Land Speed STi Chassis/Rollcage


So what does it take to survive a nasty crash?


#rsdlsr 08/09/2019


We’re back and we’re talking about safety. Specifically, the cage. You know, that thing which keeps the car from imploding around you and possibly though you. It does not matter who you are, at the end of the day, we are all ultra-soft and incredibly squishy. And much like us silly bi-pedals, these 90’s Japanese cars are also a bit soft and squishy. Not good for performance, and even worse for safety, so let’s fix that.




The roll cage is an integral part of any racecar. It has to keep the car ridged which helps reduce chassis flex, and greatly improves handling and predictability, but more importantly, it has to protect the driver when things go horribly wrong. Now you might think it would be best to just weld in some steel I-beams, all through the car, essentially turning it into a tank, but when it comes to impact protection, it’s all about the energy and how to absorb and displace that energy around the driver, all while remaining structurally intact, even during multiple collisions. So basically that means that it has to be both ridged as to not collapse, but it also has to be malleable and bend to absorb energy. This is no easy task.

It’s easy to make an incredibly strong and ridged cage, but during a crash, all of that energy is transferred directly to the driver, which is very very bad. Now on the other hand, you could make a cage that bends easily, and in a low speed event, this would actually be really nice, much like the 5MPH crash bumper structures that are mandated here in the U.S.. They are designed to fold like origami thereby taking most of the energy from the impact. But if you’re involved in anything more than a simple fender bender, you might be better off having no cage at all, as you’re now just creating more points that can come in contact with your body.

So what’s the options? Well assuming we had an unlimited budget and the class allowed it, building a near immovable cage directly surrounding the driver, and a carbon fiber structure around that. However due to budget restrictions as well as class restrictions, we are going to do the simple and cheap version of exactly that using both factory and aftermarket solutions. We’ve opted for the AutoPower Rally Roll cage kit which includes thick 1.75 inch by .120 inch DOM Steel tubing to provide a fairly immovable structure directly around the driver. Surrounding that we are relying on the OEM crumple zones to help absorb energy in the event of a crash. Now most likely we will not be involved in a front or rear end collision, so we wanted to make sure the cage went above and beyond the specifications of the class, and with that we have also added some additional bracing and gussets to help protect the driver even further. Not only will this provide ample protection, it will also allow us to use this car in other types of racing after our land speed attempt.





And what about the body?
As we said in a previous episode, this car will be racing in the production 1 liter class and let’s dig into what “production” actually means. Well basically it means that as far as the body is concerned, it needs to be stock with a few exceptions. And I know what some of you guys are thinking as I’ve seen it in the comments. You have an Impreza L, it’s not even a WRX, let alone an STI. And that’s where we are using the rules of the class to our advantage. First, in order to even run a turbo engine, we have to be able to prove that these cars came with a turbo from the factory, which they did… just not here in north America. However, the organization now allows “world” cars, which means we can legally enter this car as a WRX or STI. So we decided to set the car up as a STI type RA for a few reasons we’ll get into. 
First I have to give a shout out to a few people who helped us find some of these JDM body pieces and that’s Dave over at RalliSpec and the guys at JDM of san diego, but with that said let’s start up front. This is the version 5/6 front bumper that you can get from your local dealership as these came stock on some of our 2.5RS models. Below that is a genuine STI front lip which is a factory option, and moving up we have the fog light covers with OEM turn signals and bumper vents to the side. Combined with the genuine version STI front grill and new OEM glass headlights we essentially have a 100% stock STI front end. Now for the hood we did go with a genuine Aluminum STI hood, and I was able to find a set of fold in mirrors as well along with replacement JDM doors to replace the damaged stock doors.
We also have a few other bits like the mid height rear spoiler and other JDM pieces and some special ultra rare under trays and some other small oem aero bits we’ll be throwing on, but at least it’s looking like a real car!







Now for the livery. Well we’re still working on that, but as you can see we have started to wrap the car in this killer textured wrap, and that’s where we’re going to end the video. We have quite a bit of work ahead of us, and very little time to do it, so make sure to stay tuned for updates and progress on the car!