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

[tygaboy]

You said race rod ...so in that spirt lose the gusset idea...does nothing but add weight....and even though the fabrication looks cool , it crosses the line of extraneous ....my opinion of course...but I am cursed with excellent taste (IMG:style_emoticons/default/smile.gif).......

"...and even though the fabrication looks cool..."
See, that right there? That's my problem!
Though it really does add (needed) strength, given that corner of the design isn't a triangle. I'll mock it up and see what I think, but it's a gusset or a tube. Something has to go there.

Keep the cards and letters coming...

[Rand]

Go ahead and place me in the "anecdotal" crowd if that's what you feel like, but I'm with ablesnead on this. The area in the triangle doesn't need more strength. It's worth more in art than function and adds weight. Which is great if that's what you want. My anecdotal belief is to use the least amount of material (and weight) to get the job done. Why add unnecessary stuff to a car that is so potentially light?

[Cracker]

No registration required Rand...you already hold a members card! Well, I was lumped into membership by Rudy too! (IMG:style_emoticons/default/piratenanner.gif)

T

"Go ahead and place me in the "anecdotal" crowd..."

[Rand]

I make sharp comments about projects. It adds something, fwiw. I don't ever mean to diss people. (Sorry to anyone who felt like I did.)

Ahh, after your edit I get another bit of where you're coming from. Good company. Love you too, Tony. (IMG:style_emoticons/default/poke.gif)

[tygaboy]

Quite the comedian. I make sharp comments about projects. It adds something, fwiw. I don't ever mean to diss people. (Sorry to anyone who felt like I did.)

Ahh, after your edit I get another bit of where you're coming from. Good company. Love you too, Tony. (IMG:style_emoticons/default/poke.gif)

All constructive criticism welcome!

I look at it like this: If we were all hanging out in my shop, working on this build together, what would you say? THAT is what I'd expect from my virtual buddies on this site. Many, maybe even most of you have way more experience than I do.

I'm expecting and hoping for input and opinions. Heck, look back at page 1 of this thread. I said "I'm just a guy with an opinion. Doesn't mean I'm right, just that it's what I believe, think..."

You all damn well better keep posting what you really think about this build and my silly ideas. I may listen, I may not. But more information is always better than less.

And when the car is done (like that'll ever really happen) and I take my cross country, US tour in it, I'll be stopping by looking for you to put your signature on the car. I'll say it again: this sort of input is helping me clarify my thinking as I build this car.

Rock on! (IMG:style_emoticons/default/smilie_pokal.gif)

[Rand]

Well said. Sometimes communicating online gets funky because we can't see the mannerisms, expressions, and all. Good thing though, we are all in the same garage here.

We rib each other, we eat meat, we drink beer, we call out stuff that doesn't make sense, we rib each other more. And you can remove any part of that you don't like if you are a vegan and don't drink. (IMG:style_emoticons/default/biggrin.gif)
I'd say anything in person that I say here. It would be interpreted differently at times I'm sure! LOL

Keep it coming. The more we get to know each other, the better the garage gets.

[tygaboy]

Keep it coming? Well OK then!

I had some time this evening so bent up the one piece, angle down door bar. Here it is. Forgive the hack MS Paint job but I wanted to get a better feel for what it might look like with the supports (ish).

Flipping the bend really changes the look. I'm not sure which I like best.

Decisions, decisions. (IMG:style_emoticons/default/idea.gif)

[Andyrew]

Real opinion? I like as much leg room getting in and out of the car as possible... the 914 is already a super tight squeeze for me anyways. Now I know you have your floor pan drop which is giving you a much needed extra room, but it still is difficult sqeezing that left leg in around the steering wheel and in front of the A pillar.

I have NO idea how Tony does it...

My point being I would prefer the front bar to terminate as early as possible with a thick plate encompasing the Long and then the front A pillar roll loop starting much before the door opening and then there a short gusset to the a pillar and lower a pillar.

Then again I am as I mentioned a big fan of the hidden roll cage, like the RUF cars and this guy.
http://www.redlinerennsport.com/CagePage.html

[Curbandgutter]

Well said. Sometimes communicating online gets funky because we can't see the mannerisms, expressions, and all. Good thing though, we are all in the same garage here.

We rib each other, we eat meat, we drink beer, we call out stuff that doesn't make sense, we rib each other more. And you can remove any part of that you don't like if you are a vegan and don't drink. (IMG:style_emoticons/default/biggrin.gif)
I'd say anything in person that I say here. It would be interpreted differently at times I'm sure! LOL

Keep it coming. The more we get to know each other, the better the garage gets.

Agreed. If all we ever said was. Yes yes yes keep doing what you're going it wouldn't be any fun. It's all good. (IMG:style_emoticons/default/beerchug.gif)

Oh yeah. Tygaboy as long as you tie it in with gussets like you said then (IMG:style_emoticons/default/aktion035.gif) Don't listen to all these guys talking about weight. You'd think you're adding 50lbs of gussets. Damn with as little as you're adding if you just make sure to take a dump before you get in, it will all be good.

[jd74914]

You said race rod ...so in that spirt lose the gusset idea...does nothing but add weight....and even though the fabrication looks cool , it crosses the line of extraneous ....my opinion of course...but I am cursed with excellent taste (IMG:style_emoticons/default/smile.gif).......

"...and even though the fabrication looks cool..."
See, that right there? That's my problem!
Though it really does add (needed) strength, given that corner of the design isn't a triangle. I'll mock it up and see what I think, but it's a gusset or a tube. Something has to go there.

