1TG Scratch Design & Build.

I've been encouraged to start a build thread for my project. Its not a GT40 or a replica of anything else for that matter, so if anyone objects and wants the thread removed or moved somewhere else on the forum thats fine by me.

I've been running a blog of sorts for the last year on the car rather than run through the whole history of the thing here if you're interested go browse through the blog and ask questions if you like.

At the moment I'm at the stage where the frame is nearly all together, detail design continues, and I am very much a believer of making the design mistakes in CAD so I tend to flog that to death before cutting metal.

Here's some pictures of the thing, the CAD renderings are a little out of date in some respects but they give the flavor of the thing.

I look forward to seeing the finished bodywork. Anyone that can do a scratch build - I don't care what it is - gets absolute respect from me!

Brian Hamilton

I'm on the verge of touching myself inappropriatel
Hey Doug,
Looks like you're well on your way to a fantastic project!! What engine are you going to use to power the beast? A V8? If weight is your main goal I have an idea for you if you'd like to hear it. Mercruiser made an inline 4 cylinder that displaced 3.7L. It made over 190hp naturally aspirated and ran forever. The cool thing about this engine is it's an all aluminum block and has a Ford 460 cylinder head. Working at the performance shop I used to, we were trying to convince some of our more insane and well off customers to opt for this setup in their SVO Mustangs when they wanted to make crazy power. In my talks with our machinest, the engine block can be overbored and the crank offset ground to produce an engine of +/- 4.0L. Now imagine that with a turbocharger sized correctly for the engine and a stand alone fuel injection system and you have a 700-800 HP monster. We have already built a 2.3L Ford that produced 650 RWHP when stroked to 2.7L so we figured 700-800 wouldn't be too far of a stretch. Anyway, just an option for you. I have a local boat junkyard who will sell me a complete longblock for like $400. I'd like to use the A460 cylinder head ported and have Comp Cams to a cam for it, be it a regrind on the stock one or an all new one if they have blanks. If all else fails, larger ratio rocker arms are always an option. Building an intake & exhaust manifold wouldn't be too difficult, you're already pretty well versed in fabrication I see. Custom pistons & rods aren't a problem either. Anyways, I'm just saying this would be a dynamite light weight package for you.
Either that or a 4 rotor Wankel engine...


Re: Superlite Coupe production
Originally Posted by Doug68


A good part of this exercise from my point of view was to do the whole thing "my way" for what I've thought were the important first principles.
For me torsional stiffness (I worked to a goal of 10,000lb/deg in the model) and occupant protection were the primary goals and I spent a lot (probably too much) of time working on structural analysis to achieve these goals (I hope). The computer model shows the completed frame coming in at 127kg (the last time I weighed it, it was about 10% less than what the model said it should have been) , the completed car I expect to way about 950kg.

Wow, that's pretty light! I am sure it will be a very stiff and safe chassis. I just don't think I have ever seen a car with that much diagonal bracing on a tube frame. Not questioning your knowledge, I wouldn't be able to get the floor ladder done on my own! Cool project.



I never really thought of it being light, quite the reverse I was actually building it up to the target weight of 1000kg.

On the X bracing when the angle of bracing gets shallow then it becomes ineffective so to stiffen an area such as the side of the frame it only seemed natural to break into sections where the bracing could be kept close to 45 deg.

On the engine front I already have one I plan to use and in the shed which is a Toyota 1UZFE (4.0L V8). Until the ting is registered the engine will remain bone stock, I've too much other work to do before I get to that.
I've shoved up on my blog the start of a thread on how I designed the frame of the car, could those of you with an Engineering background give it a read to make sure I'm not spreading falsehoods.

For anyone else who cares to read it let me know if you think its in anyway useful and I'll continue.

hmm Beer...
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Trevor Booth

Lifetime Premier Supporter
your blog part one. Steel is marvellous stuff. One of its more or less unique properties is that if not stress beyond its yield point it will not fatigue, which is great for something like a car that’s constantly being bounced and vibrated from many sources.

Not quite correct. You need to stay below the endurance limit for indefinite fatigue life. The endurance limit could be less than 45% of UTS. You really need an S-N diagram of the material to obtain the endurance limit for the design life of the vehicle in terms of number of cycles. If you really want to get serious you need to check the fundamental frequency of the structure and make sure it does not match the road frequency to which the vehicle may be subjected.
This shows the Chassis Rotisserie in action, this is about as far over as it'll go before getting too unstable.

Another week of evenings welding and the frame should be ready for the engineer to inspect.


Got it off of the stands this evening which gave a chance to weigh the thing currently according to the bathroom scales it is 240lb (109kg) this is basically structurally complete bar a bit of welding. Everything else to go on the frame is a bracket of some sort.

Also you can see it's a bit taller than a '40 it'll probably finish 1/2" higher than this on its wheels.

Here's the latest attempt at starting a body for the thing.
This version is a fair bit different from the one shown in avtar, frankly I find doing body design a real PITA and if I could hand it off to someone who do a good job of it (for free (yeah right)) then I would.

Obviously this isn't finished, particularly there are cut outs missing to let air out from various places.

The rest of my current progress is posted on my web page (see sig)


I like how its going. That front clip really looks good. What are you going to use for a windshield? Make you own or use an OEM piece?

Keep up the good work.

Hi Chip.

Thanks for the comments, I was beginning to think no one cared :sad:

The windscreen will be cut from flat laminated glass. I went this route for mostly practical reasons, but the idea has grown on me of it as some sort design statement "Practical Speed" say versus "Sexy Speed".
There are just so many cars with good shaped glass that you can use. I decided on useing 911 glass because is is fairly narrow and leans inboard. I recall a Mosler car that he built before the M900 that had flat glass. No matter how fast or how many races it won, the glass was always the topic.
So it weighs in at about 280 lbs so far. That should really be stiff as well. It sure is hard to weld in all the tight spots. I will read up on you site more to catch up. Are you useing Solid works?