Bertone rear wing aerodynamics

[BCx19]

Ok, back to the topic, it would be interesting to put some measurements on the front of the car to see it lift at higher speeds. Would be curious to see what is going on when you get above 80. Is it lift from the front, or is it the turbulence in the rear which is causing it to go squirrely.

Can't be worse than this! No wonder the steering gets light. Pretty much removes 20% of the weight off the nose.

 

[Rupunzell]

Can't be worse than this! No wonder the steering gets light. Pretty much removes 20% of the weight off the nose.

View attachment 81627

Triumph Spitfire has swing axles in the rear which produces this "jacking" action by design. Swing axles were the focus of Ralph Nader's "unsafe at any speed" in the Corvair (one of the best moto designs from GM). GM was a far better target than VW or Triumph or Renault or Fiat or Porsche and many others from that era as GM was known in the USA moto market with "deep pockets", the imported brands back then lacked public awareness as a brand and did not have the deep pockets GM did..

The entire swing axle thing should have never been allowed into a mass production moto as it was a cost reduction_ed means of trying to put Independent Rear Suspension into motos for the lowest cost possible.. as IRS was a marketing desirable during that era..

While all that swing axle rear suspension was in full swing, Colin Chapman at Lotus had none of that designing a proper IRS in the Lotus Elan & Europa.. Same with the exxe, it also had an absolute excellent rear IRS design... yet the Porsche 550 Spyder had swing axles (re-designed no less than three times) and was perceived as an ultimate "race car".... Back in the days when it was believed sliding out the rear was the fast way around a corner on a road course...

As for the rear "wing" on the later exxe, purely decorative.

Bernice

 

[GregS]

I found this on xweb. There have been many different values posted over the years.

I need the coeficiant of drag and frontal area of an X 1/9

I bought a g-tech pro fanatic to do some measurements on my X. To convert measured Hp to engine Hp i need to have those numbers for fine tuning. Did anyone have these numbers? I did some xweb search, there are topics but no numbers It's this device: http://www.gtechpro.com/ss_fanatic.html

xwebforums.com

Interesting. But some of those Cd figures look pretty sus. Urraco for instance, I have seen figures of 0.377 to 0.4. Anything under 0.3 was pretty rare back in that era.

 

[oliverhen]

Does anybody know if the rear wing on a Bertone X1/9 was standard, optional, or dealer installed?

I assume it is strictly aesthetic and not really functional, or at least I couldn't find any reference to it being functional. Certainly not on period race cars, anyway. The drag Cd of 0.380 is the same between an 89 & 80. Anybody ever seen numbers for the front/rear aero lift? My Spitfire generated 270 and 70lbs respectively. I installed a front air dam to try to make the front better.

I think the wing looks a little 'boy racer' to my taste (Neither a boy nor a racer any longer ). So off it may come, in a reversible manner, if it was original equipment.

The rear wing on the Bertone X1/9 was typically a dealer-installed option rather than standard. While it may enhance aesthetics, its functionality in terms of aerodynamics is questionable. Removing it for a cleaner look seems reasonable, especially if it's reversible. Good luck with your modifications!