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      04-14-2015, 11:37 PM   #1
arllc
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APR rear wing setup

I know there's a few guys on here that have the same APR setup front and rear that I have now on my Z4M Coupe. The question I have is, what angle of attack do you guys use for your rear wing on the track?
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      04-16-2015, 05:00 PM   #2
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I'm guessing that from your post that you are running the splitter as well. I run 0 degrees with noticeable improvement in high speed straight line stability and high speed straight line braking stability. IMHO if you are looking for increased medium speed rear and grip (70-100mph) then you would have to increase the aoa to 5-10 degrees but then may have to think about high speed relative understeer. A lit also has to do with overall suspension setup, tire width choices and tire pressures.
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      04-17-2015, 08:31 AM   #3
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Thanks for the reply. Yes I'm running the APR front splitter and the rear wing. I turned my Z4M coupe into a track car, it's completely stripped with a 6 point cage, running custom ground control coilovers with 275's Z214 square. I'm mainly looking for maximizing my downforce in 75mph to 120mph corners.
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      04-17-2015, 02:00 PM   #4
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They have placed the e86 in a wind tunnel and have calculated that at 125mph the front axle is generating 61lbs of lift and the rear axle has 95lbs of lift. That's scary stuff, which is why that wing can help so much. Since you are running a square setup then a little more rear end down force will help. 5 degrees should be good esp if you have the gurney flap option imho.
Aside from that, blocking off all openings in the front that don't directly cool the engine or components will help front end down force.
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      08-09-2015, 02:43 AM   #5
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^ Whoa, that's interesting info. Where did you find such details?
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      08-09-2015, 10:24 AM   #6
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+1
Who is "they" and do you have more info on how the test car was set up?
Would love to know more.
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      08-09-2015, 02:36 PM   #7
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I honestly have to say, on the back stretch of Mid-O where I reached ~130-135...I've felt the front end get a bit floaty.
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      08-10-2015, 06:07 AM   #8
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Subbed for link to lift data.
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      08-10-2015, 10:50 AM   #9
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Lift

Hey guys,
I'm sorry I didn't see the question earlier...

Here is a link where those numbers come from.

I must first say that I DO NOT in any way support nor condone the ideology the a-hole that posted this on a different forum, nor do I know where specifically he got this data (said that he relayed this from another source)... I thought the info itself was interesting, and have no reason to suspect that it is inaccurate.

http://www.genmay.com/showthread.php?t=827884
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      08-10-2015, 08:21 PM   #10
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Wow, the amount of lift for our cars at speed is definitely depressing
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      08-11-2015, 09:51 AM   #11
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3100lb car
+ 50/50 weight distribution
= 1550 lbs on the front axle

60lbs of lift on the front end at 125mph (according to the link)
= 4% weight change on front axle

If people are saying they can feel it I am mightily impressed. Speaking for myself, I'm not concerned by those numbers in any road conditions short of autobahn. And the 0.33Cd is a pretty sweet number.

I'm also curious as to whether that is a sport suspension. The car seems to sit higher than mine, which has sport suspension. Even a wee bit less space under the car is going to have an effect on the numbers.
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      08-11-2015, 10:29 AM   #12
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Driving on the highway you are not going to feel it... driving on the track where speeds regularly reach 125mph plus... it is very important as good lap times rely on driving on the edge of the friction circle. the largest difference I saw was braking.... prior to wing, the rear end was very squirrely under hard braking off the front straight...to the point where I couldn't stay to the outside of the track....this is because the rear of the car is already unweighted by 100lbs then braking transfers weight to the front, further dropping rear grip... with the wing,the rear of the car is planted I am braking much later with no rear end squirm.
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      08-14-2015, 06:34 PM   #13
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Quote:
Originally Posted by wdb View Post
3100lb car
+ 50/50 weight distribution
= 1550 lbs on the front axle

60lbs of lift on the front end at 125mph (according to the link)
= 4% weight change on front axle

If people are saying they can feel it I am mightily impressed. Speaking for myself, I'm not concerned by those numbers in any road conditions short of autobahn. And the 0.33Cd is a pretty sweet number.

I'm also curious as to whether that is a sport suspension. The car seems to sit higher than mine, which has sport suspension. Even a wee bit less space under the car is going to have an effect on the numbers.
The reason you would want aero front and rear is to add grip in a corner, has little to do with reducing lift. Say the mass of the car is fixed at 3,100 lbs, it takes the same amount of power to move it, but if you can add downforce to the front and rear while cornering, every little lbs counts.

4% more grip up front is 4% more grip, if you're 2 mph faster in a 40mph turn, you're 10mph faster at the end of the straight after the turn and 2/10th of a second faster, just for that one corner. On a course with 12-15 turns that's a couple of seconds just from aero.

