abodyjoe
Well-Known Member
but did you stay at a holiday inn express last night? that could make all the difference..
Sub-frame connectors... Please build them correctly!
- Thread starter 4mulaSvaliant
- Start date
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but did you stay at a holiday inn express last night? that could make all the difference..
4mulaSvaliant
Well-Known Member
A-body Joe: Yours has a factor that helps considerably that has not been discussed. How much of the floating connecter attaches to the sub frame section. You have a considerable amount of material that make the side wall of the tube transfer the stress well.
As for what I do... There wasnt really any reason for all that but no, I do not hold an engineering degree, but I design sheet metal structures on a daily basis. Machine equipment that we assess all of these same factors on and in the same manner.
As for what I do... There wasnt really any reason for all that but no, I do not hold an engineering degree, but I design sheet metal structures on a daily basis. Machine equipment that we assess all of these same factors on and in the same manner.
Beatnik
Well-Known Member
Rob this what I was trying to get at I guess. It was night and day the amount of twist that was reduced when jacking from a corner after adding connectors (non floor integrated)
abodyjoe
Well-Known Member
4mulaSvaliant
Well-Known Member
Vert: That big heavy c-channel is what you also accomplish by welding the connectors to the floor pan. It ties the top plane to the bottom plane. Which is all Im trying to get across.
TrailBeast
AKA Mopars4us on Youtube
Same here and using 2x3 .085 wall laying flat.
I know I know, standing up would have been stronger because of exaclty the structural reasons he was stating.
I noticed a HUGE difference as soon as one front tire transitioned from one surface level to another.
(Like out of my driveway and onto the paved street.) and it was really obvious when going into a gas station or store parking lot.
Not to mention the amount of interior noises that didn't exist afterwards.
4mulaSvaliant
Well-Known Member
What is interesting to me here, is the amount of people saying that there is so much flex in these cars. Its obviously a known problem, but to notice a difference from just the little bit of added strength from the floating type of connectors is pretty crazy.
*Thats not sarcasm or disbelief. Its truly crazy that they flex so damn much.
*Thats not sarcasm or disbelief. Its truly crazy that they flex so damn much.
4mulaSvaliant
Well-Known Member
Let me restate it this way then............................
The Better way..... to build in sub frame connectors is to weld them to the floor pan!
LOL
The Better way..... to build in sub frame connectors is to weld them to the floor pan!
LOL
Take an a body that leaves reasonably hard to the track and see how much the car flexes. It's huge. Put a set of do nothing connectors on and see what happens. Normally the cars, even with the extra weight, go faster, especially in the first 60' because the torsional rigidity is increased and transferring the power to the ground. It's not being wasted flexing the body.
I'd love to do a side by side to see if the floor pan tied really helped the 60'.
I have 2x2 .083 connectors on my current build car and have used anything from 2x3 .120 and smaller. All have made big improvements in performance.
It's so much fun to have the left front fender a foot higher than the right front! Not... LOL
TrailBeast
AKA Mopars4us on Youtube
4mulaSvaliant
Well-Known Member
Here's the kicker smarty pants! LOL I dont even have ANY in my car! Not yet...
But when I do, I plan to connect the floor into the equation.
Not yet... But when I do, I plan to connect the floor into the equation.
4mulaSvaliant
Well-Known Member
Fun place the internet is! Hahahah... I am seriously not trying to get under anyone's skin! Most of you that have dealt with me at all know that. I always try to lend positive comments to the board as a general rule. So please.... again.... know that I am not trying to start a big mess over this topic.
I always try to lend positive comments to the board as a general rule. So please.... again.... know that I am not trying to start a big mess over this topic.
4mulaSvaliant
Well-Known Member
OK, to understand the stresses we are even talking about... I threw together a mock stress analysis.
This image shows what is happening under say a "hard launch" at the track.
This image shows what is happening under say a "hard launch" at the track.
4mulaSvaliant
Well-Known Member
Here is the Connector not attached tot he floor pan. Note the number in the highest stress range. 77.97
4mulaSvaliant
Well-Known Member
Here is the stress with the 2x3 tube welded fully to the floor pan. the results would minimal difference if this 2x3 were replaced with a sheet metal "C" shape that the laser cut pars are.
Note the number in the stress range here. "52.97" That is a significant difference.
Note the number in the stress range here. "52.97" That is a significant difference.
TrailBeast
AKA Mopars4us on Youtube
Here's the kicker smarty pants! LOL I dont even have ANY in my car!
But when I do, I plan to connect the floor into the equation.
I hear ya, and if my car was up in the air on the barbie with all the interior out I would have done mine the way you plan on doing yours.
In my own car the front end needs it more than the cabin now, so the next priority in the stiffening dept will be radiator support and front framerails to shock towers to firewall.
All in good fun.
