The mighty group C cars (and a bit of IMSA)

[Pedrolito]

Here the 905 evo 1 with its front wing at Circuit Paul Ricard in test session (summer 1991, probably in july). This chassis made its first race at the Nürburgring on 8/18.

[Pedrolito]

Jaguar XJR14, Peugeot 905 and Mercedes C291 (Schumi on board in fifth) at Nürburgring start (8/18/1991) :




Other pics of the race (905 and XJR14) :

[MadMatt]

Great pictures! It would be nice to see the underside of these cars!

Here is the Porsche 962:



Joest 962C:



Mazda 787B:



Few extra pictures of the Jaguar XJR14:







Finally, story about the Allard here and about the C291 here!

Also check this video of the Toyota TS010, music for the ears:

[wesley123]

Love the IMSA XJR-14. The huge flap really shows the difference between European and American circuits. It also showed very well that the XJR-14 wasn't built for this.

The AAR Eagle Mk. III dominated the IMSA GTP's in the early 90s. One of the first Prototypes to utilize a front diffuser.

[MadMatt]

Despite its look that Toyota was very well advanced and refined. Is there any picture of that front diffuser wesley?

[Pedrolito]

Few extra pictures of the Jaguar XJR14:

http://www.mulsannescorner.com/JaguarXJ ... 92-PA1.jpg

What a shame to repaint a legendary livery like the XJR14 one!

It would be nice to see the underside of these cars!

Ok! there is some pics of the 905 :

First drawing (press release):



Other sketch:


Model (work in progress):

Wind tunnel model:



The show car:



First tests at Paul Ricard:






To be continued...

[wesley123]

Mulsannescorner.com has a good article about the Mk III, including a page about it's front diffuser.

http://www.mulsannescorner.com/ToyotaEagleMkIII.html

[Pedrolito]

following...
905 at Silverstone '91:



905 at Le Mans '91:



905 at Nürburgring '91:


905 at Mexico '91:


905 at Paul Ricard in test session (11/1991):


905 (the most technical pics !):


Bonus 905 spider:

[MadMatt]

Is there a reason why the underside at the front of the 905 was just flat?

[Pedrolito]

Is there a reason why the underside at the front of the 905 was just flat?

I think there is headlight and other piece from the fairing in this area.
EDIT : I think especially the underside flat because of weight. The only function of this piece is to be part of flat bottom (we can see the rods for the rigidity on the sides)

P.s.: before my last, I posted a first message with some "technical" pics. It seems that it must be validated by an administrator.

[wesley123]

Prototypes of that age never "considered" a front diffuser or such a device. The thing that differs from the Mk III to any other Prototype of that era is that the Mk III was the first to properly vent the front diffuser.

Front downforce in that era mostly came from the creation of a pressure difference or rather crude front wings(ie XJR-14 or the 905).

[marcush.]

The Eagle was at the same time already exploiting the concept of a front difusser magnificently...

picture taken from mulsannes corner -Mike Fuller -

[mep]

Great pictures. I am just trying to get a bit familiar with that kind of class. Does anybody have some supporting data to these cars too? Especially aero figures, weight and power would be interesting.

[MadMatt]

Mep, check last page I posted aero values. Power depended on the engine a lot and from the era a lot. But I don't think it ever reached 800bhp. However the cars were really light! Weight varied a lot, not only depending on the engine, but also the year and class so it is difficult to summirize everything in 1 post but I will try to find sources that explain the weight regulations.

[Cold Fussion]

What were the pit stops rules in Group C like? If it were like modern LMP1, I would have thought removing the rear body work covering the tyre would add a significant time penalty compared to the drag reduction (or perhaps the drag reduction is bigger than i realise?).