OSIR cf spoiler installed

[chrisbryan89]

West's biggest argument is "tack tested." West you do realize there are quite few other members here who track regularly right? And some of those people seem to disagree with you quite often. Do you honestly believe that you are correct in all your arguments while the rest of the community is constantly wrong? While I do notice quite a few members trolling you and acting immature, there are many that clearly negate your arguments and yet you always avoid those comments, or you post some nonsense that has no bearing on the conversation.

This trunk lip is clearly for aesthetics, yet you keep comparing it to stock RS5 and Tesla spoilers that are nowhere near the same thing as your "glue on" trunk lip. Quit comparing two vastly different products!! I do think it is cute that the same person who would say something like "I am the only person on audizine who cares about engineering" would put so much confidence in a product that is clearly designed for looks alone. Please point me to the osir literature that states this product is designed to create down force... or that any osir product is designed to enhance performance.

West, if you like the damn thing that is great, but stop trying to convince everybody you are getting 150 lbs of down force out of this, because anybody with a brain can do the research and see you are delusional. By the way, where did you even come up with those numbers? Just curious...

[westwest888]

The Cayman GT4 seen testing (next to a 997 GT3 RS):

[ejohnson]

I'll just leave this here for all the naysayers - http://www.nytimes.com/2000/02/20/au...-5-deaths.html



Notice anything similar between West's lip spoiler and that one?

It must be nice knowing that no matter what West says, if you disagree with him, the entire forum will back you up. Good stuff since it means you can know nothing about a topic that he might have actually thought about, and you can still call him the dumbass.

[NWS4Guy]

I'll just leave this here for all the naysayers - http://www.nytimes.com/2000/02/20/au...-5-deaths.html



Notice anything similar between West's lip spoiler and that one?

It must be nice knowing that no matter what West says, if you disagree with him, the entire forum will back you up. Good stuff since it means you can know nothing about a topic that he might have actually thought about, and you can still call him the dumbass.

As pointed out:
- The TT has a very low and sloping C pillar, which preserves the airflow down the back of the car, unlike our sedans.
- The Spoiler shown on the Gen 1, is about 3-4 inches in height, in spite of the fact that the airflow is already going down the rear of the car, following the body unlike our sedans, and is much more substantial than a tiny lip.
- The problems occurred at speeds in excess of 110MPH, when you can actually generate downforce with a spoiler, unlike on a track, which has tight turns, you are taking a half those speeds, where no spoiler that size will help.

Additional to previous points:
- The article clearly states that there are also suspension components replaced, as well as ESP, an electronic stability control module which monitors steering angle, and uses ABS to keep the car stable. The accidents occurred at 110+ MPH during sharp turns or abrupt lane changes/ This is not a "we slapped a spoiler on and fixed it good!" kind of thing.
- The Gen 1 Audi TT was exactly a VW Golf that had Audi body panels placed on it in order to get something like a Miata out on the market for Audi, and was not as completely thought out as it should have been IMO, and I told several people as much back in 1998 - 2000 when I had friends interested in them - well before the accidents in Germany (of which there were precisely zero in North America I will add).

[chrisbryan89]

As pointed out:
- The TT has a very low and sloping C pillar, which preserves the airflow down the back of the car, unlike our sedans.
- The Spoiler shown on the Gen 1, is about 3-4 inches in height, in spite of the fact that the airflow is already going down the rear of the car, following the body unlike our sedans, and is much more substantial than a tiny lip.
- The problems occurred at speeds in excess of 110MPH, when you can actually generate downforce with a spoiler, unlike on a track, which has tight turns, you are taking a half those speeds, where no spoiler that size will help.

Additional to previous points:
- The article clearly states that there are also suspension components replaced, as well as ESP, an electronic stability control module which monitors steering angle, and uses ABS to keep the car stable. The accidents occurred at 110+ MPH during sharp turns or abrupt lane changes/ This is not a "we slapped a spoiler on and fixed it good!" kind of thing.
- The Gen 1 Audi TT was exactly a VW Golf that had Audi body panels placed on it in order to get something like a Miata out on the market for Audi, and was not as completely thought out as it should have been IMO, and I told several people as much back in 1998 - 2000 when I had friends interested in them - well before the accidents in Germany (of which there were precisely zero in North America I will add).

Thank you.

Johnson, you're comparing two vastly different cars to one another and expecting the same result, which is precisely what West does and why he gets a lot of heat on here. Did you not notice that the TT and S4 are actually shaped differently, and provide different aerodynamics? Again, not one person in this thread is negating the fact that a proper spoiler provides quality down force benefits. People are however shooting down his belief that a 1 inch tall trunk lip (which is also below the line of airflow) is going to provide any benefits. OSIR does not even advertise that as performance product! It is purely for aesthetics! That is what everybody has been saying the entire time.

