Unmasking the FR-S / BRZ / FT-86 Mule

[WingsofWar]

fixed other items and the headlights to be less aggressive, more round, added a rear view with changed rear bumper & taillight shape of the test-type.

[Calais]

thanks wings i always enjoy your chops

Originally Posted by WingsofWar

iv also worried about this, when i tracked my S14 for the first time i thought i had a good brake setup with R32 front brakes and a large Master Cylinder, with performance pads and new sets of brembo rotors. But i still experienced reallllly bad brake fade because of inadequate ducting..figured it out when local guy who was tracking with me that day took a digital thermometer to my rotors and it hotter than 2 naked Brazilian chicks massaging each others tits...

I know im going to track the FR-S...i hope they provide good ducting to cool those brakes....and speaking of brakes..i hope they provide some big aluminum 4pots.

HAHAHAHAHA good to see your sense of humor hasn't changed since you had a daughter lol

[ft86cbx]

Originally Posted by WingsofWar

fixed other items and the headlights to be less aggressive, more round, added a rear view with changed rear bumper & taillight shape of the test-type.

Serious talent you got WoW!

You actually restored my faith in what the car will look like after seeing the mule I started to doubt it.

Any chance you can do it in the Five Axis red pls?

[Kage]

WoW Toyota needs to give you a job in design, that so far is my favorite rear bumper. But the only thing about that chop is it has the nice sleek side mirrors. The ones on the mule just throw off the whole design.

[ft86cbx]

Originally Posted by Kage

But the only thing about that chop is it has the nice sleek side mirrors. The ones on the mule just throw off the whole design.

I really hope they don't go with those table tennis bats off the mule.

[Nambo]

Looks nice Nice job Wings, better watermark it before some other Auto Blog steals it lol

[Maxim]

Originally Posted by Calais

thanks wings i always enjoy your chops



HAHAHAHAHA good to see your sense of humor hasn't changed since you had a daughter lol

He had a daughter? How did I miss that?

Congrats wings!

[Maxim]

Originally Posted by serialk11r

The thing is I've seen on the internet "active brake cooling" devices that are just small ducts with tiny fans. A wheel is rather large, even if it's not shaped ideally for pushing air, it is one big fan. I think at 60mph your wheels are spinning around 1000rpm or so (this might be completely wrong btw, I haven't bothered to think about it), which is actually pretty good. A 120mm low speed case fan spinning at 1200rpm pushes a pretty good amount of air. If you use the whole rim as a fan (albeit a not so ideally shaped fan) you can likely provide more cooling than a typical duct.

The actual power it takes to do this is pretty small, on the order of 10s or hundreds of watts most likely. Think a cooling fan for your house (do people in America even use them? lol). The really fat ones are like 300W, but they spin rather fast and have crazy huge blades. Also remember that most rims aren't very aerodynamic anyways and have some sort of loss to aerodynamic drag via spinning anyways. We could go further, use a centrifugal type blower fan and a housing that threads through the hub, and use it to directly enhance airflow around the side of the car but that would be rather complicated and mostly pointless.

And you don't need left and right wheels, they all blow outward.

No, if you swap a wheel/tire to the opposite side of the car, the rim will be flipped backwards. It can be somewhat difficult to mentally rotate that in your head, but if you have a small fan handy you can get an easier, physical example of it. Take a fan and set it facing you, then note the direction the blades are traveling on the upper 180 degrees. Now, turn the fan so it's facing away from you. The air will be blown away from you, but the upper 180 degrees of the blade rotation will be opposite what it was before. With a car, since both left and right tires are rotating in the same direction (unlike the fan example), that means that the airflow would be reversed.

And you are right, it's about 1000rpm, depending on wheel diameter. But a fan rotating at that speed will not produce the same airflow if it has to suck air that is already traveling at high speed in a perpendicular direction. A large proportion of the possible thrust would instead be consumed in turbulance. Helicopters, with their rear tail rotars, have to counter this by increasing the tail rotational speed at between a 3:1 and 6:1 ratio with the main drive-shaft. In an automotive equivalent, this means that the rim rotation would have to increase at a multiplicative rate to the speed of the drive-shaft in order to maintain the same helical thrust on the surrounding air. Because rims are several orders of magnitude larger in diameter than the driveshaft, and connected via a reduction gear, they are always spinning at a fraction of the speed, meaning that the faster the car goes, the less effective the rims would become at producing a suction - the exact opposite of the desired effect. And the turbulance would greatly increase aerodynamic drag as well.

Originally Posted by Dimman

I believe this was tried in the 70s and 80s on certain racing cars but I don't know if it was for brake cooling, or to pull air out of underneath for downforce, or why it stopped. Maybe they could try again with better computer designed spokes/fan blades? (But I don't know if I would go for the looks...)

