BUILD-OFF CHALLENGE: Tygaboy's '75 LS3, It seemed a good idea at the time... Options

[tygaboy]

With the firewall patching complete, it's back to work on the chassis stiffening.
I hole sawed through the seat belt retractor area as well as the support pads for that area. This allows me some for/aft adjustment as I get to fitting the door bars.

Note that in the pics, the bars are shifted rearward over 3" because I have yet to trim the front end of the bar. So the angled part will sit a bunch forward from how it looks - see the pics earlier in thread for a more accurate view.

Anyway, once everything is welded in, I'll dress any part of the tube that may poke through and weld around the tube, securing it to that support pad.
Then another support pad goes on the engine compartment side and I run the tube from there, back to the cross bar/rear shock tower.

And the vertical support is just there to support the bar. Final locations for all the verticals are tbd upon completion of trimming the front of the tube and determining where the rear-most vertical will be.

I'm liking the way this is coming together.

[tygaboy]

However, before the door bars go in, I want to more securely tie the front hoop to the chassis. As mentioned, I decided I wanted to run a tube from the hoop to the front suspension. Before I can do that, I have to add support pads to the suspension area.

This is proving to be a lot of work. Not a flat surface to be seen! And my initial mock up wasn't going to be sufficient - I need to use at least 12 gauge for the support pads so it's back to the drawing board.

First I made up paper templates then cut the material to size. Now, how to shape it?

How about this handy curved chunk of wood and a rubber mallet? (IMG:style_emoticons/default/smash.gif) These and some various size scraps of tube from 1" to 3"...

Here's the result. I was surprised that, within not a very long time, I was able to get a pretty tight fit and good side-to-side symmetry.

These pieces wrap the "upper" part of the tower.

Oh, and note to self: Push the top of the struts all the way back to be sure there's suitable clearance for everything!

[tygaboy]

Then it was on to the "lower" pad. This is a real bitch of a compound curve.
I'm not done shaping but you get the idea how this will all go together.

Next, I need to bend up the bars. Or maybe just go to a bar... (IMG:style_emoticons/default/beerchug.gif)

[tygaboy]

This time, I used a piece of pretty stout welding rod to mock up an initial guestimate of the shape of the tube.
Doing all this by myself can be "fun". Trying to hold something in position while bending the other end while trying to keep the stinkin' thing in the middle of the hole I want it to pass through....!

And it worked! I got it on the first try. Then it's copy the shape for the other side.
I used the same jig approach and I nailed the shape of tube #2 with just one additional adjustment.

Still have to do final trimming on both ends of both tubes.

[tygaboy]

Then I finished up my day by prepping the vertical supports' support pads. After careful consideration, I think I'll have three verticals per side, plus the hoop.

Chris Foley (Tangerine Racing) was kind enough to sell me just the pads. However, because I skinned my longs, the radius Chris uses doesn't work for my car and needs adjustment.

I devised a way of using a vise and trusty rubber mallet (IMG:style_emoticons/default/smash.gif) to tighten the radius. Then I have to reset the angle. Not too bad, though. And each one fits nicely where it needs to be.

I'm calling that a successful day. Almost ready to weld all this stuff in! That will be a major accomplishment and big milestone in the build. (IMG:style_emoticons/default/smilie_pokal.gif)

Maybe next week/weekend?

[tygaboy]

With the chassis stiffening coming together, I started thinking about closing up the lower firewall. Initial mock up was one piece but with all the systems that have to pass through it, I decided to make it with a removable center section.
So I started playing with one of the outer pieces. This is just a test piece in my typical approach of "I need to see it in physical form before I know if I like it".
Plus, it gives me a chance to practice with the bead roller.
It's little things like connecting the last bit of the bead to where it first started.
You can see I just barely missed (center of the top section.)

And design wise, I think I can come up with something more interesting than this first draft.

This was also my first attempt at hammer forming. (IMG:style_emoticons/default/smash.gif) I used this technique on the flanges and am really happy with how it wraps the corner at the top of the long. It nicely fits the curve!

I'm confident I can get these pieces to turn out really well within a couple more attempts.

[914dave]

Looking good!!! I'm impressed with all the details...

[bbrock]

Nice work! Would love to see a pic of your form. What are you using for a corking tool to hammer in those beads. I'm heading to town for some hard maple this afternoon. Maybe you have something better?

