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Discussion Starter · #1 · (Edited)
As promised, I'll start putting together an illustrated story of how we made our rocker panels into a super-duty frame connector/rollcage base. It starts with a piece of 4"x4" x 1/8" square tube that will reach from tire to tire, 70" per side. Forty two dollars worth at February 2003 steel prices, according to my records... Fire up the torch and rip it lengthwise right down the middle of one side. Go to the next side and rip it lengthwise again 7/8" away from the corner. In other words, from the square tube cut out an angle iron measuring 2"x3-1/8". This angle iron isn't the part you need though, what's left of the square tube is your new rocker. Grind all the ickies off your cuts and it will look like this:
 

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BQS4 said:
"ickies?" I love this type of techno-babble!!! :D :D
It's not just techno-babble .... did you see the race car in the background, it looks like a Dale Sr. replica.

In all seriousness .... can't wait for more info on this mod.
 

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Discussion Starter · #6 · (Edited)
The next step is where we're gonna lose 99% of the audience. It gets too radical for the faint of heart. You need your rocker panel exposed its full length. In other words, you need your GT so gutted, so viciously stripped and hacked that it probably never will be a GT again as you know it. I know if I wanted to I could put it all back but I haven't ever done that, what we were doing was making a race car that is GT skin only attached to an almost Nextel-cup rollcage. So if you're doing this to a street GT you'll probably want to plan on using the neat fiberglass front ends. Or you can put the steel front end back on like I did and make it removable. Anything is possible!
Here is a picture of Speedway GT after day one on the jig. Lots of gutting has occured, don't get this carried away unless you are building a full tilt race car... By all means don't cut anything apart like this without the car firmly welded to the jig, ours is hooked on at nine points. I left the radiator support bulkhead because at that time the Compact Class rules said we had to run the stock radiator in stock location on stock mounts; when that rule changed so did the entire front of the car! What's left of the body in this picture is still attached by the fenderwells and rear floor, but not for long...
It has to stay in place during the rollcage build so you know where to put the main hoop and the upper halo.
 

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Discussion Starter · #7 · (Edited)
The next step is to position the new rocker panel cover over the old rocker panel, or what's left of it in most cases I'm sure. The rear needs to be trimmed to fit nicely up to the wheelwell. I had mine sticking out as far as I dared, this makes the bottom of the body wider than original; if you need to keep the stock shape then just push it in tight. I then just started skip welding it in, as my car was extremely rust free (even compared to Namba's)
this was no problem, for the rusty ones just get it attached any way you can! Your rollcage and new flooring will weld to it later and it will stay put...
At the front I trimmed the cover at an angle to blend in nicely with the original contours of the original lower firewall/ "frame". This picture shows actually a lot of other progress going on with the rollcage, disregard all that and just look rocker panel for now. Tomorrow we'll go to the other side I'll show how we finished off the front and tied it in all the way to the front suspension mounting area.
Oh, notice at this point we have eight points of the rollcage in and the car is off the jig. The jig kept it all true during the hacking phase, now the rollcage keeps the car together. The car is set on two jackstands, it is mostly hanging from the ceiling! Two guys can pick the car up and carry it away.
Here you can see the front frame horn has been modified a bit, too. A little channelling and reinforcement has occured prior to putting in the front rollcage "knee".
 

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Discussion Starter · #8 · (Edited)
Okay, now let's pray for a speedy recovery of all those who fainted at the sight of "GT on jig" and were found with their foreheads bashed into the keyboard. Sorry about that.
I see we lost most everyone so I'll wrap it up. See, this wasn't exactly a fix that occurs between commercials, it's just the beginning of making something out of a GT that was spared the crusher. The parts involved aren't delivered in a box by the guy with the brown truck, and they don't install by peeling the backing tape and pressing firmly into place... It takes a little extra effort and commitment, probably even as much as restoring a dead GT back to showroom condition.
So I'll take you to the left side of the car and you'll see how I closed up the rocker panel cover and tied it into the firewall and front frame. Starting with cardboard and scissors, just make something that fits right, then trace the cardboard onto 1/8" steel, cut it out, grind edges smooth, bend it around a bit to fit, and weld it on to the GT . Ta-dah! Rocker panels, Done! Now we have a nice solid place to hook in the door bars. Nothing like the feeling of a good strong car. Chances are we'll be crash testing this vehicle sooner or later, and I prefer to survive the ordeal and be able to have the damage fixed before the next race.
Excuse me if I make it sound so easy, but, actually, it is! Nothing has to be perfect, just reasonably solid, all parts tie in to each other for strength. There's no need to make it a shrine for the fabrication gods, it's not going to any concours car shows. The worst of it is the mess, the grinding of old paint and metal and slag and that's not to mention all the awful noise. Yes, the noise of my wife complaining about all the time spent out in the shop. But notice the look on the face of the guy on the wall with the sunglasses. He approves...
 

