Go Back   EcoModder Forum > EcoModding > Aerodynamics
Register Now
 Register Now

Reply  Post New Thread
Submit Tools LinkBack Thread Tools
Old 05-09-2015, 01:55 PM   #11 (permalink)
Ultimate Fail
Cd's Avatar
Join Date: Feb 2008
Location: Austin,Texas
Posts: 3,340
Thanks: 2,690
Thanked 937 Times in 556 Posts
Originally Posted by gumby79 View Post
another reason for the pinch front . Snow. .. if the tires of the truck pack snow on the inside = bad
I was going to mention curbs as well. If the truck runs over one, the skirts tuck under, versus tearing off.

  Reply With Quote
The Following User Says Thank You to Cd For This Useful Post:
aerohead (05-09-2015)
Alt Today
Popular topics

Other popular topics in this forum...

Old 05-09-2015, 02:55 PM   #12 (permalink)
Master EcoModder
aerohead's Avatar
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 13,041
Thanks: 20,895
Thanked 6,373 Times in 3,958 Posts
out of the wheelwell

Originally Posted by MPGomatic View Post
Great stuff, Aerohead! What about influencing the air that comes off the tires out of the wheelwell/away from under the car with a gentle sweep by integrating a small flap at the back of the wheelwell that blends into the skirt? Instead of a 90 angle, it might be 100?
On the T-100 I did a crude representation of the Scaglietti (Ferrari) edge radius off the back of the front wheelhouses which has seen service on many cars,including the 1st-gen Insight.

I believe that they're especially beneficial in crosswinds although I'm not sure about zero-yaw conditions.
If you can get the air to round the nose onto the flanks of a car,it tends to just flow back and jump the wheelhouse opening.
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/

Last edited by aerohead; 05-09-2015 at 02:56 PM.. Reason: add second image
  Reply With Quote
The Following User Says Thank You to aerohead For This Useful Post:
BamZipPow (05-10-2015)
Old 05-09-2015, 03:13 PM   #13 (permalink)
Master EcoModder
aerohead's Avatar
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 13,041
Thanks: 20,895
Thanked 6,373 Times in 3,958 Posts

Originally Posted by whatmaycome14 View Post
Aerohead, I appreciate what you've said, but it stirred a question in my mind. I couldn't help but notice that on the bottom of the McLaren mp4-12c has some very short "skirts" behind the front wheels. Is this at all related to the fact that the car doesn't have any side skirts hanging that low?

The McLaren is low,and subject to ground strikes,and to keep customers happy no doubt have had to be careful that in day to day driving,the car doesn't lose all utility.
The skirts they have help channel air for the rear cooling functions and they are Whitcomb-waisted to moderate pressures along the pathway.I suspect that they spent $100,000 developing them.
These supercars pay particular attention to high speed stability,low drag taking a back seat on priorities.
Sports cars lead low drag design until the Maxda GLC entered the market.Ever since,the average,entry level passenger car has had lower drag than these ubercoupes.
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
  Reply With Quote
Old 05-09-2015, 07:09 PM   #14 (permalink)
Master EcoModder
freebeard's Avatar
Join Date: Aug 2012
Location: northwest of normal
Posts: 20,412
Thanks: 5,723
Thanked 6,655 Times in 5,373 Posts
Are those behind the front wheel or ahead of the rear wheel?

That's the shape I was suggesting for the back edge of the front wheelwell. But in this case it looks like it feeds the rear diffuser.
  Reply With Quote
Old 05-09-2015, 11:23 PM   #15 (permalink)
Master EcoModder
gumby79's Avatar
Join Date: Dec 2014
Location: Butte, Montana
Posts: 725

little jona - '91 Dodge D 250 first gen cummins LE
Team Streamliner
90 day: 23.4 mpg (US)

Little Jona airo modded - '91 Dodge RAM 3/4 TON D 250 24 AUTO
Team Cummins
90 day: 18.5 mpg (US)

The Salted Hound Jenny. - '87 Dodge Ram 50/D-50 5sp 4X4
90 day: 20.24 mpg (US)

Jona Allison aero - '91 Dodge Ram D-250 Le
90 day: 20.76 mpg (US)
Thanks: 208
Thanked 425 Times in 276 Posts
Are those behind the front wheel or ahead of the rear wheel?
they start in front of the wheelwell and travel past the wheel well then turns out. stableize air under the belly pan From thewheel wash and brake heat and re direct it out . spread causes a low pressure (high negative force =down force) center of Mass
I also see a trip edge around the the rear fairing
1st gen cummins 91.5 dodge d250 ,HX35W/12/6 QSV
ehxsost manafulld wrap, Aero Tonto
best tank: distance 649gps mi 24.04 mpg 27.011usg
Best mpg : 31.32mpg 100mi 3.193 USG 5/2/20

'83 GMC S-15 Jimmy 2door 2wd O/D auto 3.73R&P
'79 Chevy K20 4X4 350ci 400hp msd custom th400 /np205. 7.5-new 14mpg modded befor modding was a thing
87' Hyundai Excel
83 ranger w/87 2.9 L FI2wd auto 18mpg on the floor
04 Mitsubishi Gallant 2.4L auto 26mpg
06 Subaru Forrester XT(WRX PACKAGE) MT AWD Turbocharged 18 plying dirty best of 26mpg@70mph
95Chevy Blazer 4x4 auto 14-18mpg
04 Chevy Blazer 4x4 auto 16-22mpg

  Reply With Quote
Old 05-10-2015, 01:07 AM   #16 (permalink)
EcoModding Apprentice
Join Date: Apr 2015
Location: USA
Posts: 148

VanDelay - '89 Ford Econoline E-150 XL
90 day: 15.93 mpg (US)

Old White Civic - '98 Honda Civic LX, AT
90 day: 33.18 mpg (US)
Thanks: 5
Thanked 50 Times in 43 Posts
I too was gonna mention the early Insight fenders. Lots of that style on race cars, both professional and the more serious amateurs like on clubroadster.net

That being said, I think Aerohead is right but for a reason nobody's mentioned. The wheels of an OTR tractor go UNDER the trailer when turning sharply. Skirts can be longer but angled in or shorter but stay straight. The landing gear is "break-even" point for trailer skirts whereas on a car or straight truck you can keep the skirts flush to the outside of the tires, which is a benefit whereas the narrower trailer skirts are a compromise.

Seeing the popularity of having dozens of license plates on an OTR truck back in the 70s might likewise lead posters here to believe if the truckers have lots of plates, we should too because they wouldn't do it if it weren't good...but that was another compromise truckers had to make and to copy it would've been foolish.

Next someone will say "yeah I like those angled trailer skirts so I'm doing that for more mpg and also dupicating the 15 liter engine cuz trucks wouldn't have those if they weren't good for mileage"

I do think the 8 tires at the rear of the truck and the necessarily large open area around them is a big source of dirty air and the fairings being stuck inside that is probably an attempt at getting all that air going in the right direction again but unless your vehicle has 8 such tires at the front, I don't think angling your side skirts is going to benefit you.

Last edited by mwilliamshs; 05-10-2015 at 01:46 AM..
  Reply With Quote
The Following User Says Thank You to mwilliamshs For This Useful Post:
aerohead (05-11-2015)
Reply  Post New Thread

Thread Tools

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com