Loving the progress! (IMG:style_emoticons/default/smash.gif)

[tygaboy]

The chassis stiffening I'm doing is just that: chassis stiffening. This isn't to be confused with a roll cage. That said, I am doing most all I can to make it correctly.
However, I'll admit to cutting a couple corners. And here's one:
Getting that 12 ga material to fit well against the front fender compound curve didn't go as well as I wanted.
So, after much debate and consultation with a couple race car fab folks (and given my "race rod" disclaimer), I decided to wimp out and make the support pads out of 14 ga.
There is a fair bit if structure up around the suspension towers already and this more than doubles the material thickness of the fender well.
Plus the force is directed (mostly) at the tower. That's my story and I'm sticking to it.
Again, my race car consultants both said that, given my application, this should be more than sufficient.
So, instead of hammering into the curved block like last time, out comes the English wheel!

It's the proper tool for making compound curves in sheet.

Here's the blank as I start to raise the shape.

[tygaboy]

14 ga material has some strength to it... It took me about 30 mins of wheeling to get it where I needed it to be. Good little upper body workout, too!

[tygaboy]

Once I had the shape I wanted, I laid out the pattern for the pieces.
Needing mirror image pieces means it's important to REMEMBER TO FLIP THE PATTERN when doing the layout... Ask me how I know... (IMG:style_emoticons/default/lol-2.gif)

After looking at this for a minute, I realized that if I ever get tired of working on cars, I can always go into business making steel bras.

[tygaboy]

Nice work! Would love to see a pic of your form. What are you using for a corking tool to hammer in those beads. I'm heading to town for some hard maple this afternoon. Maybe you have something better?

Loving the progress! (IMG:style_emoticons/default/smash.gif)

Sorry, I cheat. I have a bead roller.

I only hammer formed the edge flanges. I did that by simply using an open inside corner I created by fixturing two steel block, corner to corner. Then I used a rounded end piece of solid round stock that was the same diameter as the corner I wanted. I just whacked the flanges down and into the corner until the material was at a full 90 degrees. Worked like a dream.

[Mueller]

Great work as usual.

[bbrock]

Sorry, I cheat. I have a bead roller.

Man I'd love to have one of those. Can't justify the expense though (IMG:style_emoticons/default/sad.gif) Still, fabtabulous work. Love the bra. (IMG:style_emoticons/default/aktion035.gif)

[tygaboy]

I was able to get all the pieces rough trimmed and fit.
You can see how, in the first pic, the piece lays nicely on the fender. In the second pic, the top part "interferes" a bit and moves it out of position.
That's OK because all the final trimming will happen as the parts are welded in and the exact intersections are able to be determined and any interference gets cleaned up.
I'm really happy with how these turned out.

[tygaboy]

Next, I went back to work on the the chassis stiffening. I have to so some fancy cutting / piecing to make the cross bar that will connect in at the top of the door bars.

It has to fit behind the seat head rest supports then pop out to clear the bump in the firewall, then pop back in and fit behind the other seat.

The mighty, mighty bender can't make the needed bends close enough together so I have to do the cross bar in pieces. Again, just fine for a race rod. And if I get it right, you'll be hard pressed to know it's not a one piece bar.

Anyway... I was diligently working away on fabbing the cross bar when UPS showed up...

And that was the end of my productivity.

[tygaboy]

I don't know what to say other than I couldn't take any more of Tony saying I'd be a fool not to do it...

Well, OK, that's no entirely true. I do know what to say:

I've always wanted an engine with ITBs. So what the hell. Now I have one.

This is so f-ing bad ass I can't hardly stand it. (IMG:style_emoticons/default/drooley.gif) (IMG:style_emoticons/default/wub.gif)

Problem is, now I'll spend the next 2 weeks standing there staring at it and not make any progress on the build.

[Mueller]

(IMG:style_emoticons/default/pray.gif) How are you going to control those 8 beautiful butterflys right there?

[tygaboy]

(IMG:style_emoticons/default/pray.gif) How are you going to control those 8 beautiful butterflys right there?

It's cable actuated. I took advantage of the fact that Borla will package up a "kit". They recommended the Holley HP ecu and since I'm a fan of the "one throat to choke" model, I went with everything from them: ITBs, injectors, ecu, harness, fuel pump, sensors, fuel filter. They even threw in a sync tool.

Coming up soon on the to-do list, I'm going to pull the motor and send it to a tuner/dyno to get an initial set up.

Any suggestions for a shop in the SF bay area that can do this work?

[Cracker]

Chris - You already know what I think about it - SICK! Now that I also own two of these systems myself I am a very interested party in your tuning experience.

Hurry up so I don't have to go first! (IMG:style_emoticons/default/poke.gif)

T

PS: For once on this build it appears you don't have to modify the firewall for the stacks...how they are canted - it looks like you DID make it PERFECT! Damn!