Moparts
How Fast before Frame Connectors are needed ?
Posted By: Anonymous
How Fast before Frame Connectors are needed ? - 11/07/14 08:10 PM
Or more accurately, how quick ? On a 70 B-body in particular, how quick could one hope to run without doing any permanent damage (twisting) to your unibody ? Do not want a bar, possibly open to the US car tool frame connectors as they look almost factory. Even with those, how quick could one hope to run, 1.50ish 60's ?? Would also boxing in the front and rear torque boxes make much of a difference ? Lower radiator core support stiffening braces ??
Posted By: Thumperdart
Re: How Fast before Frame Connectors are needed ? - 11/07/14 08:31 PM
Speed really isn`t the issue it`s tying the frames to make a better working more rigid chassis.
Posted By: Anonymous
Re: How Fast before Frame Connectors are needed ? - 11/07/14 09:09 PM
Quote:
Speed really isn`t the issue it`s tying the frames to make a better working more rigid chassis.
As I said, I know it is not the speed, but the quickness or 60' times would be the biggest factor.
I did find this video of what appears to be a 70 Bee with no Rollbar, runs 10.60's with 1.56 60' times......looks to have caltracks....
https://www.youtube.com/watch?v=Pzc3yt9M21E&list=PLryldDmlkIM3zhPot22ErcCdMzCXDMWdz
Posted By: d7cook
Re: How Fast before Frame Connectors are needed ? - 11/07/14 09:17 PM
Quote:
Or more accurately, how quick ? On a 70 B-body in particular, how quick could one hope to run without doing any permanent damage (twisting) to your unibody ? Do not want a bar, possibly open to the US car tool frame connectors as they look almost factory. Even with those, how quick could one hope to run, 1.50ish 60's ?? Would also boxing in the front and rear torque boxes make much of a difference ? Lower radiator core support stiffening braces ??
I had a 67 RT that ran mid 11's that had cracking in the paint up each side of the cowl by the fender. It got pretty obvious over time. Frame connectors or a roll bar would have probably stopped it. Also are you racing every weekend or an occasional blast on TNT night?
Posted By: Anonymous
Re: How Fast before Frame Connectors are needed ? - 11/07/14 09:20 PM
Quote:
Quote:
Or more accurately, how quick ? On a 70 B-body in particular, how quick could one hope to run without doing any permanent damage (twisting) to your unibody ? Do not want a bar, possibly open to the US car tool frame connectors as they look almost factory. Even with those, how quick could one hope to run, 1.50ish 60's ?? Would also boxing in the front and rear torque boxes make much of a difference ? Lower radiator core support stiffening braces ??
I had a 67 RT that ran mid 11's that had cracking in the paint up each side of the cowl by the fender. It got pretty obvious over time. Frame connectors or a roll bar would have probably stopped it. Also are you racing every weekend or an occasional blast on TNT night?
This is for a 98% Street Car, maybe twice a year at the track.
Posted By: Challenger 1
Re: How Fast before Frame Connectors are needed ? - 11/07/14 09:28 PM
It needs it even if you don't go to the track. They are like a wet noddle without them.
Posted By: CMcAllister
Re: How Fast before Frame Connectors are needed ? - 11/07/14 09:43 PM
I would think once it got to the point where it needed a bar (12.0 - 11.50s) it needs to have frame ties. Mid 13s and quicker it will certainly help. I wouldn't put a bar in without them. How you tie it up makes a big difference also. Bolt-ins are a waste of time. The 2x2 pre-fab weld-in kits are OK, but if you want it as stiff as possible, 2x3 sectioned into the floor is how it should be done.
Posted By: an8sec70cuda
Re: How Fast before Frame Connectors are needed ? - 11/07/14 09:50 PM
These old unibodies need frame ties regardless in my opinion. If the motor will be somewhat healthy and you'll drive like it was meant to be driven, then put some connectors on it.