Keep the cards and letters coming...

I feel like you need something there if you really want to stiffen it up. The bar is good, but a shear panel to transfer load into a wider area seems better. Rudy can weigh in here, but I feel like the sheet metal would be a more effective stiffener than another bar for triangulation. You're not using stupid thick sheet so it really shouldn't be that much heavier than a tube.

It looks cool too! (IMG:style_emoticons/default/biggrin.gif)

[mgp4591]

I like that design for the side bar because I'm still a little squeamish about contact with another vehicle and I want all of the protection I can get.
Would it help if the rear short hoop was angled on the long behind the bulkhead so far as giving you the room you need behind the seats? I know what I'm thinking of but without the car in front of me to look and assess my ideas it's kinda hard...
And Andy, Tony uses lots of lube... LOTS of lube.... to get in and out of his car. (IMG:style_emoticons/default/biggrin.gif)

[Mueller]

I like the side bar, I had a harebrained idea of putting the main hoop for a cage on the "other" side of the back window for more room. Of course the targa bar would have to be butchered up beyond putting car back to stock easily. I think you are past that point currently (IMG:style_emoticons/default/smile.gif)

[mbseto]

If you are going to add something just for aesthetic value, right there in the door opening is a good place... You've already got a theme going, I think I'd do it. Ties the room together. So to speak.

[Curbandgutter]

You said race rod ...so in that spirt lose the gusset idea...does nothing but add weight....and even though the fabrication looks cool , it crosses the line of extraneous ....my opinion of course...but I am cursed with excellent taste (IMG:style_emoticons/default/smile.gif).......

"...and even though the fabrication looks cool..."
See, that right there? That's my problem!
Though it really does add (needed) strength, given that corner of the design isn't a triangle. I'll mock it up and see what I think, but it's a gusset or a tube. Something has to go there.

Keep the cards and letters coming...

I feel like you need something there if you really want to stiffen it up. The bar is good, but a shear panel to transfer load into a wider area seems better. Rudy can weigh in here, but I feel like the sheet metal would be a more effective stiffener than another bar for triangulation. You're not using stupid thick sheet so it really shouldn't be that much heavier than a tube.

It looks cool too! (IMG:style_emoticons/default/biggrin.gif)

Couldn't agree more. Use gussets on A and B pillar. There won't be that much of a weight difference and sheet metal is 100 times better at transferring the shear loads. The bonus is that it will fit with your theam and be functional as well. Welding tubes onto sheet metal in a punching shear action is a joke. I see it almost exclusively done everywhere on the forums. It doesn't make it right.

[tygaboy]

OK, structural guys: A little help. Does this make sense, strength wise?

Box/plate from the front hoop to the inner fender. Where the plates (side and top) hit the inner fender and A pillar wall, I'll fold an angle, suitably sized so I can spot weld it. Everything else gets seam welded and I'd add some lightening holes

NOTE: the door bar hits pretty low on the front hoop so my assumption is that this "support box"needn't be much higher than that. Good assumption?

[Rand]

Don't listen to all these guys talking about weight.

I know some racers who fight for ounces. It all adds up. Sometimes the cheapest horsepower is less weight, and it's even more important in the corners.

[tygaboy]

Don't listen to all these guys talking about weight.

I know some racers who fight for ounces. It all adds up. Sometimes the cheapest horsepower is less weight, and it's even more important in the corners.

Rand -
I agree. That said, for THIS build, hp won't be an issue and while I plan for the occasional track day, I'm not after the last X% of performance. (I have another build in mind that I've started collecting parts for that will be all about lightness.)

Don't get me wrong, I won't go crazy with the unnecessary bits but I think the extra pounds that find their way in aren't going to add up to being too much.

Now, back to the strength issue - any comments/suggestions on the front hoop-to-chassis tie in?

[Cracker]

Although you are correct (technically) very few drivers even get close to pushing the cornering limits of their cars. Even at a hefty "teener" weight of 2400 pounds - it is ridiculously light compared to let's say, a 918 (or a GT3 Cup, etc.). Chris could make his entire car an "art piece" and it wouldn't matter for its intended purpose. Spirited laps on summer tires will (still) be fun - in the right hands, still a rocket.

T

Don't listen to all these guys talking about weight.

I know some racers who fight for ounces. It all adds up. Sometimes the cheapest horsepower is less weight, and it's even more important in the corners.

[Curbandgutter]

OK, structural guys: A little help. Does this make sense, strength wise?

Box/plate from the front hoop to the inner fender. Where the plates (side and top) hit the inner fender and A pillar wall, I'll fold an angle, suitably sized so I can spot weld it. Everything else gets seam welded and I'd add some lightening holes

NOTE: the door bar hits pretty low on the front hoop so my assumption is that this "support box"needn't be much higher than that. Good assumption?

When the object that you are adding to transfer a load is longer than it is taller, it will transfer it's load primarily through bending. That is what you currently have. If you do it that way that piece will transfer 0 load vertically. What happens is that the vertical panel just behind the "a" pillar is probably 10 to 20 times stiffer than what you are adding. It's similar to having two dissimilar springs together taking a load. The spring that is twice as stiff will carry twice the load. What you want to do is to transfer the load through shear. So make your panel taller than it is longer and attach it the way that I'm showing.

Obviously the inside piece that transfers all the way to the bottom wont be rounded at the top, but it's the best I can do with paint. Remember though you need the diagonal back to the B pillar roll bar.

My 0.02$

[Cracker]

Rudy...you did mean Chris, correct?

T