Author Topic: Can the tork cause cracking in the paint  (Read 7895 times)

Offline Kevin71

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Can the tork cause cracking in the paint
« on: January 23, 2016 - 03:31:01 PM »
71 challenger was painted a few years ago.  Before it was painted there was a spot of paint 1 inch diameter the was missing from the center of rear of the roof.  Also cracks in the paint along the area where the roof meets with the top of the fender.  They are back.  This was originally a 318 car, but now has a 522 stroker in it.  Doesn't have the tork boxes on it.  So before I try to get the paint fixed I need to figure out why it is doing this.  Could the car be twisting from the tork and causing the paint at these two places to do this?




Offline Kevin71

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Re: Can the tork cause cracking in the paint
« Reply #1 on: January 23, 2016 - 03:31:59 PM »
Here is another pic

Offline BIGSHCLUNK

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Re: Can the tork cause cracking in the paint
« Reply #2 on: January 23, 2016 - 03:35:32 PM »
I've had cracks on top my Q's on both side for a long time. Connecting my subs stopped them from getting worse tho....  :grinyes:   :working:
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Offline dfrazz

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Re: Can the tork cause cracking in the paint
« Reply #3 on: January 23, 2016 - 04:24:47 PM »
Did you take it down to bare metal?  Could be bondo.  Could also be another area of the car that was not welded good unless you stripped the whole car.  I agree with Biggs that subframes stop the twisting of the frame.

Offline jimynick

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Re: Can the tork cause cracking in the paint
« Reply #4 on: January 23, 2016 - 05:33:32 PM »
Well, I'd say it was cracking bondo, but it's cracking due to flexion IMHO. These cars had torque boxes put in for a reason by the factory and guess what that reason was? The roof is more of a question. I wonder if the car flexes to the point where the 1/4 and roof flex at the centre like that and that's why it pops off. You've probably got 50% more power than the original, torque boxed cars had and your body- and it's attending filler- is paying the price. I'd subframe connect and torque box it asap, but then, that's just my  :2cents:   :cheers:

Offline Kevin71

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Re: Can the tork cause cracking in the paint
« Reply #5 on: January 23, 2016 - 07:07:31 PM »
I have a set of bolt in subframe connectors. They are two 1 inch tubes side by side to a plate on each that bolts.  I thought welding those in but I am thinking I need to put torque boxes in.  But I don't know if i should get the more common type of subframe connectors thats like channel that welds to the floor board.  I guessing the latter woud be way better.  Any advice is appreciated. 

Offline dfrazz

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Re: Can the tork cause cracking in the paint
« Reply #6 on: January 23, 2016 - 08:37:40 PM »

I have a set of bolt in subframe connectors. They are two 1 inch tubes side by side to a plate on each that bolts.  I thought welding those in but I am thinking I need to put torque boxes in.  But I don't know if i should get the more common type of subframe connectors thats like channel that welds to the floor board.  I guessing the latter woud be way better.  Any advice is appreciated.

Welding is way better. Bolt on make a marginal difference, but if your going to do it then do it right.

Offline 70chall440

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Re: Can the tork cause cracking in the paint
« Reply #7 on: January 23, 2016 - 11:00:02 PM »
Your pictures seem to indicate poor paint prep; however torque could I suppose be a contributing factor. How much HP are you running? Are you launching it hard?
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70 Challenger RT 440-6 EFI, 73 Cuda 416-6 EFI
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Offline Kevin71

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Re: Can the tork cause cracking in the paint
« Reply #8 on: January 24, 2016 - 11:17:36 AM »
It is 550 HP and around 650 lbs of torque.  don't launch hard.  Never had slicks on it or ran it a strip.  Have had a transmission vibration problem for years so can't hit to hard or the damn will probably come apart.

Offline 1 Wild R/T

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Re: Can the tork cause cracking in the paint
« Reply #9 on: January 24, 2016 - 11:46:43 AM »
Your pictures seem to indicate poor paint prep; however torque could I suppose be a contributing factor. How much HP are you running? Are you launching it hard?

I agree... Before you take it to someone take a grinder & dig those areas out down to bare metal & see what's going on... Your last painter just smoothed & blended over the problem, that works for people who aren't committed to long term ownership  (Read Flipper) but it's not how you repair a car your gonna keep... Grind it down, find the problem & post pictures to get a recommended solution...
JS27N0B 70 Challenger R/T Convertible  FJ5 Sublime, Show Poodle w/90,000 miles since resto
WS27L8G 68 Coronet R/T Convertible  PP1 Bright Red, Project
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Offline Kevin71

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Re: Can the tork cause cracking in the paint
« Reply #10 on: January 24, 2016 - 06:05:13 PM »
Thanks for the advice.  I will have to get time to do it.

Offline BIGSHCLUNK

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Re: Can the tork cause cracking in the paint
« Reply #11 on: January 24, 2016 - 09:12:24 PM »
Bodywork non withstanding , don't kid yourself these cars flex Big time. Not just from hard launches either, any off angle inclines at speed to a point.....
70 Chally R/T Convertible- Yes she's really got a HEMI, no she's not a Charger!
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Offline jimynick

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Re: Can the tork cause cracking in the paint
« Reply #12 on: January 24, 2016 - 09:41:00 PM »
I have a set of bolt in subframe connectors. They are two 1 inch tubes side by side to a plate on each that bolts.  I thought welding those in but I am thinking I need to put torque boxes in.  But I don't know if i should get the more common type of subframe connectors thats like channel that welds to the floor board.  I guessing the latter woud be way better.  Any advice is appreciated.

You'll get people who swear that bolt in connectors work well, but it's hard to argue that full length, 1/8" steel, conformal connectors welded their full length to the floor pan AND crossmembers don't work better. I put the US Cartool connectors and torque boxes in my car and while they don't just fall on; in my opinion, they're superior to any other type, bar none. Stick a GoPro on the 1/4 and point it at the lower rear corner of the door where it meets the rocker/ 1/4 junction and then take that 550hp beast out and run it through the gears- and then check the GoPro. I'll bet you that the movement that you'll observe will open your eyes.  :cheers:

Offline 1 Wild R/T

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Re: Can the tork cause cracking in the paint
« Reply #13 on: January 24, 2016 - 09:57:35 PM »
Bodywork non withstanding , don't kid yourself these cars flex Big time. Not just from hard launches either, any off angle inclines at speed to a point.....

I could accept the area on the quarter panel is caused by flexing but the area in the back center of the roof, no way, if it where the roof would have permanent waves & the back glass would have exploded...

I'm not saying adding sub frame connectors isn't a good idea, it absolutely is...... But if you think it would have prevented the paint issues on this car your mistaken...
JS27N0B 70 Challenger R/T Convertible  FJ5 Sublime, Show Poodle w/90,000 miles since resto
WS27L8G 68 Coronet R/T Convertible  PP1 Bright Red, Project
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Offline dodj

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Re: Can the tork cause cracking in the paint
« Reply #14 on: January 24, 2016 - 10:15:00 PM »
around 650 lbs of torque.  don't launch hard.
:clueless:
650 FT/LBS and you don't launch hard?  :smilielol:
As to your original question, yes it can, but I don't think where yours cracked can be attributed to torque/body flex.  :2cents:
« Last Edit: January 24, 2016 - 10:18:05 PM by dodj »
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