yeah legacy was a twin turbo and the new legacy sti is a twin turbo in japan.

 

The current model legacy went back to single turbo as the twin turbo was pretty much crap.

 

Yes, Subaru Legacy B4 RSK, 280hp twin turbo, Very hot car. Owns the M3ish niche in Japan.

 

this is the Subaru Legacy B4 RSX

http://www.fantasycars.com/sedans/html/legacy.html

Okay, the RSX is no super car, but my point is we get the Type S here, but the Japanese get the Type R with brembo brake, 17" rims, 6 speed and 220hp.

 

I was under the impresssion the MR's tires were the same A046 Advans as on the base Evo and Evo RS. Even if they are different, the Evo's tires are extremely grippy - it'd be tough to considerably improve on that without totally destroying the tire life.

Dampers don't affect quasi-static cornering, which is what the skid pad test is. They have a huge effect on dynamic events, but when you're holding a constant radius and fairly constant speed, they don't come into play - only spring rates and sway bar stiffness.

What I highlighted in red is contradictory. To go faster through a turn, you need more grip. My understanding of AYC is that it gives the car more grip by using power distribution to aid the front tires in rotating the car (yaw). In a skid pad test (going counter clockwise), the back right tire would get more power than the back left, which would push the car around the circle at a higher rate than simply using the front tires' lateral forces. Depending on the effectiveness of the power distribution, this could contribute quite a bit of lateral acceleration.

 

don't dampers increase rebound rate if they are more stiff (i picture that if your damper were just a stick then your spring would never load at all, you'd get maximum rebound from shock, then again this is uncomfortable and you'd also get weight transfer too fast and that would decrease grip)? as in if they are stiffer they will reach that point where you can't compress them that much more faster (in the skid pad round the circle isn't this like... the spring is compressed in balance to support the car and the shock is loading on it's cushion of air and the air is compressed making some small amount of rebound effects)? i guess i'm just speculating and the reason i speculate is because in the road and track article it said you do get these new suspension components and you do get different tires (in japan), dunno what we get here, i don't think anyone does, but in the case of japan that's what it was and that's why i speculated the way i did.

ayc works by moving the outter wheel faster than the inner wheel, but it does so "intelligently" so you get a decreased slip angle = faster turn (especially theoretically), i find it hard to believe that this actually increases grip though because a tire only has so much longitudinal and latteral grip, anymore grip distributed towards the longitudinal direction through accelerating the wheel is going to take away from the lateral right? it's just in ayc cars this translates into faster turning because the outside of the car is "running away" faster than the inside of the car. i guess this could translate into skid pad g numbers, but again i'm not really sure. i'm not trying to say i'm right i'm really interested in what you have to say though, cuz honestly i'm not 100% sure.

 

I think you're missing a bigger part of the "big picture" of why we don't get those cars.

1) Until recently, how many people were willing to pay $50,000 for a Japanese high performance automobile of any make? Not many. Supra, RX7, and 300ZX sales tailed off greatly as the cost approached $40,000 for these cars. The NSX's sales fell rapidly as the price escalated from it's early 90s price of ~$60,000 towards $90,000 in the mid 90s. Some of the specialty models that you mentioned would have pushed the costs even higher. How many people would have paid $45-50,000 for a B4 RSK? Don't kid yourself - true enthusiasts of Japanese cars with that type of bankroll are few and far between in the US.
2) There's a huge engineering/service challenge in bringing these specialty cars to the US. We drive too much. Cars sold in Japan might see 3000-5000 miles in a year. Cars sold here might see 15000-25000 miles in a year. Things like HICAS and S-AYC might do fine for 15,000 miles (3 years driving in Japan), but not for 50,000. So they either have to be beefed up (R&D and manufacturing costs = $$$), more money has to be included for warranty work (further driving the selling price up), or the features get dropped for a more reliable, less expensive low-tech solution. Companies are leary of investing huge R&D money for a questionable market; raising the price is never a good option in a competitive market place; so we usually end up with the watered down version.
3) Certainly, as you said, the majority of Americans tend to favor luxury over performance. Car makers are in the business of selling cars in order to make money, so we're going to get what sells enough cars to be profitable. Luxury sells. Feature content sells. Insane performance only sells when the feature content and luxury is there (i.e. Porsche 911). Selling 500 $35,000 cars isn't profitable.