[Spike00513]

Does anybody know where the video of the white B8 A4 2.0T avant passing this guy on the track is? If you do, please PM me it.

The guy is a forum member, but I can't find it.

Thanks

[helix139]

Does anybody know where the video of the white B8 A4 2.0T avant passing this guy on the track is? If you do, please PM me it.

The guy is a forum member, but I can't find it.

Thanks

QUA77RO is the guy you're looking for

[westwest888]

Does anybody know where the video of the white B8 A4 2.0T avant passing this guy on the track is? If you do, please PM me it.

The guy is a forum member, but I can't find it.

Thanks

It's not a race, man. Sometimes you let someone pass. Sometimes you're the one passing. I learn a lot from following Marcel for a few laps. He's got a highly developed Avant with at least $25k of work in it (at the moment). It's extremely capable, as any car can be made to be.

[drob23]

It's not a race, man. Sometimes you let someone pass. Sometimes you're the one passing. I learn a lot from following Marcel for a few laps. He's got a highly developed Avant with at least $25k of work in it (at the moment). It's extremely capable, as any car can be made to be.

Unless it's a BMW, right West?

[westwest888]

Unless it's a BMW, right West?

A BMW can be taught new tricks. Usually needs camber plates to dance. And a lot of driver training because the rear end steps out on command, which is the slowest way around a track. Unless you just the computer (M dynamic mode) make you think you're driving an Audi.

[Ynnekdude]

West, when are you going to mount a giant carbon fiber splitter down the center of your car?

[westwest888]

The presence of aero on the 911 and the TT does not make a sedan shape impervious to aero. The track ready models from every manufacturer of sedans have a deck lid spoiler about 20% of the size of the one I installed. I'm sorry that I can't buy an RS4 but I can treat my trunk like an MB Black Series or a BMW M car and appoint the trunk as such.

A pizza box shouldn't be tall enough to fly off of the back of the car according to you guys. Somehow air hits it (this is shocking) and it flies off of the car. Maybe some of that air is hitting my spoiler too. I could put a 45 pound plate from the gym back there and it would also fly off, just from air!

I could take a GoPro video of me driving at 130 MPH with a fog machine pointed out the sunroof and the board would concede "OK WEST AIR HITS IT BUT NOT HOW YOU THINK".

[Joe85sti]

It's not a race, man. Sometimes you let someone pass. Sometimes you're the one passing. I learn a lot from following Marcel for a few laps. He's got a highly developed Avant with at least $25k of work in it (at the moment). It's extremely capable, as any car can be made to be.

Hilarious! When you're supposedly doing circles around S6's, M5's and C63's, it's because they're not track gods like your S4, but you get passed by an A4 and it's because "it's not a race".

The presence of aero on the 911 and the TT does not make a sedan shape impervious to aero. The track ready models from every manufacturer of sedans have a deck lid spoiler about 20% of the size of the one I installed. I'm sorry that I can't buy an RS4 but I can treat my trunk like an MB Black Series or a BMW M car and appoint the trunk as such.

A pizza box shouldn't be tall enough to fly off of the back of the car according to you guys. Somehow air hits it (this is shocking) and it flies off of the car. Maybe some of that air is hitting my spoiler too. I could put a 45 pound plate from the gym back there and it would also fly off, just from air!

I could take a GoPro video of me driving at 130 MPH with a fog machine pointed out the sunroof and the board would concede "OK WEST AIR HITS IT BUT NOT HOW YOU THINK".

Please do this, but the fog machine needs to be in front of the car.

[S|Quattro|4]

The presence of aero on the 911 and the TT does not make a sedan shape impervious to aero. The track ready models from every manufacturer of sedans have a deck lid spoiler about 20% of the size of the one I installed. I'm sorry that I can't buy an RS4 but I can treat my trunk like an MB Black Series or a BMW M car and appoint the trunk as such.

A pizza box shouldn't be tall enough to fly off of the back of the car according to you guys. Somehow air hits it (this is shocking) and it flies off of the car. Maybe some of that air is hitting my spoiler too. I could put a 45 pound plate from the gym back there and it would also fly off, just from air!

I could take a GoPro video of me driving at 130 MPH with a fog machine pointed out the sunroof and the board would concede "OK WEST AIR HITS IT BUT NOT HOW YOU THINK".

Put a banana on your hood and see how fast you have to go for it to fly off.

[typer100]

OP, I love the suitcase.

