Ford Model A Bonneville roadster tunnel testing

[aerohead]

Found this HOT ROD article online.Pretty fun!
I ran some numbers from their data.If I discount the air density by 12% (a typical density altitude at Bonneville) I get around 22.05 sq-ft frontal area for the roadster after all the mods.If so,then they dropped the Cd from 0.521,to 0.467.Better than an Indycar/F1 car sans wings.
Thacker and Shine A-V8 Roadster - Hot Rod Magazine

[freebeard]

Can they call it free horsepower when they had to ship the car to England (and back)?

We began by dropping the front 111/42 inches from our baseline and that resulted in a staggering 10hp increase in drag and an increase in front lift of 42 pounds... Consequently, we put the front back to baseline and lowered the rear of the car 11/42 inch.

I'm available as an editor.

Do you think lowering the parachute attachment point would help the front-end lift. I know tractors pulling a plow do so. This one appeared to be attached directly to the differential.

[aerohead]

I think that the teams are concerned about parachute deployment enough that they will put them high up on the tail,even pointing them up into what is hopefully 'cleaner ' air so as to 'catch' some air into them.
The dirtier the car shape,the more important this becomes.

[freebeard]

I was thinking of the attachment point.

Proper System Mounting

Mounting the parachute system on the rear of the vehicle is a critical part of the installation. In order to ensure that the parachute ‘sees’ the air flowing over the rear of the vehicle properly, it should be mounted 45 degrees from horizontal, and up and behind the spoiler.

This is a very important note; if the ‘chute is mounted under the spoiler, it won’t see the proper amount of air for deployment and could fail to open when you need it most. In addition, the ideal anchor point is centered on the car (left to right) and should be at the center of the mass of the rear of the car. Stroud recommends somewhere through the crankshaft or camshaft centerline on a door car.

Five Things You Need To Know About Parachutes With Stroud Safety - Dragzine

It turns out they're pretty high maintenance.

[aerohead]

The lift issue I think they'd live with if it meant no parachute,favoring the higher location.