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

[WingsofWar]

Originally Posted by Maxim

Another issue. Even if there was no material behind the fogs, and it led directly on to the tires and into the wheels/brakes, if there aren't actual ducts to direct the airflow out via the wheels, you're letting considerably more air under the car....which results in lift.

with big retarded possibly non-functional vents in those fenders..im sure we can figure out a way to reduce lift if that was the case...again...ghetto fabulous.

[Maxim]

Originally Posted by serialk11r

Weird idea, but how about using the rims as a fan? It would suck air from the bottom of the car and improve aerodynamics as well. BMW has that duct that lets air move around the sides of the car, the increased velocity of air due to that type of thing could possibly draw air through the rotors as well...and what about attaching heatsinks to the pistons? lol sorry if these are silly just bored and throwing ideas out there.

I've thought about this too, but I don't think that the typical speed of a rotating wheel would provide any meaningful aero. If the wheels were shaped so severely as to create meaningful suction, they would also be creating a whole lot of resistance to rotation as well.

Plus, it would require rims to come in sets of "left" and "right." If you take the same rim and put it on the other side of the car....it's spinning in the opposite direction...so one side of the car would be sucking air UNDER the car while the other sucked it OUT. That would negate any aerodynamic benefits, and if the wheels were designed to create enough airflow to make a difference in brake cooling, it would also generate a distinct "pull" to one side at high speeds.

[WingsofWar]

Originally Posted by Maxim

Unfortunately, big, high quality brakes are almost a waste if the car doesn't have any ducting.

You've read Car and Driver's Lightning Lap story with the Nismo 370z right? Their 370z (equipped with huge brembos) boiled it's brake fluid and suddenly lost all braking power with no warning at 130mph. It hit the sidewall so hard that they had to use heavy towing equipment to pull it out of the wall. They did a big story on it afterwards too, to figure out exactly what went wrong. They concluded it was the ducting. Replacing the pads and fluid let the Z's brakes last much longer, but they still faded much more quickly than the 450lb heavier Camaro SS, which surprisingly experienced essentially no brake fade, even though it's braking surface area to weight ratio was worse.

http://www.caranddriver.com/features...ng_lap-feature

nice, i haven't read that article...thats pretty bad. While my R32 brakes wern't considerably big and fancy..they were brakes used in most of Nissans sports coupes, 300zx, s15..i just wanted something better than my small single piston small rotor front brakes. I just had never thought of ducting at the time....i think its been almost 10 years since then. Even with good rotor ventilation and a good alloy for heat dissipation..i thought it was enough. But running 90-110mph, then diving into hard braking into a corner..doing that probably 5-6 times in a row..i quickly learned i was dead wrong..I'm just happy that the brake fade didn't cause me to slam into a wall like that 370z.

[bofa]

Originally Posted by Maxim

Unfortunately, big, high quality brakes are almost a waste if the car doesn't have any ducting.

You've read Car and Driver's Lightning Lap story with the Nismo 370z right? Their 370z (equipped with huge brembos) boiled it's brake fluid and suddenly lost all braking power with no warning at 130mph. It hit the sidewall so hard that they had to use heavy towing equipment to pull it out of the wall. They did a big story on it afterwards too, to figure out exactly what went wrong. They concluded it was the ducting. Replacing the pads and fluid let the Z's brakes last much longer, but they still faded much more quickly than the 450lb heavier Camaro SS, which surprisingly experienced essentially no brake fade, even though it's braking surface area to weight ratio was worse.

http://www.caranddriver.com/features...ng_lap-feature

That's crazy. I'd expect much better from them...

[Maxim]

Originally Posted by bofa

That's crazy. I'd expect much better from them...

Really? Nissan has a history of lying about performance....

For example: the new GT-R isn't nearly as fast on the Ring as they claim.....Porsche BOUGHT one and let their best test driver lap in it to try and reproduce the times Nissan quoted and they were way off. A 3800lb car with 480hp and less tire simply cannot outrun a 3500lb car with better aero, tires, and brakes on a high-speed track like the ring, regardless of the wondrous electro-nannies.