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Discussion Starter · #10 · (Edited)
A question came up in the chat room last night about how I mounted the main hoop of the rollbar to the new rocker panels. The problem with how I did my left side is that it mounts so far outboard that it won't work with stock door jambs in place. So I'll take you to the right side and show how a plate was added between the rocker and the rear frame rail. Notice how this plate ties the rear frame rail to the rocker panel, the same plate was put on the left side for that reason, had nothing to do with the hoop mounting on the left side. My rollcage, in fact the whole car, is built on the common "lefthander" theory in that just about everything about it favors the left side of the car. This is because we want the left side to be heavier than the right in oval track racing. In my class here there is no rule about how much more the left side can weigh than the right, in more serious classes there are rules. So everything about the rollcage shape and placement considers this factor as well as extreme strength and safety. Also I wanted the driver to have as much elbow room as possible, everybody who has test fitted themselves in my car is pleased with how much room they have compared to other race cars.
For more on this, and how to mount the main hoop in a more intact (less gutted) car with opening doors, look in Racing Forum for "roll cage progress" which shows lots of really nice rollcages done in different ways. There is no right or wrong, just some differences in how strong we build things for various reasons.
 

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Discussion Starter · #12 · (Edited)
Thanks, Dave!
As long as I've got the race car photo album out I may as well show another little part I thought would help keep the front end hooked in nice and solid.
This photo shows the plate added to the inside of the front frame and firewall/tunnel. It really ties it all together pretty good, attaches to the motor mount framework in the bottom of the tunnel even. Which turned out to be pretty good because later I had to hack a huge hole through that corner a bit aft of the plate to get the exhaust pipe through. Yeah, I know you're all wondering "exhaust pipe?". Yup. The track record holder in the compact class is a Mustang, has a neat trick I copied. The exhaust system is inside the car, muffler and all! Enables a bunch more body drop without breaking the 3" ground clearance rule. Picture 2 shows this going together, were there room for a passenger we would call it "the mother of all seat warmers" :D The first picture shows some of the 1" pipes that "spiderweb" between the frame, knee bar and upper hoop.
 

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I saw an E-Mod Solo II GT that had the header pipes going up instead of down one time then the exhaust ran right where the passenger seat would go.

I want to see how you tie the top of the shock mounts to the cage.

since that's the problem i have

I just wasted another $500 on my trip back to TX letting someone else work on my GT.


Davegt27
 

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Discussion Starter · #15 · (Edited)
That header sounds trick. I did mine this way because first, it was a perfectly good header and it came with my junk car. Go figger! Secondly, because the compact class rules just changed last spring allowing us to use a header instead of stock manifold. "Hurray!" we all said but then were warned to keep it simple, that discussion led to the rule finalized as "primary pipes not to extend beyond flywheel." So, we keep it simple. Really don't want to freak them out too bad, my car already does that just because of where the engine sits.
Okay, here's a photo that shows pretty much the finished product as far as the shocks go, I didn't add anything to the top of the tower as it looks plenty strong to hold the up and down push/pull of the shock. However, do look a little lower at the plate welded to the outside of the frame. Barely visible behind the upper A arm is a hole in the tower to give access to a bolt I added to more securely tie the tower to that plate. The bumper kind of hides how that plate tabs around the main crossmember/suspension bracket to help make sure it can't go anywhere. Just in case, ya know?
To me this all looks like plenty. Another photo of the other side is in Bill's thread about coil over shocks, look at that one too.
 
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