Discuss 1966 coupe subframe stiffening? on AllFordMustangs.com, the place for Mustang enthusiasts.
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I am looking for a way to tighten up the car without a 6 point cage. I have firewall to monte carlo bar braces, but nothing from the firewall back - any ideas? I know Mustangs plus offers a kit but it is kind of vague - especially the pictures and description.
If you don't mind my asking, why are you wanting to stiffen the body, are you going to be racing it (either track or drag strip), or are you installing a big block motor, or are you wanting firmer handling, or is the unibody flexing when you are driving? Good Luck?
I have a set of 2x3 black steel beams weld under my 69 when I bought it. I love them. I can jack the rear tire and the front tire comes off the ground. The car's really tight. I don't no what kind they are or just but they look like the regular black steel that you can buy from the local metal shops
To answer you Rex - I dont want a full blown racecar, but I do like to take it to track days at Laguna Seca 3 or 4 times a year. Once I put the stroker in the flex became noticable.
Okay, that makes sense, there is also a front torque box for the convertibles that might it stiffer as well as what the other guys suggested. Do you have a brace between the shock towers? Are you required to have a roll bar where the back seat area is? Good Luck.
I did subframes, 1 inch front sway bar, MC bar, export brace, L/R front torque boxes, 4 1/2 mid eye rears, 620 in inch lower front, KYB gas-adjust front, GR2 in the rear, roller idler arm and perches and traction master underriders. No x brace and no rear sway bar. The body is nice and stiff but the thing that suprised me the most is how quiet the suspension is over bumps and uneven pavement! I have RaaMat in the cabin, trunk and doors and that may be a factor. but it seems that only things that are supposed to move, move and things that should't move, don't.
Something I saw on the pro touring forums was to take your back seat out, and tack in a sheet metal firewall that separates the cab from the trunk. This won't do that much for front to rear flex, but it will help noticeably in the turns when there is a lot of side to side force acting on the car. This would be a safety feature as well as it seals off the trunk and gas tank. Alternatively you could (to save weight) weld in two diagonal cross beams to form an x brace. In addition to the stiffness, it's also safer in the unfortunate event of a side impact crash.
Of course all these techniques in this thread compound, doing only one isn't going to do much, but add them together and that's one stiff pony.
Thanks for the tips everyone - I am going to look into the torque boxes for sure, I have everything else - 1" front sway, monte carlo bar, export braces, 5 leaf reverse eye rear and 620 front springs with the shelby drop. Some guys at the track suggested a panhard bar and then somebody gave me one. Does it matter which side you mount it to?
+1 on this, but more than a "tack in" The example I saw was rosette welded across the original structure in a very complete fashion. It should provide help in rotational flex. Also, I'm curious if anyone has experience with the x-bracing sub-frame connectors, seems like it should help.
Quote:
Originally Posted by Corson
Hey guys,
Something I saw on the pro touring forums was to take your back seat out, and tack in a sheet metal firewall that separates the cab from the trunk. This won't do that much for front to rear flex, but it will help noticeably in the turns when there is a lot of side to side force acting on the car. This would be a safety feature as well as it seals off the trunk and gas tank. Alternatively you could (to save weight) weld in two diagonal cross beams to form an x brace. In addition to the stiffness, it's also safer in the unfortunate event of a side impact crash.
Of course all these techniques in this thread compound, doing only one isn't going to do much, but add them together and that's one stiff pony.
I have a '68.5 coupe that I just put sub-frame connectors and new slightly stiffer rear springs on,and it made a world of difference in handling and ride.Mine did flex a little before.I have a 302,.40 over,crane cam,Hi-po heads,headers etc.The sub connectors and rear springs are not very expensive.
1966 coupe subframe stiffening? 
