Estimation of the Cd-reduction

[red91sit]

Originally Posted by Kilpuri

...Does anyone have any hands on ideas what to do the rear of the car. I assume that rear has very big influence to the total drag created. Our car is crashed from behind, so it is already quite "interesting"...

After looking at your car, it seems like there won't be too much you can do to reduce rear end drag without major work. A spoiler might actually improve aerodynamics. Other than that, there is really no attached flow to work with here, so your going to be left with a large wake above and behind the trunk as far as i can figure.

I would run the exhaust back out the rear of the car, where it can help reduce the wake (albeit, by a very small amount) as well as stick a nice smooth underbody/diffuser there.

[Kilpuri]

Originally Posted by red91sit

I would run the exhaust back out the rear of the car, where it can help reduce the wake (albeit, by a very small amount) as well as stick a nice smooth underbody/diffuser there.

We wanted to have the exhaust from side due to other reasons, but I will proceed with the diffuser. According to Katz: Race Car Aerodynamics diffuser should be in 4 degree angle when lowes drag is preferred.

[Kilpuri]

Next saturday back to business with Honda.We are planning to install diffusor, belly pan (under motor) and aerokit to rear tyres.