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Aerodynamics of the Gremlin

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WesternRed View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote WesternRed Quote  Post ReplyReply Direct Link To This Post Posted: May/20/2023 at 6:12am
Just for fun one of my work buddies had a crack at some Computational Fluid Dynamics (CFD) using the Autodesk Fusion 360 software, it's a pretty crude model at this stage, but still looks cool:





Red is high pressure, blue is low pressure.

If anybody has an accurate 3D cad drawing of a Gremlin, let me know.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Trader Quote  Post ReplyReply Direct Link To This Post Posted: May/20/2023 at 4:43pm
You would think the factory rear spoiler curved down like they did with the TransAm cars would reduce drag some by sending some high pressure air into the vacuum at the rear.
My cousin used to run stock cars and although they had many class rules, they all took advantages in hopes of not getting caught and getting an edge. He would rake back the windshield 3/4" to 1" and pull side panels/fenders in were it was hard to accurately measure. Radiuses of some curves were increased and others near the bottom sharpened. Never had the software as you show, but getting an extra lap out of the tank of fuel and winning races was all the proof of concept he went by.
You see new cars like my son's Honda with the full aluminum underbelly engine pan and almost smooth bottom under the car.
The 1-1/2" air dam added to the front bottom of the motorhome added a measurable 0.4 to 0.5 MPG.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote BBO UK Quote  Post ReplyReply Direct Link To This Post Posted: May/21/2023 at 6:19am
I also thought that a Breedlove type spoiler which splits the air flow and sends some down into the vacuum at the back of the car might help? Similar spoilers are fitted to modern hatch backs and a front air dam to stop air going under the car will help.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote WesternRed Quote  Post ReplyReply Direct Link To This Post Posted: Jun/03/2023 at 6:06pm
This popped up on my facebook feed this morning, Wally Booth's Gremlin running a front spolier:



It's the only picture I can find anywhere of a Gremlin running any sort of front aero device, so I'm thinking either it didn't work, or was not allowed under the rules. Do notice that they tended to run the cars very low at the front, which might reduce the amount of air going under the car or maybe they just ran a lot of rake on the cars to try to help with downforce at higher speeds.

I suspect the front spoiler would be against the rules, they were pretty strict on maintaining stock appearance by the looks of it.?


Edited by WesternRed - Jun/03/2023 at 6:18pm
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Post Options Post Options   Thanks (0) Thanks(0)   Quote PROSTOCKTOM Quote  Post ReplyReply Direct Link To This Post Posted: Jun/03/2023 at 6:38pm
I don't think NHRA would have ever allowed that spoiler. However a lot of Pro Stock guys match raced during the week or the off weekend when an NHRA event was not scheduled. My guess it was used during a match race where the rules weren't enforced or required. Jim Landis (Hurst390) has a Pro Stock Gremlin from the day. He might have more of an idea about the spoiler in the photo.

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Hurst390 Quote  Post ReplyReply Direct Link To This Post Posted: 6 hours 37 minutes ago at 12:26pm
I do not have or have never claimed to have an original Pro Stock Car. 
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