Sneak Peek: S13 Tube Chassis Drift Car, Part I

Sneak Peek: S13 Tube Chassis Drift Car, Part I

By Khiem Dinh with a heavy dose of Gary Castillo influence

Khiem Dinh is an engineer for Honeywell Turbo Technologies at the time of this writing.  All statements and opinions expressed by Khiem Dinh are solely those of Khiem Dinh and not reflective of Honeywell Turbo Technologies.

A few of you have probably heard of Gary Castillo of Design Craft Fabrications, you know, the guy who can fab just about anything.  He’s got a buddy named Greg Kruse.  Greg is from the land down under and has his own company GK Tech producing S-chassis drift parts.  Greg is the type of guy who gets motivated to make stuff for one simple reason, because he wants it.  In this case, he wanted a tube chassis S13 for drifting.  

There is a plan behind the madness leading to a goal.  What’s the goal?  Well, we have to back up a little and explain the situation a bit.  You see, down in Australia, S-chassis cars are barely legal.  Anyone doing any modifications to the cars makes them completely illegal for road use.  So how do you get around the legality issue?  You make a “kit car”.  Greg got the idea after a friend imported an Ultima GTR from the UK with a LS7 dropped in.  So, Greg’s plan is produce a tube chassis which still utilizes the stock front and rear subframes.  Why keep the subframes?  Two reasons I can think of would be to reduce cost and also allow the use of the gazillion S-chassis suspension parts already in existence.  The end result is a “kit car” that is completely legal to drive in Australia and completely badass.  Greg has no illusions of making any money on this project, but he didn’t do it to make money; he did it because he wants one.  With that being said, after this tube chassis is completed, Greg plans on doing a 3D scan of it.  After a bit of FEA optimization, duplicates of the tube chassis can be made using Greg’s fancy CNC mandrel benders and tube notchers should anyone else want a tube chassis S13.   Of note, because the SR20 is not emissions compliant in Australia for use in a kit car, people will have to resort to engines which are emissions legal.  I personally think the supercharged LS9 would be fun, but I suppose a more mundane LS7 would do too.  Or maybe a brand new LT1…


To start the project, Gary needed a donor car.  This particular car has changed hands between a few members of the Nerd Alliance.  Gary’s employee Peter was the originally owner.  Our own Eric Hsu was Peter’s boss back in the day at XS Engineering and Eric owned it next.  Gary was going to fabricate a cage for the car for Eric, but that never ended up happening.  Whatever crazy plans Eric had for the car died somewhere along the way and our KW Suspension Nerd Alliance member Chris Marion bought the car from Eric.  Why?  Why not?  The car has gone full-circle now and is back in the hands of Gary and Peter.  

In case you were wondering how much the chassis weighed without the engine and the weight distribution, Gary put the car on scales.  The new tube chassis version should be significantly lighter than the sheet metal unibody.

A funny thing can happen when you start hacking up the guts of a unibody; the body can get a bit distorted.  So, the first step was to fabricate a body jig to keep all the panels lined up.

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