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

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 03-18-2009, 02:30 PM   #1 (permalink)
Master EcoModder
 
Join Date: Mar 2009
Location: Northeast Ohio
Posts: 269

The Wife's Hot Rod - '09 Pontiac G8 GT
Last 3: 23.22 mpg (US)

Big Outback - '13 Subaru Outback 2.5i

Little Outback - '02 Subaru Impreza Outback Sport
Thanks: 0
Thanked 16 Times in 16 Posts
Jeep Wrangler aerodynamics - yea I know

Yea I know.

I have a Jeep Wrangler that does get driven off road somewhat. Most of the driving is on road. To aid with slow speed cooling I was thinking about adding a set of hood louvers to allow hot air to exit the engine bay. I have a the option of putting louvers on the side of the hood also.

I know there is an eddy that sits in front of the windshield.

I was wondering how will "injecting" air into this eddy affect dthe flow around the windshield/roof area. Do you think it will increase or decrease drag?

Thanks
Don

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 03-18-2009, 07:58 PM   #2 (permalink)
Master EcoModder
 
gascort's Avatar
 
Join Date: Jun 2008
Location: Saint Louis, MO
Posts: 548

Gascort RIP - '93 Ford Escort Wagon
90 day: 43.01 mpg (US)

WifesCruze - '11 Chevrolet Cruze LT
90 day: 31.1 mpg (US)
Thanks: 14
Thanked 24 Times in 16 Posts
You probably have such high pressure there that air would go down into the hood vents - like the interior air vents - you can get a breeze from them without the fan on at highway speeds.
__________________
Gasoline, Wind, Solar, Gravity Hybrid-to-be! http://www.scientificmethodfueleconomy.blogspot.com/
  Reply With Quote
Old 03-19-2009, 01:03 PM   #3 (permalink)
Master EcoModder
 
wagonman76's Avatar
 
Join Date: Jun 2008
Location: Northwest Lower Michigan
Posts: 1,006

Red Car - '89 Chevrolet Celebrity CL 4 door
Team Chevy
90 day: 36.47 mpg (US)

Winter Wagon - '89 Pontiac 6000 LE Wagon
90 day: 28.26 mpg (US)
Thanks: 8
Thanked 17 Times in 16 Posts
A Wrangler would be a great vehicle for aero improvements, I think. Having a detachable top would give you the liberty to make a perfect kammbacked top that you could use whenever.
__________________

Winter daily driver, parked most days right now


Summer daily driver
  Reply With Quote
Old 03-20-2009, 03:03 PM   #4 (permalink)
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 11,202
Thanks: 17,954
Thanked 5,964 Times in 3,622 Posts
hot wrangler

If you've actually got an over-heating problem,I'd do some back-tracking first.You need the fan shroud if you don't have that,and a good thermo-actuating coupler for the fan if it's given up the ghost,along with a properly operating thermostat and bug-free radiator.-------------------------------------------------------------- If after all the bits and pieces are restored,and she's still overheating,she may have oil lining the cooling galleries of the block and head.If the coolant was ever left in the engine too long,the ethylene glycol could have bio-degraded back into the petroleum from which it is derived.Heat can't penetrate an oil film and it acts the same as 10-inches of solid cast iron that the water see's before it can transfer.You might need to do a chemical flush/rinse/fill.
  Reply With Quote
Old 09-03-2010, 11:24 AM   #5 (permalink)
44 Dan
 
44Dan's Avatar
 
Join Date: Jan 2010
Location: Dewey Az
Posts: 6
Thanks: 0
Thanked 0 Times in 0 Posts
I went to Home Depo and bought a couple of chrome vent covers, matched them up side by side on the hood and cut some holes. The covers look sharp and it gives the air coming off of the fan some place else to go besides down. I didn't have overheating problems but doing slow steep crawls in extreme temps while running the A/C (I'm old ya know) made the engine run better, I'm guessing because it was running cooler. You can put your hand over the vents and feel the blast of superheated air, but you can't hold your hand there long This worked great for me and several other friends that did their Jeeps after I did mine.