Something like it was tried in the 70's and 80's. However, the fan was completely separate from the rims, and it was oriented up and down, not side to side. It also functioned using a multiplicative gear-set (just like a helicopter tail rotor), as opposed to a tire rim, which uses both the transmission and differential as a reduction gear....the exact opposite. It was outlawed because it worked too well.

Sorry for the fluid dynamics and mechanical engineering lesson. I promise I'm done.

[Sea1monkey2]

Because i'm so impatient, i made these real quick, here ya go guys... and thanks to wings for the gorgeous body chops

[ichitaka05]

Originally Posted by Sea1monkey2

Because i'm so impatient, i made these real quick, here ya go guys... and thanks to wings for the gorgeous body chops

WOW that red is hella awesome red!!!!!! Chrome red? Thanks Sea1!

[Maxim]

Originally Posted by ichitaka05

WOW that red is hella awesome red!!!!!! Chrome red? Thanks Sea1!

I hate chrome with a passion. EW EW EW EW EW GROSS.

Function is beauty. Performance is function. Chrome adds weight while increasing required upkeep and cost.

Out satan, out!

[Sea1monkey2]

I'm not really a fan of chrom either. When i get this car, i plan to go gunmetal with darg grey/black trim. I was trying more to go for the fr-s color but laziness and they way wings made the original made it tough.

Here's take2 on the fr-s red

[Want.FR-S]

Originally Posted by Maxim

Something like it was tried in the 70's and 80's. However, the fan was completely separate from the rims, and it was oriented up and down, not side to side. It also functioned using a multiplicative gear-set (just like a helicopter tail rotor), as opposed to a tire rim, which uses both the transmission and differential as a reduction gear....the exact opposite. It was outlawed because it worked too well.

Sorry for the fluid dynamics and mechanical engineering lesson. I promise I'm done.

According to GT5, the Chaparral 2D/2J use the fan to *suck* air out under the car to improve traction. This is also done on that Red Bull X1. Yes, it was banned because it worked too well to give unfair advantage, and similarly the ground effect on F1 cars in 70/80's.

As Maxim pointed out, using the rim as a fan will have its complication. However, to solve the problem of brake cooling by air, I wonder if we can either do the two things: channel air from undercarriage or from the front bumper. If it is designed right, the air directed from undercarriage can be directed towards the hub to cool the rotor and then be directed again not hitting the rim because it could create turbulence. I think the design study on Red Bull X1 reflects this so that they put a wheel cover to stop air from going out of the rim (but then how do you change the tire.....). On the other hand, if you simply punch holes on the wheel arc or front bumper, the air may not enter the hub for brake cooling. It may just cool the tire for that effect.

Hmmm.. this is harder than it seems to be.

[Maxim]

Originally Posted by Want.FR-S

According to GT5, the Chaparral 2D/2J use the fan to *suck* air out under the car to improve traction. This is also done on that Red Bull X1. Yes, it was banned because it worked too well to give unfair advantage, and similarly the ground effect on F1 cars in 70/80's.

As Maxim pointed out, using the rim as a fan will have its complication. However, to solve the problem of brake cooling by air, I wonder if we can either do the two things: channel air from undercarriage or from the front bumper. If it is designed right, the air directed from undercarriage can be directed towards the hub to cool the rotor and then be directed again not hitting the rim because it could create turbulence. I think the design study on Red Bull X1 reflects this so that they put a wheel cover to stop air from going out of the rim (but then how do you change the tire.....). On the other hand, if you simply punch holes on the wheel arc or front bumper, the air may not enter the hub for brake cooling. It may just cool the tire for that effect.

Hmmm.. this is harder than it seems to be.

No no. Don't let my digression into horrible flashbacks of college distract you from how simple it is to add functional brake ducting to a car.

In the case of a lack of ducting, holes in the bodywork can be cut. From there, cutting a hole in the back structure behind the bodywork, and welding in a couple flat pieces of thin steel can direct airflow out towards the brakes.

It's just that you then have to cleverly disguise said holes in bodywork, not to mention get somebody to actually do this custom job, regardless of how simple in execution it really is. It's a simple solution to a simple problem.....which means it SHOULD be provided at the freaking factory.

We don't know yet that there aren't panels directing some airflow from the gaping maw on the car....it's perfectly possible that they're there. However, if they're not, that is indicative of Toyota/Subaru putting style before substance on the car, going for a sleek look rather than functional bodywork. That suggests there may be other areas of the car where the same reasoning was used.

Just something to think about. No way to tell if it's correct or not at this point.