Presented by Nine Lives Racing
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gencollon
gencollon New Reader
6/21/19 8:56 p.m.

Yessir, that's the one. 

Johnny_at_NineLives
Johnny_at_NineLives GRM+ Memberand New Reader
6/25/19 9:36 a.m.

the more air you have the more downforce you can make. We have a 1994 indycar floor at the shop with 2 huge scoops. they shove air under the car and create a vortex. most splitters can pinch off the air flowing under the car and thus the splitter will stop making downforce. so put a big gap in the center. the air still flows, consistency stays. and consistency is the way to win championships. 

StuntmanMike
StuntmanMike New Reader
7/16/19 8:28 a.m.

So would that raised center splitter work the same as a two piece splitter for a bottom breather car? I have a 1999 Camaro that I dont want to convert to a front breather so I was wondering if a two piece splitter would work. Keep the center open to feed the radiator, have an air dam and splitter on either side, with a vertical fence (blue line) that connects the inside of the dam to the flap underneath that deflects air to radiator. Hopefully my crappy drawing makes sense, luckily I can drive slightly better than I can draw.

 

 

 

 

 

 

 

Johnny_at_NineLives
Johnny_at_NineLives GRM+ Memberand New Reader
7/16/19 10:45 a.m.

i can say it should work. unless we did some testing we couldn't say with 100% certainty. 

sleepyhead the buffalo
sleepyhead the buffalo Mod Squad
3/6/20 10:12 a.m.

bump to stop giving the last canoe free advertising

Johnny_at_NineLives
Johnny_at_NineLives GRM+ Memberand New Reader
3/31/20 1:18 p.m.

can't argue with that. 

drock25too
drock25too New Reader
4/8/20 9:06 p.m.

Is there any advantage to a dual element wing verses a single? Or are the more show than go? I have a 98 Dodge Avenger with an aluminum single element that is 53 inches wide. Got it at a swap meet for $20. Has "Alta Otto" stamped in the end plates. 

Robbie (Forum Supporter)
Robbie (Forum Supporter) GRM+ Memberand MegaDork
4/10/20 10:23 a.m.

In reply to drock25too :

Dual element wing makes more downforce for similar drag.

In general.

What are your goals for the wing? What are you trying to achieve?

drock25too
drock25too New Reader
4/11/20 8:13 p.m.

In reply to Robbie (Forum Supporter) :

I'm pretty happy with the car right now with the wing that is on it. At this point I'm not sure the car is really fast enough to take advantage of the wing, but I think it looks better than the big flat deck lid. I haven't messed with angle or anything, I just mounted it like it was when I bought it. Not sure what angle it should be set for. Hopefully with the new engine package, it will make a difference. I was just curious about the pros and cons of each type.  On our circle track cars we are limited to a six or eight inch spoiler depending on engine size.  

Johnny_at_NineLives
Johnny_at_NineLives GRM+ Memberand New Reader
4/13/20 9:40 a.m.

In reply to Robbie (Forum Supporter) :

sorry, Robbie. Dual elements can substantially increase drag. On our wings, our Lift to drag went from 15:1 to 12:1 but the down force doubled. 

cyow5
cyow5 New Reader
7/8/20 7:24 a.m.
Johnny_at_NineLives said:

In reply to Robbie (Forum Supporter) :

sorry, Robbie. Dual elements can substantially increase drag. On our wings, our Lift to drag went from 15:1 to 12:1 but the down force doubled. 

Robbie said "for similar drag" they'll make more downforce. Your own math shows an improved lift/drag ratio which is Robbie's claim. Had you not doubled the downforce, you could've lowered the drag. 

Claff
Claff Reader
7/9/20 12:30 a.m.

Quick potentially stupid question that's probably been asked 5000 times already:

Car is a '90 Miata with all the bolt-ons (118 RWHP) that does a handful of track days a year as well as street duty. Body is stock with R-package front lip and trunk spoiler. The car handles phenomenally, does everything I ask of it, no surprises, very stable. Home track is Dominion Raceway.

I wonder if I even need aero at this point. I mull over something ike the Blackbird Fabworx lexan trunk spoiler but wonder if the drag on the straights would cancel out any gain I made in the corners considering the car is so low-power.

Marcus_NineLivesRacing
Marcus_NineLivesRacing GRM+ Memberand New Reader
7/9/20 12:14 p.m.
Claff said:

Quick potentially stupid question that's probably been asked 5000 times already:

Car is a '90 Miata with all the bolt-ons (118 RWHP) that does a handful of track days a year as well as street duty. Body is stock with R-package front lip and trunk spoiler. The car handles phenomenally, does everything I ask of it, no surprises, very stable. Home track is Dominion Raceway.

I wonder if I even need aero at this point. I mull over something ike the Blackbird Fabworx lexan trunk spoiler but wonder if the drag on the straights would cancel out any gain I made in the corners considering the car is so low-power.

Downforce will make the car faster, drag can hurt certain track elements(straights). Your min speeds through the turns will be higher and exit speeds will be higher with downforce, though.

The air-dam and undertray alone reduce a LOT of drag on the NA. A 9LR wing is also very small amounts of drag, 9lbs of drag at 100mph with 0* AOA. 

