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

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 12-12-2008, 06:17 AM   #1 (permalink)
Master EcoModder
 
Join Date: Feb 2008
Location: belgium
Posts: 663

vectra a - '95 Opel Vectra GLS
90 day: 37.51 mpg (US)
Thanks: 14
Thanked 61 Times in 44 Posts
grillblock in front, not against grill ?

has anyone ever tried an external grillblock that sits in front of the grill rather than against it?
the idea is that i'd install a lip (a found a very nice piece of plastic that's just right) in front of the open area of my lower 'grill', basically turning the intake from faceing forward to faceing downwards

the red area is the dam i plan to install


the basic thought behind this is that it might cancel out the ram effect somewhat reducing the air intake at speed, but allow a maximum volume of air to enter naturally or be sucked in by the fan when the car is moving slowly and most at risk of overheating.

i plan to try this but does it look like it might work or should i look for a different approach?

__________________
aer·o·dy·nam·ics: the science of passing gass

*i can coast for miles and miles and miles*
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 12-12-2008, 08:32 AM   #2 (permalink)
Administrator
 
Daox's Avatar
 
Join Date: Dec 2007
Location: Germantown, WI
Posts: 11,166

CM400E - '81 Honda CM400E
90 day: 51.49 mpg (US)

Daox's Grey Prius - '04 Toyota Prius
Team Toyota
90 day: 49.53 mpg (US)

Daox's Insight - '00 Honda Insight
90 day: 64.33 mpg (US)

Swarthy - '14 Mitsubishi Mirage DE
Mitsubishi
90 day: 56.69 mpg (US)
Thanks: 2,464
Thanked 2,535 Times in 1,529 Posts
Why not just block the entire thing?
__________________
Current project: A better alternator delete
  Reply With Quote
Old 12-12-2008, 09:18 AM   #3 (permalink)
Master EcoModder
 
Join Date: Feb 2008
Location: belgium
Posts: 663

vectra a - '95 Opel Vectra GLS
90 day: 37.51 mpg (US)
Thanks: 14
Thanked 61 Times in 44 Posts
Quote:
Why not just block the entire thing?
cause i'm pretty sure that'll get me into trouble. i can get away with a full top block on my normal commute, but during the summer i once got stuck for maybe 10-15 minutes in very slow moving traffic, and temps went way beyond where they should be... needle was all the way up into the red by the time i pulled ont the driveway.

i maybe get traffic like that once in 2 months for maybe 10 to 15 minutes, but it's usually not the sort of traffic that allows you to pull over to remove a grillblock, so whatever setup i have needs to cope with these situations.


both grills are quite small and the topgrill as more than 50% blocked from the factory so i think the engineers did their math.
on the other hand i do feel like the existing area while small is only really needed when the cars moving slowly, so i thought it would be great it i could make some sort of shield that would push the air aside as the car punches trough the air, but leaves enough room around the sides and so that the same volume of air can easily be sucked in by the fan.

the question is will this happen or will the same volume of air still enter the radiator regardless of what's in front of it.

i'd like an all season setup that's an improvement over stock even if this isn't ideal compared to a full block, but doesn't needs me to look at the temp gauge all the time
__________________
aer·o·dy·nam·ics: the science of passing gass

*i can coast for miles and miles and miles*
  Reply With Quote
Old 12-12-2008, 08:17 PM   #4 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 22,125

Blackfly - '98 Geo Metro
Team Metro
Last 3: 70.09 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 53.56 mpg (US)

Winter beater Metro - '00 Chevrolet Metro
90 day: 61.98 mpg (US)

Fancy Metro - '14 Mitsubishi Mirage top spec
90 day: 58.72 mpg (US)

Even Fancier Metro - '14 Mitsubishi Mirage top spec
90 day: 64.03 mpg (US)
Thanks: 3,758
Thanked 6,570 Times in 3,406 Posts
Personally, I think the best solution is a variable/adjustable grille block. Like this one: http://ecomodder.com/forum/showthrea...abin-6358.html
__________________
Honda mods: Ecomodding my $800 Honda Fit 5-speed beater
Mitsu mods: Oops, I did it again! Bought another cheap, 3-cylinder Mirage. Mods in progress...
Ecodriving test: Manual vs. automatic transmission MPG showdown



EcoModder
has launched a forum for the efficient new Mitsubishi Mirage
www.MetroMPG.com - fuel efficiency info for Geo Metro owners
www.ForkenSwift.com - electric car conversion on a beer budget
  Reply With Quote
Old 12-13-2008, 04:59 AM   #5 (permalink)
Master EcoModder
 
