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Old 04-06-2012, 01:05 AM   #14 (permalink)
Tesla
Master EcoModder
 
Join Date: Feb 2012
Location: Australia
Posts: 355

The Truck - '02 Nissan GU Patrol ST
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Quote:
Originally Posted by Sven7 View Post
He's saying that when the wheel arch is closed like stock the air will form a sort of bubble and under-body airflow will treat it just like a "phantom" belly pan. Letting air out of this bubble somewhere else will just direct air into this high drag area, increasing your overall drag.

What comes out, has to go in. And "in", in this case, is a very turbulent area.

Honda's Insight and more notably Ferrari's 250 Testa Rossa have rounded the rear of the front arch to facilitate better flow in this turbulent area. My advice is to install flat wheel covers, block in the front and top of the wheel gap, and leave it alone. Using a rear wheel skirt will help you a bit but rounding out the edge of the arch is probably a waste of time afaik. You could attempt some front wheel skirts but I'd be more concerned about a boat tail at this point. Low hanging fruit.

I hope that helps.
Thanks mate,
Yeah it does help,
I did understand where Aerohead was coming from, my confused comment was more of a generalisation about how many different concepts are out there and how to choose whats best.
Thanks for your opinion on the wheels as well.
I have temp partial front wheel skirts on currently, as per a previous thread, am happy with the basic idea, but longer term I think the front wheel area could actually benefit from a vent which can be done, in my case the actual plastic guards stick out about 2" from the body and with a bit of redesign a vent could be put at the rear of that guard, which would allow the vent air to run along the channel formed between the lower body and top of sidesteps as it merges with the rest of the side air. As said I plan full rear skirts and am letting go of the venting idea, too many unresolved questions there.
I appreciate your comment on the low hanging fruit, but at the moment I am investigating a wide range of ideas to get a picture of the final product, then work towards putting it all together.
Funny you should mention the boat tail, I have been looking at how to do that as well, but starting another thread for that one.

Thanks to everyone for their comments, I really appreciate all the help and I feel like I am starting to get a much better handle on all this aero stuff, but still lots of study and work to do.
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