Project Valkyrie

By Kelly Schoof

When you were growing up did you ever wish to own a really exotic car? Maybe a Ferrari, Lamborghini or Porsche? If you started to become a car nut in your teens you probably realized something: people that have those cars usually have a lot of money but often have no idea what is under the hood or how it works. So most of us real car nuts came to a conclusion: either we have to make about $200K more in a year or find different performance cars to own. Not willing to sacrifice power to weight ratio, most of us red blooded North American guys went for the muscle cars, which is great. It’s even better when you can teach the rich kid in the sports car a lesson at the lights with your Javelin or ‘Cuda. However, by the time you roll up to the next set of lights the other guy challenges you to start the race at 120 mph or maybe go for a road course type race. This is where most of us run out of cards to play. Even though our muscle cars make their Porsches look silly in the ¼ mile, we start to run out of options around 140mph - especially if there are tight corners involved.

Several years ago I was inspired by a fellow named Rick Ehrenberg. Rick is the technical editor of Mopar Action magazine (http://www.moparaction.com/Tech/index.html). He put together a team and a car, an unlikely car at that, to compete at the One Lap of America event. They used a 1969 Valiant (http://www.onelapofamerica.com/History/1997/OneLap1997frm.htm) with a (Mopar) 360 crate motor, did some modifications, won their class and came fourth place against the kind of big dollar cars I’m talking about. Chrysler engineers did not intend the Valiant to be a race car, in fact, Rick and his team referred to it as the ‘Brick’. However, with some special parts and the genius of Mr. Ehrenberg, it kept pace with the big buck, ‘high tech’ machines. Since I started following his success, it has become a dream and long term goal of mine to enter a competition like One Lap of America, but first I need a car.

I have decided to embark on a project of ridiculous proportions (at least for me) that will create a performance car that will take on those exotics head to head and beyond. After consulting with a number of close friends, family and acquaintances, with experience ranging from the local garage, speed shop, AMC club, to some people currently working in the automotive engineering field; we believe the goal is achievable. The proposal was met with great enthusiasm from all of these individuals; many of them have offered their help and expertise to complete this project - I’ll be calling you guys soon … you know who you are! The late night pizza is on me.

We want to create a car for low dollars that will beat the best and we are going to accomplish that buy doing the engineering and fabrication our selves. Besides, someone once said ‘all we ask is blood, sweat, and gears’; so why not? After all, if you want it done right you have to do it yourself! Right? A good friend of mine recently told me that the problem with a large project like this is that it takes so much of your thought, time and money that when it’s all over you don’t know what to do with yourself. Well I don’t know about rest of you, but I’m sure we’ll figure out what to do with the car when we’re done. I have decided to call this project and the car that is born from it “Valkyrie”.

What is a Valkyrie?

What is a ‘Valkyrie’ you ask? Well the Valkyries come from Norse mythology. They were warrior goddesses in service to the supreme god Oden. Some of you may recall the classical music piece ‘Ride of the Valkyries’ written by Richard Wagner in 1856. More recently, a very impressive mach 3 strategic bomber prototype referred to as the ‘Valkyrie XB-70’ was built by North American Aviation in the early 1960s. For those of us building, the Valkyrie might seem like a lot of work, but, as my friend also said about a project like this ‘truly, the fun is getting there’.

A side view of Valkyrie shows the rear quarter vent door, new fuel cap location and the side scoop for rear brake cooling

More than just a Bull Fighter

The platform for Valkyrie is the 1974 – 1978 AMC Matador Coupe; specifically, the one that will be used is a 1977 model. Since AMC engineers and the Penske racing team designed the Matador as a race car for NASCAR racing, rather than a passenger car being converted to race car, there are many design features of the Matador platform that are conducive to this kind of performance. The wind tunnel designed body, unequal length double wishbone front suspension and the multi link rear suspension are great starting points for such a car. The cavernous rear wheel wells the Matador was equipped with speak of one thing: NASCAR sized tires. The AMC power plants, although requiring some modifications to their oiling system configuration, have some of the best breathing heads in the industry, making the high RPM capabilities which are beneficial in road course racing easier to achieve.

