When are subframe connectors necessary?

[Runner 68]

I guess I ruined my numbers matching 68 Roadrunner then.
Sorry purists.

 

[dvw]

I saw those same cracks as early as 1972 in more than a few 68-70 B bodys
Doug

 

[funnykarman]

I worked on a friends Roadrunner about 25 years ago . I was doing tubbing and frame work at the time . He was running a mild 440 with a 727 and slicks that would fit , but wanted to go to a bigger tire . He wanted to move the springs into the frame and mini tub it . When I pulled the back seat and the carpet I found that the floor on the drivers side had several large splits on both sides in the floor pan in front of the frame rails . They were over 8 inches long . I called his and asked him to come by and take a look at what I had found . He took a look and it scared him , and said that when he was at the track and would leave the starting line the car would hook up and then break loose and that he thought it was the tires . I built a set of frame connectors and installed a roll cage in the car . He went back to the track and everything worked much better with no more problems . At the time he was running super stock springs . The car was a strip and street car for years but he did not buy it new and did not know how abused it had been before him owning it . So taking all this with a grain of salt if you are going to keep it stock think about not racing it , ALL of our car are over 50 to 60 years old and may have been beat up before our owner ship . Looking at the pieces to do frame connectors on the market US Car Tool weld in frame connectors are the best that I see at this time . When doing my work I would split the floors and put in a 2x3 piece of tubing . Hope this helps John

 

[Remusa12]

My dad's 69 bee twisted the body enough that the door couldn't close when he put slicks on it so he took it home and pulled it out and welded in connectors and didn't have another problem. His is an automatic too.

 

[6PKRTSE]

I have welded them in on several cars over the years. Just above stock builds all the way up to full on race cars. They definitely help make a difference even on a mild street car. I say unless a number's matching, all original show poodle, put them on.

 

[hunt2elk]

I weld connectors in all my cars. I don't have any Hemi or A12 cars though and probably would not weld them in rare cars like that.

 

[66Satellite47]

My '65 Coronet sedan was a factory 426 Street Wedge, 4 spd. It had seen MUCH abuse. Evidence of some welded in traction bars, socket head screws in the 426 valley(roller lifters?). I immediately switched to 727. After couple years added the 2x3 through the floor connectors, springs moved in, roll bar, mini tubs. Amazing improvement in chassis/body stiffness. Jack anywhere on one side, the whole side raises evenly. My Satellite has the same '70's style 2x3 through frame connectors & roll bar setup. Stiff as can be. Also has bars from firewall to front subframe at front of K member, firewall triangulated down to roll bar side bar. Car is real stiff.

 

[Derwud]

My car is numbers matching, but it is the 383 magnum, 4 speed..."the little brother". Good collector value or great collector value?

I have a set oh the Hotchkis to install.. Do it, the Hotchkis can be removed a lot easier if need be.

 

[Remusa12]

I'd put them in a hemi car probably if I somehow got a 70 charger or cuda convertible maybe not but if I put intake, can and headers on a 66 coronet I'd put reinforcements in cause it's not that valuable.

 

[Speedbird]

Welding upside down laying on your back is difficult.
Put that in the "negatives" column.

 

[6PKRTSE]

Welding upside down laying on your back is difficult.
Put that in the "negatives" column.

Yes, very true. Always get a nice burn or three while doing frame connectors or any exhaust pipe welding.

 

[kiwigtx]

 

[Dennis H]

Doors close better. More like a modern car on washboard streets.

 

[zyzzyx]

Those cracks in the top of the door jambs on B bodies are from repeatedly slamming the doors, NOT from the
lack of sub-frame connectors! The cracks start at the inside and work their way outward. Every time you close
the doors hard, the top of the quarter gets pushed in tearing the sheet metal a little bit each time. The sheet
metal gets work hardened and starts to tear. Mig it up from inside the panel and you'll be good for another 20
years. The cracks and busted out lead joint where the windshield posts meet the cowl are from the car flexing
from not being stiff enough.

 

[Runner 68]

Those cracks in the top of the door jambs on B bodies are from repeatedly slamming the doors, NOT from the
lack of sub-frame connectors! The cracks start at the inside and work their way outward. Every time you close
the doors hard, the top of the quarter gets pushed in tearing the sheet metal a little bit each time. The sheet
metal gets work hardened and starts to tear. Mig it up from inside the panel and you'll be good for another 20
years. The cracks and busted out lead joint where the windshield posts meet the cowl are from the car flexing
from not being stiff enough.

With all due respect, bullshit.
I miged them from the inside the first time I fixed them and after several years, the passenger door was the first one to crack out and it was closed a 10th of the time the driver side door was. Under 500+ foot pounds of torque these cars flex like a bitch without connectors.
We welded in some additional steel behind them this time.

Welding upside down laying on your back is difficult.
Put that in the "negatives" column.

No ****. I have the scars to prove it. Hard to make a pretty weld as well.
I have seen guys weld them in on a rotisserie but question how much "bow" is welded in.
US CAR Tools recommends they be welded in with the car's feet firmly planted on the ground.

 

[Dennis H]

My welder ended up in the emergency room with an awful rash from scraping off the undercoating in summer heat. Ride was transformed. Amazing result with the welded USCartools.

 

[DeltaV]

My welder ended up in the emergency room with an awful rash from scraping off the undercoating in summer heat. Ride was transformed. Amazing result with the welded USCartools.

Asbestos in that undercoating?

 

[66Satellite47]

Welding upside down laying on your back is difficult.
Put that in the "negatives" column.

Very true. My Coronet connectors were welded mostly from the inside. Only the attachments at the front & rear subframes from underneath. And the welder was an expert, built many of the best Pro Stock chassis in the country at the time.

 

[kbfallon]

I have no doubts that welding in subframe connectors on my stock '70 Charger 500 (383 magnum, 4 speed) would help stiffen it up, but at what point would subframe connectors be necessary? I am asking because I might stray away from the stock engine.

Here's a little test to see for yourself....Put the car up on a two-post lift and check to see how your doors work with the weight off....some won't even open or close at this point. That shows how much your car is actually flexing. My shop puts them in at least 75% of the cars we build. We had a customer call awhile back who got rear ended and he Thanked us for putting them in and saving his azz ....the car folded up but the connectors kept the center of the car from collapsing. Not to mention how much better the car feels and reacts. If you do put them in be sure the car is supported under the wheels as it would be sitting on the ground and Level.

 

[John B]

I've heard of rear windows popping out of Road Runners and B body cracks/splits where the forward edge of the rear quarters wrap around into the door jamb.

Surely this 69 Charger SE 330 horse 383 was putting out waaaay too much power, now has frame rail connectors. I bought a new 86 Mustang GT 5.0 and had the C-pillar welded twice because of uni-body twist. Those that don't have it are lucky but seen it enough to spend the few extra $ to prevent a repaint down the road.