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

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 12-27-2011, 03:13 AM   #1 (permalink)
Master EcoModder
 
vacationtime247's Avatar
 
Join Date: Dec 2010
Location: Crescent City, CA
Posts: 278

The Toylet - '87 Toyota Supra 350 Chevy V8 / 700R4

In-Durrrr-Oh - '09 TMEC Enduro TMEC 200cc Enduro
90 day: 60.9 mpg (US)

Tem-poo - '86 Ford Tempo GL 4 Door 2.0 Liter Diesel 5 Speed
90 day: 47.52 mpg (US)

Ass Tick - '01 Pontiac Pontiac Aztek GT 5 Door

Green Baby Poop Stain - '01 Pontiac Aztek Aztek Base Model

Black Track - '01 Pontiac Aztek GT
Thanks: 12
Thanked 34 Times in 20 Posts
Ford Tempo Kammback

Going to mock up a kammback for the Tempo. Try it first with some cardboard and wood. If it looks ok, I'll start with the thin galvonized sheet metal. Needs some rear wheel covers too. Was wondering, in this pic, what should the angle be from the roof line to the end of the kammback? Is this something that only tuff testing will determine? Will extend from the roof back to around the bumper.
Will the added area cause a noticable push with crosswinds? What % increase in general will this add?


  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 12-27-2011, 12:58 PM   #2 (permalink)
Aero Wannabe
 
COcyclist's Avatar
 
Join Date: Dec 2007
Location: NW Colo
Posts: 563

TDi - '04 VW Golf
TEAM VW AUDI Group
90 day: 55.07 mpg (US)
Thanks: 390
Thanked 124 Times in 98 Posts
Quote:
Originally Posted by vacationtime247 View Post
in this pic, what should the angle be from the roof line to the end of the kammback? Is this something that only tuff testing will determine? Will the added area cause a noticable push with crosswinds? What % increase in general will this add?
15 is usually considered "safe". But it depends on lots of factors. Vekke did an adjustable one on his diesel VW Lupo and tuft testing revealed he could go lower than his first attempt. I only see a profile shot of your Kammback. Are you going to taper the sides in as well? Are the corners between the sides and top gently rounded? How smooth is the transition from roof to Kammback?
__________________
60 mpg hwy highest, 55+mpg lifetime
TDi=fast frugal fun
make NOx not Carbon


Quote:
Originally Posted by freebeard View Post
The power needed to push an object through a fluid increases as the cube of the velocity. Mechanical friction increases as the square, so increasing speed requires progressively more power.

Last edited by COcyclist; 12-28-2011 at 10:44 AM..
  Reply With Quote
Old 12-28-2011, 02:10 AM   #3 (permalink)
Master EcoModder
 
vacationtime247's Avatar
 
Join Date: Dec 2010
Location: Crescent City, CA
Posts: 278

The Toylet - '87 Toyota Supra 350 Chevy V8 / 700R4

In-Durrrr-Oh - '09 TMEC Enduro TMEC 200cc Enduro
90 day: 60.9 mpg (US)

Tem-poo - '86 Ford Tempo GL 4 Door 2.0 Liter Diesel 5 Speed
90 day: 47.52 mpg (US)

Ass Tick - '01 Pontiac Pontiac Aztek GT 5 Door

Green Baby Poop Stain - '01 Pontiac Aztek Aztek Base Model

Black Track - '01 Pontiac Aztek GT
Thanks: 12
Thanked 34 Times in 20 Posts
Quote:
Originally Posted by COcyclist View Post
15 is usually considered "safe". But it depends on lots of factors. Vekke did an adjustable one on his diesel VW Lupo and tuft testing revealed he could go lower than his first attempt. I only see a profile shot of your Kammback. Are you going to taper the sides in as well? Are the corners between the sides and top gently rounded? How smooth is the transition from roof to Kammback?
Going to try to get the sides tapered in as best as possible with the top. The corners between the sides and top are sloped, but not completly rounded. The transition between the roof to kammback should be nearly seamless. 15* was the magic number I was looking for, thanks!

Want to mock up a carboard and duct tape demo to do tuft testing. My final goal is to have a metal kammback. Affixed or detachable, doesn't matter much.
VT247
  Reply With Quote
Old 12-28-2011, 05:38 PM   #4 (permalink)
Master EcoModder
 
vacationtime247's Avatar
 
Join Date: Dec 2010
Location: Crescent City, CA
Posts: 278

The Toylet - '87 Toyota Supra 350 Chevy V8 / 700R4

In-Durrrr-Oh - '09 TMEC Enduro TMEC 200cc Enduro
90 day: 60.9 mpg (US)

Tem-poo - '86 Ford Tempo GL 4 Door 2.0 Liter Diesel 5 Speed
90 day: 47.52 mpg (US)

Ass Tick - '01 Pontiac Pontiac Aztek GT 5 Door

Green Baby Poop Stain - '01 Pontiac Aztek Aztek Base Model

Black Track - '01 Pontiac Aztek GT
Thanks: 12
Thanked 34 Times in 20 Posts
First attempt at a mock up tonight. Got a large section of cardboard free from Lowes and some duct tape. Camera's ready for some pics. Not sure how long it'll hold on for, but it's worth testing. Will try to get a video of tuft testing during daylight tomorrow. Think conforming the sides with the slant of the kammback roof will be the challenging part.
VT247
  Reply With Quote
Old 12-28-2011, 10:44 PM   #5 (permalink)
Master EcoModder
 
vacationtime247's Avatar
 
Join Date: Dec 2010
Location: Crescent City, CA
Posts: 278

The Toylet - '87 Toyota Supra 350 Chevy V8 / 700R4

In-Durrrr-Oh - '09 TMEC Enduro TMEC 200cc Enduro
90 day: 60.9 mpg (US)