They also originally shipped it with launch settings that destroyed the transmission in a very short amount of time. The original 350z (first few model years) also had a habit of grenading it's manual transmission...so frequently that Nissan had to install a heavier duty (and much heavier) transmission after the first model year.

They're not truthful about the weights of the Z either. They quoted figures more than 100lbs lighter than what anybody was getting when they took their car to a scale for both the 350z and 370z.

It doesn't surprise me one bit that they'd ship the track oriented variant of their sports car with brakes worse than a Camaro. Nissan is one of the few car companies that I genuinely do not trust.

[bofa]

Originally Posted by Maxim

Really? Nissan has a history of lying about performance....

For example: the new GT-R isn't nearly as fast on the Ring as they claim.....Porsche BOUGHT one and let their best test driver lap in it to try and reproduce the times Nissan quoted and they were way off. A 3800lb car with 480hp and less tire simply cannot outrun a 3500lb car with better aero, tires, and brakes on a high-speed track like the ring, regardless of the wondrous electro-nannies.

They also originally shipped it with launch settings that destroyed the transmission in a very short amount of time. The original 350z (first few model years) also had a habit of grenading it's manual transmission...so frequently that Nissan had to install a heavier duty (and much heavier) transmission after the first model year.

They're not truthful about the weights of the Z either. They quoted figures more than 100lbs lighter than what anybody was getting when they took their car to a scale for both the 350z and 370z.

It doesn't surprise me one bit that they'd ship the track oriented variant of their sports car with brakes worse than a Camaro. Nissan is one of the few car companies that I genuinely do not trust.

The only issue I heard about with the earlier Zs was tire feathering. My 2006 was lemon-lawed though for excessive oil consumption (they tried to blame aggressive downshifting in front of the arbitrator... ). My 08 has been much better though but i admittedly haven't had the time or money to put into it as previous cars. I guess I should probably not give them as much credit as I do... I think though, that regardless of the "performance brake option" offered, if you truly intend to track the vehicle, you are always better off going with an aftermarket setup.

[Maxim]

Originally Posted by bofa

The only issue I heard about with the earlier Zs was tire feathering. My 2006 was lemon-lawed though for excessive oil consumption (they tried to blame aggressive downshifting in front of the arbitrator... ). My 08 has been much better though but i admittedly haven't had the time or money to put into it as previous cars. I guess I should probably not give them as much credit as I do... I think though, that regardless of the "performance brake option" offered, if you truly intend to track the vehicle, you are always better off going with an aftermarket setup.

Yes, better parts are always available in the aftermarket....but I can't ignore the fact that during the same test, the heavy ass Camaro suffered from zero brake fade (and significantly faster lap times...). One of the reasons the Camaro is as heavy as it is lies in the fact that GM included extra cooling, larger than needed radiator, heavy duty brakes, a transmission oil cooler....basically a bunch of extra track-grade components...as standard...on the SS.

In fact, the 2010 SS completed the lightning lap only .3 seconds behind the 200lb lighter, track-package 2011 Mustang GT (which costs about 4k more than the Camaro it essentially tied). That's the same Track Pack 2011 Mustang GT that essentially tied the M3 in track performance....(the BOSS runs times comparable to a freaking R8. How nuts is that?!) The Mustang was also wearing significantly more aggressive rubber....

The 370z also has radiator issues. Both the Nismo and standard 370z are prone to slipping into an engine saving limp mode that lasts for 5-10 minutes after less than 10 minutes of track time. A large, aftermarket radiator completely eliminates the problem. The Nismo comes with a larger radiator...but it still suffers the problem because it's STILL not enough.

I just don't trust Nissan....they cut corners on their performance cars. I would rather a vehicle be built to take the type of punishment it's clearly intended to take and be 50-100lbs heavier than ship with substandard parts.

