Building A Race Car Frame: How To Not Die At 200 MPH

Superfast Matt is supported by:

[blackbuttecruizr]

As my fabricator friend Phil used to say... "Anyone can build a barn that will last forever. But it takes an engineer to build a barn that will 'barely' last forever..."

[deviljz]

This is a whole new level of project cars. I’m speechless with the laser cut tubes. I feel like a caveman now using my Harbor Freight tube notcher.

[turboslugfiero]

Your paper clearance method was something I learned way back in school in the '70s. It gives just enough space on a riveted pivot joint or as you used it for a demountable junction. Good job!

[stanceworks]

I absolutely love this. I'm eager for the next episode. As someone who's built a complete tube chassis car and a LOT of roll cages by hand, I can't even begin to explain how envious I am of the laser cut chassis. I am going to have to explore this for my next tube chassis build. I may have some questions!

Did you weld underneath your tube nodes where your tubes overlap? (I'm asking as I watch, apologies if you cover this later!)

[mr_voron]

I know it was a throw-away line, but “I took a class in X and forgot everything” is sadly too true. It’s especially painful when you’re still paying loans for things you’ve forgotten.

[paulnielsen]

Gotta respect a guy who has jackstands for furniture.

[craigmatthews]

In the bolted joint you need to put vertical tubes inside and flush with the rectangle tubes in order to prevent crushing when bolted together. hope that's clear:)

[thearth]

Using the roll cage as intake runners is a very clever touch. I've heard of using them for coolant or even oil, but not for intakes! Getting the benefit from that high pressure zone at the nose without too much extra plumbing is brilliant.

[theflyingfish]

When he's explaining how the fins on the car act like the fins on a dart, the red car in the illustration is a Dodge Dart

[nimblybimbly]

My newest welding helmet has a grinding setting. Used it once and forgot to switch it back kind of like your clear mask situation. Sunburn on the eyes... Good times...

[seanw.]

+1 for spray painting vs. powdercoating for race car frames. I had the frame of my Exocet powder coated, it aggravated me every time I had to scrape off powder coat to mod/weld something.

[splat]

Instead of paper I keep a deck of playing cards in my toolbox. Since they're stiff and slick they make good shims and you can easily get good repeatable results side to side by adding and subtracting cards. Keep up the awesome work.

[Miata]

That is going to be pretty heavy. I assume you have taken that into consideration, but just as available space on any project magically shrinks, mysterious weight often appears as components get added. Cool project.

[bradmaas]

Those bolts through the frames to attach the halves together might be a good idea to weld some tubing for anti-crush and resistance to pulling apart.

[GermanDragon]

Hey Matt!
Heres a quick hint from somebody who's selling welding equipment for a living across the big pond.
Please don't blind yourself while welding! if you're doing a lot of back and forth between grinding and welding then a lot of automatic welding Masks (even cheap ones) have "Grinding" modes, so they dont dimm down when there a grinding sparks flying around. some more expensive ones (like the 3m Speedglas 9100FX ) even have fold up visors with a gigantic clear screans for better grinding visability.

Keep up the awesome work tho! Its very entertaining to watch! ^^

[shadowuaw-]

Always a good day when you release a new vid. Never watched one without laughing at least once. Keep up the good work. I look forward to seeing how this project progresses. All hail the algorithm.

[evolutionmonkey]

Always great when a new SFM video drops <hope I don't find that that's an acronym for some random or maybe not....>. Thanks for the great vid as always, some really good progress on the race car! That's going to be a ton of welding right there!

[bottleheadaudio]

Paint instead of powder coat is a good idea. The salt will find it's way under the powder coat after a couple years of racing and then it's off to the powder coater again to strip and refinish the entire frame. Paint isn't better corrosion protection but it is easy to sand and touch up the rust spots. I bring a paint pen to the salt to touch up the inevitable paint chips made during the week. Another necessity to fight corrosion on the salt - chuck every steel fastener you have and replace it with 316 stainless, Bumax88 or titanium.

[TheSnivilous]

Awesome video! Just some suggestions (just like everyone else and their mom is giving you). At the bolted joint, put some weld washers or something to decrease the bearing stresses on the sheet metal, it doesn't look like you have shear features so those holes may wallow out. One guy suggested welding a tube inside the square to stop it crumpling which I think is a good idea, and will increase the surface area for the bolt to dump load into. The biggest thing I have to harass you for is metal prep! I started TIG welding a year ago for my buggy chassis, and the biggest thing I've learned is prep is everything. At a minimum you "should" get the millscale off the metal and the oxidation off the laser/plasma surfaces. I like to just scotch brite and then acetone/alcohol wipe it down, but even just hitting everything with a wire wheel really fast will immensely help your weld quality. You should also leave the TIG pointed at the weld once you're done until the post flow turns off so the weld can cool a bit before introducing oxygen to it. Welding Tips and Tricks on Youtube is an amazing source for help! Also Furick cups can help a lot for acute angles of tubes since you can get a lot more stick out. I'd also recommend beveling any future surfaces with a flappy disk so you can get full cross section penetration. Prep turns into the longest part of the welding process I've come to realize after going down the TIG rabbit hole.... Otherwise nice work! I like the alignment tabs for the tubes, I've never seen that. I want my next chassis to be all laser cut, I've very jealous!

[iowa_don]

In almost no time, SuperfastMatt will actually be going SUPER FAST! Can't wait!