Formula for Success: My #TougeCarChallenge Entry

He-hey, everybody! It’s me, Mickey Mouse! Today, I’m participating in a #BuildPost challenge that Debodeep started. To compete in this challenge, one must build a street-legal touge race car that is ready to tackle the Usui downhill, the road that Keiichi Tsuchiya calls his home course. For this, the cars must be built for handling first, acceleration next, and top speed last.

With that being stated, let’s push the boundaries of what a road car can do!

Starting Point: 1988 Pontiac Fiero Formula

The Pontiac Fiero was the American MR2. Not only did it have a small size, a low curb weight, and two driven wheels at the rear, it also had a selection of either four cylinders or six cylinders, only manual transmissions, and a “very proud” emblem of a bird. For Pontiac, it was their first two-seat coupe since the 1930’s, and it was a successful one. The 2M4 version of this was one of Car and Driver’s Ten Best for 1984, and it even beat its sibling, the new 1984 C4 Corvette, to a pace car position at the Indianapolis 500. In fact, it may be more similar to a Toyota MR2 or a Honda NSX than it is to the flagships Chevrolet.

1988 was considered its best year, and as such, I wanted one in its best condition, Given my rotation between European, American, and Japanese cars, I chose it from the American pack. Oddly enough, I can count on one hand how many other people are using American cars. With how nimble it is, I thought this was the best pick. Eventually, I came across a Fiero Formula of that year that was for sale with 85,000 miles, scooping it up quickly so it wouldn’t be snatched by someone else. Such a short distance between the engine and the driven rear wheels was, from my drive, the right move; I even kicked the tail end out a bit!

The deadline was closing in rapidly; I had to get to work at a breakneck pace. First off, I refabricated the chassis from carbon fiber into a monocoque, ensuring that any bit of weight on it would be shredded away. I then went about with eschewing the old suspension in favor of a set of pushrods with an adjustable ride height for any speed bumps, sticking standard springs, semi-active dampers, and active sway bars into the chassis. Its layout stayed with a transverse engine and rear-wheel drive; I knew this would be my best bet for the mountain pass I would be challenging.

Body: Suntrust Racing Pontiac Daytona Prototype's Aerodynamics

If I race anywhere in the world, aerodynamics are always something to consider. How the air interacts with the car is crucial to how the car handles; with loads of downforce, one can corner quickly and move on to the next one. Since this is going to have more corners than even my NSX GTB had to deal with while rallying, massive amounts of downforce are going to be essential. That’s why I’m turning to the Riley Daytona Prototype, this one being the one that won the 2005 running of the 24 Hours of Daytona.

It was a Pontiac, and I was to take full advantage of its aerodynamics, picking the wing, splitter, downforce-oriented undertray, and diffuser from it. I added a second spare rear wing that I had from the aforementioned NSX and stuck it between the wing’s pillars, modifying both of these wings to utilize active aerodynamics. I was not finished yet with the body: I remade it from carbon fiber in a similar manner to the chassis, opened up the front grille and vents more, attached Embrace Racing Dual Bi-Xenon Flushmount Headlights (with a white halo configuration), smoothed those headlights down to ensure that the drag coefficient was as low as possible, put an F40’s hood-based NACA ducts on this car’s hood, increase the side vent’s area, and cut a grille in the rear between the taillights that allows two large exhaust pipes to protrude from the 1,529.7-pound body. As I replaced the stock glass panels with Gorilla Glass panels manufactured to fit the car, I pressed a sticker of me peering out of the car on the right of the rear windshield and a sticker of the CarThrottle gate on the left side of the same glass. I painted it in its factory red color, including the white-striped livery that the number-six Ferrari 250LM proudly sports. Finally, I stuck a license plate on the rear to keep it street-legal.

