Aerodynamic Discussion Thread - Page 23 - 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 10-15-2013, 10:47 AM   #441
Junior Member
iTrader: (1)
 
Join Date: Apr 2012
Posts: 186
Total Cats: 2
Default

The purpose of serrated edges/slats on the bottom of wing edplates, in regards to F1, is to straighten turbulent air ejected off the tire sidewall. They also help with the upwash of the rear wing by accelerating airflow at the base of the endplate.
motormechanic is offline   Reply With Quote
Old 10-15-2013, 11:48 AM   #442
Supporting Vendor
iTrader: (3)
 
Join Date: Jul 2006
Location: San Diego
Posts: 2,647
Total Cats: 294
Default

Interesting. So they are multiple vortex generators in a single file line then.
ThePass is offline   Reply With Quote
Old 10-17-2013, 05:15 PM   #443
Senior Member
iTrader: (1)
 
Join Date: Dec 2008
Location: Manassas, Virginia
Posts: 1,247
Total Cats: 57
Default

I've been wondering why airfoil shapes are still being developed and are team secrets. I would have thought that an optimal shape would have been found long ago and would be public knowledge now. I mean they're all slight variations of a teardrop shape, right? Just find the shape with the best ratio of drag vs. lift.
mx5autoxer is offline   Reply With Quote
Old 10-17-2013, 07:23 PM   #444
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: NH
Posts: 8,813
Total Cats: 92
Default

Quote:
Originally Posted by mx5autoxer View Post
I've been wondering why airfoil shapes are still being developed and are team secrets. I would have thought that an optimal shape would have been found long ago and would be public knowledge now. I mean they're all slight variations of a teardrop shape, right? Just find the shape with the best ratio of drag vs. lift.
Not even close. You can find the optimum shape for a single element at different speeds in an open environment pretty easy, they're not all published still. Adding more elements, making it interact with the ground, the car, the wall, the cars around you, cross winds, rain, etc all takes a dick load of modeling.
Leafy is offline   Reply With Quote
Old 10-23-2013, 07:39 PM   #445
Junior Member
 
Join Date: Dec 2012
Location: Charlotte, NC
Posts: 231
Total Cats: 14
Default

Going back to this picture, is there any other practical place on the car for the exit duct? Wondering what options would be for an RX7 where you don't have a trunk or have extremely limited spacing between the tail lights. Alternately, would you still see a benefit, albeit a diminished one, if you had to neck down the exit to be narrower than the inlet?

Attached Thumbnails
Aerodynamic Discussion Thread-evosucker4.jpg  
Supe is offline   Reply With Quote
Old 10-23-2013, 07:39 PM   #446
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: NH
Posts: 8,813
Total Cats: 92
Default

I'd aim for somewhere in the middle of the rear hatch glass, lol.
Leafy is offline   Reply With Quote
Old 10-23-2013, 08:02 PM   #447
Junior Member
 
Join Date: Dec 2012
Location: Charlotte, NC
Posts: 231
Total Cats: 14
Default

Quote:
Originally Posted by Leafy View Post
I'd aim for somewhere in the middle of the rear hatch glass, lol.
Don't think I haven't given it thought! Glass is coming out for lexan anyways!
Supe is offline   Reply With Quote
Old 10-30-2013, 08:41 PM   #448
Junior Member
iTrader: (1)
 
Join Date: Sep 2013
Posts: 186
Total Cats: 10
Default

Supe, what about the 2 exits on the side of the car in the rear? Make it look like a GT car or something. Here is kind of what I am talking about on a modeling of an s14.

Attached Thumbnails
Aerodynamic Discussion Thread-2009-vizualtech-nissan-gt500-1.jpg  
carbon is offline   Reply With Quote
Old 12-24-2013, 01:53 AM   #449
Senior Member
Thread Starter
 
Join Date: Oct 2011
Location: The Race Track & St Pete FL
Posts: 574
Total Cats: 49
Default

I haven't been on here in sometime, since my computers charge cord broke. Is there any updates to any aero ideas? I'm about to start working on my vented radiator hood vent.
1993ka24det is offline   Reply With Quote
Old 12-24-2013, 08:40 AM   #450
Junior Member
 
Join Date: Dec 2012
Location: Charlotte, NC
Posts: 231
Total Cats: 14
Default

I'm in a bit of a vent conundrum.

I was making a fiberglass outlet duct coming off the radiator that would exit the sides of the hood so as not to direct air into a forward facing hood scoop. However, the duct is very large and is creating issues with brake duct locations, accessibility to engine accessories, coolant hose routing, and is occupying space I may need for future "upgrades".

This drives me back to the traditional center-exit ducted radiator vent which is fine. However, I'm also not wanting to force feed warm air into my throttle body. Does anyone foresee this being an issue if I were to use a cowl induction setup with a center exit radiator duct? Options are very limited, though an offset cowl induction setup may be possible now that the brake booster/master cylinders are gone.
Supe is offline   Reply With Quote
Old 12-24-2013, 12:25 PM   #451
Junior Member
 
Join Date: May 2010
Location: Tampa, FL
Posts: 84
Total Cats: 1
Default

Assuming you are using the old style filter that sits on top of the "carb" (I noticed you're running Holley EFI), I would run a standard hood vent, and then get an air filter cover that you can attach hoses/pipes to, to route air from the front bumper or fenders.