But, of course, that means you can already drive at or near the limit effortlessly to truly appreciate that 4% more grip.
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      09-02-2015, 06:18 PM   #14
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Quote:
Originally Posted by fullerra View Post
They have placed the e86 in a wind tunnel and have calculated that at 125mph the front axle is generating 61lbs of lift and the rear axle has 95lbs of lift. That's scary stuff, which is why that wing can help so much. Since you are running a square setup then a little more rear end down force will help. 5 degrees should be good esp if you have the gurney flap option imho.
Aside from that, blocking off all openings in the front that don't directly cool the engine or components will help front end down force.
Quote:
Originally Posted by wdb View Post
3100lb car
+ 50/50 weight distribution
= 1550 lbs on the front axle

60lbs of lift on the front end at 125mph (according to the link)
= 4% weight change on front axle

If people are saying they can feel it I am mightily impressed. Speaking for myself, I'm not concerned by those numbers in any road conditions short of autobahn. And the 0.33Cd is a pretty sweet number.

I'm also curious as to whether that is a sport suspension. The car seems to sit higher than mine, which has sport suspension. Even a wee bit less space under the car is going to have an effect on the numbers.
I can "confirm" this. I lived in Germany for 2 years and drove ~10 miles of Autobahn to and from work every day. Whenever someone asks me, "How fast have you had it?" I can smile and say I've maxed it out 155 just to say I did it and in every story I always talk about this "floating" sensation around 130 (on the speedo) but somewhere between 140-150 mark it feels like it sucks back down. You can actually feel the car lift, the steering gets light and you're afraid to move anything. Scary as shit! One small movement of the wheel....yeah. IT was at that moment when aero went high on my list of stuff to get! But this sounds like exactly what you're talking about they talk about in the wind tunnel tests.

I didn't see that speed ever again after that (maybe on the Schwedenkreuz corner/straight on the Ring It's a flat out 6th gear ~1km stretch but I doubt it...
starting at 2:42 is Flugplatz, then a double apex right hander into the stretch I'm talking about for those that don't know the corner names)
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      09-05-2015, 10:05 AM   #15
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Very interesting about the front lift. I'm running a front splitter and rear wing on my Z4M coupe race car and it has helped a lot with lap time. What I ended up doing to set up my rear wing was, I starting with the rear wing with a very aggressive angle and it made the car understeer badly. I just kept backing off on the attack angle until the car stopped under steering and that's where I left it. I am also running my car very low. I think this helps a lot when it comes to how good the front splitter works.

Here is a photo of my Z4M coupe race car in turn 10 at Sonoma.

007MCoupe, I was at the Nurburgring for track down the July 28th. I was testing a 130i race car and I'm going to move there for a month next summer and race in a couple VLN races.
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      09-05-2015, 04:24 PM   #16
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Quote:
Originally Posted by arllc View Post
Very interesting about the front lift. I'm running a front splitter and rear wing on my Z4M coupe race car and it has helped a lot with lap time. What I ended up doing to set up my rear wing was, I starting with the rear wing with a very aggressive angle and it made the car understeer badly. I just kept backing off on the attack angle until the car stopped under steering and that's where I left it. I am also running my car very low. I think this helps a lot when it comes to how good the front splitter works.

Here is a photo of my Z4M coupe race car in turn 10 at Sonoma.

007MCoupe, I was at the Nurburgring for track down the July 28th. I was testing a 130i race car and I'm going to move there for a month next summer and race in a couple VLN races.
Do you know what angle you're running on the rear? Are you at zero in the front as well? Curious...

Let me know! I never made it out to a VLN race but know a few guys who race. I'm aiming for a track day at Spa on the 18th of October, if you've go a race that weekend, let me know and I'll make a weekend out of it!
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      01-02-2016, 04:50 AM   #17
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Quote:
Originally Posted by arllc View Post
Very interesting about the front lift. I'm running a front splitter and rear wing on my Z4M coupe race car and it has helped a lot with lap time. What I ended up doing to set up my rear wing was, I starting with the rear wing with a very aggressive angle and it made the car understeer badly. I just kept backing off on the attack angle until the car stopped under steering and that's where I left it. I am also running my car very low. I think this helps a lot when it comes to how good the front splitter works.

Here is a photo of my Z4M coupe race car in turn 10 at Sonoma.

007MCoupe, I was at the Nurburgring for track down the July 28th. I was testing a 130i race car and I'm going to move there for a month next summer and race in a couple VLN races.
hi, do you mind sharing your spring rate? and how you managed to fit 275 square? what is the offset of your wheel? no spacer?
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