Go Back   986 Forum - The Community for Porsche Boxster & Cayman Owners > Porsche Boxster & Cayman Forums > Performance and Technical Chat

Post Reply
 
LinkBack Thread Tools Display Modes
Old 01-31-2015, 07:47 PM   #1
Need For Speed
 
KRAM36's Avatar
 
Join Date: Feb 2013
Location: Funville
Posts: 2,114
Garage
Quote:
Originally Posted by JayG View Post
You need some kind of an airfoil to get down-force. Again, it's aerodynamics/physics. I don't think air flowing through those vents will give you down-force.
Sure they can. Why do you think Porsche added them to the GT2 and GT3 cars? The new Z06 does it with vents on the hood.
KRAM36 is offline   Reply With Quote
Old 01-31-2015, 08:40 PM   #2
Track rat
 
Topless's Avatar
 
Join Date: Nov 2006
Location: Southern ID
Posts: 3,701
Garage
Tailgate Up or Down
__________________
2009 Cayman 2.9L PDK (with a few tweaks)
PCA-GPX Chief Driving Instructor-Ret.
Topless is offline   Reply With Quote
Old 01-31-2015, 08:48 PM   #3
On the slippery slope
 
JayG's Avatar
 
Join Date: Mar 2014
Location: Austin and Palm Springs
Posts: 3,799
Garage
Quote:
Originally Posted by KRAM36 View Post
You don't need a dyno to figure out mpg.

I couldn't find anything the aerodynamic of racing link showing that having the spoiler up would increase mpg. It did mention drafting would cause the car in front to have less drag.
I was being sarcastic about the butt dyno
The problem is that to calculate MPG, you need to have constant conditions, speed, etc, so using a dyno actually would be a good way to get a good caculation

as far as less drag via drafting, again it comes down to aerodynamics and physics. Drafting produces a partial vacuum and effectively sucks the car behind in. Please someone correct me if I am wrong

Quote:
Originally Posted by KRAM36 View Post
Sure they can. Why do you think Porsche added them to the GT2 and GT3 cars? The new Z06 does it with vents on the hood.
Sorry, but the front vents are for cooling the brakes and radiators, they don't produce down-force. The front apron/lips generates down force, not the vents. I would guess the same is true for the Vette, cooling. I could be wrong, maybe someone can comment differently
__________________
2004 Boxster S 6 speed - DRL relay hack, Polaris AutoTop DIY
2004 996 Targa Tip
Instructor - San Diego region
2014 Porsche Performance Driving School
2020 BMW X3, 2013 Ram 1500, 2016 Cmax, 2004 F-150 "Big Red"

Last edited by JayG; 01-31-2015 at 08:50 PM.
JayG is offline   Reply With Quote
Old 01-31-2015, 09:01 PM   #4
Need For Speed
 
KRAM36's Avatar
 
Join Date: Feb 2013
Location: Funville
Posts: 2,114
Garage
Quote:
Originally Posted by JayG View Post
I was being sarcastic about the butt dyno
The problem is that to calculate MPG, you need to have constant conditions, speed, etc, so using a dyno actually would be a good way to get a good caculation

as far as less drag via drafting, again it comes down to aerodynamics and physics. Drafting produces a partial vacuum and effectively sucks the car behind in. Please someone correct me if I am wrong



Sorry, but the front vents are for cooling the brakes and radiators, they don't produce down-force. The front apron/lips generates down force, not the vents. I would guess the same is true for the Vette, cooling. I could be wrong, maybe someone can comment differently
I'm talking about the vents at the top of the bumper. They make the air flow more closely to the contour of the car.

Check out this video, skip to about 5:25

2015 Chevrolet Corvette Z06: We Speak to the Men Who Made It – Video – Car and Driver

Also on the drafting, it does affect the aft vortex behind the car.


Last edited by KRAM36; 01-31-2015 at 09:09 PM.
KRAM36 is offline   Reply With Quote
Post Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -8. The time now is 09:29 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0
Copyright 2025 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page