Posted By: Monte_Smith
Re: How Fast before Frame Connectors are needed ? - 11/07/14 10:41 PM
Everything needs the frames tied together regardless of ET. If it twists or flexes even a little bit, that's too much. Don't waste your time on bolt ins
Monte
Posted By: radar
Re: How Fast before Frame Connectors are needed ? - 11/08/14 12:21 AM
I welded some into my demon- wow what a difference just normal driving. A lot of squeaks were gone, it cornered flatter, launched straighter, just plain felt better. Night and day. I used 1/8" wall 3x2 steel and instead of notching the floor I notched and tapered the rear up to surround the front of the rear frame stubs.
Sorry to pile on the bandwagon even though I don't have any twisting at launch info but just do it!
Posted By: Anonymous
Re: How Fast before Frame Connectors are needed ? - 11/08/14 12:28 AM
Quote:
Everything needs the frames tied together regardless of ET. If it twists or flexes even a little bit, that's too much. Don't waste your time on bolt ins
Monte
I'll second that...
Posted By: dogdays
Re: How Fast before Frame Connectors are needed ? - 11/08/14 01:50 AM
The first time I saw the cracking/deformation was in the '70s and it was pretty much any unibody with a 440 in it.
I don't think it's a waste even if you never hit the track. Jack up one corner of your car and watch the door gaps change.
Chrysler made the cars to serve the 99% of people who used them to drive to work or the market or on vacation or etc. They were not building drag racers unless it was one of those special cars, even those they figured the real racers would be modifying the car for their purpose.
Chassis science has improved by a factor of five over the years. Don't be stuck in the '70s.
R.
Posted By: CMcAllister
Re: How Fast before Frame Connectors are needed ? - 11/08/14 02:21 AM
The stamped floor pan is where most of the strength of the unibody is. Sectioning the tubing into the floor and fully weld it, as opposed to a couple of inches of attachment in the front and rear, makes a big difference. I also like to see the cage attached to the inside of the body in strategic locations, rather than just sitting on the floor pan. Make the body shell one interconnected unit, top to bottom, where the pieces all strengthen and support each other.
Posted By: Anonymous
Re: How Fast before Frame Connectors are needed ? - 11/08/14 02:57 AM
I appreciate all the comments. It seems the consensus is the make it as rigid as possible, but like I said this will be a car that goes to the track maybe twice a year. I personally like things looking as original as possible, yet I would be bored running 13's , 12's....
Any first hand experience with using the US Car Tool Connectors ?
My biggest concern is they are only 12 gauge, and the floorpan is probably less, so....
Do they really stiffen things up ?
What about additionally boxing the front and rear torque boxes, is that worth doing ?
And the front Radiator support stiffener ?
In theory it looks like a good idea, just wondering if anyone has first hand experience with these items.
It is an Original 6 bbl car, so the most I am willing to do is install the US Car Tool style connectors/parts, as they look somewhat factory, to me.
What brought this to mind is this video I saw of a 70 Bee running 10.60 with 1.56 60' times without a bar. This is the type of car that appeals to me.
https://www.youtube.com/watch?v=Pzc3yt9M21E&list=PLryldDmlkIM3zhPot22ErcCdMzCXDMWdz
Posted By: DLewis
Re: How Fast before Frame Connectors are needed ? - 11/08/14 04:49 AM
I'm currently putting the complete chassis stiffening pack and frame ties from US tool in my B Body. Not sure where you are in WI but I'm in MN and you're welcome to come check it out. My last car had 500HP and I did weld in frame ties that only fastened at the front and back (not along the floor). I never took it to the track but like stomping the throttle on my way to the Saturday night car shows. When I sold the car it was pointed out that the car had started to twist. I'm not a structural engineer but the material from US Tool is thicker than the floors, frame, and rockers on the car. It's just shy of $800 to put all their stiffening products in the car and really doesn't take too much more time than just doing frame ties. Theirs doesn't require cutting slots in the floor so the carpet will lay down right and the stock appearance isn't changed at all. I can't tell you how well it all works yet, but it seems like reasonable insurance.
Posted By: OUTLAWD
Re: How Fast before Frame Connectors are needed ? - 11/08/14 05:03 AM
I'd put them on anything I was planning to drive. As others have mentioned, stiffening the chassis can help preserve the car.
