What is this bracket called

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B.R.E.Demon

B.R.E.Demon

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So im restoring my 71 demon drag car and Im looking for the bracket for the under side of the firewall between the rocker and frame and I wanted to know the proper term for the part so I can search for a replacement. I attached some pictures for reference

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I would say yes as a lot of them were cut out for fenderwell headers.
 
We did the same thing and ran a tube from the bar to the rail in the front. We also used US steel frame ties. We left ours in but we are going to use Zoomies for exhaust. doing a 25-3 cage

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Remember that the rocker panel and its extension that you are talking about is actually a "box beam", though it isn't square, that is part of the "frame" of the original car so tying it to the front subframe is really important. Those two side to side pieces tie two parts of the "frame" together. If you go with a beefy subframe connector like that runs right to the front subframe (like OldManMopar did), the "rocker beam" is less critical, though still important. The big holes drilled in those pieces don't help you (I don't know why they are there) and you might consider welding patches over them if not needed.
 
str12-340 said:
Remember that the rocker panel and its extension that you are talking about is actually a "box beam", though it isn't square, that is part of the "frame" of the original car so tying it to the front subframe is really important. Those two side to side pieces tie two parts of the "frame" together. If you go with a beefy subframe connector like that runs right to the front subframe (like OldManMopar did), the "rocker beam" is less critical, though still important. The big holes drilled in those pieces don't help you (I don't know why they are there) and you might consider welding patches over them if not needed.
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I agree. Not sure what kind of power plant you intend to go with but I believe that "splash shield/support would be tied together with the rocker, torsion crossmember, and frame rail on a 4spd car from the factory.(tourque box) The factory also installed rear torque boxes just in front of the rear springs. (Again on a 4spd) My opinion is to box em in. Don't remove. You may disagree.
 
That is the front frame gusset, and if you look at the overall picture, it structurally supports where the firewall and kick panel side come together. That is an area that is also gusseted with a torque box on some higher performance models. It’s an important area, I would leave it in.
 
str12-340 said:
Remember that the rocker panel and its extension that you are talking about is actually a "box beam", though it isn't square, that is part of the "frame" of the original car so tying it to the front subframe is really important. Those two side to side pieces tie two parts of the "frame" together. If you go with a beefy subframe connector like that runs right to the front subframe (like OldManMopar did), the "rocker beam" is less critical, though still important. The big holes drilled in those pieces don't help you (I don't know why they are there) and you might consider welding patches over them if not needed.
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yes exactly this car is a full 71 spec prostock chassis. So to gain strength I intend to install 1 5/8" piece of chromoly where this panel/bracket was on both sides as to maintain strength and weight savings. As for the holes the body they are weight reduction this car is nothing more than a shell. last weigh of 432lbs bare, hope to get to 380's, that was told by the original Pro stock guys these would average (before tube chassis)

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Bennoel 10 said:
I agree. Not sure what kind of power plant you intend to go with but I believe that "splash shield/support would be tied together with the rocker, torsion crossmember, and frame rail on a 4spd car from the factory.(tourque box) The factory also installed rear torque boxes just in front of the rear springs. (Again on a 4spd) My opinion is to box em in. Don't remove. You may disagree.
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The Engine will be a 16 plug gen 2 hemi prostock motor. Like I said prior I dot intend to eliminate it I will instead remove it and run a 1 5/8" chromoly tube where the panel was as I can't find a replacement. The car is a coil over car and doesn't have the torsion bars so so the need for boxes are none. the rear frame rails are goin to be split in half moved in like the butch leal A/MP car with the leaf spring boxes moved to match the leading edge of the 1" wide rail
 
cosgig said:
That is the front frame gusset, and if you look at the overall picture, it structurally supports where the firewall and kick panel side come together. That is an area that is also gusseted with a torque box on some higher performance models. It’s an important area, I would leave it in.
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Understandable Being its a racecar im going to supplement the part with a piece of 1 5/8" chromoly tubing as its not available as a replacement
 
It may not look like much but like stated already, that stamped vertical support/bulkhead is there to tie everything together. There's one in the rear too where the front spring perch is. If you can't find them from AMD get someone to cut them out of a parts car and make sure they get some of the surrounding pieces so it can be lined up properly.

Think about it - by removing that bulkhead you'd be left with an open space between the inner and outer structures with a lot of force acting on it when the engine torques over. Is it better to have a solid support all the way around that area or just a tube across the bottom? IMO, you would make the structure weaker by eliminating that bulkhead. Plus all the heat from fully welding around the ends of the tubing - forget it.

If you went full tube frame then sure, go for it but for now you're still mostly relying on the unibody structure for strength so don't compromise it. The cage will help some but it's not tied into that point. The hemi will be a lot of weight in front too so consider that as well.

