back half book

Shocks, Springs, Brakes, Frame, Body Work, etc

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prairiehotrodder
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back half book

Post by prairiehotrodder »

i'm doing my first back half on a race car. The car is my friends 78 Pontiac Lemans with a 423 SBC. He bought a competition engineering back half kit with a 4 link and a fabricated 9" housing. I've never tackled a job this big and i was wondering if anyone could suggest an instructional book ? With lots of pictures ? Its the sheet metal fab that has me the most worried. I want it to look good. I don't know if i should use the dzus fasteners or weld up the floor and wheel tubs ? Also since the car has a full frame and the body is held up off the frame with bushings, should i keep it that way or connect the body and tubs directly to the frame ? Also do the tubs weld right to the outer fender skin ? Thus burning the pain ? Lots of questions.
Brian
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dannobee
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Re: back half book

Post by dannobee »

The tire size will dictate how much you need to cut it up. And what class does he plan on running? What rules apply?

The frame should still use the factory mounts as much as possible. If you need it to look factory, use as much of the factory sheet metal as possible and just add strips or sections of sheet metal. If he plans on running a big slick, you'll need to section the outer fender too.

I haven't seen any books on it, but if there are any nhra super stockers in your area, that could be a starting point with respect to tubs and big tires.
rebelrouser
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Re: back half book

Post by rebelrouser »

Sheet metal fabrication is a complicated subject, at least to make it look good. Like most things the right tools really help. Most people do not have the money or garage space to buy and learn to use, sheet metal break, bead roller, English wheel, shrinker-stretcher, etc. But having been a poor boy most of my life and built several cars, a bead roller and a sheet metal break are about the minimum you need to have to start. I have used 2x4 and some big C clamps many times. I do have some friends that are in the heating and A/C business, I borrow, and have them do stuff for me all the time.
Aside from that, the biggest mistake I think most make when doing a back half, is the engineering. You are destroying a whole bunch of the strength of the car when you cut it all out, the new stuff you put in needs to bring back the strength, plus add more for the car to work good. How the new frame rails and cross members tie into the car should be done carefully. I do things that many do not to add strength, for one I weld tabs to the roll cage to the body, firewall, and C pillar. When looking at the car try to visualize the stress points during the launch, and if it should roll over.
I remember one time I was building a 64 Dodge, and toward the end of my welding, a spark got me and I hit one of the jack stands with my creeper trying to get away from it. The jack stand slid out from under the car and the car just sat there on the three remaining ones. Stiff car to do that.
The kits are good, I have used them, they save time and money, but don't think all you need is in one.
rebelrouser
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Re: back half book

Post by rebelrouser »

But you wanted a book, two best books I recommend if you want to build and set up a drag car are Doorslammers by Dave Morgan, and Jerry Bickels chassis book,
https://chassisengineering.com/index.ph ... suspension

I attended a seminar by Dave Morgan way back when he worked for Alston, and built my first four link the next week, using his book, under a 1948 Anglia, an old gas car that was stupid crazy to drive until I did the four link. I would say the Bickel book has more info for todays drag cars. But both are really good.
Ladderbar
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Re: back half book

Post by Ladderbar »

both of the above books are very good. don't know if Dave still dose his school but well worth it. Bickel had videos they were excellent, they deal with pro cars but the info is well worth the buy.
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