Engine: Ferrari Tipo 232

Here’s an odd choice for a Pontiac: a Ferrari engine. Except it is not an odd choice; when I perform engine swaps, I tend to stick with engine manufacturers that have at least an affiliation with the car’s maker. Ferrari had exactly that with this division of the General. It was for a one-off car, the Pontiac Pegasus. In the Chevrolet division, a designer named Jerry Palmer was trying to bring a new design to the Camaro, eventually sketching a 1958 Ferrari 250 Testa Rossa’s front end on it. Bill Mitchell, his boss, was so impressed with it he took it to Pontiac to develop into a concept car. Hearing of this, Enzo Ferrari offered a 365 GTB/4’s V12 for the engineers, which they shoehorned in successfully.

That is how the link is established, and I am going to use it to its full potential by installing a 2.0 L 180° V12 made by Ferrari. It powered the obscure 1969 Ferrari 212 E Montagna; it was a once-made engine built solely for this application by increasing the displacement on one of its Formula One V12’s of the mid-1960’s. With approximately 300 horsepower, it pushed a 500-kilogram shuttle through the 1969 European Hillclimb Championship with lightning speeds, winning every single race and the title. To establish a link like this is, admittedly, a stretch, but it is worth it in how the engine is small, but powerful.

In this application, I kept the same 65.0 millimeter bore, but enlarged the stroke from 50.0 millimeters to 65.0 millimeters. The block was recast in magnesium while the heads were produced from aluminum silicon; to update the valvetrain, I utilized the 60-valve dual overhead camshafts from an F50. To withstand the high operating speeds this engine would naturally aspire to reach, I implemented a billet steel crankshaft, I-beam titanium connecting rods, and lightweight forged pistons. Cranking the compression up to 14.6:1 and fitting race-ready camshafts, I installed a 360’s Phase Variator; originally a variable valve timing system for only the exhaust camshaft. However, I reworked it to work with the intake camshaft, too.

Fuel is directly injected into these cylinders through a Bosch system akin to that on the 599 GTB Fiorano. Each of the twelve has an independent throttle body, with a racing intake providing plentiful air. The fuel it runs on is of the 95.0 AKI blend, mixing fuel and air at a ratio of 12.0:1. A highly-advanced ignition timing is present, along with race tubular headers that become two two-inch exhaust pipes. Now displacing 2,588 cubic centimeters, twenty more than an RB26DETT does, it conjures 456 horsepower at 9,900 RPM, summons 282 lb-ft of torque at 7,800 RPM, and screeches to 11,500 RPM.

Wheels and Tires: Volk Racing ZE40 Wheels and Michelin Pilot Super Sport Compounds

The fact that such a tiny, 218.9-pound, freely-breathing engine can produce those numbers astounds me. The fact that it needs to stick to the road like it is superglued to asphalt is another one that I have in my mind; the tires must be sticky if I want them to provide the mountains of grip I desired. To keep the car street-legal, I looked for semi-slicks that were meant for this sort of racing.

Drawing upon my experiences with past cars, cars I sat in, and, primarily, the Corvettes my fellow drivers and I had access to at Spring Mountain Motorsports Park, I went with Michelin Pilot Sport Cup 2’s with a reserve set of Michelin Pilot Super Sports for those times when the tarmac is wet. The tires were chosen with a size of 345/30ZR19 for the rear wheels and a size of 295/30ZR19 for the front wheels. The wheels that they surround are Volk Racing ZE40’s that are composed of carbon fiber, keeping the weight to the bare minimum touge racing smiles upon.

Set up in this manner, this Fiero can smash sixty in 2.3 seconds, fly by a quarter mile in 9.42 seconds, and howl past a standing kilometer in 17.58 seconds. On a skidpad, it can corner twenty meters while pulling 1.37 g at 37.0 miles per hour, but for cornering 250 meters, it hauls a ludicrous 2.53 g at 176.1 miles per hour. As a reference point for this metric, at 124.3 miles per hour, the car is weighed down by a total of 785.5 pounds of downforce (18.2 pounds at the front and 767.3 pounds at the rear); this is slightly over half of the car’s weight. With this great ability comes great responsibility held by four Brembo carbon-ceramic brakes measured to be 160 millimeters all around, with Hawk street and track-approved pads and red calipers helping them bring the object at a motion of 62 miles per hour to rest in just 74.4 feet.

