Notices
Racing & Drivers Education Forum
Sponsored by:
Sponsored by:

dumb aero question

 
Old 03-18-2008, 03:31 PM
  #31  
chrisp
User
 
Join Date: Jun 2004
Location: CT
Posts: 1,614
Likes: 0
Received 0 Likes on 0 Posts
Default

It is not you, it is the car. I spoke about this very subject of D/E stock SC airflow optimization with Mark Hupfer at Road America last Fall. I am a big fan of his. He dreams up the slightest adjustments to make our cars go faster... he is all about drag reduction.
Let's definitely chat at the LRP Club Race.
chrisp is offline  
Old 03-18-2008, 03:32 PM
  #32  
SundayDriver

Lifetime Rennlist
Member

Small Business Sponsor
 
SundayDriver's Avatar
 
Join Date: May 2001
Location: KC
Posts: 4,929
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by smlporsche View Post
While we're talking about all things aero has anyone tried those louvers you see over the front wheels of many race cars?

Do you then take out the plastic wheel well?

Does it only help if you're doing 150+??

Inquiring minds want to know...
They work by venting high pressure air inside the wheel well and reduce the lift from that section. Driving in the rain, I can tell you that in my car, anything over about 60mph and you can see the water blasting upwards from the louvers so they are doing the job from those speeds upwards.
SundayDriver is offline  
Old 03-18-2008, 03:32 PM
  #33  
Yargk
Addict
Rennlist Member
 
Yargk's Avatar
 
Join Date: Sep 2004
Location: SF Bay Area, CA
Posts: 1,761
Received 0 Likes on 0 Posts
Default

Hey Jack, could we see your current underbody?

It's funny you mention ABS plastic as a less common mod on the wrx is to put on the underbody panels from the STI. This includes plastic panels running the length of the rockers and about a foot to a foot and a half in on each side as well as a small rear diffuser. Supposedly these factory Subaru bits were either tested or developed for the ring, they increase high speed stability, and even increase gas mileage by 1-1.5 mpg on the highway. Also, a subaru factory splitter claims a 30% reduction in lift and a .02 point reduction in the coefficient of drag. This stuff works, keep air out from under the car with a low front and keep the underbody smooth.
Yargk is offline  
Old 03-18-2008, 03:32 PM
  #34  
FredC
Super User
 
FredC's Avatar
 
Join Date: Feb 2006
Location: CT - NY Metro Area
Posts: 2,760
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by chrisp View Post
Let's definitely chat at the LRP Club Race.
absolutely. I look forward to meeting you.

Fred
FredC is offline  
Old 03-18-2008, 09:53 PM
  #35  
C.J. Ichiban
Platinum Dealership
Rennlist
Site Sponsor

 
C.J. Ichiban's Avatar
 
Join Date: Sep 2005
Location: Exit Row seats
Posts: 9,021
Received 14 Likes on 8 Posts
Default

thanks sundaydriver, I'd love to race someday, and am just trying to get as much knowledge on car setup as possible.
C.J. Ichiban is offline  
Old 03-19-2008, 11:56 AM
  #36  
stownsen914
User
 
stownsen914's Avatar
 
Join Date: Nov 2007
Location: Ossining, NY
Posts: 974
Received 0 Likes on 0 Posts
Default

Originally Posted by chrisp View Post
That car definitely has proven itself to not need one that's for sure! I may bolt something up just to test the idea. I'm probably not fast enough to really tell though.

No harm in trying if you're inclined to do it ...

Scott
stownsen914 is offline  
Old 03-19-2008, 12:05 PM
  #37  
stownsen914
User
 
stownsen914's Avatar
 
Join Date: Nov 2007
Location: Ossining, NY
Posts: 974
Received 0 Likes on 0 Posts
Default

Originally Posted by JackOlsen View Post
I built a diffuser. I built a front wing. The front wing was especially dumb.

The other thing you can do for the air that does get down underneath is to make sure that the car's underside is generating as little turbulence as possible. Smoothing out the underbelly of my car with a sheet of ABS plastic made a noticeable difference in my laptimes.

Jack -- I see you've built a diffuser. This is for a 911? I built one for my 914 track car, and am just in the process of testing it since late last year. How did you build your diffuser?

I also flat-bottomed my car, using aluminum sheet.

Scott
stownsen914 is offline  
Old 03-19-2008, 12:07 PM
  #38  
chrisp
User
 
Join Date: Jun 2004
Location: CT
Posts: 1,614
Likes: 0
Received 0 Likes on 0 Posts
Default

I have the material and am hoping to have it ready to test end of April. I'll report back if i actually get it done.
chrisp is offline  
Old 03-20-2008, 08:54 AM
  #39  
Willard Bridgham 3
Addict
Rennlist Member

 
Willard Bridgham 3's Avatar
 
Join Date: May 2001
Location: Parral, Chihuahua, Mejico
Posts: 918
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by chancecasey View Post
I've noticed that with just about every front bumper/splitter setup, the designs always seem to "peel away" the layer of air very close to the ground, usually with a splitter that is parallel to the ground.
Now, for more counterintuitive aero: the front plastic apron on 944 cars (bottom of bumper) is curved so as to make a reverse wing and increase downforce. I have driven my car with it both on and off and, with it off, car understeers worse. An aftermarket splitter has both the profile of stock and a low splitter, but the drag increases and downforce increases reducing understeer.

I think that all undertrays on front ends are really to reduce drag and assumes that the air under the car is soooooo dirty (turbulent) that it won't affect lift much. The air gets very dirty from the car that went through it just before you got there (see flipping Porsche clip).
Willard Bridgham 3 is offline  

Thread Tools
Search this Thread

Contact Us - About Us - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: