FR-S vs S2000

[ayau]

Originally Posted by Mike

Because I am buying the car to track it, and Cd matters. Case in point: My CR hits the same top speed Mark(colatkitty) hits at WSIR entering T9. He's exiting T5 at LEAST 3-4 mph faster than I am (my stock suspension vs his dialed in coilovers). I'm certainly not making more power than he is, so why am I accelerating faster? Because of Aero. I run a much smaller wing. He's still far faster than I am.

The official Cd of the s2k isn't published, but the math works out to be about 0.38-0.39 with the top up

Cd matters.

Non-existant aerodynamics? Have you seen the latest round of exotics? There's an insane amount of simulation that goes into these things. Top rally and race cars have horrible Cd and frontal area because they're made for extreme downforce, not to cut through the air with as little resistance as possible.

i'm not arguing that you're wrong, but don't you think that are a lot of other variables to take into account?

tires, suspension, driver skill, engine conditoin, etc, etc.

you're not isolating the aero parts as the only variable that can affect those exit speeds.

[ayau]

Originally Posted by Mike

adding.

I wouldn't mind having a type-s-ish car like yours :p

LOL, sounds like you're from s2ki and saw my faux-type-S for sale thread and or pictures.

what was your handle on s2ki? i'm pretty sure i've seen you around in the cr thread. i rarely go to s2ki now since i don't own one.

sold the car a while back and now im looking at either the FRS/BRZ as a new daily. gonna trade in the fit probably.

[Stigmaru]

Originally Posted by Mike

Because I am buying the car to track it, and Cd matters. Case in point: My CR hits the same top speed Mark(colatkitty) hits at WSIR entering T9. He's exiting T5 at LEAST 3-4 mph faster than I am (my stock suspension vs his dialed in coilovers). I'm certainly not making more power than he is, so why am I accelerating faster? Because of Aero. I run a much smaller wing. He's still far faster than I am.

The official Cd of the s2k isn't published, but the math works out to be about 0.38-0.39 with the top up

Cd matters.

Non-existant aerodynamics? Have you seen the latest round of exotics? There's an insane amount of simulation that goes into these things. Top rally and race cars have horrible Cd and frontal area because they're made for extreme downforce, not to cut through the air with as little resistance as possible.

You missed my entire point. I'm saying CD doesn't matter in this discussion and in cases where you are comparing apples to oranges. You compare two cars: your CR and colatkitty's S2K. Both cars with same profiles minus the difference in wing area. Assuming all else equal, both cars went around the track the exact same way, and both driver skill levels are identical -now you are comparing apples to apples.

Will the S2K beat the FT86 on the track? Will the 40HP difference be too much of a disadvantage? Will the lower CG and weight distribution be an advantage? Beats me...I don't know but I'm excited to find out coming Spring.

My second point was that CD is unfortunately an afterthought in the automotive industry as aesthetics are more important than engineering. Experimentals and exotics? We're already talking about apples and oranges and you show up with a coconut?

I have a degree in aerospace engineering with emphasis on aerodynamics and computational fluid dynamics so I care about CD more than anyone here probably. As brought up before, FT86 is a lower budget car with different design goals from the S2000. It has competitive handling, speed, balance, and weight characteristics. I would say bringing drag into the discussion is pointless if one doesn't do the calculation of acceleration taking into account ALL the vehicle dynamics unless 6 months later someone does go race the two side by side for an actual bench test.

Look at these numbers! They are all over the place.
http://en.wikipedia.org/wiki/Automob...ag_coefficient

Some people might see numbers, but I see well engineered cars like the Nissan GTR with a 0.26 CD. Sure it's relatively low, but not lower than a Honda Insight. The car's form factor and profile must be built around the interior mechanics because what is most important for an automobile is vehicle dynamics on the road rather than external forces and moments like an aircraft. The GTR doesn't need a CD of 0.15. Aerodynamics was sacrificed to build a better handling car, a car that can handle that large engine, and a better looking car.

[Mike]

Originally Posted by ayau

i'm not arguing that you're wrong, but don't you think that are a lot of other variables to take into account?

tires, suspension, driver skill, engine conditoin, etc, etc.

you're not isolating the aero parts as the only variable that can affect those exit speeds.

