View Single Post
Old 09-04-2009, 07:39 AM   #1 (permalink)
aero guerrilla
Piwoslaw's Avatar
Join Date: Oct 2008
Location: Warsaw, Poland
Posts: 3,538

Svietlana II - '13 Peugeot 308SW e-HDI 6sp
90 day: 58.1 mpg (US)
Thanks: 1,056
Thanked 630 Times in 396 Posts
"Intelligent" Kammback

On our trip to Romania, I had a friend drive at speeds of 130-140km/h on the highways (we switched since I knew she'd have more fun than I would at those speeds), so I was free to observe how the car's aeromods behave at those speeds. First, I noticed that the Kammback is stable, that is it doesn't wobble or flap in the wind. That's good. But at speeds above 120km/h I noticed that the center seemed to curve upward. I have two posssible explanations for this. The first is an updraft from below pushing up. I'll add that the Kammy is of the open back design. The second is separated airflow over the top sucking from above. The second hypothesis would imply that the angle is too steep. This may be the case, since when the Kammback was being constructed the car was empty, while during the trip it was packed, and the rear was around 10-15cm lower, changing the angle. Also, maybe at higher speeds a flatter angle would be better than at 70-90km/h? I guess that I would find most of the answers if I did some tuft testing.

All of this gave me the idea of an "intelligent" Kammback, which would adjust its angles depending on speed and whether the trunk is full. I guess this would be very complicated with not too much to be gained?

e·co·mod·ding: the art of turning vehicles into what they should be

What matters is where you're going, not how fast.

"... we humans tend to screw up everything that's good enough as it is...or everything that we're attracted to, we love to go and defile it." - Chris Cornell

Piwoslaw's Peugeot 307sw modding thread

  Reply With Quote