Posted By: 383man
Re: How Fast before Frame Connectors are needed ? - 11/08/14 05:16 AM
I put frame connectors and a 6 point rollbar in my 63 street/strip car. I feel the 6 point rollbar stiffened it more then the frame connectors. Its run 10.70's with a best sixty of 1.50. Ron
Posted By: 70blackfish
Re: How Fast before Frame Connectors are needed ? - 11/08/14 07:41 AM
you will tweak the body , mess up a nice paint job. Then wish you had done it
Posted By: rowin4
Re: How Fast before Frame Connectors are needed ? - 11/08/14 08:03 AM
I used to have a 64 plymouth 4 speed street / strip car, no frame connectors or bar as it only ran 12.50's. When I got rid of that car there was not only cracks on the A pillar, I could stick my finger between the windshield and the A pillar because the body was twisted so much. On my 67 Barracuda , A pillars have cracked and the floor tunnel is twisted / buckled even with frame connectors and a 6 point bar. Also , most sheet meat on older cars were 20 gauge or less. 12 gauge is fairly thick, 10 gauge is 1/8".
Posted By: gdonovan
Re: How Fast before Frame Connectors are needed ? - 11/08/14 01:41 PM
Quote:
Everything needs the frames tied together regardless of ET. If it twists or flexes even a little bit, that's too much. Don't waste your time on bolt ins
Monte
If you can find a set of bolt ins cheap weld them in place, it makes a difference.
My '67 was beat on so bad I cracked the trans tunnel over time. I ended up installing a used set from a swap meet missing the hardware so we just welded them in. Night and day difference!
Edit- I was running 13.0's at 112 on street tires.
Posted By: ahy
Re: How Fast before Frame Connectors are needed ? - 11/08/14 02:12 PM
My first modification was connectors... the car drove noticably better with them installed running a 318/auto. As several have said, these cars benefit from connectors regardless of power level.
Posted By: Mattax
Re: How Fast before Frame Connectors are needed ? - 11/08/14 02:39 PM
My co-worker, John Soemer, ran his '67 GTX without them. His 'trick' was to park the car all week on jack stands so the body would settle back to straight. Eventually the axles broke and that ended the weekend short drives, but the body had stayed fairly straight. Obvious this is not a solution for everyone. Car was running just around 11 seconds with the last motor combo (and slicks of course).
Posted By: gregsdart
Re: How Fast before Frame Connectors are needed ? - 11/08/14 03:27 PM
I just welded in a pair on my 65 street Dart, and forgot how important it is to support the front end in more than two positions to keep it from flexing when jacked and then winding up tweaked just a bit. As a result I have a very small paint chip on the left front fender where it meets the bottom of the body and the panels are tighter there than they were when painted.
I think we need to remember how old these car bodies are, and that support systems are even more important now than when new.
Posted By: 340B5
Re: How Fast before Frame Connectors are needed ? - 11/08/14 04:01 PM
Open your door, then jack up the front of the car and open the door. If you can tell a difference you definitely need the connectors. That being said; if you just do it anyway, you'll prevent future rattles and squeeks from popping up.
Posted By: domingo
Re: How Fast before Frame Connectors are needed ? - 11/08/14 04:34 PM
Any car will benefit from them regardless power level. These unibodies flex a lot!!!!
Having said that, the FAST guys can go 10s without em on stock tires!
Posted By: dvw
Re: How Fast before Frame Connectors are needed ? - 11/08/14 04:52 PM
The only issue I see with the formed style is that they are U-channel and not a piece of tube. Still better than a piece of tube hanging below the floor. Once the tube is installed it looks the same from the bottom anyway. I failed to put them in my street Challenger. Big mistake, even a small block 4 speed 12.50 car has tweeked the C-Pillar 1/4 to roof. I like to cut the bottom of the rear frame rail away. Drill a few spot welds and clamp the rail sides to the tube. Push the floor down to the tube at the front a 1/2" or so and it'll all be solid.
Doug
Posted By: dvw
Re: How Fast before Frame Connectors are needed ? - 11/08/14 04:56 PM
all done
Posted By: dvw
Re: How Fast before Frame Connectors are needed ? - 11/08/14 04:59 PM
Bottom, disregard the roll cage and ladder bar stuff. Look at the fit to the floor pan.
