Mk3 Supra Cage

[Wiisass]

I just got done with this car earlier today. I did the cage, made a rail for the new buddy club seat and cut the dash to fit. Anyway, pictures are better, so here you go.















And the rest are here:
http://www.theoryinpracticeengineeri...llery/Robcage/

Tim

[04 Turbo Spec]

nice tim!!!

if only i knew you before i got my cage built

[whitezenki]

Awesome work

[PA Z06]

Very Nice work

[Nick 95 6sp]

That is one sturdy looking cage ...nice job, Tim.

[__owens__]

looking good like always Tim ... keep up the good work

[BMS]

Very nice!!! is that your mk3 or your brothers.

[adamkob32]

Wow very nice cage. I might be getting in touch with you sometime in the next year. :D

--Adam

[Wiisass]

Thanks for the comments guys.

Scott, it's a customers car, the guy is from Baltimore. But my brother's car will be getting something very similar, very soon. But a lot more gussets.

Adam, sounds good, just let me know.

Tim

[jc8889]

One hell of a cage, whats the process with painting the cage? I assume your gonna have to spray it in the car?

[SoStock92]

Although it looks nice, that cage would not pass for tech inspection in an NHRA required setup for weld inspection. Incomplete welds and poor shielding (resulting in the brown/orange contamination) gas coverage and penetration - if MIG welding a cage you really need to get good penetration. TIG welding is conventionally preferred, and when TIG'ing, you will fail again if you undercut the weld.

Additionally, since you did do a front portion weld-in, you should have fabricated NASCAR bars into the door recesses for added side impact protection, but honestly I am not sure those welds wouldn't justify the effort.

I do not mean this as an insult, only to let you know that the cage, although physically substantial, would more than likely fail tech.

[cmr076]

^^ not @ atco haha

[Wiisass]

jc8889, I'm not a painter and I don't paint the cages I do, so I can't say how people actually do it. I'm sure it involves a lot of tape and newspaper and you spend a lot more tape masking stuff off than you do painting. But yes, it gets sprayed in the car, it's easier if you're spraying the whole interior at the same time. Then you just remove as much as you can, tape off the windows and what's left and start spraying.

Sostock, where do you see incomplete welds? There are none, every joint is welded the full 360 degrees. And I can assure you that there is proper penetration. I have tested the settings on use on the tube that I use. But it does look like that brown/orange "contamination" has spread to the tubes, it's all over the place. It's also just on the surface and it's commonly known as rust and will come off with a quick hit with the wire wheel.

As for TIG welding being preferred, I don't know why you would think that. MIG welding is a fine procedure and creates a weld just as strong as a TIG weld. TIG is nice for it's smaller heat affected zone and the control you have, but it doesn't mean a stronger bond. And I really don't care much about NHRA and what they think. I care about SCCA, NASA, US Drift, FD, D1, etc and I know this cage will past their inspection.

And why would I need NASCAR bars? I put an X-bar in because that's what the customer wanted. The x-bar is bent slightly outward which was mainly for seat clearance, but will also help to absorb a side impact in the event of a crash. But the door bar is still in the car, it is still running windows and all of that, so there is no room for NASCAR bars. And according to every rulebook that I've read, NASCAR bars are only required if the crash bar in the door is removed or the door structure is modified. So unless the customer asks for all of that, I don't do NASCAR bars. I like the x-bars and I feel they are more than adequate for safety.

So don't worry, I know what I'm doing and I know that my cage will pass the tech is needs to pass, provide good safety to the driver and stiffen up the chassis.

Tim

[anthracite93]

Originally Posted by SoStock92

Although it looks nice, that cage would not pass for tech inspection in an NHRA required setup for weld inspection. Incomplete welds and poor shielding (resulting in the brown/orange contamination) gas coverage and penetration - if MIG welding a cage you really need to get good penetration. TIG welding is conventionally preferred, and when TIG'ing, you will fail again if you undercut the weld.

Additionally, since you did do a front portion weld-in, you should have fabricated NASCAR bars into the door recesses for added side impact protection, but honestly I am not sure those welds wouldn't justify the effort.

I do not mean this as an insult, only to let you know that the cage, although physically substantial, would more than likely fail tech.

I've never heard of tech being done using online photos...nor do i remember being a member of roundyroundfunforums...

Tim does quality work. I saw this cage in person this past Saturday and its awesome. Once my next project gets going Tim will be building my cage...whether the NHRA likes it or not...not that i give a ****.

[Wiisass]

Thanks Jimmy. Rob ended up not being able to come pick it up this weekend, so you should stop by tomorrow and see the finished product.

And NHRA is drag racing.

[SoStock92]

You don't need to be a rocket scientist to see instant oxidization and contamination in a weld. But what do I know ;)

The floor pan welds will fail in corner fillets. The orange discoloration is due to improper shielding.



.... if you say so.



If you run any X bracing up front with out running nascar bars you should have your eyes opened - that X brace there is going to shatter his pelvis on side impact. I would not drive that car on a race track let alone the street. But wtf do I know I only hang around 10 second bmws

[04 Turbo Spec]

Originally Posted by SoStock92

You don't need to be a rocket scientist to see instant oxidization and contamination in a weld. But what do I know ;)

The floor pan welds will fail in corner fillets. The orange discoloration is due to improper shielding.



.... if you say so.



If you run any X bracing up front with out running nascar bars you should have your eyes opened - that X brace there is going to shatter his pelvis on side impact. I would not drive that car on a race track let alone the street. But wtf do I know I only hang around 10 second bmws

you say engineering is you hobby....Tim has his degree in engineering i would take his word over yours.

there are alot of guys who hang around fast cars but that doesnt make them instantly know more

[SoStock92]

I hope the guy is never in a wreck is all I am saying. I am on QUITE a few welding forums. I don't care what you have a degree in - those welds are bad.

[Wiisass]

My welds are not bad, they are perfectly structural. The thing about MIG welding is any of the crap that may be left on the surface or inside the tube will come to the top of the bead, this doesn't mean that the bead itself is not strong, it just means that the piece could've been cleaner to start. And if you notice all the other tubes they started to rust once I cleaned off the grease or whatever was on there when I got them. So some of my welds may not be the prettiest, who cares, I'm not the kind of person that will only post pictures of something pretty.

And what floor pan welds with what discoloration? If you didn't realize, non of the welds have been cleaned after welding, so some of the stuff that you're seeing is an effect of the welding process. But I don't know what a TIGged, stainless steel exhaust mani has anything to do with.

As for x-bracing being unsafe, if he gets in a side impact that would be enough to crunch the OE door bar, and make the x-brace go into him, then he's probably going to have a lot more to worry about.

Anyway, I'm glad all the things you have read on the internet have taught you enough. And it seems you some how learned the ability to x-ray a weld through a computer screen. I'm on a few welding forums as well, maybe I'm on the wrong ones.

[anthracite93]

Originally Posted by Wiisass

Thanks Jimmy. Rob ended up not being able to come pick it up this weekend, so you should stop by tomorrow and see the finished product.

And NHRA is drag racing.

I'll see if i can stop by either tonight or tomorrow after work. when is he picking it up?

and i know NHRA is drag racing...i was talking about the nascar bars