I am thinking about having some tabs welded to my subframe connectors when I have them put on tomorrow. The steel tabs I have are 7 gauge plate. I want to experiment with some bolt in cross braces and see what happens. The cross braces will be removable in case I need access to the exhaust or anything else under the car.
My questions are:
Does anyone have any ideas on this? Would cross bracing make the car even stiffer than the SFCs alone?
Should it just be one cross brace alone (essentially an H brace) or should I place one near the front and one near the rear?
I could use two braces that form an X under the car. This is a little more complicated but is that the way to go?
Let me know your thoughts.
Jon
i would go with the x bracing by far the most rigidity. i would also pm bigballedox he has been talking with logan motorsports bout extra bracing for his car or just call logan and speak with dewayne
If you're talking about the framerails, your car should now be plenty rigid without cross bracing. Without gobs of power on tap, you're just adding weight for a minimal - perhaps non-existant benefit.
That said, since you're just experimenting, you could possibly set something up like a rear strut tower bar with the opposing thread direction for adjustment.
Seems to me the rails vary in width, so you'd need lots of adjustability and/or various lengths of bar to work with.
Well, I had my SFCs welded in yesterday. I have a problem with them rubing a rear exhaust hanger but no big deal. BTW my car is a 98 zetec.
My car is also not lowered and therefore I have massive amounts of ground clearance. It will be coming down a little with the upgrade of the rest of the suspension but nothing that will cause cross bracing to scrape.
I also will be re-doing my exhaust. This will allow even more clearance. I am purchasing some weld tabs from some racing fabrication places.
I am wondering if I can build the cross bracing from the same size rectangular tubing that the SFCs are made from. This would assure clearance. The only thing is making sure the center of the X is built well. I really don't want to add 80 lbs of steel under my car. I could always use a hole saw to take some weight out of the cross brace without significantly reducing strength.
If you are truly interested in doing this job correctly, do not use rectangular ERW tube. It sucks compared to round DOM tube.
Using the right materials is at least half the job. Proper design, then execution.
I agree, It will need to round tubing. My only concern is how to build it in such a way that it is removable.
Would heim joints be strong enough for the load? If so, you could weld brackets onto the SFC's and attach the heim joints to the cross tubing, then bolt the heims to the SFC brackets.
They might well be but would complicate things from a fabrication point. I would actually like to find someone locally that could crush form the ends of round tube. This would allow me to drill/punch a hole through the end and bolt them at each end. It would look somewhat like the end of sway bars.
The other way that could work would to weld a verital piece of tubing on the end of the cross tubing. Press in an approriate size bushing and use that to bolt to the the mounting points.
I haven't had the mounting tabs welded in yet. I need to spend some quality time under the car finding the best place to put them.
I have noticed there is a section of my SFCs that are not flush to the body. This could let me experiment further. I am thinking of building a true bolt on cross brace. I could build a mounting point that sandwiches the SFC. Similar to how a leaf spring mounts to a solid axle. Then I wouldn't have to commit to a location.