[westwest888]

OP, I love the suitcase.

Tumi.

[chrisbryan89]

Hilarious! When you're supposedly doing circles around S6's, M5's and C63's, it's because they're not track gods like your S4, but you get passed by an A4 and it's because "it's not a race".



Please do this, but the fog machine needs to be in front of the car.

Put a banana on your hood and see how fast you have to go for it to fly off.

Tumi.

Proving my point west... People making valid points countering what you say, and because deep down you know you are wrong, you ignore their comments.

[westwest888]

Proving my point west... People making valid points countering what you say, and because deep down you know you are wrong, you ignore their comments.

The spoiler is a risk management strategy, similar to buying more car insurance than I need. Every tweak I make to the car is supposed to make it more stable on track. Eurocode sways may have been a mistake, as I suspect they made the car more tail happy especially on cold tires (this is fun but not my goal of anchor stable).

No matter how benign this change was, it inches the car in the direction I want it to go. Audi did an amazing job on this car and the tweaks should be subtle. You're more likely to make the car worse with a drastic change than you are to improve it. A gigantic DTM wing is in that category.

[LINDW4LL]

Greg, why not just buy an extra trunklid for the track and attach a real spoiler to it?

[LINDW4LL]

Oh baby, I made it in to West's sig!

[jpbadonk]

The Porsches you call out have raised wings that are raised into the airflow. If they could get away with a little lip, do you think they would?

I'd go raised on my car if class rules allowed. But the big IROC style I have is the most I can do within the rules. And this thing hangs out beyond the rear bumper...

[IanCH]

To be fair, after watching Chris Harris drive a DTM car, I am 100% certain they share only body shape with our cars.

[NWS4Guy]

To be fair, after watching Chris Harris drive a DTM car, I am 100% certain they share only body shape with our cars.

RWD only, V8 engines only, NA only allowed...ya think?

http://en.wikipedia.org/wiki/Deutsch...nwagen_Masters

[s4buckeye]

To be fair, after watching Chris Harris drive a DTM car, I am 100% certain they share only body shape with our cars.

RWD only, V8 engines only, NA only allowed...ya think?

http://en.wikipedia.org/wiki/Deutsch...nwagen_Masters

Now, now. The MB C Coupe and the RS5 run V8s just like the street counterparts.

[NWS4Guy]

Now, now. The MB C Coupe and the RS5 run V8s just like the street counterparts.

They do not run in RWD mode ever on the street, they have to run very specific engines across all the platforms - a 4.0L V8, not the 5.2 found in the street car, and not FI either - not something Audi offers in street cars period. 650HP @ 7500 RPM, ~369lb-ft of TQ, and a 9,000 RPM redline.

I would love if Audi sold that engine, but they don't and these cars are very purpose built for the DTM races, nothing at all representative on what is on the road really.

[drob23]

I've seen guys on the F30 message board say their "M-Performance CF Spoiler" made them more stable on the track. Anyways, who really cares, this debate has gone on for wayyyy too long. Just let West do his thing in the paddock about how awesome his downforce is, people will roll eyes, who cares.

[s4buckeye]

lol dude, I know all of that. it was a joke, but I guess it was too subtle.


Sent from my iPhone

[NWS4Guy]

The spoiler is a risk management strategy, similar to buying more car insurance than I need. Every tweak I make to the car is supposed to make it more stable on track. Eurocode sways may have been a mistake, as I suspect they made the car more tail happy especially on cold tires (this is fun but not my goal of anchor stable).

No matter how benign this change was, it inches the car in the direction I want it to go. Audi did an amazing job on this car and the tweaks should be subtle. You're more likely to make the car worse with a drastic change than you are to improve it. A gigantic DTM wing is in that category.

So you are saying it provides 200lbs of down force at speed. That means it has to be able to withstand 200lbs of force from the wind pushing down on it. Do you think you could push down on it with 200lbs of force and it not fly off? If not, there is obviously no way it's adding that much down force, and I dare say it won't take that much force.

From your own past post, you can see the size wing it will take to get into the airflow of a sedan just to add 116lbs of down force - one MUCH larger than you have and sticking up MUCH farther.

The question here is not whether I am reducing lift with this spoiler. I most certainly am. The OEM factory car has (positive) rear lift at 125 MPH. Is it undeniable. Whether I can overcome 100% of the lift and actually generate downforce is what is in question. This is a rather large spoiler compared to the lip spoilers on the M3 and C63, which are designed to promote both fuel efficiency and reduce lift when possible. It's not as extreme as a wing which can generate serious downforce. But it's a big ass spoiler.

