Aerodynamic Discussion Thread - Page 37 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to   Members

Race Prep Miata race-only chat.
Sponsored by:
Sponsored by:

LinkBack Thread Tools Search this Thread
Old 08-15-2016, 10:09 PM   #721
Senior Member
iTrader: (21)
Join Date: May 2008
Location: San Antonio
Posts: 712
Total Cats: 16

Here's an interesting build to check out...

The RP968 It's a bit of a thing... - Rennlist Discussion Forums

rlogan is offline   Reply With Quote
Old 08-29-2016, 02:21 AM   #722
Supporting Vendor
iTrader: (3)
Join Date: Jul 2006
Location: San Diego
Posts: 2,806
Total Cats: 423

ThePass is offline   Reply With Quote
Old 08-31-2016, 12:58 AM   #723
Senior Member
Join Date: Oct 2011
Location: Northridge, CA
Posts: 565
Total Cats: 248


So I might not have the DRS finished in time for MRLS, but I'll still have the wing on Morpheus..
Blackbird is offline   Reply With Quote
Old 09-25-2016, 06:38 PM   #724
Junior Member
Join Date: Dec 2012
Location: Indianapolis
Posts: 65
Total Cats: 35

Been a while since being in here. Bought a 2016 ND Miata though so the development begins. Since I am an aerodynamicist, aero work is of course going to be first.

Overall Cp plot on the car. Cp is better metric to look at in my opinion than just pressure. Cp of 0 = freestreem pressure. Cp>1 = high pressure zone. Cp<1 = low pressure zone.
Name:  diffuser_cp_iso_1_WM_zpsfhhaaslb.png
Views: 35
Size:  273.2 KB

Cp plot on miata with streamlines of the wall shear vectors (aka how the flow regime is acting on the surface)
Name:  diffuser_cp_iso_2_WM_zpsaphoaudj.png
Views: 35
Size:  418.3 KB

Underbody shot of diffuser development. Yes this has a simplified underbody as I will be doing a completely flat floor.
Name:  diffuser_cp_btm_carwm_zpstcdxand7.png
Views: 35
Size:  213.3 KB

Vortex forming at one of the strakes on the diffuser. This helps keep flow attached at higher angles of attack on diffusers
Name:  diffuser_stake_vortices_1wm_zpshdpnovzx.png
Views: 33
Size:  737.2 KB

Another vortex on the strake on the diffuser. Notice the low pressure in the core of the vortex.
Name:  diffuser_cp_vector_1wm_zpsk1fpgduj.png
Views: 33
Size:  786.7 KB

Streamlines off the rear of the miata
Name:  diffuser_cp_streamline_1wm_zpskkswxvll.png
Views: 34
Size:  572.6 KB

Oh and here is the actual car
Name:  20160924_150834_zpsrswb3drr.jpg
Views: 33
Size:  288.5 KB
plucas is offline   Reply With Quote
Old 09-26-2016, 11:28 PM   #725
Junior Member
iTrader: (6)
Join Date: Feb 2011
Posts: 419
Total Cats: 8

Quick question for you guys. How important is shape/size of a splitter fence?
Twibs415 is offline   Reply With Quote
Old 09-27-2016, 11:47 AM   #726
Supporting Vendor
iTrader: (1)
OGRacing's Avatar
Join Date: May 2014
Posts: 1,746
Total Cats: 50

much excite.
OGRacing is offline   Reply With Quote
Old 12-17-2016, 11:21 PM   #727
Elite Member
iTrader: (6)
Join Date: Feb 2013
Location: Staunton, Va
Posts: 2,311
Total Cats: 192

Thread bump to provoke thought, memory and innovation.

Did anyone after all these ears, ever put together a decent CFD model, top and actual bottom (not just a flat) ?
ryansmoneypit is offline   Reply With Quote
Old 12-31-2016, 10:58 AM   #728
Junior Member
Join Date: Apr 2013
Location: toronto
Posts: 123
Total Cats: 8

Originally Posted by ThePass View Post
Yeah I understand that's it's not a nice pretty bubble of pressure inside like having the windows up, it's very turbulent, but the 'parachute' effect is an exaggeration - I don't think the guys who pulled the rear window out were seeing significant MPH changes at the end of straights, from what I have heard it was much more differences in wing performance.

I run a rear lexan window though, so I cannot comment from personal testing. I've considered doing some sort of quick disconnects on it such as Dzus fasteners so that I could do back to back tests.

How high the wing is mounted plays a big role in that too though. The APR GTC-200 for example mounts pretty low, and IIRC even with the 2.5" risers still isn't at the roofline, so the no-rear-window configuration might benefit those wings much more than it would for someone who has gotten their wing up higher..

spec Miata 2007 runoffs, someone with a cracked rear window removed it, picked up a bunch of mph. Instant protests/ban. They don't run wings so yeah, it reduces drag. After that happened, I've even read of enterprising SM racers running "floating hardtops", where side/rear attachment points are raised a bit so cockpit air can escape from underneath rear bottom edge of the top. Also got caught, instant ban. Flyin miata had a track car with a vented rear window, placed on lower lower third of rear plexi. Kept their wing low for lower drag with same downforce (compared to same wing but high mount) . I'm removing rear window to install a vented plexi same as the flyin Miata car. This is all with front windows down. Windows up still best as, pre cage, I gained 4-5 mph on the back straight at mosport. Almost 135 mph. I could probably figure out a way to attach side windows back on for racing but don't think the cockpit temperature issues will be solveable.

Last edited by endura; 12-31-2016 at 12:06 PM. Reason: sp
endura is offline   Reply With Quote

Related Topics
Thread Thread Starter Forum Replies Last Post
OTS Bilstein to motorsports ASN conversion stoves Suspension, Brakes, Drivetrain 5 04-21-2016 03:00 PM
My solution for Oiltemp and Oilpressure input into Megasuirt (MS3) Zaphod MEGAsquirt 41 01-24-2016 12:25 PM
Going back to stock. Need some 1.6 parts. Trent WTB 2 10-01-2015 12:15 PM
Leaky Wilwoods mx592 Suspension, Brakes, Drivetrain 1 10-01-2015 12:45 AM

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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 Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

All times are GMT -4. The time now is 01:08 AM.