AMC incorporated several features in the Matador bodies that simply make sense. The flush/integrated rain sill over the windows, the flush door handles, the hide-away wipers all clean the car up from a styling and aerodynamic stand point. The wiper arms even have integrated window washer jets that move as the wiper arm moves; this results in a consistent spray pattern that is not effected by wind velocity as it is the problem with most cars. However, there were some design aerodynamic features that engineers had to exclude in order to make the car cost effective and practical for public sale. The headlight assembly and rear quarter windows are such examples. So, in the interest of aerodynamics, functionality and maybe just for the sake of doing something different, a number of body modifications are planned. The headlight assembly will be remolded and smoothed back to reduce drag, and for the same reason, the rear quarter window will be removed. In place of the rear window, a flush mounted, opening and closing, reverse vent will be installed. This will aid in drawing air from the front cowl vents, crossing the occupant’s legs and upper body to exit the car in just behind the side window. Intake scoops on the hood will feed the engine’s supercharger, while scoops on the side of the car will duct air to the rear brakes. Cooling to the front brakes will be provided through ducting from the front air dam. Consider the possible weight advantage by manufacturing the entire front clip’s skin from composites; not only would dramatically reduce the weight of those components, but it would aid in further improving Matador’s [already good] front to rear weight distribution.

It would likely be wise to change the OEM 15X7” rims to 19x8” aluminum alloy rims in the front and 19x9.5” in the rear there by reducing the side wall height and associated side wall roll over. Good candidates would be 245-40R19 and 305-50R19 in the rear. It is possible that other tire and rim combinations could be used, however the overall rim diameter will likely remain between 17 to 19”.

Body rigidity is going to be key issue in achieving the handling characteristics we expect. The unibody will have to be stiffened to reflect the types of repeated loading that the car will be subjected to and help the suspension maintain its geometry under duress. Subframe connectors will be must and a six point roll cage attached to the subframes. The number of welds in the unibody will be increased to add stiffness; in some cases seams will likely be welded solid. However, there is a balancing act that must be performed when it comes to welding in braces: too much bracing with out graduation can cause stress concentrations. This in turn can lead to body cracking and a far worse situation than if the car was left stock. There is no doubt that caution will have to exercised along with regular chassis/structural inspections while the car is in use.

Consider some interior changes such as changing the car from a 2+2 to strictly a 2 seater. Who needs a back seat in a race car any way? A rear seat just adds weight and takes away usable space. A five point race harness would keep the driver and passenger in place during violent maneuvers. It would be nice to include a heads up display that would enable the driver to keep track of vital information such as speed, RPM, oil pressure and coolant temperature without taking his eyes off the road.

While the exact engine configuration is not set in stone yet, it will likely be a 5.6L (343 cid) V8 with forged pistons, forged rods, and forged crank. One thing is pretty well for sure, the mill will have a 3.28” stroke so it can reach the revs without grenading. It will also be equipped with a disengaging clutched Paxton or Vortec supercharger producing about 7 psi boost. Some computer dyno simulations with this configuration have been done. The results are: 570hp at 7000rpm and 545ft-lbs at 3200rpm. Although these preliminary results are likely not 100% accurate, we are fairy confident the numbers are within 10% of reality. By the way, the simulation showed this motor only lost 10ft-lbs of torque all the way from 3200rpm up to 5500rpm. Gotta love a blower!

Transmission choices are numerous, but it is likely best to choose one that will offer more than just three speeds as is the case with the most common automatics. We feel that a manual gearbox is pretty well a must for Valkyrie. There are several choices even in the manual category. While options are plentiful some important factors must enter the decision making process. Issues such as reliability, must be carefully balanced with cost and performance. Either a 5 speed TKO with overdrive or a Richmond 6 speed are distinct possibilities. No final decision has been made as to which one at this point, however, due to the favorable durability reports on the TKO and its attractive price it is likely the best choice.

Will You Need An Automotive Engineering Degree To Operate It?

You may ask what the drivability of such a car will be like after all these changes. Well, your Acura will still be the car to take when performing such pedestrian tasks as getting groceries for the weekend BBQ. Valkyrie, on the other hand, is intended not only to turn heads, but perform as a touring/race car over long periods, all at a cost minimum.

