I'm curious if anyone remembers how far to stand off the targa top to help break the vortex generated at the rear window. Anybody from "back in the day" do this and remember?

-Aaron

You'll have to search unless someone has it bookmarked.
A university group did wind tunnel testing on a 914 to study drag. In the results they show the wind bubble at the rear window helping pull air from under the car through the engine compartment. It seems like that would help with cooling. Experts?

Found this with a quick google search. Interesting stuff!

http://www.cassidy-online.com/porsche914/a...aids/index.html

That's a pretty sweet link. Thanks

I love that link, but that doesn't seem to have captured this old school trick. I've sent him an email in the past. Maybe I will again...

I thought it was 1/2 to 3/4"...

I remember hearing it.. but this was a long time ago..

Hell it could be 3/4 to 1 1/2 for all I know.. Im curious why the racer guys are not responding.. They know.

I used aluminum tubes (3) that were 2 inches long. I did this around 2002 or so and the stability factor at tracks like Willow Springs and the first race I did at the new (to us vintage guys) CA Speedway was amazing. I would not try to use the stock latches in any way since the roof could possibly slide back and forth. Here's a pict.

As a side note, the famous #22 car driven by Wayne Baker used the low pressure issue to it's advantage and actually had some slots or intakes cut in the bottom of the longitudinals on both side with air outlets at the top rear so the air would get sucked up and out behind the rear window generating a mild amount of down force. Note the floor on that car was removed and tubes added and the bottom covered with aluminum sheet.

This is great! Thank you!

Mine is lifted too, but only an inch or so. Hard to tell exactly because it is a skin not a stock top. I could easily raise it a bit more if I knew for certain it would improve things.

The last time I was at the Festival of Speed at Ontario, I saw a 914 rallye car that had small vortex generators glued to the trailing edge of the top. Not sure if it worked but looked interesting. The yarn testing is easy and fun to do. Tape the yarn to your car and have someone drive next to you and video the car at speed. Then post it here. Might be fun to do with the Yellow Zonker to see how the air flows around the Sheridan body. Hopefully some one will buy the damn thing before I get a chance.
Cheers, Elliot

I've got $30 in my pocket...

;-)

Check this out. http://www.airtab.com/gallery/racing.html