1970 540 HEMI Cuda - Pro Tourer

Technology, performance, functionality. These are the main characteristics of the customizing of our Super Street 1970 Barracuda. Lacking any superfluous glamour, decoration we try to provide the modern man with a modern „toy”.

Design

We did not want to alter the legendary shape of the Cuda of 1970 but we wanted to transfer it into the 21st century. Thus we had to reduce the ride height and the centre of gravity to the level of the current days’ super sports car. We increased the wheels and placed them into the position that complements the car’s shape most. The muscle cars of the 60s and 70s were characterised by a strong back, flat nose and high construction. The back area of the Cuda is a perfect masterpiece, but the nose area is too flat. This is disturbing aesthetically and with the low ride height it can’t receive the huge Hemi engine either. We did not want to put a hood scoop or an accessory with a rectangular shape onto the car, therefore we decided to raise the original ’Cuda hood’ and complement the fender with a nice arch, like a tiered engine case, which gives a powerful European taste to car. With this the appearance became perfect for us, a monster full of power and harmonising with the rear area. We opted for the final colour of the car to be white, with black wheels and black moldings. Only white and black. We did not want to follow the trend of the years 2000 with the shaved and too-bright design. The original handles and bumpers of the Cuda remained untouched, only the rear lock got under the licence plate. We have constructed a luxury-sleeper that is not kitschy, it is mannish, possessing the ancient power, but radiates high quality. In the interior we planned Porsche leather in Espresso, Cognac or Beige colour fits with white excellent.

Function

We designed the car for high speeds, mostly for street use so that it is suitable for long trips and is relatively economical, but with minimal reassembling to be able to make maximum 10 laps on the race course where the lateral acceleration can be over 1G. This is not a small task since we have to consider contradicting designing criteria for the street and race-course use, such as tyre wear, operational heat-degree, fuel consumption and comfort. That is why we had to design the undercarriage to be multifunctional, to over assure the cooling and maximise the body rigidity.

Designing
Technically we considered everything from high speed perspective. The designing took place with the 3D CAD software where we created the geometry of the undercarriage, together with the frame. The frame of the car is a structure with a very low centre of gravity, the weight distribution is 50-50% on the front and rear axle which can be shifted forward or backward by +-10% respectively onto any corner. For the base setting of the camber we designed replaceable spacer set, with a medium value of -1° for the street and -3° for the race course. The spacers are simultaneously setting the camber and the vertical position of the upper control arms since other control arm angle is required for the street and other for the race course (tyre wear, less oversteer, comfort etc). The camber, caster and toe-in of all 4 wheels respectively the ride height can be adjusted freely. The height of the connection point of the upper control arms can also be calibrated and as such the weight transfer and the roll centre can be fine-tuned. The steering connection point of the front knockle and hubs can also be adjusted. We modelled the basic street and race course settings for the car and during the virtually 3D test we set the rolling axles of the suspensions, the rollin axis of the car, the maximal tire patches bay the weight transfer and the dislocation of each suspension element. We designed and fabricated adjustable coil over shock absorbers made especially for the undercarriage. Te shocks were made from the Swedish Öhlins elements.

Into the external empty shell of the Cuda we built an extremely rigid, low-centre-of-gravity tubing-frame system that runs along the entire car from bumper to bumper, made of 0.150 in. wall thickness cold drawn seamless tube with rectangular tubing base. The tubing-frame provides the spine of the car that supports the drive train and the undercarriage. We designed the rockers with a double-chamber system. We remade the Cuda’s original external rocker with the „C” cross section, made of 0.08-in. thick steel, we closed it with a vertical wall, this became one of the chambers, and we welded a rectangular tubing to it with a 0.118-inch wall thickness, this became the other chamber. We connected the strong rockers obtained as such into the tubing-frame. Under the dashboard there is a strong double frame transferring the twisting power from the spine onto the rockers. This frame holds and simultaneously protects the front area of the cabin, and when colliding it leads out all the power toward the rockers which protect the cabin as strong beams. The front fenders and the hood are held by a complementary and adjustable frame which behaves like a creasing zone when colliding, regardless the tubing frame. The wind-tunnel corridor of the tubing-frame is being connected by an “X” unit that can be dismounted under the torque tube. We designed a removable lower frame under the transaxle. In this way the entire drivetrain can be assembled easily, the tubing frame is closed and rigid, and the „X” frame does not let air from the wind-tunnel under the car. The European law does not permit the construction of the roll cage that can be seen in the cabin, therefore we could build a pipe near the columns, running along the carpets. However the rocker with the closed wall and the tubing frame are suitable to immediately weld in any kind of roll cage.

This is how the body became most rigid, it avoids any twisting, in this way it assures the most accurate fine-tuning of the undercarriage. We built the undercarriage from Corvette C6 Z06 control arms, knockles and hubs, in order to ease the maintenance and replacement. In this way it can be substituted freely for any adjustable and rod end type C6 Z06 control arm. The characteristic of the rear suspension can be adjusted from the neutral to the oversteer range.

Aerodynamics was also an important criterion during the designing. We designed carefully the route of the air coming onto the front of the car. We don’t the air led to the radiator then farther to build up turbulence and braking air-pressure in the engine room. As accordingly we designed for the firewall a tunnel running along the middle of the car and a huge inlet funnel. Minimal air gets under the car. The air entering the radiator is passing the engine then by cooling the exhaust manifold and the exhaust system it goes through the mid-canal of the car, then exiting in the rear through the diffuser it forms the clamping force. The rear diffuser is going to be the bottom of the fuel tank itself. The floor plate of the car is flat beneath, for the clamping force.