General feedback on our medium kit is it increases driver confidence, allowing them to drive at or near the limit more consistently. This translates to faster lap-times, typically seconds are dropped. If you're not limited by rules, 10/10 recommend aero.

asphalt_gundam
asphalt_gundam New Reader
7/20/20 12:00 p.m.

Spoiler vs Wing when it comes to drag, downforce and feel?

I realize this varies by car significantly but is there a general rule of thumb or comparison data of spoilers vs wings? I know several people that really like a spoiler and I personally have felt the huge improvement on my car but also noticed the speed loss. Especially above 80mph acceleration in 4th gear and 5th is nearly useless.

I'm currently working on increasing mechanical grip to then reduce drag by laying down the spoiler. But as I make aero improvements to the front of the car I have been and will continue to be chasing balance.

Johnny_at_NineLives
Johnny_at_NineLives GRM+ Memberand New Reader
7/27/20 6:16 a.m.
ONEBADBUG
ONEBADBUG
11/29/20 4:29 p.m.

I have a flat bottom A_Mod car. Our event surface is too rough to use skirts. Can you provide any insight into how F1 manages the airflow under the car? Also, how rake affects the airflow.

Thanks.

ONEBADBUG
ONEBADBUG New Reader
12/5/20 3:39 p.m.

I guess not!

NOT A TA
NOT A TA SuperDork
12/5/20 7:26 p.m.

In reply to ONEBADBUG :

F-1 aerodynamics is a whole different world than the one most of us play in. Currently the y250 vortex seems to be the major concern in trying to manage under floor airflow by interacting with either J vanes or cape vortices which in turn act on the vortices created by the barge board features. Trying to mimic F-1 flow management in the hopes it would work on a car like your's is probably a waste of your time.

The front wing of a current F-1 car has to have a "neutral" area extending 250 mm from the car's centerline before they can have features as required by rules. So the vortex created by the front wing features closest to the centerline is called the y250 vortex and greatly affects what happens after it. A google search will probably give you a lot of info on the y250 vortex.

For lots of F-1 aerodynamic discussion threads   https://www.f1technical.net/forum/viewforum.php?f=6

As for chassis rake. Perhaps someone with a car similar to yours will chime in.

jh36
jh36 Reader
12/10/20 4:45 a.m.

I'd like to get a big picture started, however fuzzy and out of focus it may be. My thread is started in this section...Gen 1 ASA Camaro. 
I could use expert input to build the aero on this car. I'd like to do this systemically rather than one piece at a time. My rules in NASA ST1 are pretty open. With a brick of a body and relatively low hp, aero is going to be essential  to be competitive. 
Not A TA has started me down the road of a solid elementary education. 
I believe a splitter, flat under tray, diffuser and wing are in my future. I would appreciate input on developing a plan on how best to have these all work together so I can start designing and gathering materials. 
My first event is at VIR, March, 2021. There is plenty of work needed to get there, so all help is appreciated!
 

Robbie (Forum Supporter)
Robbie (Forum Supporter) GRM+ Memberand MegaDork
12/10/20 7:15 a.m.

In reply to ONEBADBUG :

that car looks awesome! I'd love to read more about it... Chassis, suspension, engine, etc. I assume as with most Amods that most was fabricated from scratch?

ONEBADBUG
ONEBADBUG New Reader
12/13/20 3:23 p.m.

In reply to Robbie (Forum Supporter) :

The chassis was built my buddy, I converted it to GSXR 1000 power. Yes, I made pretty much everything. I don't guess this is the proper forum to talk about it.

ONEBADBUG
ONEBADBUG New Reader
12/13/20 3:31 p.m.

In reply to NOT A TA :

Thanks,there is some good info there.

Rigante
Rigante New Reader
1/11/21 3:57 p.m.

Porsche 356 Coupe (4k) - YouTube

Here's a very open ended question on aero. I'm building a 356 rep. GRP shell and custom chassis. mid engined with an Audi v6 and OB3 6 speed trans. max power would be around 300bhp. It'll be a grand tourer, not a race car so needs maximum luggage space and a long range fuel tank, so packaging is at a premium. I'm thinking of taking air in under the nose, and blowing it out into the wheelarch and through louvres above the wheels, 917 style. Do you have any thoughts on the best coolling solution. the other idea is countach style with vertical honda civic rads just ahead of the rear wheels with some scoops and vent it out of the rear. Wheels will be pushed back as far as possible to maximise wheel base. 

suspension will be 350z front and rear subframes, chassis a mix of steel sheet tub, with simple roll cage and tube front and rear.  might look at using the audi front subframe in the rear as their suspension is nice, but need to look at roll centres

 

 

sleepyhead the buffalo
sleepyhead the buffalo Mod Squad
1/13/21 5:37 p.m.
Rigante said:

Porsche 356 Coupe (4k) - YouTube

Here's a very open ended question on aero. I'm building a 356

I mean, you said "open ended"... so, I've got to go with "boil-off cooling system":

https://www.airspacemag.com/flight-today/how-reno-racers-keep-their-cool-16828199

otherwise, I dunno... all your plans seem to ruin the lines of the 356... if I'm picturing them right, imho.

NOT A TA
NOT A TA SuperDork
1/13/21 8:57 p.m.

"I'm thinking of taking air in under the nose, and blowing it out into the wheelarch and through louvres above the wheels, 917 style. "

Why do you want to do this ^^^?

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