Rear downforce options

[Fabman]

Actually, there's a fair amount of usable flow toward the outer sides of the decklid. This is one reason why '3d' spoiler designs have a higher angle of attack on the outer section of the wing. That flow comes from the air that 'spills' over the sail panels/quarter window area.

As an engineer, I *always* question what another engineer says. And to be fair...that spoiler video looks like one of his older videos dated in May '13. His videos get better

As a guy who works with *and often saves* a lot of engineers I do a lot of questioning myself. He covers the point you made about the twisted wing in another video. It's great watching.


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[Grant 302]

As a guy who works with *and often saves* a lot of engineers I do a lot of questioning myself. He covers the point you made about the twisted wing in another video. It's great watching.

https://www.youtube.com/watch?v=PmaKmz9cqRY&list=PL6R7zR4ZbGkOny_RGsc2V3DULdd2SPwSU&index=16

I don't think he and I are saying quite the same things there. Wings on airplanes are twisted for a property called 'washout' where the outer part of the wing will not stall as soon as the upper part of the wing. It's not done to reduce wingtip vortices as Kyle says. Without washout in the wing, airplanes would be dangerously sensitive to stalling conditions.

 

[Fabman]

https://www.youtube.com/watch?v=PmaKmz9cqRY&list=PL6R7zR4ZbGkOny_RGsc2V3DULdd2SPwSU&index=16

I don't think he and I are saying quite the same things there. Wings on airplanes are twisted for a property called 'washout' where the outer part of the wing will not stall as soon as the upper part of the wing. It's not done to reduce wingtip vortices as Kyle says. Without washout in the wing, airplanes would be dangerously sensitive to stalling conditions.

The point I got from him (may be a different video) was that as we know, the air that flows around the cabin is less disturbed and better utilized by the spoiler/wing. This is why I mentioned in my first post the fact that the roofs on these new cars is so much better. The smoother the flow over and around the roof, the more effective the rear spoiler/wing. How effective? I don't know, but like I said, I'd like to see some real data. There's a lot of monkey see monkey do out there. Fancy ads don't impress me. I like to see numbers.

 

[Grant 302]

The point I got from him (may be a different video) was that as we know, the air that flows around the cabin is less disturbed and better utilized by the spoiler/wing. This is why I mentioned in my first post the fact that the roofs on these new cars is so much better. The smoother the flow over and around the roof, the more effective the rear spoiler/wing. How effective? I don't know, but like I said, I'd like to see some real data. There's a lot of monkey see monkey do out there. Fancy ads don't impress me. I like to see numbers.

Agreed. But I think he was talking more about the relative angle of the incoming air as the main reason for the 'twist'.

While I'd prefer numbers and real data too, all of my personal testing has been old school/low-tech with wool tufts and water droplets for flow testing.

 

[Fabman]

Agreed. But I think he was talking more about the relative angle of the incoming air as the main reason for the 'twist'.

While I'd prefer numbers and real data too, all of my personal testing has been old school/low-tech with wool tufts and water droplets for flow testing.

Right up my alley, old skool real world testing.
(not to be confused with butt dyno claims)

 

[steveespo]

G Stream with FR-A struts. All the scientific and practical testing has been done. Why reinvent the wheel.
Steve

 

[Mad Hatter]

G Stream with FR-A struts. All the scientific and practical testing has been done. Why reinvent the wheel.
Steve

Steve, Do you think a APR GS200 wing like this would be worth it?? Its about half the price of the bigger wings but only 60.5"

 

[steveespo]

Steve, Do you think a APR GS200 wing like this would be worth it?? Its about half the price of the bigger wings but only 60.5"

APR makes quality stuff, but the height and width of that wing make it less efficient than the 68" G Stream on the Boss S FR-A struts. Reason was explained in those videos, the roof is masking the clean air to the larger portion of the wing and the outboard sections are not far enough out to get clear. You will make downforce with this wing, I would not think as much as the G Stream.
Steve

 

[Mad Hatter]

Thanks, I guess you get what you pay for... the question is can you pay for it! If only I had another 10,000 bucks to put into the car again... :'(

It now a balance in-between new 18x11 wheels, CJ oil pump, adding down force etc etc

For next season a pair of Camaro Zl1's are going to 335/30-18 R7's all around, so will need all the tweeks I can some how afford!!

 

[VoodooBoss]

With your relatively short tracks the wider wheels and a set of 315 square R7's are going to get you faster lap times.

 

[2012-Boss]

I know you are debating what to spend your limited funds on this winter. I think above all else, you should think reliability. You cannot win if you don't finish. Based on this frame of reference, my recommendations are:

1. Air to oil engine oil cooler
2. Larger, baffled oil pan for improved oil control. The aluminum Moroso unit is very nice and has all of the needed fittings.
3. CJ oil pump

As far as going faster, I agree with Rick about wider and stickier tires preferably on an 18 x 11 wheel if your class allows it. I would then look at aero. If you are at your class limits for tires, then the aero moves up in priority.