Colatkitty's a faster driver, but it doesn't take much to floor it from turn 6 through 8; there's almost no variable other than engine output and aerodynamics. S2ks are power limited through that section. We all take the shortest line, and there's not enough lateral load for it to matter there; I've done it flat with all-season tires on in a buddy's CR. :p

s2ki handle is psychoazn

Originally Posted by AeroWRX

You missed my entire point. I'm saying CD doesn't matter in this discussion and in cases where you are comparing apples to oranges. You compare two cars: your CR and colatkitty's S2K. Both cars with same profiles minus the difference in wing area. Assuming all else equal and both driver skill levels are identical -now you are comparing apples to apples .

My second point was that CD is unfortunately an afterthought in the automotive industry as aesthetics are more important than engineering. Experimentals and exotics? We're talking about apples and oranges and you show up with a coconut?

I have a degree in aerospace engineering with emphasis on aerodynamics and computational fluid dynamics so I care about CD more than anyone here probably.

How does it not matter? T6-T8 has no other significant variables in that every s2k takes the same line. Furthermore, the comparison extends out to other cars with stunning accuracy. S2ks with a GTC-200 low mounted and CR wings will hit the same top speed as S2ks with a high mount GT wing. The high mount GT winged cars are universally exiting T5 faster, and ALL s2ks are flat from the T5 exit to T9 entry. My sample size is roughly 30 cars of varying setups that all consistently yield the same data. Most of these cars are running dataloggers, which confirm the findings.

The tire variable, besides rolling resistance, is eliminated because lateral grip is not an issue, and the s2k doesn't have enough power to spin the tires at triple digit speeds. There's enough variance in rims without correlating data to effectively eliminate that. The section of track involves flooring it for 30+ seconds; everyone can do it, eliminating the driver variable. Power output of the given cars are more or less equalized.

Great, you have a lot of theoretical knowledge. I have real world results. You're welcome to our data if you'd like to take a look. How about a zero-lift G37? I'm sure that was an afterthought.

Aero matters.

[ayau]

Originally Posted by AeroWRX

You missed my entire point. I'm saying CD doesn't matter in this discussion and in cases where you are comparing apples to oranges. You compare two cars: your CR and colatkitty's S2K. Both cars with same profiles minus the difference in wing area. Assuming all else equal and both driver skill levels are identical -now you are comparing apples to apples .

My second point was that CD is unfortunately an afterthought in the automotive industry as aesthetics are more important than engineering. Experimentals and exotics? We're talking about apples and oranges and you show up with a coconut?

I have a degree in aerospace engineering with emphasis on aerodynamics and computational fluid dynamics so I care about CD more than anyone here probably.

I'd imagine hybrid/electric vehicles have a pretty big emphasis on aerodynamics during the engineering phase?

I could see that having the most aerodynamic vehicle may not be pleasing to most consumers' eyes, and that is why it's mostly an after thought.

[Mike]

For someone with an aero background, I'm surprised you're not bring up frontal area. The number that truely matters is CdA (in which, again, the FT is superior), but is not commonly discussed.

Similarly, everyone is concerned with HP, no AUC.

[Stigmaru]

Originally Posted by Mike

Colatkitty's a faster driver, but it doesn't take much to floor it from turn 6 through 8; there's almost no variable other than engine output and aerodynamics. S2ks are power limited through that section. We all take the shortest line, and there's not enough lateral load for it to matter there; I've done it flat with all-season tires on in a buddy's CR. :p

s2ki handle is psychoazn

How does it not matter? T6-T8 has no other significant variables in that every s2k takes the same line. Furthermore, the comparison extends out to other cars with stunning accuracy. S2ks with a GTC-200 low mounted and CR wings will hit the same top speed as S2ks with a high mount GT wing. The high mount GT winged cars are universally exiting T5 faster, and ALL s2ks are flat from the T5 exit to T9 entry. My sample size is roughly 30 cars of varying setups that all consistently yield the same data. Most of these cars are running dataloggers, which confirm the findings.

The tire variable, besides rolling resistance, is eliminated because lateral grip is not an issue, and the s2k doesn't have enough power to spin the tires at triple digit speeds. There's enough variance in rims without correlating data to effectively eliminate that. The section of track involves flooring it for 30+ seconds; everyone can do it, eliminating the driver variable. Power output of the given cars are more or less equalized.

Great, you have a lot of theoretical knowledge. I have real world results. You're welcome to our data if you'd like to take a look. How about a zero-lift G37? I'm sure that was an afterthought.

Aero matters.