So a normal German car generates 70 pounds of lift at 125 MPH. A car with aero treatment generates 70 pounds of downforce. The difference is 140 pounds, or the weight of an adult male. Here is some evidence:

lol dude, I know all of that. it was a joke, but I guess it was too subtle.


Sent from my iPhone

I would have thought you of all people would know, guess we need a sarcasm font

[s4buckeye]

yes, we can start our own forum for that very purpose


Sent from my iPhone

[westwest888]

MW X6 M
frontal surface area (A) 2.85m²
cw (cd) 0.38
airdragindex (cd x A) 1.07
at 200km/h (125mph)
lift front axle 69kg
lift rear axle 48kg



Audi R8 V10 5.2
(A) 2.024m²
(cd) 0.36
(cd x A) 0.72
at 200km/h
lift front 23kg
downforce rear 3kg

Mercedes SL 65 AMG Black Series
(A) 2.17 m²
(cd) 0.37
(cd × A) 0.80
at 200km/h
lift front 56kg
downforce rear 22kg



Corvette ZR1
(A) 2.059 m²
(cd) 0.32
(cd × A) 0.66
at 200km/h
lift front 39kg
lift rear 14kg


Ford GT
(A) 1.92 m²
(cd) 0.35
(cd × A) 0.67
at 200km/h
downforce front 44kg
lift rear 2kg

Mini Cooper S John Cooper Works
(A) 2.05 m²
(cd) 0.36
(cd × A) 0.73
at 200km/h
lift front 17kg
lift rear 20kg

Lexus IS-F
(A) 2.22 m²
(cd) 0.30
(cd × A) 0.67
at 200km/h
lift front 31kg
lift rear 7kg

Ford Focus RS
(A) 2,35 m²
(cd) 0,36
(cd × A) 0,86
at 200km/h
downforce front 8kg
lift rear 4kg


Nissan GT-R
(A) 2,30 m²
(cd) 0,31
(cd × A) 0,71
at 200km/h
lift front 3kg
downforce rear 8kg


Porsche GT3 facelift
(A) 2.04 m²
(cd) 0.32
(cd × A) 0.66
at 200km/h
downforce front 15kg
downforce rear 19kg


Audi TT-S
(A) 2.10 m²
(cd) 0.32
(cd × A) 0.68
at 200km/h
lift front 42kg
lift rear 17kg



Lamborghini Gallardo LP 560-4
(A) 1.93 m²
(cd) 0.35
(cd × A) 0.67
at 200km/h
downforce front 4kg
lift rear 37kg



Alpina B3 Coupe
(A): 2.14 m²
(cd): 0.29
(cd × A): 0.63
at 200km/h
lift front 12kg
lift rear 13kg



Aston Martin DBS
(A): 2.11 m²
(cd): 0.36
(cd × A): 0.76
at 200km/h
lift front 11kg
lift rear 10kg



Abarth Grande Punto esseesse
(A): 2.21 m²
(cd): 0.34
(cd × A): 0.75
at 200km/h
lift front 26kg
lift rear 31kg



Mercedes C 63 AMG
(A): 2.18 m²
(cd): 0.32
(cd × A): 0.69
at 200km/h
lift front 35kg
lift rear 42kg



BMW Z4 3.0si Coupé
(A): 1.94 m²
(cd): 0.33
(cd × A): 0.64
at 200km/h
lift front 28kg
lift rear 43kg



Lotus Exige S
(A): 1.62 m²
(cd): 0.44
(cd × A): 0.71
at 200km/h
downforce front 5kg
downforce rear 24kg


Porsche 997 Carrera S facelift
(A): 2.02 m²
(cd): 0.29
(cd × A): 0.59
at 200km/h
lift front 24kg
lift rear 14kg



Ferrari 430 Scuderia
(A): 2.02 m²
(cd): 0.33
(cd × A): 0.66
at 200km/h
lift rear 4kg


Audi S5
(A): 2.18 m²
(cd): 0.31
(cd × A): 0.67
at 200km/h
lift front 52kg
lift rear 34kg

Lamborghini Murcielago LP 640
(A): 2.04 m²
(cd): 0.35
(cd × A): 0.71
at 200km/h
downforce front 30kg
downforce rear 11kg

Honda NSX-R (2002)
(A): 1.7800 m²
(cd): 0.34
(cd × A): 0.60
at 200km/h
downforce front 32kg
downforce rear 5kg

Porsche Carrera GT
(A): 1.95 m²
(cd): 0.37
(cd × A): 0.72
at 200km/h
downforce front 49kg
downforce rear 40g


Mitubishi Evo VII
(A): 2.12 m²
(cd): 0.37
(cd × A): 0.79
at 200km/h
downforce front 37kg
downforce rear 8kg