Transmission: Modified ZF 7DT-45HL Six-Speed Dual-Clutch Transmission

With oodles of downforce to play with, the tires cannot send the car past 200 miles per hour; instead, they rocket the car to 178.4 miles per hour. The tires are not the sole reason why the car can go this fast; it is the transmission that capitalizes on it. I would want to stick a manual transmission into this car, but I knew that the best way to consistently, quickly, and crisply change gears was with paddles forged from the fiber previously mentioned and positioned on the steering wheel.

Going with ZF again, I selected the 7DT-45HL transmission, which did service in many 911 Carreras by shifting quicker than a blink of an eye, providing seven forward ratios and two clutches, and withstanding up to 331.9 lb-ft of torque. My main concern was the highest operating speed it could support: 9,000 RPM. It was impressive, but for a car of this caliber, it was too little, meaning that it needed some reinforcement. Alongside that, I was concerned with seven ratios. Again, this was impressive, but given this car’s power band, how much downforce it produces, and how much of a focus is put on acceleration and not top speed, I thought it would be best to remove one of the forward gears. After getting ZF’s blessing, guidance, and support, I proceeded to do that while gearing the car for 182 miles per hour and shrinking the spacing. I then installed a carbon clutch from a Formula One car, a carbon-fiber driveshaft, and an electronic differential, the same eLSD that can be found in modern Corvettes.

Interior: Stripped, but Practical

With a touge car, so much of a focus is put on a light weight because it ensures that a car will be able to overcome inertia more easily while cornering. It is why I worked tirelessly on the body, chassis, and engine. On the interior, the same rule applies, but it is different because of how the car needs to be able to drive like a normal car. Therefore, I must go through the car and remove the weight that is important while keeping what is essential.

All around the cockpit are the visible threads of the chassis and body panels. The portable radio present here is capable of picking up AM and FM radio stations with the ability to store purchased songs from a computer to the radio’s solid state drive (there’s at least forty eurobeat songs already saved in there). Most importantly, it connects the driver to a team radio that is accessible via its associated button on the Momo FWM/02 racing wheel. The wheel’s digital display usually relays the engine’s RPM and the car’s speed. However, every time the car completes a lap or finishes a course, for a few moments, the displays change, relaying the lap/run’s time and the lap/run’s delta from the fastest lap/run. This information is then logged into an internal computer to save it for future reference/validation.

The wheel would be mounted on an NRG SRK-200BK quick release painted in the same red as that of the exterior, with there being electronic boost, oil temperature, oil pressure, and fuel gauges being displayed behind the two. A driver and passenger would sit in two Recaro Profi seats; in between the two of them would be a racing-approved fire extinguisher. To strap them in, red Sparco six-point racing harnesses would be utilized, and in tandem with an FIA-approved, titanium, hand-built roll cage, it would ensure that the drivers are safe in the case of an accident. Surprisingly, thanks to how much space was freed up, there is more space in the front trunk!

One Step Further

Since this is a touge car that must be tested on a touge course to observe and test its potential in touge racing, I began searching for mountain passes with a downhill race. It took some looking, but eventually, I found one, Panorama Highway, situated on Mt. Haruna. Upon further researching this, I found out that this road was the Akina Pass prominently featured in Initial D. Seeing that this was similar to what the Usui was like, I decided to take the car down the road at race pace.

I do not have the times that Bunta and Takumi Fujiwara set on this course, but I did not care. I was not here to break records; I was here to have fun! The car cornered eagerly and accelerated briskly, contributing immensely to a time of 3:46.86.

All of these factors coming together in the manner they did was this car’s formula for success.

Below are some pictures of the car!

Thank you for reading my #BlogPost! What do you think of my build? If you want to submit your own rally build for a car, please post it with the hashtag #TougeCarChallenge; I look forward to seeing your cars!