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

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 01-30-2009, 10:37 PM   #1 (permalink)
EV OR DIESEL
 
Join Date: Dec 2007
Location: South Louisiana
Posts: 1,733

FarFarfrumpumpen - '03 Volkswagen Jetta Wagon GLS Premium

Quorra - '12 Tesla Model S P85
Thanks: 55
Thanked 99 Times in 79 Posts
Send a message via AIM to dremd
What do you guys think about a grill block behind the grill?

Just like the Title says.

I'm considering doing a motorized grill block on the TDI; but I'd rather it look stock (I get enough questions already). I'm aware it wouldn't be quite as effective as on front, but how much difference do you guys think it would make?

__________________
2012 Tesla Model S P85
2013 Nissan LEAF SV totaled by now deceased intoxacated driver.
2012 Nissan LEAF SV
6 speed ALH TDI Swapped in to a 2003 Jetta Wagon
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 01-31-2009, 04:51 AM   #2 (permalink)
Master EcoModder
 
Join Date: Jan 2009
Location: Maui, Hawaii
Posts: 813
Thanks: 5
Thanked 34 Times in 26 Posts
If the radiator creates so much drag that you need to block air with a flat piece of material from it, then you already have an inside grill block don't you? .....
  Reply With Quote
Old 01-31-2009, 07:02 AM   #3 (permalink)
Master EcoModder
 
tasdrouille's Avatar
 
Join Date: Jan 2008
Location: Mirabel, QC
Posts: 1,672

The Guzzler - '08 Hyundai Elantra GL
90 day: 33.12 mpg (US)

Got Soul? - '11 Kia Soul 2U
Thanks: 35
Thanked 83 Times in 55 Posts
A block behind the grille, as in right behind the grille so it's pretty much sealed, should be almost as effective as a block in front of the grille at speed.
__________________



www.HyperKilometreur.com - Quand chaque goutte compte...
  Reply With Quote
Old 01-31-2009, 08:18 AM   #4 (permalink)
Master EcoModder
 
vtec-e's Avatar
 
Join Date: May 2008
Location: Ireland
Posts: 507

De Yaris - '04 toyota yaris T2
90 day: 69.55 mpg (US)
Thanks: 111
Thanked 32 Times in 22 Posts
Quote:
Originally Posted by tasdrouille View Post
A block behind the grille, as in right behind the grille so it's pretty much sealed, should be almost as effective as a block in front of the grille at speed.
Agreed. Now if your grille block was stuck to the radiator, you'd have good heat but your aero properties would be slightly at a loss. Then again, if you dont often travel at speed it won't matter much.
I blocked the rad on my kia cee'd on the outside but found it also blocked my intercooler and blocked the air inlet too so fuel consumption was way worse. Now i have cardboard shoved up between the rad and the aircon rad. This still affects the aircon when my wife drives so she leaves it on longer (all the time)
and the fuel consumption is like everybody elses. Sometimes i wonder why i bother!!

ollie
  Reply With Quote
Old 01-31-2009, 08:54 AM   #5 (permalink)
Administrator
 
Daox's Avatar
 
Join Date: Dec 2007
Location: Germantown, WI
Posts: 11,127

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: 2,443
Thanked 2,491 Times in 1,503 Posts
I'm gonna agree that there probably isn't a real large difference. However, you'd have to look at specific applications and make the best educated guess you can. Its all going to depend on the grill and shape of the front end. If you have a hugely recessed grill, then its probably much better to make a block that completely eliminates the recessed cavity vs just a block that goes over the front of the grill. In the case of my Matrix and its lower grill, I'm still debating if its worth the hassle of doing a flush mount, or just put it behind. I'll post that info in my arduino grill block thread most likely.
__________________
Current project: A better alternator delete
  Reply With Quote
Old 01-31-2009, 09:30 AM   #6 (permalink)
Master EcoModder
 
metroschultz's Avatar
 
Join Date: Dec 2007
Location: Norfolk, Va. USA
Posts: 869

CPT SLO - '93 GEO Metro plainjane
90 day: 53.91 mpg (US)

SilverHairBeauty - '01 Toyota Avalon XL
90 day: 24.06 mpg (US)
Thanks: 14
Thanked 33 Times in 28 Posts
Send a message via AIM to metroschultz
I know you want motorized to account for the times you need more air.
I live in Virginia, near the ocean, the low temps here don't get much below freezing in winter but the highs in summer get to 99*F @ 99% humidity. Heat index around 120*F.
My daughters grill is 100% closed. I used foam pipe insulation and crammed it between the horizontals. White car + blue foam = odd look. You might want to color match.
My point, (ah good you think, finally a caboose to his train of thought)
She never had an overheating problem last summer and she drives like a maniac.
Two speeds;
Haul@$$ &
!STOP!
Maybe you don't need the motor?
Just my .02,
Schultz
__________________