I really don't know why you got all defensive and started continuing arguing something I'm not even talking about. We're not talking about whether or not a difference in wing changes aero by 3mph (still assuming all else equal because I wasn't the one who challenged u on variables). Like you, i was also using specific cars to make a point. But a GTR or G37 is a needle in the industry. There are so many cars and so many other cars in history. My point is that I'm disappointed that aerodynamics hasn't taken a more important role in consumer vehicle design. I am not saying aero doesn't matter. Why do I need to look at your data loggers to tell me one wing is more draggier than the other? Yes there are a handful of well engineered cars, but just a handful. I'm addressing a deep problem in automotive design that aero needs to be utilized more in the whole industry not just for the few cars. Anyone can put on a nice enough wing and cancel out lift on a car. Anyone can get upgrade to a nice enough aero kit to give enough downforce at the front to help cancel out lift.

Originally Posted by Mike

For someone with an aero background, I'm surprised you're not bring up frontal area. The number that truely matters is CdA (in which, again, the FT is superior), but is not commonly discussed.

Similarly, everyone is concerned with HP, no AUC.

As you can see from the Wiki link, there is a chart with CdA and yes it is still all over the place. This isn't a aero lesson, this is FT86 vs S2K.

Originally Posted by Mike

The GT-R doesn't need a great CdA; the frontal area is tiny. It's smaller than a Prius (which we can assume is pretty aero optimized). Not sure what your point is. They don't need to focus on Cd alone, but aero is VERY well paid attention to.

I still maintain that the FT will likely have an aero advantage on the S2k. Do you know what the single biggest on-track performance modification you can make on a s2k is besides horsepower or tires? It's a wing.

I'm just trying to say there are other variables to optimize than aerodynamics when i brought up the GTR. Don't know what you mean by not needing a great CdA. CdA... front area is a function of CdA... You don't really pay attention to what i'm saying and too busy chasing your own tail creating tangent arguments.

[Mike]

The GT-R doesn't need a great CdA; the frontal area is tiny. It's smaller than a Prius (which we can assume is pretty aero optimized). Not sure what your point is. They don't need to focus on Cd alone, but aero is VERY well paid attention to.

I still maintain that the FT will likely have an aero advantage on the S2k. Do you know what the single biggest on-track performance modification you can make on a s2k is besides horsepower or tires? It's a wing.

[serialk11r]

Originally Posted by Mike

The GT-R doesn't need a great CdA; the frontal area is tiny. It's smaller than a Prius (which we can assume is pretty aero optimized). Not sure what your point is. They don't need to focus on Cd alone, but aero is VERY well paid attention to.

I still maintain that the FT will likely have an aero advantage on the S2k. Do you know what the single biggest on-track performance modification you can make on a s2k is besides horsepower or tires? It's a wing.

I think what he's saying is that aero is generally not paid attention to, but sometimes it is. Nissan GTR for example has relatively good aerodynamics, but most cars aren't like that. Honda S2k and Mazda Miata don't trade off drag and downforce, they just simply have bad aerodynamics.

Considering that drag can sap >100hp at typical track speeds I think it's pretty important to reduce drag. Things like wings increase drag to make handling better, but the body of the car itself need not be as big of a compromise, when it typically is due to styling/space concerns.

A good example of this is perhaps the wheels of a car. Enclosing the wheels with bodywork (like the old Honda Insight) causes a pretty good reduction in drag, but no one does this. Similarly, a cover over the spokes of the wheel helps a bit but no one does this since it looks funny. I think if you had fan blade like spokes (or attachments) it's possible to even reduce the drag, and it would also provide brake cooling, but the point is when it comes to wheels people want what looks cool.

[fatoni]

Originally Posted by Mike

The GT-R doesn't need a great CdA; the frontal area is tiny. It's smaller than a Prius (which we can assume is pretty aero optimized). Not sure what your point is. They don't need to focus on Cd alone, but aero is VERY well paid attention to.

I still maintain that the FT will likely have an aero advantage on the S2k. Do you know what the single biggest on-track performance modification you can make on a s2k is besides horsepower or tires? It's a wing.

im too lazy to look it up but what are the frontal areas for the gtr and prius? also i think a roof has alot to do with how effective a wing on a s2k is

[Mike]

Originally Posted by serialk11r

I think what he's saying is that aero is generally not paid attention to, but sometimes it is. Nissan GTR for example has relatively good aerodynamics, but most cars aren't like that. Honda S2k and Mazda Miata don't trade off drag and downforce, they just simply have bad aerodynamics.