Tem-poo - '86 Ford Tempo GL 4 Door 2.0 Liter Diesel 5 Speed
90 day: 47.52 mpg (US)

Ass Tick - '01 Pontiac Pontiac Aztek GT 5 Door

Green Baby Poop Stain - '01 Pontiac Aztek Aztek Base Model

Black Track - '01 Pontiac Aztek GT
Thanks: 12
Thanked 34 Times in 20 Posts
Well here's the test fit. Duct tape and cardboard. Fun, lol. Looking at it now that it's done I think the slope may be to steep going down. Perhaps it's good enough, I'll add some tufts and see tomorrow. Here's some pics.
VT247











  Reply With Quote
The Following 3 Users Say Thank You to vacationtime247 For This Useful Post:
Piwoslaw (01-31-2012), Sven7 (12-29-2011), SwamiSalami (01-30-2012)
Old 12-29-2011, 02:48 AM   #6 (permalink)
Aero Deshi
 
ChazInMT's Avatar
 
Join Date: Jan 2010
Location: Vero Beach, FL
Posts: 1,060

MagMetalCivic - '04 Honda Civic Sedan EX
Last 3: 34.25 mpg (US)
Thanks: 430
Thanked 658 Times in 352 Posts
Looks great VT, I analyzed your car and figured a 12 angle would be optimal. You look a tad low with your mock up.

my 2
  Reply With Quote
Old 12-29-2011, 09:34 AM   #7 (permalink)
Aero Wannabe
 
COcyclist's Avatar
 
Join Date: Dec 2007
Location: NW Colo
Posts: 563

TDi - '04 VW Golf
TEAM VW AUDI Group
90 day: 55.07 mpg (US)
Thanks: 390
Thanked 124 Times in 98 Posts
Nice! Now your Tempo looks like a DeLorean. Do you have a coasting point on your regular route or will we have to wait for a few tanks to see if it is working?
__________________
60 mpg hwy highest, 55+mpg lifetime
TDi=fast frugal fun
make NOx not Carbon


Quote:
Originally Posted by freebeard View Post
The power needed to push an object through a fluid increases as the cube of the velocity. Mechanical friction increases as the square, so increasing speed requires progressively more power.
  Reply With Quote
Old 12-29-2011, 02:08 PM   #8 (permalink)
Master EcoModder
 
vacationtime247's Avatar
 
Join Date: Dec 2010
Location: Crescent City, CA
Posts: 278

The Toylet - '87 Toyota Supra 350 Chevy V8 / 700R4

In-Durrrr-Oh - '09 TMEC Enduro TMEC 200cc Enduro
90 day: 60.9 mpg (US)

Tem-poo - '86 Ford Tempo GL 4 Door 2.0 Liter Diesel 5 Speed
90 day: 47.52 mpg (US)

Ass Tick - '01 Pontiac Pontiac Aztek GT 5 Door

Green Baby Poop Stain - '01 Pontiac Aztek Aztek Base Model

Black Track - '01 Pontiac Aztek GT
Thanks: 12
Thanked 34 Times in 20 Posts
If my friend will hurry up and get here I'll make a video of tuft testing. Think Chaz is right, it's probably to low. This means that there will be air seperation going back right? Don't have a coast down area. I'm low tech, redneck. Will have to see it's effectiveness with my next fill up. Think I'll have to cut it and raise it some. Make it a little more water proof.
VT247
  Reply With Quote
Old 12-29-2011, 05:21 PM   #9 (permalink)
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 9,847
Thanks: 14,604
Thanked 5,220 Times in 3,052 Posts
Template

If you haven't seen the Aerodynamic Streamlining Template yet,it was developed for projects just like yours.
I realize you're in pretty deep already but the Template could save you time and money.
PS,the hard edge transition from roof to side is going to reduce the K-form extensions performance.

Last edited by aerohead; 12-29-2011 at 05:24 PM.. Reason: PS
  Reply With Quote
Old 12-29-2011, 05:23 PM   #10 (permalink)
Aero Deshi
 
ChazInMT's Avatar
 
Join Date: Jan 2010
Location: Vero Beach, FL
Posts: 1,060

MagMetalCivic - '04 Honda Civic Sedan EX
Last 3: 34.25 mpg (US)
Thanks: 430
Thanked 658 Times in 352 Posts
No, you won't see separation, it will just create a bit more lift than it should and the drag reduction won't be optimized. It will still work well I'm sure, it could just be a little better if it were a tad higher. I figure you'd be 8" from the rear deck lid to the top of your Kamm.

Here's my overlay and Kamm shape attempts. Bigger detailed link below cause Ecomodder don't like big pics.



Big Copy of Template on Tempo

  Reply With Quote
The Following 3 Users Say Thank You to ChazInMT For This Useful Post:
aerohead (12-29-2011), mcrews (02-15-2012), vacationtime247 (12-30-2011)
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com