A friend of mine submitted this article to my attention, and I though it was worth sharing obviously, since it uncovers some of the most intriguing aspects of the new ARX-02a LMP1 car, from the mouth of Nick Wirth imself:The Way It Is/ Acura's ARX-02a LMP1 car
by Gordon Kirby
Unfortunately (and logically)
, there's no comprehensive explaination of the rear wing's philosophy. I read at another place that those wing's supports might have the same purpose than Red Bull's (and other F1's)
shark fins, by potentially straightening the flow over the upper plane and reducing the influence of yaw on the aerodynamic efficiency. Also, I don't remember where I read it (might be here)
, but someone told the upper part of the wing (due to build pressure)
is less sensitive to perturbations than the underside (which is meant to develop a depression)
. I can't argue over this so feel free to correct me if this is nonsense. Last point over this wings struts is that their shape is rumoured to be "gentle" with streams hitting it (not too much disruptions comparatively with angular designs)
. Another point open to correction eventualy...
Back to our article, here's what we can learn about the very surprising choice of symetric wheel mounting from rear to front (18 inches)
, and it's effect on wheight repartition:
"When it's working well, it works well."
In my blog at Motor Sport's website last week Wirth explained his concept of getting more rubber on the road and increasing the overall contact patch area by up to ten percent. The big front tires make the car look like a 4WD machine. They allow more weight to be brought forward so that the car enjoys close to a 50/50 weight balance. Loads on the Acura's front tires are much bigger than normal, requiring the complicated power-assisted steering system, but the drivers report the car is still physically difficult to drive.
"One of the first things that jumped out the first time I drove the car is that it has a lot of grip in the corners and under braking," de Ferran commented. "Our biggest challenge so far has been how to make the best use of the grip.
"Making the decision to have the same size tires all-round has unearthed a whole lot of engineering problems and challenges that didn't previously exist," de Ferran continued. "One of them is the steering system because the loads are huge. Together with all the HPD engineers, they have developed probably one of the most complex and sophisticated power systems and that's very much an item that is on a very steep development curve. When it's working well, it works well.
You have to love that last sentence.
After a quick disgression over the way the car was designed and developed (worth reading btw)
, Wirth is back,insisting about the hydraulic nightmare of their car:
The power-assisted hydraulic steering system and its fiendish mechanical geometry also created a challenge in packaging.
"We were very, very aware of the inherent reliability issues that would bring with it," Wirth commented. "There are certain reasons why in the future it might be advantageous to have hydraulics on the engine for other engine-related functions you're allowed to do in P1 that you're not allowed to do in P2. So it was a longterm goal that we needed to look at but certainly there were some packaging aspects to do with the monocoque which meant it was an optimum solution.
"All of us--HPD, Acura and ourselves--went into it knowing that we might end up halfway through Sebring regretting that we have hydraulics on the car. It was extremely complicated from the start and we've certainly found it's a very big challenge. The supply of hydraulics and keeping that supply all through the race under all circumstances is quite a challenge and continues to be a challenge. It's my fervent hope that we get on top of it before the race at Sebring. We certainly seem to be turning the corner on it, but it was a known and calculated risk to do that."
I must say I am surprised he makes such a story of it. For sure the particular need of their heavy front train engenders the power steering system to suffer more loads, and thus compromises it's reliability, but he seems to be impressed by the complexity of integrating the hydraulic system to the car. I thought having hydraulic management of the transmition, or power steering (and even suspentions in Peugeot's case if you believe the rumors)
was quite common in LMP...
Then I won't quote all the part on the transmition, developed in collaboration with Xtrac, but that piece of the beast seems to have it's secrets also, being very heavy and sturdy looking from the outside, actually used as a part of chassis stiffness, as the (less exiting at the moment I must say)
engine itself. Gil de Ferran certainly seems to enjoy shifting performance from that box...
Lots of other stuff you need to read there. But unfortunately, HPD's boss Erik Berkman states in the begining: "Our goal this year is to win the P1 and P2 championships and, of course, to win here at Sebring at the start of the season. We have no plans at this time, to race at Le Mans."
It is obvious to a lot of observers that this ARX-02a is an ALMS exclusive beast, developed to cope with relatively high downforce needs, and supposedly unsuitable to race at Le Mans...
With Gordon Kirby adding "The Acura brand is not sold in Europe, of course, so any decision about the ARX-02a racing at Le Mans appears to depend on Honda developing a plan to sell cars in Europe as well as how the evolution of the ACO's P1 rules for Le Mans take shape over the next few years." I must say I am tired of this strange way of thinking (such brand doesn't sell products there so they won't advertise there, etc)
, because I find it to be totally irrelevant! I can't see any difference in following LMS through motors TV, and following ALMS through Motors TV too.
I think for exemple Peugeot fans from Europe had as much visibility from the two ALMS rounds the 908s did than the five LMS ones (even more actually since ALMS didn't collide with F1 GPs...)
Now he wants to make us believe that a manufacturer won't compete at LM because they don't sell cars in Europe? Please, don't take us for fools, Le Mans 24 hours race is certainly the most watched endurance event in all continents! I wouldn't believe american endurance addicts turn their eyes off to LM because it's not actually located in the USA... Seriously...
I think Acura, Aston, Audi, Peugeot (& any other car maker involving itself)
should all compete in ALMS full season, with equal TV feed toward all continents, and do the 24 hours as well. LMS is crap since it's so badly managed, so IF it survives it's own poverty, it should become a privateers-only serie. 5 round won't ever make a championship anyway, so they should rename it LMS "cup" or "trophy"...
Sorry for the little rant.
BTW I'm going to assist the LMS test at Paul Ricard (8 & 9 March)
, I'll try to shoot the Aston as much as possible!