Aerodynamic Data for GT40s

Hi everyone. Sorry I've been quite busy and Lynn was nice enough to let me know there was an aero discussion going on.

Last winter I attached linear potentiometers to each corner of my suspension. Using a controlled power source and my LM-1 lambda gauge I gathered ride height data from zero to 160 mph and kept that speed for a half mile.

Yes that nasty Beast got to 160 inside a half mile with half throttle in first, half throttle through half of second then WOT the rest of the gears.

Maxton AFB is very bumpy. I did a lot of averaging to get the median data. With my series 1 splitter and side sill extensions I got about 300 lbs down force in the front and 150 lift still at the rear. I've redone the side sills and affixed a small tab (ala 2005 GT) and I'm headed for the wind tunnel.

If I have rid the car of lift I have the Series 3 stuff in mind to remove drag. It's been a lot of fun. You need to pick up the video of my 162 mph run and take a close look at the rear part of the nostril section. THAT needs to stop.

So I'm really close to being able to test the car's real top speed. But I seemed to have run out of the gobs of cash it took to get this far so I've come up with a side venture. (Obvious commercial plug here) Six Minute Instructor - Home Anyone making quality videos you think might fetch a price, I host them for free. Go live at end of March.

Cough, cough. Did I say that?

So all I'm waiting on now is a single radiator exhaust opening nose piece and I'm off for some wind tunnel testing.

The splitter works perfectly but there is still some lift at the rear. And that's the MkI ERA.

One major caveat here is each manufacturer's GT40 nose is different so no one splitter will work for all cars. I have molds for the ERA and for the tube frame CAV which is also..... brain fade. Anyway gotta run. Filming Tae Kwon Do forms tonight. Hiiii Yaaaaa!
 
Hi Mark. Good work.


Let me say that it is in my opinion that the best concepts I have seen (similar to the New GT, and by Mark) are to use a front splitter, sides skirts and a rear diffuser. They are what is needed to get the aero better on the car without greatly affecting the looks. That being said the configurations will have to be tested on road and/or in wind tunnel to get the final configuration that has the right aero balance.
 
bchildress said:
The Quest for Automotive Holy Grail
GT40 Aerodynamic Information

It would be hard to imagine what technical information would be more interesting and maybe more useful to all the current GT40 fans than real scientific aerodynamic test result of the GT40. Don’t you think it is strange that GT40 aerodynamic information is not available somewhere either from the original cast of GT40 drivers, owners, designers, crews, etc. or from at least from the personal collection and library of some passionate GT40 car buff. Wouldn't it be interesting to know all the details!

To help find this information we need help from every forum member and from your personal network of other car experts and historians. We are looking for a hardback trade publication called “Style Auto,” specifically English language volumes 20, 22, and 23.

A one-page flyer { Search for GT40 Aerodynamics ( GT40 Aerodynamics in Style Auto.JPG )} has been uploaded to the Gallery section to help track down Style Auto Volumes 20, 22, and 23 which may have the real controlled test data about GT40 aerodynamics. Please copy the file and forward the flyer to anyone who you think might help in this search. As the search continues we may find other references and add those to the list of search publications.

What do you think? Can we make this a worldwide group project?

Bob
I have the very old, and rare issues of Style Auto n° 20 and 23, what do you need from it?

If I can help......

Cheers
Italo
 

Neil

Supporter
I know that this is an old thread but is anyone still interested in GT40 aerodynamic data? I have some data from the MIRA wind tunnel tests during the period 1969 to 1974.


Regards, Neil Tucson, AZ
 

Brian Kissel

Lifetime Supporter
Neil, are you " Neil Albaugh " as in from Tuscon ? While the GT40 info, would be nice, I would be more interested in any info you might have on the LolaT70MKIIIB. I follow your posts on the Mantacars yahoo group. Always very informative posts.
THANKS for any info you put up.

Kindest Regards
Brian
 

Neil

Supporter
Yes, Brian, that is me. I will have a look in my data. I know I have data on a Ford F3L, GT40, Porsche 917K, and various Gulf Mirage models.


Regards, Neil Tucson, AZ
 

Neil

Supporter
Let me pass on an observation made by John Horsman regarding the Lola T70; John said that the Lolas were very light but they frequently broke parts of their chassis and suspension. While the GT40 was handicapped by its higher weight, the additional robustness of its construction gave them better reliability in endurance racing.


Regards, Neil Tucson, AZ
 
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