Also, if you were to go that route, you would probably want to close up that forward facing scoop.
vintagerust is offline   Reply With Quote
Old 12-24-2013, 01:32 PM   #452
Junior Member
 
Join Date: Dec 2012
Location: Charlotte, NC
Posts: 231
Total Cats: 14
Default

My problem is hood clearance. Presently running no air filter other than a mesh screen. Between the low hood clearance and the strut tower brace, I don't think I'd be able to route anything without some serious hood surgery.
Supe is offline   Reply With Quote
Old 12-24-2013, 02:55 PM   #453
Supporting Vendor
iTrader: (3)
 
Join Date: Jul 2006
Location: San Diego
Posts: 2,647
Total Cats: 294
Default

I would not want to have my motor intaking the hot radiator exhaust air.

"Ram air" is virtually a myth (until you're talking about a well-engineered setup at 150mph like on the yamaha R1), so given that you can't find a packaging solution other than a center hood vent just forward of the hood scoop for the intake, I would say close off the front of the scoop and open up the back side. Essentially changing it from a 'scoop" to a "cowl" , although this won't solve the issue entirely because the warm air will still be passing over the hood and get inhaled from the back side, it would give the cooler air around the car more time to mix with that warm air before it reaches the intake, so probably net effect would be cooler intake air.

Another option might be a vertical flap ~1-2" forwards of the scoop opening, same height as the scoop - basically a big gurney flap to create some lower pressure right in front of the scoop opening. This could help push hot air up to pass above the scoop, and the scoop would source air from the sides more.

-Ryan
ThePass is offline   Reply With Quote
Old 12-24-2013, 05:51 PM   #454
Junior Member
 
Join Date: May 2010
Location: Tampa, FL
Posts: 84
Total Cats: 1
Default

I would go for a cowl induction hood, and a sealed vent up front for the rad.
I think a hood scoop in the path of the rad vent would be kind of counter intuitive, and creates more drag.
Either way, I'd try to graft something on your hood, so you can at least run some sort of filter.
vintagerust is offline   Reply With Quote
Old 12-24-2013, 06:06 PM   #455
Junior Member
 
Join Date: Dec 2012
Location: Charlotte, NC
Posts: 231
Total Cats: 14
Default

Sorry, probably not giving a good image here.

Radiator will be a sealed duct that exits just forward of the hood centerline, with a small gurney flap on the leading edge. The rest of the hood right now is flat.

My line of thinking is along the lines of ThePass right now - the radiator exit air would likely be drawn through a cowl opening, which is why I was contemplating trying to offset a cowl-induction based intake that was biased off to one side.
Supe is offline   Reply With Quote
Old 12-24-2013, 09:29 PM   #456
Senior Member
iTrader: (1)
 
Join Date: Dec 2008
Location: Manassas, Virginia
Posts: 1,247
Total Cats: 57
Default

Why not vent the radiator underneath the car? There should be low pressure there to pull air through the rad. Lower the splitter a little bit to return the air flow volume to what it was before the vent so as not to lose downforce. Or maybe it will need more air (raise splitter) to keep the under-car air moving and therefore pressure low.
mx5autoxer is offline   Reply With Quote
Old 12-24-2013, 11:15 PM   #457
Senior Member
Thread Starter
 
Join Date: Oct 2011
Location: The Race Track & St Pete FL
Posts: 574
Total Cats: 49
Default

I the reason I want to run a hood radiator is 1 the radiator has more air flow to disperse the heat and 2 is because, look at the CFD of a Miata. There is a big negative pressure zone right where the vent would exit.
1993ka24det is offline   Reply With Quote
Old 12-25-2013, 12:28 AM   #458
Supporting Vendor
iTrader: (3)
 
Join Date: Jul 2006
Location: San Diego
Posts: 2,647
Total Cats: 294
Default

Radiator exhaust exiting hood is preferrable over under car, but it's very difficult to accomplish on a miata without relocating the radiator. On an FC with that engine config, might be entirely possible to fit the necessary ducting. If that's the case, definitely better to try to make that happen than go the easy route of letting it exit under the car.

-Ryan
ThePass is offline   Reply With Quote
Old 12-25-2013, 02:12 PM   #459
Junior Member
 
Join Date: Dec 2012
Location: Charlotte, NC
Posts: 231
Total Cats: 14
Default

Quote:
Originally Posted by ThePass View Post
Radiator exhaust exiting hood is preferrable over under car, but it's very difficult to accomplish on a miata without relocating the radiator. On an FC with that engine config, might be entirely possible to fit the necessary ducting. If that's the case, definitely better to try to make that happen than go the easy route of letting it exit under the car.

-Ryan
The radiator is very low, moved forward a bit, and significantly angled forward (maybe 30 degrees from flat). It's a straight shot in with the duct work with plenty of room to exit out the hood right in a low pressure zone. No conceivable way to efficiently duct under the car given the current configuration and space limitations.
Supe is offline   Reply With Quote
Old 12-25-2013, 03:01 PM   #460
Junior Member
 
Join Date: May 2010
Location: Tampa, FL
Posts: 84
Total Cats: 1
Default

vintagerust is offline   Reply With Quote
 
 
Reply

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 08:13 AM.