Mr X

OK, a little more about the splitter...

As I mentioned earlier, the material is called ACM- it is a plastic core with micro veneers of aluminum. It's used for sign making and commercial building facades like car dealerships. I salvaged a bunch of it from a dumpster at a local construction site.

I determined that the height I wanted would be the bottom of the front cross member. It will act as a splitter, a scoop to force more air through the radiator for cooling, and the beginnings of a flat bottom for aero. The cross member sits about 2 1/2" below the bottom of the front bumper wrap, so I had to make 2 curved extension pieces to connect the splitter to the bumper.

ACM is not designed for curves. So I cut tabs in it, and routed bevels into the back of it to allow me to fold and curve it. I riveted it to the bumper, and sealed it with aluminum polyurethane caulk.

Mr X

I made the hangers brackets from a couple of scrap mending plates, and notched them through the splitter. I bolted them to the splitter with a piece of flat steel underneath for additional support. I hung them from the bumper mounts and radiator mounts with airplane cable.

Mr X

The splitter makes a complete flat surface from the bumper back to the cross member. It is screwed to the cross member with self-drilling screws. I cut curves at the radius of the tires to allow about 1/2" of clearance when the suspension is at full droop.

To complete this, I will make canards for the 2 ends, a small scoop inside to divert the air from the face of the splitter up into the radiator, and 2 end panels to prevent the air from taking the easy route around the ends of the radiator.

Note that the stock belly pan was gone from this car when I got it, so my splitter will replace that, and is therefore part of the cooling system.

I will also seal the edges with foam window/ door insulating tape.

4eye4valve

Awesome job!!

Thanks for the pics and info.

Now where to find this material........
I'm guessing I wont be fortunate enough to stumble across a dumpster full of it. LOL

Mr X

I have built a similar splitter out of 1/2" plywood. Cabinet plywood lays nice and flat. If you maintain the paint, it can survive the weather. I've got a plywood one on another car that has been in the rain for 2 years just starting to show some wear.

Lexan would work too.

Of course, aluminum plate would be best, but I don't tig weld.

A splitter is very vulnerable to destruction. This one won't be too bad, because I'm not lowering the RX8, so it sits fairly high. But my previous one was only about 1.5" above the ground on a flat surface. I can't fit my toes under it. I figured the plywood was a good thing, because if I ever destroyed it, I'd just replace it without crying too much.

If you are lucky enough to see a commercial construction site using the stuff, ask. They throw a LOT away (it can easily be $200K on a typical install, and they ship a few extra panels in case of damage. $1000 worth of spare material is a small insurance policy for a project like that).

Angel187

900!!! You struck gold my friend....
Get yourself a SOHN so you can start premixing and increase reliability a little.

VTRX8

congrats, I just bought an RX8 race car this week. haven't gotten it yet, but know the previous owner. I plan to use it mostly for HPDEs.

Mr X

This is my last weekend for prep before the $2016 Challenge. I've got the car together, but haven't really put it through it's paces or done a shakedown run.

I've got a lot of details and cleaning to do. I'll hit the street the afternoon, and that will leave me tomorrow for any issues.

Mr X

I picked up tags and insurance for it yesterday. Took it for a ride to bed the brakes, then after they cooled properly, took it for it's first shakedown run.

I am really please with the drivetrain response. 6 puck clutch and a lightened flywheel get it through the gears quickly.

It's a few hundred pounds lighter than stock, and while I was under it I gutted the cat (yeah, I know some of you hate that maneuver. For low budget racing, it's a reasonable approach). It's also got a cold air intake (which I made), and the aero changes (from the splitter, etc).

The tires are staggered and pretty worn, so it's a bit compromised in that department, but the 315's on the rear still have plenty of bite. It's hard to break it loose on launch, etc.

I am used to a car that weighs nearly 1000 lbs less with similar horsepower, so I don't think I would call it nimble. But I'll bet those of you who are more familiar with the driving characteristics of an RX8 would find it a hoot! I like how it plants itself at speed.

I've got a bit more cleanup and detailing, then I'll load it on the trailer. This is the first car I've ever taken t the Challenge that I COULD have driven, but I feel better about taking the trailer in case of breakdown, etc.

I will keep you posted on how she does. I am expecting to be in the top third, but a top 10 finish is still feasible.

Wish me luck!

4eye4valve

Good luck!!
Keep us updated on how it goes.

Greasyman

I, for one, will be watching. It would be great if you get a top ten finish, but I'm really hoping you get a top one finish.

Mr X

Hmmm... pictures didn't attach. Let me try again.

Mr X

Awesome sentiment, and thank you for the well wishes, but this is not a top 1 car. At the Challenge, top 3 cars need to be able to pull off a top 5 finish in the autocross, and run AT LEAST 12 seconds in the 1/4 mile.

This is not a top autocrosser (old tires, no suspension upgrades, heavy car with minimal low end torque), and it certainly won't run 12's.

But I sure like your attitude!

Mr X

There was actually an award I could have won. They have a class for under $1000 cars. It would have been possible to keep the budget for this car under $1000, but I blew that by buying a new flywheel.

It's OK. I am going for the fun, and to have the first RX8 at the Challenge.

Next year this car could be a contender for the overall win, if I decide to go that route.

Greasyman

I was just looking at some of the cars from past years. I'm always amazed at the quality of many of the cars, and find it hard to believe they were built for $20xx. They look more like they were built for at least $20,0xx. How well do the organizers check build costs? If these cars are built for that little, how do people manage to do that, with all the expensive racing equipment and fancy paint jobs many of these cars have. Does it not count towards the total if you already have stuff lying around? That's about the only way I can imagine fielding some of those cars.

Angel187

Good Luck! I wish their was events like that around my way, you should record a video to see what your up against

Mr X

The best thing I can tell you about doubting the budgets is that I doubted too. So I dug into their stories, and did it myself, and now I don't doubt. Sure, there are some fakes. Most of us know who they are. They don't even make the top 10.

With VAST amounts of time, great cars can be built with very few dollars.

I know people with over 4000 hours in their $2000 car. I know a man who bought a Kirkey race seat, took it apart to use as a pattern, cut identical pieces and welded it together himself so his race seat could be identical to a Kirkey but built out of scrap metal. Dumpster diving, swap meets, and lots and lots of time on ebay. I built one car that went over budget, found a better price on the suspension components, bought them cheaper, then removed the original suspension and reinstalled an identical cheaper version. Some of the stories are plain crazy.

If you've watched past years, you've seen some of my cars. I am now one of the people you would doubt. My paint job last year copied the 787B Lemans car! I did it entirely with rattle can spray paint.

It's all about time. Silly amounts of time go into these cars fabricating things that could easily be bought off the shelf.

the best way to understand it is to come, and talk to the builders. They are cool people, and always welcome questions. If you'd like to come with me, come on!

CelestialGryphon

iTrader: (1)

Dude. I want that splitter.

Mr X

You can have it, but you might have to buy the rest of the car from me!

Chibana

Yep, I remember your car from last year. And here's their article with photos from 2015:

https://grassrootsmotorsports.com/ne...015-challenge/

Mr X

This is my car from last year.

https://i.imgur.com/fZVGJyV.jpg

I made the overall podium, for the first time in 11 years! (Though, I've made the top 3 for autocross for the last 3 years)

Mr X

Mr X

It's a Miata, but it looks a little different because of the fastback roof I built for it.

72edneck

Well mr x I want to inform you I am the new proud owner of this lovely RX8!!

wannawankel

Kewl - where's the pic?