John McNeil – Turning The Nasamax Corner
In an ideal world we would have caught up with Team Nasamax Technical Consultant John McNeil before the team’s DM139 design made its first track appearance at Paul Ricard in early April. But the heavily revised car was only just ready in time for that test, and anyway Ricard and the Le Mans Test Day were so early into the car’s life, it was expecting a lot for the Nasamax to be finding real form that soon into its development. But by early May at Monza, the Nasamax Judd was already beginning to shine: here was the point to catch up with John McNeil, after Monza but before the next major test – Le Mans.

Nasamax is in a unique position, of course – the only entrant of an LMP1 car running to the 2004 LMP1 rules. They were also the only team to have entered an 01Q Reynard for the 2003 24 Hours in LMP 900, a chassis that conveniently matches several of the basic requirements of a 2004 spec. prototype.

John McNeil began by explaining what the FIA had set out to achieve with the new rules – so here we have McNeil’s Guide to the 2004 FIA Prototype Regulations.

“The main requirement was to reduce the pitch sensitivity and to increase the aerodynamic stability during unusual on track events such as high speed spins. The LMP900s weren’t necessarily pitch sensitive, but the ones that were sensitive were typically those with long overhangs front and back. You’ll have noticed that our chassis has short overhangs anyway.

“With the LMP 900s, you had to be very careful when setting the rake of the cars. Typically you’d see ground clearance of 30mm at the front and 75-80 at the rear, but if the rear was reduced – to reduce drag, say by fitting soft rear springs or reducing ride height – as we’ve seen, you could get into trouble.

“Large front and rear overhangs made the cars more pitch sensitive as a large proportion of the down force available was being produced outside the wheelbase of the car; good gains in down force and efficiency were possible however and designers were tending to maximise both the front and rear overhangs… The limits on front and rear overhang mean shorter cars.

“The FIA also had a desire to see cars with a symmetrical appearance from the front view. The asymmetry had got to the point where the cars looked a little odd, in their view.

“This gave them a chance to look at driver protection, and the regs. included the requirement for a primary roll structure and secondary roll structures, for the driver and nominal passenger. Each area is strictly regulated, so that for example we can’t put the airbox entry within the secondary roll structure on the passenger side.

“You can’t have ‘pods’ as part of the bodywork now, such as those on the EX257: the bodywork has to be within certain, strictly regulated, dimensions.

“Then there’s the underflow. Across a width of one metre (above), the ‘floor’ at the front is raised by 50mm above the reference plane. Either side of this one metre width, the floor level in front of the front wheels is as it was.

“Behind the front wheel centre line, instead of the flat floor of old, we now have the floor sloping upwards at an angle of seven degrees, so that the sills end up around three and a half inches higher than they would have been (right). The curve of the sills is a specified radius, the aim (of this curve and the slope of the floor) being to reduce the cars’ tendency to lift when going sideways.

“Then there are the mandatory tunnels: these have to follow the specified shape exactly, but their length can be altered according to the length of the rear overhang. “Behind the rear wheels are the mandatory ‘boxes’, which are designed to help prevent cars lifting if they end up going backwards. The rear wings are smaller, and apart from the plank, that’s about it.”

The plank: it’s this that has produced the greatest single change to the cars, claims McNeil.

“It’s a 20mm thick piece of Jabroc, with a mass of around 24 kg, and the fixings are all mandated. It is attached centrally to what used to be the flat floor: the lower surface of the plank therefore protrudes below the reference plane, so in effect it’s pushed all the masses of the car upwards by 20mm. That’s the complete 900 kg of the car, plus the driver, plus the fuel (and the plank itself) – all lifted up by 20mm, to the detriment of the C of G. This has been the most awkward part of the 2004 regulations.”

So in practice, how have you found that the car works on the track?

“We’ve got ourselves an aerodynamically tuneable car, with plenty of forward balance if required. Levels of down force are perfectly acceptable, and the drag increase is as predicted. We can run negative or positive rake, or absolutely level: however we run the car, it doesn’t show any tendency to lift (and get into the porpoising / pitching mode) because with the higher ground clearance you can’t shut the flows down. Aerodynamic porpoising occurs when the front gets pulled down and then the airflow is shut off, making the front lift as down force is suddenly taken away. We don’t get any of that with this car.

“The reduction in down force is of the order of 25%, but the limiting factor is at the rear. We can generate more front down force than we need, but not enough at the back to balance it, we have also lost some ‘cantilever’ moment due to the restricted rear overhang, therefore we have to ‘tune’ the front down force to balance the car. Drag is up by about 10 – 15% depending on the configuration chosen.

“So what we’ve got is a situation where the search for mechanical solutions is more significant than for a LMP 900. We can and will improve the aerodynamics but this takes time and development and we must remember that the LMP1 regulations were designed to reduce down force and increase drag.

