Aero// Hardtop glass delete? - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


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

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 05-02-2016, 05:34 PM   #1
Junior Member
Thread Starter
 
Join Date: Apr 2013
Location: toronto
Posts: 124
Total Cats: 7
Default Aero// Hardtop glass delete?

NA, caged. W2W, T/A, lapping. splitter/GTC 200/hardtop. Tracks are high speed, Mosport GP, 140 MPH. Any consensus on hardtop glass delete for aero? Hurricane in cockpit past 80 MPH, unbelieveable buffeting. Searching brings up nothing conclusive, anybody do back to back testing on this?
endura is offline   Reply With Quote
Old 05-03-2016, 07:03 PM   #2
Junior Member
iTrader: (4)
 
Join Date: Sep 2010
Location: Australia
Posts: 168
Total Cats: 10
Default

I run no windows but still have hardtop glass (plexi actually). No buffeting problems up to 120mph.

My understanding was that for a low mount 3D wing, you keep the glass as the wing is designed to manage the central airflow over the roofline, unaffected by the removal of the window. For 2D wings though, you remove the window in order to provide more (and straighter) airflow over the centre of the wing.

My hardtop window will be disappearing when I move to a high mount 2D wing.
zossy1 is offline   Reply With Quote
Old 05-03-2016, 10:50 PM   #3
Junior Member
iTrader: (1)
 
Join Date: Apr 2012
Posts: 187
Total Cats: 3
Default

airflow coming out of the cabin is not going to go over the wing if you have a high mount 2D wing IMO. It should be quite turbulent too.
motormechanic is offline   Reply With Quote
Old 05-03-2016, 11:59 PM   #4
Junior Member
Thread Starter
 
Join Date: Apr 2013
Location: toronto
Posts: 124
Total Cats: 7
Default

tks. I've got a medium height 3D, I'll keep the rear glass in place.
endura is offline   Reply With Quote
Old 05-04-2016, 03:27 AM   #5
Elite Member
iTrader: (1)
 
cordycord's Avatar
 
Join Date: Dec 2011
Location: SoCal
Posts: 1,775
Total Cats: 148
Default

If you get one of these truck window deflectors, not only will buffeting be cut down but you can smoke while you race too.

Attached Thumbnails
Aero// Hardtop glass delete?-80-th_1f2fde3acee8c2ffeea7154a409c6dc54023e8b7.jpg  
cordycord is offline   Reply With Quote
Old 05-06-2016, 04:29 PM   #6
Senior Member
iTrader: (1)
 
Join Date: May 2008
Location: south texas
Posts: 1,419
Total Cats: 9
Default

Matt Andrew's back to back class championship winning NA at Super Lap battle/Redline time attack had aero designed by the now world renowned aero engineer Andrew Brilliant. He didn't have the rear glass and I would have to imagine that it was for a reason. Although, it was a custom carbon hardtop so there's a small chance that he just didn't buy a glass or lexan window for it. That was the situation with mine, I wanted actual glass and couldn't find one so I just ran without it. No problems to report with wind (hurricane) and for a track car without AC, the breeze is nice.
Attached Thumbnails
Aero// Hardtop glass delete?-mamiata.jpg   Aero// Hardtop glass delete?-untitled.png  
spoolin2bars is offline   Reply With Quote
Old 05-06-2016, 04:33 PM   #7
Senior Member
iTrader: (1)
 
Join Date: May 2008
Location: south texas
Posts: 1,419
Total Cats: 9
Default

Oops, that blue car was supposed to be this pic of my car/hardtop.
spoolin2bars is offline   Reply With Quote
Old 05-06-2016, 04:38 PM   #8
Senior Member
iTrader: (1)
 
Join Date: May 2008
Location: south texas
Posts: 1,419
Total Cats: 9
Default

dammit! lol
Attached Thumbnails
Aero// Hardtop glass delete?-spoolinmiata.jpg  
spoolin2bars is offline   Reply With Quote
Old 05-06-2016, 05:04 PM   #9
Supporting Vendor
iTrader: (3)
 
Join Date: Jul 2006
Location: San Diego
Posts: 2,864
Total Cats: 485
Default

Clearly he just wanted easy access to the adjusters on the remote reservoirs.

That car (Matt Andrews) still holds the Miata record at Auto Club Speedway. *shakes fist*
ThePass is offline   Reply With Quote
Old 05-06-2016, 10:04 PM   #10
Junior Member
Thread Starter
 
Join Date: Apr 2013
Location: toronto
Posts: 124
Total Cats: 7
Default

Yup, Matt Andrews car is what got me thinking about rear window delete in the first place.
endura is offline   Reply With Quote
Old 05-06-2016, 11:16 PM   #11
Junior Member
 
Join Date: Jul 2014
Location: Canberra, sort of
Posts: 126
Total Cats: 1
Default

Two aspects to this, car drag, and wing performance. Wing performance is easiest to see, tuft the airflow in front of the wing and see what changes with/without the rear window, that should directly translate to changes to how the wing is working. My guess is that wing position would be a big factor in any changes brought about by a window-delete - the higher the wing, the less impact it would have. OTOH, maybe that extra flow in that location has a stabilising effect on the otherwise turbulent airflow off the rear window and/or reduces the downwash over the top onto the wing ...

More extensive tuft testing of the flow above the boot should show up what changes occur there, but you'd be interested in drag primarily and I am not sure exactly how turbulence manifests as drag. Coast-down testing might be the go for this?

Of course, it is easy just to follow what (seems to) work, but it is nice to understand what is happening, and perhaps why.
Gee Emm is online now   Reply With Quote
Old 05-10-2016, 02:44 PM   #12
Senior Member
iTrader: (1)
 
Join Date: May 2008
Location: south texas
Posts: 1,419
Total Cats: 9
Default

I used tufts and a go-pro to find optimum angle. Wing works great, but I've never had a glass (or lexan window) to compare.
spoolin2bars is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Looking for deleted thread whitrzac Insert BS here 15 05-05-2016 06:50 PM
Output Test mode - Idle Valve RuckRider MSPNP 7 04-28-2016 10:53 AM
Hardtop with Stand FocusTI Miata parts for sale/trade 15 04-28-2016 09:30 AM
Is getting an OBD2 miata past emissions inspection as easy as....... joekitch DIY Turbo Discussion 13 04-26-2016 09:52 AM
Six speed shopping list ThatNewGuy Suspension, Brakes, Drivetrain 4 04-23-2016 09:25 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 06:25 AM.