When you are courting a nice girl an hour seems like a second. When you sit on a red-hot cinder a second seems like an hour. That's relativity.
Albert Einstein
  Reply With Quote
Old 01-31-2009, 04:07 PM   #7 (permalink)
EcoModding Apprentice
 
Join Date: Jul 2008
Location: Edmonton, AB, Canada
Posts: 128

Schwartzejetta - '00 Volkswagen Jetta TDI GL
90 day: 52.87 mpg (US)
Thanks: 18
Thanked 16 Times in 16 Posts
I'm driving a 2000 TDI, and here's been my situation with static grill blocks, to compare with the need for an active one:

I'm up in Alberta, dealing with a temperature range between -40C to +38C (-40F to 100F).

Since November 2006, I've had two pieces of coroplast stuffed against the radiator, behind the upper and lower grill, and behind the bumper, and the radiator support in front. About 2/3 of the radiator has been blocked internally.

In the summer of 2008, I blocked off the lower grill entirely, and then covered the lower half of the upper grill (avoiding the upper driver's side quadrant, where the stock engine air intake is).

The only time I had an issue with being too blocked off, was with the lower grill entirely blocked in the summer during a long highway drive (4-1/2h each way, 35C, very humid, and driving 90-100kph). After that drive, I made a gunslit in the centre of the lower block, about the size of the hole on the plastic grill piece -- so, about 1/9th the original open area. And as an extra precaution, I removed one of those two interior coroplast rad blocks.

At colder temperatures, in the winter, I had to tape up that 1/9th hole when temperatures approached freezing.

Summer peak temperatures:
Air temperature at 30C-38C
Highway cruise: 70-85C
After highway city stop-and-go: 75-90C

Winter temperatures IF I could warm up:
Air temperature -40C to 0C
Highway cruise:
65C-72C when lower grill was 8/9ths blocked.
58-64C when the lower grill was full open.
City stop and go: 55-70C.
When temperatures approach 0C (freezing point), the engine would be 65-75C.


An active block would probably be more ideal for the TDI. There are times you need the grill more open
  • mainly city driving after a long highway cruise
  • in a near standstill city stop and go where you're inching ahead

Again, all of this was done with 2/3 of the radiator blocked off, topped off with exterior blocks.

Being dremd's stomping grounds are MUCH warmer than mine in Alberta, he'd have more need for an active grill, than I would.

Myself, I really don't see there being much room to work with behind the grills. That's why I originally went with radiator blocks (to let the engine warm up faster in winter). I'd concentrate on an active slot or flap off a blocked lower grill, and there'd be a few inches of working room. I'd suggest dealing with the lower grill or space behind for any sort of active/motorized block.

I do think there's merit in pursuing a grill block with your TDI, dremd. The TDIs benefit more from faster warmup, summer, OR winter. So, a near 100% block benefits the car in almost all seasons and temperatures. The active block ends up being a "safety" for ensuring you get enough airflow to avoid having the fans running and/or overheating.

P.S. My 2 cents are TDI-centric. YMMV for other vehicles, of course.

Last edited by ChrstphrR; 01-31-2009 at 04:08 PM.. Reason: Post Script!
  Reply With Quote
Old 02-02-2009, 02:03 PM   #8 (permalink)
Master EcoModder
 
Join Date: Jul 2008
Location: Silly-Con Valley
Posts: 1,417
Thanks: 173
Thanked 226 Times in 174 Posts
Quote:
Originally Posted by metroschultz View Post
She never had an overheating problem last summer and she drives like a maniac.
I have a coroplast panel completely blocking the front side of my CRX's radiator, behind the grille. The temps got too high for me on two occasions:

1- When driving 70 MPH on a long freeway trip on a relatively cool night. Backing off to 50 MPH brought the temps back down to the normal operating range.

2- When driving 55 MPH on that same longish freeway trip on a very warm (~70F) afternoon. Slowing down to 50 MPD did not bring the temps back down, so I had to remove the block. It has since been re-installed for my short daily commutes.

-soD

  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
Airdam and grill block on the Mirage BrianAbington Aerodynamics 5 10-15-2008 06:54 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 - 2020, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com