turbine powered Indy 500 cars, to airbrake or not to airbrake...

[djb]

Howdy all,

This enquiery comes about from looking at the very accomplished photos of the recent Goodwood event by Stefen-check them out if you haven't seen them btw (in "cool sites" now methinks). In a discussion about turbine powered cars at Indy, I seem to remember some footage of one of these types of cars using some sort of air brake going into one of the corners. Am I imagining this and/or mixing a memory up of a Mercedes at Lemans (wasn't it a Merc that used one?)?

anyway, I figured to get a straight answer I'd pop it in here and see what you lot remember.

cheers

[Vitesse]

Not sure on the turbines, but Mercedes certainly used air brakes on their sports cars in the 1950s.

[paulzinho]

Airbrakes? What are they?!

[Vitesse]

On the Mercs, a section of the rear bodywork was raised when braking from high speed into slow corners (eg at the end of the Mulsanne Straight). This created what we would recognise today as downforce, as well as using aerodynamic methods to slow the car: strangely, Mercedes seemingly didn't recognise that this would have roadholding advantages in performance cars, despite the May brothers fitting a horizontal wing to their Porsche sports car at about the same time.

[djb]

Paul, you may have noticed from a window seat near a wing in a landing jet how that upon touchdown, flap-type looking things raise up on top of the wing to help bring down the aircraft's speed. Fighter jets have had them along the rear of the fuselage on either side that open out sideways to create drag. The Mercs flap was behind the driver rising up from the boot so to speak, I think with the open end towards the front.

So....after that lecture, anyone remember if a turbine Indy car ever used it? I tried looking up a google search on these types of cars to see if any photos showed anything, but no luck.

[Armco Bender]

I'd say they never used an airbrake on the turbo cars,this is the thread we did a while back on the Lotus 56;http://tentenths.com/forum/showthrea...threadid=38594 ,theres no sign of any airbrake in any of those pictures.You have to remember from what I've read about the turbo cars is they had to compensate for the lag in the turbo winding up if they took their foot off the throttle and accelerated again.This caused them to have to brake and accelerate at the same time when cornering,having to juggle an airbrake would probably have been beyond the drivers.Especially as say the Lotus 49 used a foot control on its big wings,so a turbo driver would need three feet to brake into a corner if a foot control device was used.

[spearce]

The Lotus 56B (the F1 version) did not use an air brake (would not have been allowed by rules anyway), I don't think the Indy version did either. I believe the 56B needed up to 70 gals fuel to do a GP, so it would have taken some stopping, especially with no engine braking !

[paulzinho]

Thanks for that explanation guys! Should have thought of that really!

[Adam43]

Originally posted by Vitesse
On the Mercs, a section of the rear bodywork was raised when braking from high speed into slow corners (eg at the end of the Mulsanne Straight). This created what we would recognise today as downforce, as well as using aerodynamic methods to slow the car:

Downforce would help under braking, of course, because it gives the tyres more grip to sustain higher braking forces (i.e. you can hit the pedal harder without locking up).

However I thought the Mercedes system was simply a means of producing drag to slow the cars. In the same way that people use parachutes to slow down.

Here is a picture of the Mercedes http://www.ritzsite.net/300SL/1955_M...00_SLR_f3q.jpg
It is found on this page http://www.ritzsite.net/300SL/03_300SL.htm

Sorry it's not about the turbine cars AFAIK, they didn't have air brakes, but that is better explained above by others.

[djb]

thanks Adam for the shots, that is how I remember it from a movie clip of the Merc turning into a corner presumabley at the end of the Mulsanne with the air brake closing down into place.

As usual, I am not doing a very good research job, but I really thoght that I'd seen a clip of some sort of Indy car repeatedly going into a corner there with an opening and closing air brake--but then I shall just reitter my disclaimer of being an old git with 'oles in me brain....

[dscwall]

as an aside Mercedes initially tried an airbrake in 1952 in practise for Le Mans on the 300SL,but the supporting struts where not strong enough for the forces involved.
The airbrake was also used in Sweden on the 300SLR.
the 300SLR also had an unusual anti lock braking system. When a brake locked the driver would press a button on the dashboard and a squirt of oil would be sprayed at the offending drum brake surface, freeing the brakes!

[Adam43]

Originally posted by djb
As usual, I am not doing a very good research job, but I really thoght that I'd seen a clip of some sort of Indy car repeatedly going into a corner there with an opening and closing air brake--but then I shall just reitter my disclaimer of being an old git with 'oles in me brain....

I know nothing about this, but a quick internet search revealed this picture.

It is from this site/page http://www.racerchicks.com/auto/future_cars7.html

This is an entertaining article written in 1971 about what racing would be like in the 1990s and also into the 21st century. It contains some interesting thoughts:

I do believe that a great deal of excitement and public interest will be added to auto racing in the next 20 years by a broad diversification in the kind of engines that we will be running. I also believe very strongly that some such equation formula as my "BTU Concept" will allow competitors to build almost any kind, size, shape, weight and type of car they wish, hewing only to a fuel limit for an equation factor. Far from becoming an economy run, as some fuzzy thinkers have charged, racing will still be just as fast as the human element will permit, and you better believe it will be a lot more interesting than watching 33 near-identical machines circle the track for 500 miles.

[djb]

and behing door number 3.............a brand new microwave oven with matching corningware dishes!!!! The predominantly housewife populated audience goes mad with envy as Mr.Adam Ashmore walks down the aisle to receive his prize.

(sorry 'bout that)

So, in other words, I've got one less hole in me 'ead than I thought, but I'm pants for doing internet searches........

thanks really Adam for the confirmation. I suspect that as in F! etc, a "non-movable aero device" rule put these sort of things to rest.

dscwall-oil! I've heard of the recent racing trucks using water cooled brakes, but oil! how did they stop the remaining stuff from interfering with proper brake action afterwards, sounds daft to me.