4mulaSvaliant
Well-Known Member
I am actually working on a fabricated laser cut part for the shock tower to firewall.
draginmopars
Well-Known Member
Back in May
When we moved the springs in
and tied the frame together,
we also move the front spring boxes forward 5"
(25" front spring segment)
added another set of bars to secure the spring boxes,
and a place to mount the upper shocks (moved to in front of the rear axle)
the bars go all the way back to the rear of the spring, over the sliders
painted the bottom side/ also so that we could get a 360* weld
most will be hid under the rear seat area.
we have recently changed the rear to a Dana 60, spool, 35 spline axles and 1350 yokes
the rear will get painted/ nice chrome cover after we set the pinion angle/weld the spring perches
the rear is 2" forward with 275 E T Pro tires
When we moved the springs in
and tied the frame together,
we also move the front spring boxes forward 5"
(25" front spring segment)
added another set of bars to secure the spring boxes,
and a place to mount the upper shocks (moved to in front of the rear axle)
the bars go all the way back to the rear of the spring, over the sliders
painted the bottom side/ also so that we could get a 360* weld
most will be hid under the rear seat area.
we have recently changed the rear to a Dana 60, spool, 35 spline axles and 1350 yokes
the rear will get painted/ nice chrome cover after we set the pinion angle/weld the spring perches
the rear is 2" forward with 275 E T Pro tires
TrailBeast
AKA Mopars4us on Youtube
I'm not the least bit surprised by that for some reason.
I'd be ok with just a water jet table, and that's all I need.
A waterjet, a nice lathe and that's all I need.
A waterjet, a nice lathe, a decent shop, and that all I need.
Steve Martin style.
If you study it long enough you can take it one step further with gussets, then one step further with X bracing, repeating until the car is solid as a tank. Can it get too rigid ? Maybe Tall buildings can ( I'm no engineer either ).
if you added any connectors in any fashion and you are happy with the results, that's all that matters. If you aren't happy with your results, suggestions will be in this forum somewhere.
I'll weld the doors closed and solid all around to see what difference that makes. May not need subframe connectors at all. LOL
if you added any connectors in any fashion and you are happy with the results, that's all that matters. If you aren't happy with your results, suggestions will be in this forum somewhere.
I'll weld the doors closed and solid all around to see what difference that makes. May not need subframe connectors at all. LOL
TrailBeast
AKA Mopars4us on Youtube
I say it all depends on your purpose. driver, drag car, ralllye racer????
I had a 69 coronet RT 440 4 speed car (stock) some years back, on concrete standing behind it, the amount the rear of the car was twisted was WILD!!!!
I had a 69 coronet RT 440 4 speed car (stock) some years back, on concrete standing behind it, the amount the rear of the car was twisted was WILD!!!!
LIME TWIST DART
Well-Known Member
Will this be something to weld in or bolt in?
1967 'cuda
Dropped on Head as a Baby
Most everyone is familiar with body damage caused by severe twist. It was very apparent on the '68 Charger R/T that we'd bought. The rear quarter was ripped next to the door seam on the left side and the right side sail panel had a noticeable dip in it. After replacing the quarters we decided to purchase subframe connectors from U.S.Cartool. Those are the ones that we will weld the entire length and are fitted to the floor. The car will be running a blown 512 stroker and a 4-speed.
On my '67 Barracuda I fabbed my own connectors that are welded front and rear but unattached to the floor. The 408 puts out over 500 horse in front of a 727. I didn't want to tear out my entire interior at the time I did the 'Cuda and figured the amount of stress created by torque would not require as much reinforcing. I also figured that the shorter wheelbase would be less prone to twist. I can't speak of how the Charger feels to drive because it's not completed yet. - But the difference is fairly dramatic after adding the connectors on the Barracuda. The car handles better, feels more solid, and has less squeaks. So my conclusions are that:
1) subframe connectors are a definite benefit - even for general street driving.
2) the amount of strength needing to be added may need to be increased as more torque is being produced.
3) there is a benefit from connectors that may be adequate (on some cars) even if they aren't attached to the floorboards.
On my '67 Barracuda I fabbed my own connectors that are welded front and rear but unattached to the floor. The 408 puts out over 500 horse in front of a 727. I didn't want to tear out my entire interior at the time I did the 'Cuda and figured the amount of stress created by torque would not require as much reinforcing. I also figured that the shorter wheelbase would be less prone to twist. I can't speak of how the Charger feels to drive because it's not completed yet. - But the difference is fairly dramatic after adding the connectors on the Barracuda. The car handles better, feels more solid, and has less squeaks. So my conclusions are that:
1) subframe connectors are a definite benefit - even for general street driving.
2) the amount of strength needing to be added may need to be increased as more torque is being produced.
3) there is a benefit from connectors that may be adequate (on some cars) even if they aren't attached to the floorboards.
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