Have you considered reducing weight? If you don't have a minimum weight and this is not a daily driver, you can remove the radio, speakers, rear seat, rear seat belts, passenger seat, carpet and backing, headliner, sun visors, etcetra. This is cheap and improves handling, braking, acceleration, and fuel consumption.

 

[ArizonaBOSS]

Steve, Do you think a APR GS200 wing like this would be worth it?? Its about half the price of the bigger wings but only 60.5"

That will work but it will look a little goofy on the 2010+ body.

Tires are going to make the biggest difference with overall grip. I like the idea of the Laguna-style spoiler but I'm not sure it will really make much difference. A wing is your best bet for downforce vs. drag. You might look into the Steeda Boss 302R wing and adapters for the 2010+ trunk. https://www.steeda.com/steeda-05-09-mustang-functional-street-wing-307-0010.html

Also Steeda has a version made specifically for the 2010-14 here: https://www.steeda.com/steeda-ford-mustang-rear-wing-476-steeda-wing.html

 

[ArizonaBOSS]

I know you are debating what to spend your limited funds on this winter. I think above all else, you should think reliability. You cannot win if you don't finish. Based on this frame of reference, my recommendations are:

1. Air to oil engine oil cooler
2. Larger, baffled oil pan for improved oil control. The aluminum Moroso unit is very nice and has all of the needed fittings.
3. CJ oil pump

As far as going faster, I agree with Rick about wider and stickier tires preferably on an 18 x 11 wheel if your class allows it. I would then look at aero. If you are at your class limits for tires, then the aero moves up in priority.

Have you considered reducing weight? If you don't have a minimum weight and this is not a daily driver, you can remove the radio, speakers, rear seat, rear seat belts, passenger seat, carpet and backing, headliner, sun visors, etcetra. This is cheap and improves handling, braking, acceleration, and fuel consumption.

THIS^^^

 

[Mad Hatter]

I know.... But I really like driving to the track and the odd weekend joy ride. I take all the seats out and just have Corbeau race seat. That, and I spend all the cash on the car instead of buying a trailer. I really like having A/C for track cool down time....I end up melting...

315/30-18 R7s and Forgestar CF5 18x11 wheels are the first performance items when possible. I do have a set of 295/30-18 R7's to start me off on slicks, on my trusty SVE 18x10 wheels.

2017 I up my class because of the R7s, here is my main competition.....

Supercharged 370Z with 450 rwhp fully lightened, zl1's with 525 rwhp (you can never get them light!), a 2010 camaro SS with 450 rwhp and full track setup plus a hoard of Evos and subis with over 400hp. Most have full aero packages.....

I was hoping to place third once in while! Reliability will be key. (oil pump etc)

 

[Grant 302]

I think you need the aero to step up to that class. I wouldn't bother with any of the lower spoilers or wings...just wasting your money. Sure, every little bit of downforce helps, but if you are getting less than 100lbs. of downforce, it's not going to do much compete with lighter cars with 300-600 lbs.

I also wouldn't used the '3d' wing you posted earlier. Our cars *do* have a pretty big separation bubble in the back and I doubt you can get the downforce numbers in APR's CFD analysis.

A straight wing that is as wide as your class allows that is mounted at least above the bottom 2/3 of your rear window would be best.

You already have the ability to adjust your ride height in the rear to accommodate a wing and a spring rate to support it.

One 'cheater' aero piece I would recommend is a '11 -'12 GT front undertray/airdam. Because of it's placement rearward from the splitter, it still increases the acceleration of underbody air without creating ground clearance issues on the street.

 

[Grant 302]

Air dam visible below splitter:

 

[LERCH]

I think you need the aero to step up to that class. I wouldn't bother with any of the lower spoilers or wings...just wasting your money. Sure, every little bit of downforce helps, but if you are getting less than 100lbs. of downforce, it's not going to do much compete with lighter cars with 300-600 lbs.

I also wouldn't used the '3d' wing you posted earlier. Our cars *do* have a pretty big separation bubble in the back and I doubt you can get the downforce numbers in APR's CFD analysis.

A straight wing that is as wide as your class allows that is mounted at least above the bottom 2/3 of your rear window would be best.

You already have the ability to adjust your ride height in the rear to accommodate a wing and a spring rate to support it.

One 'cheater' aero piece I would recommend is a '11 -'12 GT front undertray/airdam. Because of it's placement rearward from the splitter, it still increases the acceleration of underbody air without creating ground clearance issues on the street.

If it's the same as a 2010 piece, I think I have one in my garage. OP it's yours of you want it.

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[Grant 302]

On the right side of this pic ->

If it's the same as a 2010 piece, I think I have one in my garage. OP it's yours of you want it.

2010s are slightly different they are higher in the middle and deeper just in front of the front tires. The '11-'12 unit goest straight across. Do you have a pic of it LERCH?

 

[Grant 302]

A couple more of the air dam:





One more 'free' aero mod, if it's allowed. Cut vents on the GT rear valence:


The bumper and rear valence are essentially parachutes. Any upward venting would help.

 

[steveespo]

Spacing the front splitter down 3/4" helps too. Balance the rear wing when you install it.