Subaru, Toyota will build small sports car

[DukeTrout]

Good point about the N/A engines. It looks like they are getting about 20 whp tuning the 2.5i N/A engines with both valve timing and lift systems. I'm not sure if they can squeeze more out of a 2.0 of either variety.

 

A rwd turbo version would be great, but that doesn't sound like the scope of this project. Maybe if it does well, they'll do one late in the model lifecycle.

[gcoonley]

I doubt that they would lower the compression as that is one of those things that are a win/win. Higher compression is one of the fastest ways to improve the efficiency of the engine. Plus it gives more power. So if they are going for good gas mileage that would be the wrong place to cut. But they could very well cut some other corners

to save costs that would effect power. Variable valve timing could be the first to look at. You could also try to reduce internal friction by removing one of the cam shafts.

 

Good gas mileage being the key would also indicate a good free flowing exhaust.

So that would help power as well.

 

The fastest way to reduce internal friction is to reduce the size of the engine. Like

going to a 1.8L from a 2.0L. Or change the gearing so the engine spins slower.

(But a 6 speed would do the trick and keep a good gear size)

 

But I am just throwing out some wild speculations.

[IwannaSportSedan]

The thing is, the newest rumor says they are cutting power, not raising it... I agree that raising compression can have a positive effect on efficiency, if it is exploited... but that seems to be the opposite of what the newest rumor seems to be saying.

 

And cutting it by 40hp is no small amount. Granted, I think they are wrong about which 2.0 boxer 4, but they do say it will still be 2 liters.

 

Dropping compression ratio reduces pumping losses. (it is easier to compress to 8x or 10x the pressure, than 12x, it takes less energy to force that volume down to size)

 

If they drop dual cams, and AVCS on top of that, they narrow the efficiency band of the valve timing, making the engine's peak efficiency RPM band narrower, not wider. Granted it would be less weight, and fewer moving parts, but ultimately reducing pumping losses by dropping compression ratio would probably be a greater gain.

 

And frankly, if they were going to drop DOHC, drop AVCS, and all that, they might as well use the old EJ20 SOHC engine, because that is the bargain basement configuration, and an engine that they already have.

 

If they were going to drop displacement, I would think that they would have mentioned it... but even aside from that... Subaru sells a 1.5 overseas as an economy engine, similarly without DOHCs and AVCS. Some of the first iterations of the EJ line were 1.8 liters...

 

The thing is, most high mileage cars ADD tech, unless they are also bargain basement price-point cars. Dual overhead cams with 4 valves per cylinder, and variable valve timing widens the efficiency curve of the engine. Any time an engine is running at an inefficient RPM, it isn't getting the mileage, or conversely the power that it could be, if the engine were running more efficiently at that RPM.

 

Since automobiles operate at a varialble speed, the wider the efficiency curve, the more widely efficient the engine can run at various road-speeds.

 

Plus, depending on the car's weight, being under-powered is no treat for gas mileage, if that puts the engine behind the 8-ball. If the engine is always struggling, and always requires more throttle input for average driving tasks, it is actually using more fuel to do the same work that a larger engine with more power can do with less fuel input.

 

If engine A is a tiny engine with little power, but at peak efficiency gets really good mileage, but has relatively little torque and horsepower...

 

And engine B is more moderate in size, with more power and torque, and gets pretty good mileage, but not as great as engine A...

 

A car of given weight, with engine A and engine B... if that weight requires engine A to be revved more often, and driven more forcefully to drive the way an average driver and traffic patterns require, it is drinking more fuel at higher rpms than it's peak mpg efficiency RPM range.

 

With engine B, the car requires less throttle input, less frequent high-RPM use, lower cruising engine speed, and while it might not meet engine A's peak number, Engine A might not reach it's peak number very often either... and Engine B might actually average out with higher mpg numbers, due to a lighter duty cycle to do the same work.

 

That is why large V8s with lots of power sometimes get better mileage than smaller, higher-strung engines. That is why some V8s aren't elligible for cash for clunkers, due to higher than 19mpg, where some 6-cylinders do qualify... And in slightly lighter cars, a V6 might have the same advantage over a 4-cylinder...

[gcoonley]

"IwannaSportSedan" I was commenting about your comment about lowering the compression ratio. You said they could be lowering it and I was explaining how that was doubtful even if their new goal was high gas mileage. I did not say anything about raising. I was saying they would at the very least keep it the same.

[IwannaSportSedan]

Higher compression is one of the fastest ways to improve the efficiency of the engine. Plus it gives more power.

 

You can't have high compression efficiency, and then magically cut 40 horsepower, without lowering compression.

 

4 horsepower, maybe.

 

It takes ENERGY to compress air/fuel mix into a smaller space. That energy is called pumping loss, because that energy is used to run the engine, rather than output.

 

The previous rumors have set the theoretical target at 2 liters, with ~200 horsepower. That reminds me of other engines like Honda S2000... hardly a low-tech engine.

 

If you cut 20% power off of that target some other way, you still have the compression pumping loss, and less energy with which to run that engine.

 

Secondly, I am not sure, other than completely choking off the intake and exhaust, how you would do that without lowering compression.

 

Choking off intake or exhaust, including the valvetrain settings, will make the engine less efficient across the board, and make the lower powerband also narrower. That isn't efficiency, that is less efficient by definition.

 

If this new Subaru/Toyota engine offers Direct Fuel Injection, which also has been rumored, the initial target compression ratio was probably pretty high...