Pagani Zonda F
(A): 2,08 m²
(cd): 0,36
(cd × A): 0,74
at 200km/h
downforce front 1kg
downforce rear 25kg


Koenigsegg CCR
(A): 1,86 m²
(cd): 0,35
(cd × A): 0,64
at 200km/h
downforce front 13kg
lift rear 11kg


Porsche 997 Turbo old
(A): 2.04 m²
(cd): 0.29
(cd × A): 0.59
at 200km/h
lift front 9kg
downforce rear 12kg

[westwest888]

I'm going to estimate a stock B8 S4 generates 36 kg-f at 200 km/h which is 125 MPH. I'm going to estimate my spoiler reduces it to 6 kg-f at the same speed. Enter this into the Audizine wiki.

I'm 90% confident in this judgement. I base it on being slightly worse than the S5 number. The C63 is much worse at over 40. I base the reduction in the achievement in the Alpina B3 at 13 kg-f compared to the 328i at 28 kg-f. I think my spoiler is as or more aggressive as the Alpina part. Our cars may more closely resemble the IS-F trunk which is at 7kg-f of lift.

If the S4 in fact has better

[CircuitTested]

I'm going to estimate a stock B8 S4 generates 36 kg-f at 200 km/h which is 125 MPH. I'm going to estimate my spoiler reduces it to 6 kg-f at the same speed. Enter this into the Audizine wiki.

You do realize you can actually run your own aero tests with just some tape, string and a GoPro, right? The data, while not quantitative, can solve this stupid debate in no time.

What would you say the aspect ratio is on your nifty little lip spoiler there? Important part of the CL calculation. +CL/Lift is not always corrected by the introduction of -CL/downforce. It can come from a reduction in turbulent flow, re-attachment of laminar flow, addition of vortices, etc...pick your poison. Once you figure out the AR, I think you'll realize what you're trying to justify through a pretty obvious bout of confirmation bias is not only nonsensical, it's got completely the wrong sign.

[chrisbryan89]

You do realize you can actually run your own aero tests with just some tape, string and a GoPro, right? The data, while not quantitative, can solve this stupid debate in no time.

What would you say the aspect ratio is on your nifty little lip spoiler there? Important part of the CL calculation. +CL/Lift is not always corrected by the introduction of -CL/downforce. It can come from a reduction in turbulent flow, re-attachment of laminar flow, addition of vortices, etc...pick your poison. Once you figure out the AR, I think you'll realize what you're trying to justify through a pretty obvious bout of confirmation bias is not only nonsensical, it's got completely the wrong sign.

I don't know what the hell you just said, but it sounded good

[helix139]

I think you'll realize what you're trying to justify through a pretty obvious bout of confirmation bias is not only nonsensical, it's got completely the wrong sign.

West is the walking embodiment of confirmation bias

[audistealth]

So you're saying a small taped on trunk lip spoiler is worth 30kg of downforce at 125mph?

[westwest888]

So you're saying a small taped on trunk lip spoiler is worth 30kg of downforce at 125mph?

No, it still generates 6 kg-f of lift. But it reduces downforce.

[squashman]

No, it still generates 6 kg-f of lift. But it reduces downforce.

Nope. It's a stick on cosmetic piece. That's all.

[NWS4Guy]

So you're saying a small taped on trunk lip spoiler is worth 30kg of downforce at 125mph?

Apparently. Which means that there is a force of 66.6lbs worth of air pushing on it at 125mph. I don't personally it having sufficient surface area to collide with air at 125 in order to provide that much down force.

I'm going to estimate that this was $450 that could have been better spent elsewhere.

No, it still generates 6 kg-f of lift. But it reduces downforce.

Yes you are saying that. It's simple math. If it was 36kg before and this is reducing that lift to 6kg, the delta is 30kg.

[rs4dreams]

I don't have much knowledge of aerodynamics, but I believe you guys are oversimplifying. If a car has X kg lift pre-spoiler and Y kg downforce with spoiler, it does not mean that the spoiler is literally producing X+Y kg downforce and bearing all that weight. Lift is produced by the overall airflow around the car which the spoiler/wing alters. Please correct me if I'm wrong.

[westwest888]

I don't have much knowledge of aerodynamics, but I believe you guys are oversimplifying. If a car has X kg lift pre-spoiler and Y kg downforce with spoiler, it does not mean that the spoiler is literally producing X+Y kg downforce and bearing all that weight. Lift is produced by the overall airflow around the car which the spoiler/wing alters. Please correct me if I'm wrong.

This is correct.

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