The braking force is assured by Brembo super-light discs and calipers. We plan to lead the brake cooling from the collecting elements near the front lights onto the discs, while the rear discs receive a part of the air gained from the wind-tunnel of the car. Through the Tilton race-pedals the braking force distribution can be adjusted during the ride from the transmission lever, between the front and rear axles.

The steering takes place through the steering column of the C6 Z06 with adjustable height and depth. The steering column is connected to the C4 rack&pinion through special joints and for its speed we redesigned the C6 steering knockles, we are supplying the modification design.

For the weight distribution of 50-50% the engine moved behind the front axle, and the transmission before the rear axle. The firewall came backward by 8 inch, the seats got before the rear axle, in this way the driver’s position is right near the centre of gravity. The rear seats disappeared because of need of space for the transaxle, a leathered storage surface can be placed instead, and that can be anything from the entertaining electronics to the luggage rack. The battery tray is behind this, top of the rear axle, on the midline of the car.

As for the engine we definitely wanted to build in a classic RB Hemi, with the modernisation that fits the body. We wanted an aspiring engine which has to have a big bore and high rpm range because of the high end-speed of the car, but with immediately pedal-reaction at the low RPM range – this is why we all love the old V8 engines. We were thinking of a new cast, stronger designed, strengthened aluminium block, with stage V CNC ported Hemi cylinder heads. The plan was a Hemi with a 540cui World Product aluminium block which was manufactured for us by the FHO workshop. We designed the engine operating with the gear ratios of the T56 MM6 6speed manual gearbox and Getrag transaxle with 3.42:1 rear end ratio and the 26.8 in rear wheel overall diameter to work well up to the possible 200 mph. The engine tests showed up 698HP and 672lb-ft on Dyno. The C6 Z06 torque tube is being connected to the Hemi engine through a specially manufactured billet flywheel and the custom made bellhousing built by the Quicksilver.

We designed a Fast XFI tuned port injection system with the 2*1300cfm throttle body, with all the required sensors, with a distributor modified and adjusted for the EFI and high volume fuel pump. An active traction control operating with the hub-sensors of the C6 Z06 knockles and hubs can be built onto the inlet of the Fast XFI TC.

The engine is being cooled by the a 4600cfm giant Flex-a-lite radiator and fans. The cabin is supplied with a Hurricane manual air-condition system, with special outlet. We built special long tube exhaust headers for the Hemi built into our tubing frame, which are going under the torque tube with 3-inch diameter end, into the wind tunnel. The entire floor plate is made as a double floorpan with gap, and there is ceramic mesh heat proofing between the two parts, so that the exhaust system that can be glowing at high RPM range using does not heat up the legroom and the cabin which is usually a serious problem with the front engine sports cars. That is why the exhaust system is in the middle under the removable „X” frame so that its produced heat is being led out of the car.

540 HEMI Cuda - technical contents

In the first step we defined the basic requirements set for the Barracuda:

  • RPM style and quality
  • High end operability identical with the features of the C6 Z06 Corvette
  • aluminum, 540cid (8856cm3) HEMI engine (698HP@5900RPM, 672lb-ft (911Nm)@4600RPM)
  • 400HP/1ton performance-weight ratio
  • 50-50% weight distribution
  • Suspension suitable for race track setting
  • Lateral stability exceeding more than 1g
  • manual transmisson + independent rear suspension, with transaxle
  • EFI system and traction control
  • Suitable comfort and interior design
The bases
2006 C6 Z06 Corvette Drivetrain

Taking into consideration the required weight distribution proportions as a starting base we chose the C6 Z06 Corvette’s hardened gear of the T56 MM6 6-speed issue of 2006 as well as the matching 9-inches ring geared, hardened bias ratio limited slip, and cooled differential. The suspension was also built from the C6 Z06 Corvette’s elements, redesigned for the Cuda dimensions and the required parameters, with a special chassis frame structure.

It was an extra challenge trying to transfer the engine’s performance onto the transmission through the Z06’s torque tube instead of various other solutions. The main reason consists of applying the proper torque arm and pushing back the original position of the engine. We don’t know any reference example for coupling the Mopar engine and the Corvette torque tube. This required the manufacturing of the special bellhouse, flywheel and crankshaft bushing work.

2009 540cid HEMI EFI engine

We have been planning for long to rebuild the Mopar’s historical classic, the 426 HEMI into an aluminium HEMI version of 540 cubic inch going to be set into a Mopar car. Due to the new technology the huge external engine features an extraordinary weight-performance ratio, this way it can be designed into vehicles with outstanding handling.

We maximised the engine’s output for comfortable road operation. Along usable idle version and non-increased service need the almost 700HP performance and the 911Nm performance are going to provide a running dynamics corresponding to our plans.

Main technical datas:

  • Block: World Products Aluminum
  • Bore: 4.502”
  • Stroke: 4.300”
  • Crankshaft: Ohio 4.30” Stroker
  • Connecting rods: 7.10” H profile, steel
  • Camshaft: custom, 241-241-113, In: .582”, Ex: .546”
  • Cylinder heads: „Stage V”, CNC ported, 168 cm3
  • Valves: 2.30”, 1.90”
  • Compression: 10:1
Further parts

There is need for further parts for preparing the accurate technical design. The break system of the Brembo Gran Turismo is going to replace the factory-made heavier Z06 elements with less cooling. The entire V-belt system is also indispensable for the dimensioning. We chose the Billet Tru Trac type due to its extremely low weight.

Chassis and suspension engeneering
Body work – restoring the external body

When restoring the body we repaired the corroded area, we replaced the front fenders and rear quarter panels with new ones. The design contains special chassis and floor panels, therefore we built the old floor panels and the rockers and we provided pieces of stronger material including the new chassis. From the taillight panel we relocated the lock under the licence plate and covered all the moldings, emblems and other bores.

Building
Body restoration