So, yes, it'd be awesome to get those niche cars just as they are in Japan. But I drive quite a bit, and I'd rather have cruise control than celebrate the origin of the car. It's just a car, any significance placed on it doesn't change that my right ankle is cramped after a 4 hour stint behind the wheel. If that makes me a whiner who's ruining the cars, so be it.

 

A spring creates force due to a change in position (relative to its no-load state); a damper creates force due to velocity. If you're going around the circle smoothly, the car should be balanced. In other words, the springs are not changing position, and therefore there's no velocity to create a force in the damper. So, the dampers have minimal effect on a skid pad. The tires could have a major impact, so if they are different (softer) that'd definitely be a factor.

 

Hmm, I think you're confusing things here.

In a normal steering system (ignore power for a second), the front tires create a side force via a slip angle, and it's this side force that actually turns the car at speed. It's not a linear rate, but more tire angle = more slip angle = more side force, up to about 15-20° of angle, after which the side force actually decreases. In normal driving, it's rare to see 10° of wheel cut, so this isn't that big of a deal. So, during our skid pad test, the front tires are creating a side force, right up to their peak lateral grip, but the rear tires are just rolling freely - they don't play a role in turning. Now, put power back into the equation - the drive tires (all 4 in this case) are also creating a longitudinal. In the rears, this is no big deal, as the tire wasn't under load before and you're not going to use all the tire with the limited power we have, but the fronts will "lose" a bit of lateral force in order to generate the longitudinal force*, though this isn't a 1:1 ratio either (i.e. you can gain 100 lbf longitudinal and only lose 40 lbf lateral)**.

So what does AYC gain us? Well, the rear outside tire has a surplus of grip available to it - if you apply a greater portion of the power, it can put it on the ground, and help rotate the car about its axis - increasing the yaw rate without requiring more slip angle of the front tires. You can do the same on the front outside tire, but it's already "used up" with generating the side forces, so the benefit isn't as great. If you wanted the absolute maximum yaw rate, you'd turn the front tires at about 20° and put 100% of the power to the outside rear tire. Of course AYC can't do this (and you wouldn't want to in driving/racing situations), but it does increase the yaw rate of the car - which shows up as g's on the skid pad and as insane handling on the track.

As an aside, the same principals of AYC are used in stability/traction control systems found on many cars. The main difference is that AYC uses power to increase yaw, stability control uses the brakes to decrease yaw.

* This is why FWD is undersirable - the front tires are overstressed.
** Look up "traction circle" on google if you want to read more on this.

 

^^^good post. it makes me sad that we probably won't get the sayc...i would have loved to test your theory at the track.

 

is my view of dampers wrong? is it not a closed adjustable volume cylinder with air in it. and hence if you change the volume of the cylinder without changing the concentration of air you will change the density of air and state ideal gas law blah blah makes more force on the "walls" of the cylinder? i mean yeah velocity does make the damper produce force, or probably more accurately a jolt, but i'm pretty sure in my thinking that dampers should create at least a negligible rebound if not more right?

i guess i don't have enough experience with with skid pads, seems a lot of what you're saying isn't negating what i said but rather just stating the natures of the skid pad test, although now that i think about it awd cars are in a unique position, they can have all 4 wheels moving, if you can get the outside ones to move more i gues that makes more grip, so i just didn't think that part through thoroughly enough.

 

1. You got it all wrong. Expensive Japanese/European cars are rare and buyers are few and far between every else in the world. You think you will see NSX type zero or R34 GTR in every street corner in Japan? Those exotic Japanese car are manufactured to showcase the company technology and as a statement piece. And make the rivals looks bad. Honda showed you the NSX vtec and want you to buy the civic vtec. At the same time, telling consumers that they are better than Toyota. BMW showed the M1 and expect consumers to buy the 325i. And tell people that they are more high tech than Mercedes. They do it for marketing purpose. Manufacturers lose big bucks on these type of vehicles. profit is not the primary concern.

Just look at those Group A (E30 M3 evolution II, 2.5 evo II, Cosworth RS500), Group B/Rally (Ford RS200, Lancia Delta Integrale HF, Renault R5 turbo) and DTM homologation car, manufacturers only make 200 - 500 copies to allow themselves to compete in the race, and they dumped millions of dollar into R&D. They are losing big money on every car they sell and all companies admit that. Have you notice the sales figure of just 2000 Lancer evo II sold in Japan and 502 Mercedes 2.5 evo II sold in Europe. They don't sell them in the US, because we have dumb car people and whiner in the US, and manufacturer doesn't think this type of advertisement work, not because of unwilling car enthusaists. Remember, the goal for speciality car is not profit, its marketing and image. Lancer Evo is the perfect example now, you think Mitsubishi is really relying on those 5000 evo a year to keep the company from sinking. They want the evo to help resurrect its image. The Evo ads money poured into the media are much more than Mitsubishi can ever make from selling the Evo. Porsche is also using the Carrera GT to strengthen its leading position in the sports car arena.

