Bertone rear wing aerodynamics

B

BCx19

Daily Driver
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.
 
I have no empirical evidence, but the consensus that I have seen has always been that it's more of a parachute than a useful aerodynamic device. Too low behind the cabin to be of any use.

As far as standard, optional, dealer installed, that would depend on year. It was definitely a factory thing on at least the last 2 years, 86 and 87. I have a factory brochure somewhere with pictures of cars with rear spoilers. I would venture to say it was "standard" on at least those 2 years, and possibly optional on other years.
 
Noting where Dallara put the wing is an indicator of how useful the factory wing is.

1707940263202.png
 
BCx19 said:
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.
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Where did you find that Cd of 0.380 figure? Do you have a link to the reference?
 
BCx19 said:
strictly aesthetic and not really functional
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Yup - and to my eyes, revolting. Degrades the lines and adds nothing but weight and probably some drag. Weight at the back too. No upside at all. It is symptomatic of Bertone laziness. No real engineering development - just tacky add ons.
 
GregS said:
Where did you find that Cd of 0.380 figure? Do you have a link to the reference?
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Unfortunately, no link. I was looking for aero info on my Spitfire and there was info on other cars. I just screen shot the tables I wanted.
 

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The rear wing was dealer installed. It was manufactured by an outside party called "Ventre" located in the states. BTW, "ventre" in French means belly. So you could guess how aerodynamic it was.
 

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DanielForest said:
The rear wing was dealer installed. It was manufactured by an outside party called "Ventre" located in the states. BTW, "ventre" in French means belly. So you could guess how aerodynamic it was.
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That execrable excrescence was on Australian delivered Bertone too. I would be surprised if it had been sourced in the US?
 
I thought the Gran Finale was a Special Edition that had the wing and a sticker put on it at the dealership.

Was the Gran Finale wing the same as the wings fitted in the US? They look similar but never thought to check
 
Not to go off the rails here, but I am really surprised the Fiat 124 is so bad with the Drag coefficient. It has such nice lines, but the drag of a brick. This is a very interesting thread. Just for comparison, the drag coefficient of the new Tesla Truck is .34 To be fair, A ford F150 or Dodge Ram truck come in at .54, so yeah....

The Fiero GT is .377 and the MR2 .35 for the early version and .31 for the Gen 2.

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.
 
GregS said:
Where did you find that Cd of 0.380 figure? Do you have a link to the reference?
Click to expand...
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
 
DanielForest said:
The rear wing was dealer installed. It was manufactured by an outside party called "Ventre" located in the states. BTW, "ventre" in French means belly. So you could guess how aerodynamic it was.
Click to expand...
I too used to think the spoilers were all dealer installed, many were obviously add-ons and not always bolted on it the same location. I have even seen a couple spoilers mounted in reverse.

Then I bought Henk's "La Storia" book and saw this picture of completed Xs sitting at the factory waiting for shipping. (Picture previously posted by Henk)
Henks La Storia factory pic of USA spoiler Xs.jpg


So there were some factory official spoilers for the US market.
 
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fastx19 said:
Not to go off the rails here, but I am really surprised the Fiat 124 is so bad with the Drag coefficient. It has such nice lines, but the drag of a brick. This is a very interesting thread. Just for comparison, the drag coefficient of the new Tesla Truck is .34 To be fair, A ford F150 or Dodge Ram truck come in at .54, so yeah....

The Fiero GT is .377 and the MR2 .35 for the early version and .31 for the Gen 2.

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.
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slight tangent. I remember back in the 80's or early 90's Car and Driver (or road and track I forget) did a test between a formula 1 car and a Nascar. everyone was blown away that the nascar had a higher top speed even being a brick. it came down to what the areo was being used for and the Formula 1 was designed to stick to the ground way more than the Nascar causing it to have to push past that force where the Nascar had little downforce. they did end up using tape after the test just to see how fast they could get the brick to go. anyway it also caused me to no longer thinking of the squared off cars as being super inefficient drag wise.

Odie
 
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