(by the way, your 08 350z has the most stoutly built parts that Nissan has put on a Z car...the transmission is fixed, the radiator is sufficient, and the brakes are better than the nismo 370z....so I wouldn't worry too much)

[WingsofWar]

^ urg..i hate agreeing with you sometimes..

im a big fan of Nissan from the 90s, but since Nissans CEO Carlos Ghosn took over..AKA Mr. Renault...the company is just...weird..especially with all their claims. I will never own a 350z ..after witnessing a friend of mine blow up 6 of them on the track. God rest his poor soul. And the GT-R transmission issue.....just put me over the edge with the company. I do have high hopes for a Silvia resurrection but at the same time scared they are going to butcher the car.

[bofa]

Originally Posted by Maxim

Yes, better parts are always available in the aftermarket....but I can't ignore the fact that during the same test, the heavy ass Camaro suffered from zero brake fade (and significantly faster lap times...). One of the reasons the Camaro is as heavy as it is lies in the fact that GM included extra cooling, larger than needed radiator, heavy duty brakes, a transmission oil cooler....basically a bunch of extra track-grade components...as standard...on the SS.

In fact, the 2010 SS completed the lightning lap only .3 seconds behind the 200lb lighter, track-package 2011 Mustang GT (which costs about 4k more than the Camaro it essentially tied). That's the same Track Pack 2011 Mustang GT that essentially tied the M3 in track performance....(the BOSS runs times comparable to a freaking R8. How nuts is that?!) The Mustang was also wearing significantly more aggressive rubber....

The 370z also has radiator issues. Both the Nismo and standard 370z are prone to slipping into an engine saving limp mode that lasts for 5-10 minutes after less than 10 minutes of track time. A large, aftermarket radiator completely eliminates the problem. The Nismo comes with a larger radiator...but it still suffers the problem because it's STILL not enough.

I just don't trust Nissan....they cut corners on their performance cars. I would rather a vehicle be built to take the type of punishment it's clearly intended to take and be 50-100lbs heavier than ship with substandard parts.

(by the way, your 08 350z has the most stoutly built parts that Nissan has put on a Z car...the transmission is fixed, the radiator is sufficient, and the brakes are better than the nismo 370z....so I wouldn't worry too much)

Hah, I had no idea. I stopped frequenting the Z forums once the 370 came out and I knew I was stuck in my 08 for a while. Plus forums have a sneaky way of making you spend more money... at least on this forum there's nothing to buy yet.

[Maxim]

Originally Posted by bofa

Hah, I had no idea. I stopped frequenting the Z forums once the 370 came out and I knew I was stuck in my 08 for a while. Plus forums have a sneaky way of making you spend more money... at least on this forum there's nothing to buy yet.

Yep. Internet forums make finding good parts (that somebody else already tested for you...hehe) much easier, which makes spending the money on them much easier which eventually results in spare organ sales and possibly hawking your neighbors wife on Ebay. But it's ok, because by that time there no WAY your neighbor will be able to catch you.

[Dimman]

Originally Posted by WingsofWar

with big retarded possibly non-functional vents in those fenders..im sure we can figure out a way to reduce lift if that was the case...again...ghetto fabulous.

?

[serialk11r]

Originally Posted by Maxim

I've thought about this too, but I don't think that the typical speed of a rotating wheel would provide any meaningful aero. If the wheels were shaped so severely as to create meaningful suction, they would also be creating a whole lot of resistance to rotation as well.

Plus, it would require rims to come in sets of "left" and "right." If you take the same rim and put it on the other side of the car....it's spinning in the opposite direction...so one side of the car would be sucking air UNDER the car while the other sucked it OUT. That would negate any aerodynamic benefits, and if the wheels were designed to create enough airflow to make a difference in brake cooling, it would also generate a distinct "pull" to one side at high speeds.

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.

[Dimman]

Originally Posted by serialk11r

The thing is I've seen on the internet "active brake cooling" devices that are just small ducts. 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.

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...)

[serialk11r]

It'd definitely be expensive to make a wheel that's both light and able to push good air most likely. Also since the brakes take up some space inside the wheel the fan would end up being thin and thus pretty low pressure, I don't really know how it would turn out, but just an interesting thought