2. Again, you are wrong in several ways. Car sold in Japan or Asia doesn't just have 3000-5000 miles a year. We don't put 3-8 times more mileage (15000-25000) on our car than they do. On the average, the difference is more like 8000 vs 12000 miles a year. Super car has low mileage not because they are in Europe or Asia. It's because super car is impractical and not intended for everyday driving even if you wanted to. When I was younger, I sold my Merc C280 for a Ferrari 348TS telling myself I would use it for daily transportation. I was such an idiot. The car has no power steering, stiff clutch pedal, cops magnet, can't go over dips, can't easily get in&out of, passenger can't get in and out, insane gas consumption, constant loud engine noise, almost useless air-con, leaking targa top, poor visibility, rough ride and millions other reason which make it impossible to put high mileage on it. I put about 3000 miles a year which is consider kind of high among Ferrari owners. Do you see people put 15000-20000 miles in a Ferrari in the US? Another view is people who buy NSX or skyline will more than likely to have more than one vehicle which will further keep the mileage down. Its not because the owner is well off, they will at least have to go do some real shopping at Ikea or Home Depot.

3. Problem here again, Selling high end car is simply not too profitable or even down right stupid in someway. Ferrari makes more money on product endorsement than their car. Lotus is relying on contracting work to keep the door open. Lamborghini always has finanical problem and got bailed out many times. Bugatti never made a dime. Honda sells 800,000+ accord and civic and how many NSX? Ford sold more than half a mil F150 and how many cobra or GT? Do you know Porsche is actually doing really bad with their 911 and Boxster, the overall sales figure appear to be healthy because of the Cayenne SUV. Without the stupid SUV, Porsche sales chart slip might looks worst than Mitsubishi. 911 is not insane performance or luxury, it just has an insane price tag and thats why it does poorly in the showroom. Did you see the new 911? It cost $80k with a 300hp motor and a POS interior.

Quite honestly, either I have a weird body or you are super tough guy. I can't travel on my friend's STI for more than 1 hour much less 4. I rather do myself a favor by buying a 10 years old $2000 accord for those long trip.

 

wow people have alot of time on their hands. why not just say, hey, your right, and get on with your day hahah.

 

Yes.

It's a closed cylinder partially filled with oil. Air (most are actually charged with nitrogen) compresses very easily with the forces in effect (700-1000 lbs force), so the air really doesn't matter. A damper creates force by pushing oil through an orifice (actually many different orifices of varying shapes and sizes), and the force created is velocity dependant, not position (like a spring). The oil doesn't compress much, and as I said the air is there to allow the oil to flow.

In simplest terms, what I'm saying is that you could get the same skid pad result if the car had no dampers - the springs and sway bars are doing the work.

Your last point is right - all else equal, AWD > RWD > FWD for skid pad testing.

 

chantaiman51 -

With respect to #1, I didn't explain point #1 well. My point was that when a typical American has a lot of money to spend on a car (for arguments sake over $75,000), he's going to look at european exotics from Mercedes, BMW, Porsched, etc. People don't go to a Honda dealer and say "I've got 100 gs to drop on a ride, what do you have?" The mentality of typical American car buyers is that Japanese cars are inexpensive appliances. So, it's not that there are a ton of exotics in Japan or Europe, just that Americans looking at exotics typically don't look to the far east. Thus, we don't get the cool toys.

#2, you have a valid point, but any way you slice it our duty cycle is much higher in terms of absolute mileage.

#3, again a valid point, though you can't really compare Porsche's business model to Subaru's or Honda's model. Porsche (until the Cayenne) lived off the 911 sales. None of the other companies wants to lose money selling a car, some are just willing to accept it for brand image.

So, all in all, I mostly agree with you... just see things a bit different as far as justification (or lack thereof) for importing specialty models.

I spent 12 hours in a lowered NSX with racing seats yesterday. Didn't bother me a bit, and I greatly preferred it to the Acura Legend I spent 12 hours in on Friday. Maybe I'm weird, but it's just a lot more comfortable to me.