Posted By: astjp2
Re: How Fast before Frame Connectors are needed ? - 11/08/14 11:43 PM
Just think how much stiffer the entire car would be by boxing in the subconnectors and tietie them into the rocker boxes. That would make a very large box structure that would tie the front to the rear and be stiff as heck. Tim
Posted By: Magnum
Re: How Fast before Frame Connectors are needed ? - 11/08/14 11:57 PM
Quote:
I put frame connectors and a 6 point rollbar in my 63 street/strip car. I feel the 6 point rollbar stiffened it more
In theory, I completely agree with this. With all the strengthening on 1 plane, front frame, rear frame, rockers and frame connectors. It's only as strong as a pick up truck which is the king of flex.
Connectors will transfer drag launching loads to the front frame but stop flexing?
Posted By: StealthWedge67
Re: How Fast before Frame Connectors are needed ? - 11/10/14 02:06 AM
Truth is, Factory should have tied the frames on any 426w, 440 & Hemi powered B-Bodies.
Posted By: ProSport
Re: How Fast before Frame Connectors are needed ? - 11/10/14 02:42 AM
After reading this thread I'm starting to realize my Mopar Performance bolt-in frame connectors are useless.
Would they be ok if I have a friend weld them in, or do they really need to come up through the floor?
Posted By: Crizila
Re: How Fast before Frame Connectors are needed ? - 11/10/14 03:13 AM
I was starting to wrinkle the fenders running high 11's. When I went to put in an 8 point cage, I added low positioned parallel bars between the hoop and front down bars. The front down bars sit directly over the front frame sections and the hoop sits over the rear frame sections. No more wrinkling and I run mid 10.s this way with no frame connectors.
Posted By: Anonymous
Re: How Fast before Frame Connectors are needed ? - 11/10/14 03:16 AM
Quote:
After reading this thread I'm starting to realize my Mopar Performance bolt-in frame connectors are useless.
Would they be ok if I have a friend weld them in, or do they really need to come up through the floor?
I have the Mopar bolt on ones on my '70 duster but,we welded them in same ones in 2 other friends cars..none of them come through the floor...
Posted By: StealthWedge67
Re: How Fast before Frame Connectors are needed ? - 11/10/14 03:41 AM
Quote:
After reading this thread I'm starting to realize my Mopar Performance bolt-in frame connectors are useless.
Would they be ok if I have a friend weld them in, or do they really need to come up through the floor?
They're not useless, but they fall short of what your goal is with them. They don't need to come through the floor, but that would be the ultimate way to stiffen the floor section. Welding them in at each end would be a good idea, and will help a lot. From there, tying them to the floor somehow, mid-span is a good idea.
Posted By: ProSport
Re: How Fast before Frame Connectors are needed ? - 11/10/14 03:58 AM
Ok sounds good, I will get them welded on each end.
I've been saying all along that this particular car will not have a cage in it but I'm starting to think a 6 point bar might from turning into a pretzel as the motor will be easily capable of running 10's if I ever take it to a track. But the rear seat needs to be accessible.....decisions decisions.
Posted By: Monte_Smith
Re: How Fast before Frame Connectors are needed ? - 11/10/14 05:01 AM
Quote:
Ok sounds good, I will get them welded on each end.
I've been saying all along that this particular car will not have a cage in it but I'm starting to think a 6 point bar might from turning into a pretzel as the motor will be easily capable of running 10's if I ever take it to a track. But the rear seat needs to be accessible.....decisions decisions.
On a street car, to have rear seat access with a roll bar, at least from the pass side, run a diagonal bar from high on the pass side to low on the driver side, then install a bar behind the drivers seat from main hoop to diagonal bar. This supports the hoop side to side, gives a seat bar and a place to mount harness and also leaves a large opening on pass side to get in back seat..........just watch your head......LOL!!! I have also gone from the middle of hoop straight down to top of trans tunnel and then added seat bar behind driver. This leaves the whole pass side area open to get in back
Monte
Posted By: 383man
Re: How Fast before Frame Connectors are needed ? - 11/10/14 06:36 AM
Quote:
Ok sounds good, I will get them welded on each end.