Considering that drag can sap >100hp at typical track speeds I think it's pretty important to reduce drag. Things like wings increase drag to make handling better, but the body of the car itself need not be as big of a compromise, when it typically is due to styling/space concerns.

A good example of this is perhaps the wheels of a car. Enclosing the wheels with bodywork (like the old Honda Insight) causes a pretty good reduction in drag, but no one does this. Similarly, a cover over the spokes of the wheel helps a bit but no one does this since it looks funny. I think if you had fan blade like spokes (or attachments) it's possible to even reduce the drag, and it would also provide brake cooling, but the point is when it comes to wheels people want what looks cool.

Everything is about tradeoffs in motorsports. An increase in drag is often taken to improve/enhance stability by reducing lift and/or generating downforce. This goes from something as simple as a bolt-on wing on a s2k, to the C6 Z06 which has a painfully higher Cd than a base C6, to a Veyron where a spoiler comes up at speed.

Decreasing drag on a production car is typically not within an enthusiast's budget, beyond taping off gaps. The key here, is that the BRZ/FRZ/FT's body will be fundamentally aerodynamically superior to the s2000, and aero is a MAJOR factor in performance with the s2000. The s2k, for whatever reason, generates a net downforce in the front, stock, and generates lift in the rear. If the FT doesn't do that, or does that even to a lesser degree, the car will already have a nice advantage. Even if the same wing is used on both the FT and S2k, if the FT's body glides through the air smoother, then it will still have less net drag. If it happens to generate less lift from the factory, then we won't need as much wing, which further exacerbates my speculated aero advantage.

As for covering the wheels, race teams generally don't because 1. brakes need the cooling and 2. the tires/wheels usually stick out a bit. You can go to the other extreme and look at hypermiling competitions, where the wheels will always be covered, because brake cooling and maximizing grip via whatever means available are no longer issues.

[Mike]

Originally Posted by fatoni

im too lazy to look it up but what are the frontal areas for the gtr and prius? also i think a roof has alot to do with how effective a wing on a s2k is

It's speculated to be a lot of things, but the big things a lot of owners believe are these:

- Front has downforce, while the rear lifts
- A planted rear minimizes variance in toe from load change (a s2k quirk; helps the car rotate on entry, but it also is what causes that legendary "snap oversteer" magazines love to talk about)
- A single exhaust opens up a massive gap in the rear where the OEM dual mufflers were
- Transmission tunnel goes very far down the car's underbody.
- Windshield is very upright, and the top makes a "bubble". The Spoon style top extends out the rake of the rear windows, making the car more aerodynamic, but at the cost of even MORE lift (which, again, is easily mitigated via wing).

Based on Wikipedia numbers, the GT-R is 6.08 / .27 = 22.5185185 ft², while the Prius is 6.24 / .25 = 24.96ft².

[catharsis]

Originally Posted by Mike

The S2k is a flying brick. A Camry has better aerodynamics. I kid you not.

I have a hardtop on my s2k, and I can tell you, it helps, but not much.

Think K20 (performance variants). Also 86x86, but 11:1 comp as opposed to 12:1. Redline is 8200, give or take, depending on the variant. With bolt-ons and a tune, they're hitting 260+. Given that TRD is going to offer a supercharger, I have no doubt that this engine can gain some power with just bolt-ons as well.

It really comes down to how the car will turn. Not many cars rotate like a s2k.

Please tell me how in the world you got 260 whp from bolt ons and tune with a k20, in the real world a k20 with bolt ons and tune will realistically be more around 200whp. To hit 260 you would need to bore the motor out to 2.2 liters, have some aggressive cams, bolt ons, and a tune. Honestly motors like the k20 are some of the worst for bolt ons cause you see virtually no gains for the money put in. The fr-s won't be any different. It's just a small 2 liter NA motor.

[Mike]

Originally Posted by catharsis

Please tell me how in the world you got 260 whp from bolt ons and tune with a k20, in the real world a k20 with bolt ons and tune will realistically be more around 200whp. To hit 260 you would need to bore the motor out to 2.2 liters, have some aggressive cams, bolt ons, and a tune. Honestly motors like the k20 are some of the worst for bolt ons cause you see virtually no gains for the money put in. The fr-s won't be any different. It's just a small 2 liter NA motor.

flywheel, not wheel.

Not at all unrealistic considering I get that from an exhaust and tune on my s2k (albeit, 2.2). Ultimately, AUC of the 2.0 and 2.2 on the s2ks are more or less equal, regardless of peak hp.