I even looked through the Motown Missle book to see if that piece was eliminated on any of those cars and as far as I could tell, it wasn't. If you have the book, look on pg. 86 there's a picture of Don Carlton's Demon - that bulkhead is still there.

I'm no expert though so maybe @HemiDenny will chime in since he rebuilt Butch's A/MP car.
 
I dunno... that looks kind of like a mess to me. Almost as if bad stuff was happening and they did what was needed to band-aid it. If starting from scratch and the rules allowed that would have been all tubing. What car is that though? I had to turn it upside down to see it better.

Little different situation with that car because it looks like the factory firewall and stamped floor are gone. They still have the OE control arms though... with a Lenco...

Are you planning to put a mid plate in? That will stiffen the firewall area and will mostly eliminate torsional twist but won't necessarily tie the overhanging outside panels to the inner structures like the bulkhead does. Perhaps a mid plate would make that bulkhead less important since there would be less force acting on that area?

Again, I know just enough to be dangerous....
 
rmchrgr said:
I dunno... that looks kind of like a mess to me. Almost as if bad stuff was happening and they did what was needed to band-aid it. If starting from scratch and the rules allowed that would have been all tubing. What car is that though? I had to turn it upside down to see it better.

Little different situation with that car because it looks like the factory firewall and stamped floor are gone. They still have the OE control arms though... with a Lenco...

Are you planning to put a mid plate in? That will stiffen the firewall area and will mostly eliminate torsional twist but won't necessarily tie the overhanging outside panels to the inner structures like the bulkhead does. Perhaps a mid plate would make that bulkhead less important since there would be less force acting on that area?

Again, I know just enough to be dangerous....
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Oh I understand Im running a mid plate in the car a dash bar and supports too at the kick well to the strut bars. The other I deal is clip the end of the rocker and make a fresh plate across similar to Motown Missile this will allow support of the fire wall and frame (attached pick) vs herbs car doesn't have any from what I can see or hurlys car

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If I were to eliminate that bulkhead I'd do something like the top picture where the cage is tied in from the outside-in. Seems like a lot of work though.

Both pictures of the old race cars show the OE firewall was removed so that could be why the extra tubing was added.

Hard to tell exactly what needs to be repaired in that area on your car but it would seem best to limit the amount of material removed and heat generated by welding to that area. It's all stamped steel so there is a good chance it could work harden and become brittle after welding. Those structural pieces were all spot welded through flanges to keep the heat away from the actual part.

There's an NSS racer I know who modified his K frame (basically stock-style front end, has both a motor and mid plate). The K member (stamped) was trimmed and welded for weight savings and clearance. The car is quick and wheel stands every pass. Recently he found good-sized cracks in the K frame where the flange was removed and welded solid which tells me that there is something to the metal fatigue idea with the OE stampings.

Whether you'd see any issues immediately, over time or at all is anyone's guess but just something to consider. Don't mean to get too deep in the weeds but I always consider the whole picture. (Analysis=paralysis)
 
rmchrgr said:
If I were to eliminate that bulkhead I'd do something like the top picture where the cage is tied in from the outside-in. Seems like a lot of work though.

Both pictures of the old race cars show the OE firewall was removed so that could be why the extra tubing was added.

Hard to tell exactly what needs to be repaired in that area on your car but it would seem best to limit the amount of material removed and heat generated by welding to that area. It's all stamped steel so there is a good chance it could work harden and become brittle after welding. Those structural pieces were all spot welded through flanges to keep the heat away from the actual part.

There's an NSS racer I know who modified his K frame (basically stock-style front end, has both a motor and mid plate). The K member (stamped) was trimmed and welded for weight savings and clearance. The car is quick and wheel stands every pass. Recently he found good-sized cracks in the K frame where the flange was removed and welded solid which tells me that there is something to the metal fatigue idea with the OE stampings.

Whether you'd see any issues immediately, over time or at all is anyone's guess but just something to consider. Don't mean to get too deep in the weeds but I always consider the whole picture. (Analysis=paralysis)
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Understandable on the bulkhead. As for metal fatigue im not as concerned as the gauge of steel and welding process (tig) will mitigate that. the best you can do is engineer something to the best of your ability's. As the professors said when I got my engineering degree "fear kills more dreams than failure ever will" so yes eventually there maybe cracks, when anyones guess, but show me a race car ever that's its never happened to. Everyone of these have been patch in one way or the other.
 
B.R.E.Demon said:
yes exactly this car is a full 71 spec prostock chassis.
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Wow. if all that cage is tied to the frame the body is just kind of hung on the cage/frame, so I think that you have all sorts of leeway with the part in your original query - just don't want the sheet metal flexing around at this point.
 
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