I've been saying all along that this particular car will not have a cage in it but I'm starting to think a 6 point bar might from turning into a pretzel as the motor will be easily capable of running 10's if I ever take it to a track. But the rear seat needs to be accessible.....decisions decisions.
Mine are the bolt in bars that are welded and dont go through the floor. But I also have a 6 point rollbar welded in that I feel does more then the frame connectors do to stiffen the car. But I have had no problems. Ron
Posted By: B G Racing
Re: How Fast before Frame Connectors are needed ? - 11/10/14 07:49 PM
Quote:
Speed really isn`t the issue it`s tying the frames to make a better working more rigid chassis.
Even a stock street car should have them if your going to beat on it.We see stock big block cars show cracks at the windshield piller/cowl area.
Posted By: cdoublejj
Re: How Fast before Frame Connectors are needed ? - 11/30/14 09:27 AM
does adding in the tube cause any issue with factory carpet/interior?
UScar tool sells some laser cut pieces,
http://store.uscartool.com/66-70-B-Body-frame-connectors.html
Posted By: gregsdart
Re: How Fast before Frame Connectors are needed ? - 11/30/14 12:33 PM
Another thought on when they are needed. Look at the math for a basically modified street car on stickys that hooks, even running 14.0s.
3.91 gears, 3,000 stall converter, mild 440 ,450 ft lbs torque at stall speed, no spin.
Torque x converter torque multiplication, times trans ratio times rear gear for the torque at the hit.
450 x 2 = 900 x 2.45 first ratio =2205 ft lbs x 3.91 rear gear = 8621 ft lbs of torque working to hurt your chassis! Now take the spring front segment length to figure force on the spring hangers.
8621 divided by 20 inch times 12 inch = 5173 ft lbs load, divided by two hangers, or 2586 lbs of force on each hanger.
It may only last the first two feet, but that is where max torque to the tires will be.
Posted By: B G Racing
Re: How Fast before Frame Connectors are needed ? - 11/30/14 01:36 PM
They can be installed in a variety of ways as not to cut,weld or modify the floor pan.
Posted By: jose jones
Re: How Fast before Frame Connectors are needed ? - 11/30/14 05:12 PM
Quote:
After reading this thread I'm starting to realize my Mopar Performance bolt-in frame connectors are useless.
Would they be ok if I have a friend weld them in, or do they really need to come up through the floor?
The Mopar Performance frame connectors work just fine, throw away the bolts and weld them in place they will stiffen the frame
Posted By: StealthWedge67
Re: How Fast before Frame Connectors are needed ? - 12/01/14 01:53 AM
Quote:
Quote:
Ok sounds good, I will get them welded on each end.
I've been saying all along that this particular car will not have a cage in it but I'm starting to think a 6 point bar might from turning into a pretzel as the motor will be easily capable of running 10's if I ever take it to a track. But the rear seat needs to be accessible.....decisions decisions.
On a street car, to have rear seat access with a roll bar, at least from the pass side, run a diagonal bar from high on the pass side to low on the driver side, then install a bar behind the drivers seat from main hoop to diagonal bar. This supports the hoop side to side, gives a seat bar and a place to mount harness and also leaves a large opening on pass side to get in back seat..........just watch your head......LOL!!! I have also gone from the middle of hoop straight down to top of trans tunnel and then added seat bar behind driver. This leaves the whole pass side area open to get in back
Monte
These are great ideas for street guys, Monte. I recently saw a bar in a chevelle that had the standard cross-bar behind the seats, but had a swing out section in it. was hinged mid-span, and swung forward, locking out a few inches inside the main hoop on the passenger side. I asked the guy if it passes NHRA, and he said "probobly not, but I've had never had it questioned at tech before".
????
Posted By: cdoublejj
Re: How Fast before Frame Connectors are needed ? - 12/01/14 05:27 AM
Quote:
They can be installed in a variety of ways as not to cut,weld or modify the floor pan.
So qualms/issues with US Car Tool product then? So far I have been reading good things about them.
