might think. also its pretty expensive.

 

laiky...you sound as if you have experience with chromoly. More details please.
Oh btw. I'm trying to accomplish as much weight reduction as I'm willing to allow and as much stiffness without putting in an 8pt cage.

 

Chromoly SFC's huh?? Considering the cost, I say it would be a better idea to spend that extra $$ on fiberglass body parts. Sure chromoly is light, but do you know how much weight you're talking here? The Kenny Brown SuperSub SFC's weight in at 8 pounds each. Getting a chromoly version might save you 4 pounds on each side and cost you an arm and a leg. Compare that to the weight savings of a fiberglass hood, fenders, or door and you'll slap yourself on the head. Glass hood will make you 50 pounds lighter and cost would probably be comparabe to a set of chromoly SFC's (which would have to be custom BTW). Use the $$ where it counts.

The reason chromoly requires different types of welding is because its an exotic metal compound. In the same category as titanium if you ask me. You cant use a normal welder, and its a real PITA to attach to common metals. If you got the $$ then go for it. But I would just stick with the common stuff.

 

Not really, but i have looked into buying it and welding it. i think you can actually gas weld it but that is considered the old tech approach. When i was in school we had allsorts of aircraft parts made from chromoly, they were some really old aircraft like from the 40's so i know they weren't tig welded. The fact is it wont be as easy or cheap to fabricate SFC's from chromoly. Welding they to the mild steel unitbody won't be easy either. I would guess if uyou fabbed your own out of chromoly the materials would run you at least 200 plus you need TIG or the right gas welding setup, plus your time. No offense but you won't do as good of a job as Steve Spohn or the others with experience building SFC's. So my advice is to get something like the Spohn's and put the money and time you save into more efficient ways to save weight.