Valkyrie’s suspension will be harsher than most cars sold today, and one will have to be careful of speed bumps, pot holes and high parking barriers, however such is life with any sports car. Since AMC decided to make the trunk of the Matador Coupe with ample room, this will carry over to the Valkyrie with one minor exception. Your touring luggage will have to share the space with the car’s battery, which must be relocated from the engine bay to the trunk. No worries about sulfuric acid on your Armani suit though, the battery will be in it’s own sealed and externally vented compartment. The absence of a rear seat will open the car up for possibility of an improved sound system and more room to recline the form fitted bucket seats if you need a nap – while you’re stopped that is.

Of course the entire point of all these changes being made is for one reason: performance. The following are some basic performance targets and specs for the Valkyrie to meet or better:

Performance targets

Acceleration

0-60mph (0-100kmph): 4.5 seconds

¼ mile: 12.8 seconds

Braking

Form 60mph (100kmph): 130ft (39.6m)

Top Speed: 180mph (289kmph)

Cornering

High g-force cornering

characteristics: Mild under steer

Speed through 700 foot slalom: 65mph (104kmph)

Skid pad: .95g

General data

Layout: Front engine/rear drive

Body: Unit body

Fuel capacity: 24 us gallons (109L)

Wheel base: 114 in. (289cm)

Track Front/Rear: 62.0/62.0 in. (157/157cm)

Steering: Recirculating ball, power assist, variable ratio, 2.7 turns lock to lock

Front suspension: Unequal length upper and lower wishbone, coil springs/adjustable shock, adjustable sway bar, polyurethane bushings

Rear suspension: Four trailing links: upper and lower control arms, live axle, coil springs/adjustable shocks, sway bar, polyurethane bushings

Useable trunk space (est.): 16.0 cu ft

Curb Weight: 1496kg (3300lbs)

Weight distribution Front/Rear: 53/47

Power to weight ratio: 5.7lbs/hp

Engine

Type OHV V8

Bore: 4.08”

Stroke: 3.28”

Displacement: 343 cu in (5.6L)

Output: 570hp @ 7000rpm

540 ft-lbs @ 3200rpm

Redline: 7500 rpm

Mean Piston Speed @ Redline: 76 ft/sec (4573ft/min)

Induction Forced, centrifugal supercharger

Carburetion: Carter Thermoquad, 4V (later: Accel multi port gen 7 programable fuel injection

Intake manifold: Edlebrock, Torker

Enhancements: Water injection

Bottom end

Crank: Armasteel or Forged (preferably forged)

Rods: Ford 300 six cylinder, forged

Pistons: Feather weight, forged aluminum

Stud girdle: Custom made

Top end

Intake valve: Stainless Steel, 2.02”

Exhaust valve: Stainless Steel, 1.65”

Lifters: Roller hydraulic

Rockers: Full Roller, 1.6:1.0 ratio

Cam Roller, stock AMC valve timing, enhanced lift (custom grind)

Timing Chain: Double roller

Heads: 58 cc AMC, ported polished.

Oiling

Oil pump: High volume,

Oil pan: 7 quart, windage screen, crank scraper

Pick up: Swivel type

Oil Distribution: auxiliary crank feed, enlarged return passages

Cooling

Radiator: Aluminum, 4 core

Fan: Electric, thermostatically controlled

Ignition: MSD 6AL, crank pickup, 8mm solid core wires, Delco RX44 plugs

Drive Train

Transmission: TKO 5 speed W/ OD, or Richmond 6 speed W/ OD

Drive axle: Mopar 8 ¾” w/ removable carrier and posi-traction

Instrumentation

Speedometer: 200 mph

Tachometer: 9000rpm

Oil pressure: pressure tube type gauge

Oil temperature: bordon tube type gauge

Coolant temperature: bordon tube type gauge

Electrical system: Voltmeter, Ammeter

Manifold Pressure: vacuum/boost gauge

Fuel: stock gauge

The component collection for this project has begun; most importantly, the car for this project while rough in appearance is secured and in a safe place – see the picture below. This project is very involved and will no doubt be time consuming. Building many of the components will not start until late 2003. The bulk of this project will likely take place the following 2 or 3 years beyond that.