Posted By: Jeremiah
Re: How Fast before Frame Connectors are needed ? - 12/01/14 05:53 AM
I am a firm believer that the frame ties need to go through or at least attach to the floor. I have the old weld in/bolt in MP (Comp Eng?) unit in my 4-speed car and they bend up and touch the floor when put the car up and the jack stands are under the frame instead of the control arms. It didn't do that when it had an eight point roll bar. If I was going to leave it without the roll bar I'd have to weld them through the floor to be comfortable. The car launches hard enough to bend leaf spring segments and I already had to repair the a-pillar to cowl joint once which entailed repainting the car. That was a ton of work that could have been avoided if my brain was functioning correctly when purchasing the connectors years ago. IMO any car that gets beat on should have them.
Posted By: cudatom
Re: How Fast before Frame Connectors are needed ? - 12/01/14 06:37 AM
Raced my Cuda regularly back in the early 80's. Wasnt real fast ran 12.80's. Drove it to the track and back. I majorly twisted the car running even that slow. Buckled one 1/4, up into the roof. I'm w/everyone else here. Put them on. It will save the car.
Posted By: B G Racing
Re: How Fast before Frame Connectors are needed ? - 12/01/14 06:25 PM
We would never cut the floorpan,but would rather weld a good stiff rail 2X2 or 2X3 minimually 1/8 thick from the trans crossmember area to heavy frame section at the rear.We add a 3"X6" flange to the rail at the front and weld it to the crossmember for eliminating any point load or twist that can tear the stock metal.You can further weld the driveshaft loop and rear suspension(ladder bar and etc) cross member to these rails to further stiffen the chassis,gussets can also be added at critical areas.If your going to start wacking and welding on the floor pans we suggest unloading the sprung weight and jigging the chassis on a frame machine.
Posted By: mickm
Re: How Fast before Frame Connectors are needed ? - 12/01/14 07:05 PM
i have the US ones. i've heard that some fit really well, and are almost a straight weld in job, but mine were quite off. i did a bit of grinding on them before i turned them over to the guy who installed them, and he did a LOT more. but they are in, and look fantastic, and make a big difference! i like these best as yes, most likely the factory would have done something like this had they done it.
Posted By: racerx
Re: How Fast before Frame Connectors are needed ? - 12/02/14 06:29 AM
Does anyone have any pics of the US frame connectors mounted in there cars?
Posted By: WyleECoyote
Re: How Fast before Frame Connectors are needed ? - 12/03/14 04:55 AM
I went 2x3. They feather IN to the car under the front seat and protrude about 1.5-inch in the rear seat floor area.
Posted By: cdoublejj
Re: How Fast before Frame Connectors are needed ? - 12/04/14 05:50 AM
Quote:
Does anyone have any pics of the US frame connectors mounted in there cars?
http://www.ebay.com/itm/MOPAR-Weld-in-Fr...555&vxp=mtr
they sell an entire chassis stiffening kit,
http://www.ebay.com/itm/US-Car-Tool-Mopa...acf&vxp=mtr
you can get them on the eBay and the official USCarTool website.
Posted By: 68KillerBee
Re: How Fast before Frame Connectors are needed ? - 12/04/14 04:05 PM
Missed Hotchkis' 25% off sale or I would have bought them from there.
Posted By: cudaman1969
Re: How Fast before Frame Connectors are needed ? - 12/04/14 05:39 PM
Making provisions for pass. to get in back seat? Yea right, the picture that comes to mind is going to hospital for the pass. concussions they get banging around inside those bars. Me and one front pass. is all it will be, if my buddys want to ride around we'll use the Mercedes.
Put the frame connectors in, who really cares what the floor looks like.
Posted By: racerx
Re: How Fast before Frame Connectors are needed ? - 12/05/14 01:47 AM
those fit the floor boards pretty well, wish I new bout these when I purchase my DC ones.
Posted By: mike s
Re: How Fast before Frame Connectors are needed ? - 12/05/14 07:54 AM
Every semi serious (12 sec) street car should have connectors and all the support items you can add. I didn't see anyone mentioning the 8-10 inch fold that appears above the rear wheels in the middle of the quarter when you don't.
Posted By: 67Satty
Re: How Fast before Frame Connectors are needed ? - 12/05/14 07:22 PM
My mid-12 second car must be an underachiever because after 80 or so runs on slicks with no subframe connectors and 1.68-1.70 60 foot times, I haven't seen any signs of tweaking or damage yet.