“What we do have is unbelievable traction, which has caused us one or two problems with the differential. With a short wheelbase, the weight transfer is greater than for a longer car, and combine that with the larger restrictors we can use, and the fact that we’re one of only two teams using the five litre Judd GV5 engine, and we’re generating very high loads in the diff.

“But we’re understanding the car more every time we run it, and we’re turning in some very good lap times already. At Monza we were 3.6 seconds away from the fastest car, and we believe that two seconds of that is easily ‘doable’.

“Fitting a plank to the other cars next year would give the other teams an idea of what we’re going through….”

Overall then, John McNeil is pleasantly contented with the down force he has available, and more than happy with the joint development that has taken place with Engine Developments on its GV5, to cater for the bio-ethanol. He happily points to the speed trap figures from Monza, where the ‘mighty’ Nasamax was comfortably the fastest thing in a straight line.

“We had problems early in the afternoon at the Le Mans Test Day, so we weren’t able to work on our straight line speed there, but I think you can expect something from us at Le Mans next month,” is all McNeil will reveal (with a smile) on this subject – except that he did indicate how fast the car could go if it was set up like a late 80s WR, for straight line speed only. That’s of little use for a 24-hour race, so we won’t even mention the figure.

But as the car was set up at Monza, the drivers had a very entertaining machine on their hands. Michael Cotton was in raptures after watching Werner Lupberger through the Ascari Chicane, during the heavy rain of Friday afternoon, and the South African was just as pleased to have such a “chuckable” car.

“Yes, we’re slower on the brakes and through the corners than the 900s, but probably more entertaining,” suggested McNeil. “The car’s on the edge of its grip but it’s nicely balanced: it’s dancing, and great to watch.

“I believe on a clear lap we would have set a 1:40 at Monza in qualifying, and I’m looking to a 3:39 at Le Mans. We were very conservative on set-up at Monza, as we were at the Le Mans Test Day. We’ll be more aggressive next month. We lost seven laps at Monza with the puncture and trip into the gravel, and another seven through pace.

“But we showed at Monza that we can run the same length stints as the Audis. The extra weight of the fuel at the start of a stint (the Nasamax carries 135 litres of bio-ethanol) is an added handicap but it does burn off, so at least we have a period where effectively there is no penalty.”

McNeil, wise fellow that he is, kept the ACO fully informed of his plans to turn the 01Q into the DM139, and the ACO seem appreciative of the fact that it has a 2004 spec. car in the top class. Adding the extra fuel at each stop won’t be a handicap, because (up to) 135 litres will flow into the Nasamax’s tank in the same amount of time as 90 litres of petrol into an LMP900.

An additional fuel tank obviously had to be incorporated into the DM139, and the only available spot was alongside the driver: a concession was therefore made to allow the team to fill the space that is otherwise set aside for that nominal passenger. The list of changes to the 01Q has been substantial, but having started as recently as last November (the 2004 ACO regulations didn’t become public until the first week of December), the task was completed in time for the Ricard test in April.

John McNeil isn’t slow to admit that his McNeil Engineering has the capacity to produce ‘replicas’, “but Nasamax don’t want to just sell a car: they would prefer joint projects due to the unique nature of the concept. Nasamax will probably run a development of the DM139 through 2005, while penning an all-new car for 2006, together with Kieron Salter from KWM. ‘Kieron has been invaluable during the gestation period of the DM139 and we look forward to further cooperation. But look at the advantages we have already, thanks to running this car so soon.”

Perhaps a New Nasamax in 2006 then?

John is a great admirer of the Judd GV family of engines, but in particular ‘his’ GV5. “The five litre was always going to be the first choice, and we wanted a normally aspirated engine for its simplicity. We knew that the larger engine would suit our fuel, and we wanted the larger, lower-revving engine because of the advantages in endurance races.”

The V10 currently in the car is the Monza race engine, and it will stay in the car through UK testing this week and then through Qualifying at Le Mans. A fresh one will go in for the race, and that will run on Saturday morning for the first time.

Meanwhile, development of the car is on-going. “Ricardo’s engineers were suitably impressed by the loadings we were putting through their gearbox and differential, and we were fitting revised components as late as the night before the Monza race. We have more developments to come before Le Mans and the response and service from Ricardo has been what one would expect from such a company. The gearbox is a transverse version of the R8 gearbox, and with no facility for a manual shift, we turned to Ian Foley’s pneumatic paddle shift system, which has been as reliable as we expected: a first class product.”

So a summary of what you’ve got John, as we approach the most important race of the year?

“We can now prove that renewable fuel is fast, we’ve got a chassis that leads the way, and we’re not giving anything away any more. We’re generating more publicity this year than ever before - and bio-ethanol smells much better than gasoline too!”
MC