Good Luck
__________________
2007 Prius 40mpg's
2010 Harley Davidson 38mpg's
  Reply With Quote
Old 09-04-2010, 05:36 PM   #6 (permalink)
Master EcoModder
 
Join Date: Jan 2009
Location: Maui, Hawaii
Posts: 813
Thanks: 5
Thanked 34 Times in 26 Posts
You don't want to push air in from the high pressure spot in front of the windshield because it will probably just fight the radiator fan.

I saw a writeup on proper Wrangler hood vent placement with tuft testing but I can't find it now. The guy concluded that the best spots were along the left and right edges of the hood.
  Reply With Quote
Old 09-04-2010, 05:39 PM   #7 (permalink)
Master EcoModder
 
Join Date: Jan 2009
Location: Maui, Hawaii
Posts: 813
Thanks: 5
Thanked 34 Times in 26 Posts
BTW, check out what I did with my XJ... I put a 10" fan in front of the radiator to help out the OEM electric fan behind it. It does help somewhat.

  Reply With Quote
Old 09-04-2010, 06:15 PM   #8 (permalink)
Master EcoModder
 
comptiger5000's Avatar
 
Join Date: Feb 2010
Location: CT, USA
Posts: 544

RaceJeep - '98 Jeep Grand Cherokee (ZJ) 5.9 Limited
90 day: 13.62 mpg (US)
Thanks: 1
Thanked 26 Times in 23 Posts
For offroad slow-speed use, it doesn't really matter where the vents are. However, for highway use, a bit farther forward is better, as you don't get the high pressure pushing into them. Take a look at the hood vent placement on the Grand Cherokee 5.9 for ideas.
__________________
Call me crazy, but I actually try for mpg with this Jeep:



Typical driving: Back in Rochester for school, driving is 60 - 70% city
  Reply With Quote
Old 09-04-2010, 11:21 PM   #9 (permalink)
44 Dan
 
44Dan's Avatar
 
Join Date: Jan 2010
Location: Dewey Az
Posts: 6
Thanks: 0
Thanked 0 Times in 0 Posts
You don't want to push air in from the high pressure spot in front of the windshield because it will probably just fight the radiator fan

The air can only flow one direction and that is out. It actually takes pressure off of the fan if any giving the air continual flow, even when stopped. I mounted my $2.29 chrome vents where I had the most open area and they worked very well as did the others. Our rolling bricks can use all the help they can get to run cooler and more effecient

Nice 10" Fan
__________________
2007 Prius 40mpg's
2010 Harley Davidson 38mpg's
  Reply With Quote
Old 09-05-2010, 04:14 AM   #10 (permalink)
Master EcoModder
 
Join Date: Jan 2009
Location: Maui, Hawaii
Posts: 813
Thanks: 5
Thanked 34 Times in 26 Posts
Quote:
Originally Posted by 44Dan View Post
You don't want to push air in from the high pressure spot in front of the windshield because it will probably just fight the radiator fan

The air can only flow one direction and that is out. It actually takes pressure off of the fan if any giving the air continual flow, even when stopped. I mounted my $2.29 chrome vents where I had the most open area and they worked very well as did the others. Our rolling bricks can use all the help they can get to run cooler and more effecient

Nice 10" Fan
If you put a vent right in front of the windshield, on the highway air will go inward, increasing pressure and forcing more air to have to exit out the bottom

  Reply With Quote
Reply  Post New Thread


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Tire size and FE with a Jeep zjrog Off-Topic Tech 22 01-24-2011 10:32 PM
Hexagonal Dimples as a way to improve aerodynamics Palionu Aerodynamics 29 10-27-2009 12:39 AM
Honda element, vw beetle, jeep wrangler... hans2vt Introductions 9 05-08-2009 04:05 PM
Off-Road Test: '08 Jeep Grand Cherokee (Rally Race) RH77 The Lounge 4 02-25-2008 03:59 PM
Aerodynamics Seminar # 4 - by Phil Knox MetroMPG Aerodynamics 0 01-28-2008 08:36 PM



Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com