But I do want to add them to see if they will improve my 60 foot times or ETs. Anyone have any before and after data regarding that?
Do the F.A.S.T. cars run subframe connectors?
Posted By: Thumperdart
Re: How Fast before Frame Connectors are needed ? - 12/05/14 08:30 PM
I added those years ago before the 6-point bar and it definately made it more consistent in a high 11-low 12 sec. car..........
Posted By: dogdays
Re: How Fast before Frame Connectors are needed ? - 12/05/14 08:38 PM
In my opinion, one should add them if one intends to put the car on the road or track. Trailer queens, maybe not so much.
What I seem to remember from back in the day is movement at the welded/leaded line where the quarter panel joins the roof. In some cases the paint would actually flake off at the joint, and there'd be a noticeable bulge.
The cars weren't all that fast back then, and it seemed to be mostly bigblock cars.
R.
Posted By: Evil Spirit
Re: How Fast before Frame Connectors are needed ? - 12/05/14 09:55 PM
Quote:
Another thought on when they are needed. Look at the math for a basically modified street car on stickys that hooks, even running 14.0s.
3.91 gears, 3,000 stall converter, mild 440 ,450 ft lbs torque at stall speed, no spin.
Torque x converter torque multiplication, times trans ratio times rear gear for the torque at the hit.
450 x 2 = 900 x 2.45 first ratio =2205 ft lbs x 3.91 rear gear = 8621 ft lbs of torque working to hurt your chassis! Now take the spring front segment length to figure force on the spring hangers.
8621 divided by 20 inch times 12 inch = 5173 ft lbs load, divided by two hangers, or 2586 lbs of force on each hanger.
It may only last the first two feet, but that is where max torque to the tires will be.
Pretty safe bet that if you could measure the loads at the front spring hangers your numbers would be way off - the right side would be much higher than the left due to torque trying to rotate the housing and pick the right tire up.
--------------------------------------------------
And food for thought - if frame connectors are so effective, why didn't the factory use them instead of torque boxes that tie the sub-frames to the rocker boxes? You see a lot of factory installed (on all makes) torque boxes on high H/P cars and convertibles, but rarely (if ever) do you see factory installed sub-frame connectors. Personally I don't bother with sub-frame connectors unless I also tie the rockers in too.
Posted By: Evil Spirit
Re: How Fast before Frame Connectors are needed ? - 12/05/14 10:03 PM
Quote:
What I seem to remember from back in the day is movement at the welded/leaded line where the quarter panel joins the roof. In some cases the paint would actually flake off at the joint, and there'd be a noticeable bulge.
R.
Many times this wasn't a "torque" issue - the lead seams didn't get cleaned properly, and the acid based fluxes would actually eat the panels away under the paint. Seen a lot of cars with damage in that area that were low performance cars and could not have stress cracked that area.
Posted By: cudaman1969
Re: How Fast before Frame Connectors are needed ? - 12/05/14 11:45 PM
" why didn't the factory use them instead of torque boxes that tie the sub-frames to the rocker boxes? You see a lot of factory installed (on all makes) torque boxes on high H/P cars and convertibles, but rarely (if ever) do you see factory installed sub-frame connectors"
The factory relied on the rockers mainly, the convertables had a 1/4 inch steel box tube inside the rockers with torque boxs tied in for strength. But controled flexing kept these cars from breaking up to last 100,000 miles in normal driving. But if hammered on, with todays roads, connecters are needed
Posted By: 383man
Re: How Fast before Frame Connectors are needed ? - 12/06/14 06:20 AM
I believe the factory went to the unibody to make the cars lighter. And when they did that in the early 60's there were no tires that really hooked much at all so they most likely did not worry about it much. I know a pics of the Ramchargers 63 shows no rollbar and a 70 Pro Stock Duster I saw just had the little round rollbar behind the seat. I dont know if either had any type of frame connectors but I would have thought a 70 Hemi Pro Stock Duster would have been hard on the car chassis without any type of rollbar to stiffen the car and they were 4-speed cars.
I can say I ran my 63 once when first on the road with my old mid 11 second 440 in the car and after I put the connectors and 6 point rollbar in the et really did not pick up any which surprised me. Ron