Sub frame connectors

Anybody ever use these sub frame connectors

http://www.mustangsunlimited.com/itemdy00.asp?T1=J7111+01

The description says "The cross bars use the seat mount bolts to strengthen the floor pans" does this mean that the crossbars bolt into the factory seat mount holes? I take it by looking at the picture that the nuts and lock washers thread right on the seat bolts that stick through the floor pans.

Is this just a street car or track car to me they look a little on the small size as walls only .100 i would step up to a set of wolfes or team z motorsports or make a set your self out of 2x2 or 2x3

The connectors in our 81 are just some 1 5/8" tubing with a slight bend, they weld to the rear lower torque box and the front subframe. We do have a full 12pt cage so that goes a long ways in making it all stiff.

If you dont mind threw the floor make your own it aint hard bout 30-40 bucks worth of 2x3 and about a hour and your done

This is going to be a street car with some drag race with 10" slicks so I would like them to go on the bottom. The rest of the subframe connectors I have looked at are .125 thick. So I think I am going to just build some myself out of some 2 x 2. Do the seat mount bracket really help, I don't have a problem building those to go with my sub frame connectors?

I would think they would help. They certainly won't hurt!! The more attachment points you have the stronger they will be IMO.

Bill

Big block fox 339 wrote:If you dont mind threw the floor make your own it aint hard bout 30-40 bucks worth of 2x3 and about a hour and your done

It sure seems to take me a lot longer than an hour but it is definitely the way I would go.

To be SFI 25.5 legal (mini tub/back half type setups) sub frame connector/inner frame rail minimum is 2 x 2 x .065" wall (box, ms & cm), or 1-1/2 x .065" wall (round cm), or 1-1/2 x .108" wall (round ms). If round ms tubing larger than 1-1/2" is used the minimum jumps to .118" wall.

To be "NHRA legal" there really isn't a reference to a minimum for "sub frame connector" them selves in the frame section of the general regs. Probably the closest usable box tubing reference in the general regs is in the roll cage section regarding either the box tube rocker bars, or roll cage to box tube frame attachment (2 x 2 x .058" ms & cm). But if you look in the Super Stock sections there are references to a box tube maximum (not minimum) of 2 x 3 x 1/8" for the "frame". And a S/S reference that the rear frame "may" be constructed of 2 x 3 x .083".

Another thing to think about is it is somewhat easier to weld the factory sheetmetal floor back to a thinner wall connector than a thick wall connector (less heat needed).

Round tube connectors like Jon suggested (1-1/2" or 1-5/8") are 100% usable & do free up some room under the car. But as mentioned they really do need a good full roll cage.

The older fox bodies used to crack the floor boards at the seat bolts.Those conectors will help that but dont expect much more from them.