Join Date: Feb 2008
Location: belgium
Posts: 663

vectra a - '95 Opel Vectra GLS
90 day: 37.51 mpg (US)
Thanks: 14
Thanked 61 Times in 44 Posts
i'm also working on a variable grillblock, but it's easier said than done on some cars.
i've looked at existing vents but found non suitable for my car's layout, and while working on a fully scratchbuild active grillblock has been fun so far, it'll be quite some time before i entrust it with the safety of my engine....

aerodynamicly speaking they're superior but they'd still require either you or a mechanical or electric device to monitor the temperatures,, all these can potentially fail and add complexity.

a device that uses the laws of physics to create a virtual full grillblock at speed, but offers no restriction when the car is moving slowly; and that without the use of moveing parts sounds quite appealing to me... IF something like what i describe can actually do that, wich is the reason for this post really.

anyway, yesterday i slaped the piece of plastic on my car, and although i only drove for a short distance i noticed that the engine temp was a little higher, but still not above my summer average (this was with the heater running though and i know that makes a big difference)

the car felt different, although not really in a nice way. i think the what the front bumper is designed with works a bit like a splitter, and perhaps the fairing removes some downforce there.
also the stagnation point might be a little lower now causing more air to go over the car, but as the lower grill is closed more air will go under as well.

to bad i don't have a ny good fe feedback of i would know immediately if it did something good or not
__________________
aer·o·dy·nam·ics: the science of passing gass

*i can coast for miles and miles and miles*
  Reply With Quote
Old 12-13-2008, 01:13 PM   #6 (permalink)
Legend in my own mind
 
trikkonceptz's Avatar
 
Join Date: Apr 2008
Location: Homestead, Fl.
Posts: 927

Evil Pumpkin - '08 Scion xD RS 1.0 #1633
90 day: 35.45 mpg (US)

Silent Silver Killer - '10 Honda Insight EX
90 day: 51.5 mpg (US)
Thanks: 2
Thanked 13 Times in 12 Posts
Can you provide us with some pictures of your front end to better understand you circumstance?
__________________
Thx NoCO2; "The biggest FE mod you can make is to adjust the nut behind the wheel"

I am a precisional instrument of speed and aeromatics
If your knees bent in the opposite direction......what would a chair look like???





  Reply With Quote
Old 12-13-2008, 01:25 PM   #7 (permalink)
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 12,647
Thanks: 20,313
Thanked 6,288 Times in 3,893 Posts
grillblock

Quote:
Originally Posted by lunarhighway View Post
has anyone ever tried an external grillblock that sits in front of the grill rather than against it?
the idea is that i'd install a lip (a found a very nice piece of plastic that's just right) in front of the open area of my lower 'grill', basically turning the intake from faceing forward to faceing downwards

the red area is the dam i plan to install


the basic thought behind this is that it might cancel out the ram effect somewhat reducing the air intake at speed, but allow a maximum volume of air to enter naturally or be sucked in by the fan when the car is moving slowly and most at risk of overheating.

i plan to try this but does it look like it might work or should i look for a different approach?
I would at least roll some radius into the lower edge of the sheet,otherwise you've got a Cd1.11 obstruction in front of your opening,almost as much drag as a parachute.
__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
  Reply With Quote
Old 12-14-2008, 12:47 AM   #8 (permalink)
Moderate your Moderation.
 
Join Date: Nov 2008
Location: Troy, Pa.
Posts: 8,919

Pasta - '96 Volkswagen Passat TDi
90 day: 45.22 mpg (US)
Thanks: 1,369
Thanked 430 Times in 353 Posts
Do a complete grille block, remove sources of external heat from the radiator. I.E. Secondary header shroud... Use a stronger fan, or a pusher fan, or add another fan to the open area of your radiator that isn't currently occupied by a fan (if you removed A/C fan) or wire the A/C fan so that it comes on with the coolant fan. This will help to draw more than enough air from places other than the grille to keep the car cool.

If you don't believe it, or need help realizing if it will work for you, do it, then drive out to a backroad on a hot day and let the car sit idling in the sun after driving it kinda hard. If the fans come on and never turn off, you need to channel more air into that area, which can be done with ducting rather than affecting the aero of the car.

__________________
"¿ʞɐǝɹɟ ɐ ǝɹ,noʎ uǝɥʍ 'ʇı ʇ,usı 'ʎlǝuol s,ʇı"

  Reply With Quote
Reply  Post New Thread


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Permanent Aluminum Grill Block and Belly Pan Markmysite EcoModding Central 41 02-27-2014 09:22 PM
Lower Grill Block 2005 Honda Civic Arminius EcoModding Central 12 10-04-2011 12:31 AM
DIY - Front Grill Block - 1991 Honda CRX SVOboy DIY / How-to 33 06-24-2011 05:16 PM
Front plate alternatives pasadena_commut Aerodynamics 8 07-12-2008 10:30 PM
96-00 Civic Upper Grill Block Impulse Aerodynamics 2 07-12-2008 03:09 PM



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