The Deltawing is still something of a love it or hate it car which has been a topic of debate ever since it was first revealed in Indycar guise back in 2010. There has been an enormous amount of development on the concept since then which has spawned a number of completely different cars, some branded Deltawing some not.
The lightweight low drag concept emphasised efficiency, but it pushed the engineers behind it hard as everything on the car had to be small and lightweight, the car pushed boundaries in a number of areas.
The first concept was a single seat car destined for Indycar, but after the ICONIC committee opted for the Dallara IR12 design, Ben Bowlby set about reworking the concept around the Aston Martin AMR-ONE chassis. This resulted in the Nissan Deltawing which raced at Le Mans in 2012, but that car is entirely different to the machine seen in the United Sportscar Championship in 2015.
One of the biggest differences between the original Le Mans Nissan Deltawing and the post Nissan Deltawing Roadster (and later its Coupe sibling) was in the back. A fascinating recent article on Jalopnik makes the following statement about the original ‘Nissan’ engine in the Deltawing.
“The engine Nissan chose was a 1.6-liter, 300-horspower inline-4. At the time, Nissan claimed it was a heavily massaged version of the Nissan Juke’s engine, although several members of the DeltaWing team contend that it was an RML engine design originally meant for a Chevrolet touring car. ”
Niether of those positions are really factually accurate, the Juke origin of the engine was really just marketing noise, while the sentiment that it was based on the Chevrolet WTCC engine is also incorrect. The early test runs of the Deltawing were rumoured to have been conducted using the 1.6 litre GM WTCC engine developed by RML but the proper Deltawing engine was a fully bespoke unit developed entirely by RML in England. Indeed it featured some significant design detail which could never be legal in any other racing class. Indeed no Deltawing or derivative has raced with anything but a bespoke or largely bespoke power unit.
When Nissan parted company with the Deltawing racing project it left the Aston Martin Chassis without any motive power so Elan Technologies in Braselton, GA, USA developed its own 1.9 litre design for the car. Initially this engine was a bit of a mixed bag of existing OEM parts which had been modified and bespoke components but as the engine developed some top level racing engine technology was required. Indeed the transition between the 2012 and 2013 season brought significant change to the whole DeltaWing project and an all new car called the Deltawing DWC13.
While Ben Bowlby’s original concept remained the DWC13 was an entirely different machine, the open topped Aston Martin/Prodrive chassis had been replaced with an all new closed monocoque designed and built by Elan. In addition to that an entirely new operating team, crew, and tyre partner joined the programme.
But with Nissan no longer involved and the stop gap engine used in the open Deltawing not as competitive as hoped an all new engine had to be developed from scratch by DeltaWing Racing Cars team and Élan Motorsports. The new turbocharged engine had an in house block and crankcase machined from billet and was topped off by a Mazda MZR cylinder head featuring direct injection
Understanding the design and time constraints, when it came to the intake manifold, design engineer Christian “Skitter” Yaeger, turned to CRP USA to assist on the design and production. The result of their combined efforts: from nothing but a Mazda head to a new running engine in 81 days, to racing at Sebring in 105 days – including a 3D printed intake manifold.
Engineers at DeltaWing Racing Cars, working with CRP USA and Windform, created a fully functional component. The result was an intake manifold designed and developed by DeltaWing Racing Cars utilising additive manufacturing (3D Printing) technology with Windform SP for its construction, to operate under boost utilised in race conditions. The resulting component has been campaigned by the team since March 2013, gaining positive results and showing the tremendous potential for utilising advanced materials technologies in partnership with 3D Printing.
“We could not have made this motor happen if we couldn’t produce parts directly from CAD files,” said Christian “Skitter” Yaeger, design engineer for DeltaWing Racing Cars. “The biggest benefit is being able to print exactly what you need. We have eight odd-shaped ports in the head, and CRP USA was able to match them perfectly, with a knife edge in between.”
“With the coupe version, we went slightly less wild, and a little more conventional in our design,” continued Skitter. “Over the past two years, the 3D Printed manifolds have covered over 12,000 testing and racing miles, along with 6 hours per unit running on the dyno.”
Prior to the production of the intake manifold, Windform was used on the DeltaWing to produce several different components such as electronics enclosures, and transmission seal covers with integrated, pressurised oil feed passages (details of those parts can be found here)
As the engineering began the redesign of the intake manifold, a high performance material was required to handle the heat and tension placed on the part. CRP USA introduced Windform SP to the DeltaWing engineering team for consideration. Windform SP is a composite polyamide based carbon-filled material.
Windform SP has excellent mechanical properties and an added advantage of increased resistance to shocks, vibrations, deformations, and most importantly, Windform SP is resistant to absorption of liquids and moisture.
“The packaging constraints required by the location of the engine within the chassis requires some creative design,” said Stewart Davis, Director of Operations, CRP USA. “The runner lengths attach at the base of the plenum and form a complex structure that would be extremely difficult to build without using additive manufacturing. Windform SP’s toughness and heat deflection temperature allow the part to be built and then raced in the endurance series. The engine is run under boost, so it sees pressure variation in addition to the vibration, shock, and temperatures changes associated with racing.”
“The work done by Skitter and the DeltaWing/Élan Motorsports team is a great example of the application of Windform for a complex problem, and utilizing Additive Manufacturing to push the boundaries in racing,” concluded Davis.
The DeltaWing Intake Manifold is 3d printed on CRP USA’s additive manufacturing SLS technology. Produced in Windform SP the intake manifold is mounted directly to engine. DeltaWing Racing Cars have run 4 copies of the intake since July 2013. The manifolds have covered over 12,000 testing and racing miles, along with 6 hours per unit running on the dyno.
The development of the DWC13 is not limited to highly innovative manufacturing processes but also around the aerodynamic package of the car. In order to be competitive on some of the tighter tracks used in the United Sportscar Championship a reworked aerodynamic package has been developed for the DWC13.
Most notable on the high downforce kit the the front wing, the current version of which features twin endplates. While not the most attractive solution the team believes it to be effective and the cars on track pace suggests that it is.
Allied to the front wing is a low mounted rear wing sitting in the space between the rear wheel pods and the engine cover. (Note the position lights in this picture). The wing is part of a rear end up date which also includes a revised diffuser and a smaller gurney on the rear of the car.
The wings are not present at all tracks (above) at Daytona for example the car runs in its ‘pure’ form. Note the rear light patterns, something that carries over from the Nissan Deltawing, it can also be seen on some Nissan production cars in Europe. But the DWC13 has nothing to do with Nissan.
One break from the original Deltawing concept is the use of wing mirrors, the Le Mans spec car was never designed to run with them, but was forced to for a perceived safety issue, despite using a rear view camera. There is a notable resulting drag increase.
With the ACO & FIA introducing deeply controversial and questionable new rules into the LMP2 class in 2017, and IMSA opting to use those new rules cars as its tops class starting the same year it may seem unlikely that the DWC13 has much of a future but it seems that the project will continue. A GT specification Deltawing is due to race late in 2015 along with the debut of the production car version. While the DWC13 and the GT car could go on to be electrified, and there are hints that the car could return to Le Mans as a full EV.