 

Lowering that compression ratio instantly lowers output, AND pumping losses at the same time, while DFI, AVCS, and other tech that keeps the power band wider, stays intact, and continues to try to optimize more of the engine's RPM range.

 

So between choking an engine, or lowering compression, with the (IMHO, STUPID) goal of lowering power output in order to raise fuel efficiency... (also a somewhat false dichotomy, where gearing can offer better results)

 

I would choose to lower compression every time, and twice on sunday. the friction and inertia of a few more valvetrain contact points is nothing compared to the extra energy required to compress every piston, one per stroke, to higher combustion chamber pressure.

 

But, then again, I don't think they should be lowering the power level in the first place. I don't think they should be marketing a RWD sport coupe as an ECO-CAR, at all.

 

If they wanted a weak engine, they should have saved their R&D money, and pulled an old SOHC non-turbo boxer off the shelf, and dusted it off, instead. Because now the price of the car is going to have to pay back R&D costs on an engine development program, so the car's price point will have to be set accordingly... but if they cut the power, they are delivering less of their results for the price of the development.

 

And cracking open an engine in a brand new car, to re-do what the bean-counters took out, in their quest for "green", is expensive after the fact, and would tend to void engine warranty coverage.

 

It isn't just a knob that you turn to turn the engine performance back up to '11', when the bean counters turn it down to 6. It isn't as easy as a turbo engine, where the turbo basically makes cylinder compression a dynamic number through forced induction.

[HarryN]

http://www.worldcarfans.com/109080620923/toyota-ceo-confirms-sports-car-collaboration-with-subaru-is-a-go

 

It's a go.

[IwannaSportSedan]

Toyota's President, Akio Toyoda, has officially confirmed the company will team up with Subaru to develop a new sports car. The announcement, made at an industry conference in northern Michigan, puts to rest rumors that the car has been permanently canceled.

 

While few details were released, Toyoda said "I want to see Toyota build cars that are fun and exciting to drive." He added that the new sports car would help Toyota accomplish this goal and that he is "...very excited about it..." and plans to fast-track it.

 

The car is expected to feature sporty styling (as these rendering suggest) and a powerful but fuel efficient engine. Speculation seems to indicate that the car will come equipped with a 2.0-liter Subaru boxer engine that would produce between 118kW (160hp) and 147kW (200hp).

 

This is the second time the Toyota/Subaru sports car has been green lighted for production. Back in April 2008, Toyota and Subaru released a statement saying a new rear-wheel coupe would arrive in dealerships by the end of 2011. Less than a year later, the car was officially put on hold, when both companies announced the economic downturn had changed their priorities

 

Good to hear official confirmation.

 

The question is, what is it that got confirmed.

 

It is a coupe of some type.

It is RWD, evidently... (not trying to jump to conclusions, here... )

 

Evidently the horsepower level hasn't been nailed down, yet... and is 'speculated' somewhere between 160-200hp, but that is being called "powerful but fuel efficient"...

 

And the head of Toyota, Toyoda is "very excited about it...", and although not a direct quote, calls it a sports car.

 

---------------------------------------------

 

So, B4, is it a sports car or isn't it?

 

I have been the one saying that it is not, because it isn't a purely 2-seat, minimum practical dimensions design, dedicated to handling performance, regardless of power, which is what I classify a sports car as being.

 

This is likely to be a 2+2 sport coupe, and regardless, it probably won't weigh as little as a 2+2 Lotus Evora...

 

...so if the hp is close to 160, I think it will be under-powered for it's intended target. That is why I don't think it should be considered by Subaru or Toyota, as an eco-car, though either.

[SLegacy99]

I don't want it if its not AWD.

[gcoonley]

This is my last post on engine compression.

 

There is no modern engine developer that would lower the compression ratio

if they can run it at a higher compression ratio without side-effects.

The boost in thermal efficiency GREATLY exceeds any additional pumping loss.

 

I also have an pre-emissions corvette. About 2 years ago I rebuilt the motor

(Mostly for fun, there was nothing wrong with it) But in the rebuild the only change I made was a set of pistons and shaving the heads to increase the compression ratio.

 

I went from 8:1 to about 10.5:1. My gas MPG went from 16-17 to 20-22.

Plus it had more power.

 

So again only an idiot would lower the compression ratio to drop power due to the

corresponding loss in fuel efficiency. If one of their main goals is fuel efficiency then they would NEVER lower the compression ratio just to make the car have less power

[sactojesse]

This is likely to be a 2+2 sport coupe, and regardless, it probably won't weigh as little as a 2+2 Lotus Evora.

Why not? The U.S. spec. Evora is no lightweight at 3,050 lbs., almost exactly the same weight as a U.S. model Impreza 2.5i (3,053 lbs.) There's no reason why w/ RWD instead of AWD, Subaru can't make this vehicle around 2,800 lbs.

[IwannaSportSedan]

That is a fully loaded $60-80K aluminum chassis, mid-engined V6 lotus, with more than 250 horsepower, compared with a base configuration, no turbo, no options, maybe even no fuel onboard Impreza... but point taken...

 

2800lbs is about where I figured they would be, before this most recent rumor of cutting power, and cutting more weight.

 

Gcoonley...

The point is, they are talking about purposefully CUTTING power, not adding power.

 

And your point about it making more MPG is because the engine made more power without revving so much, and made more latent torque in the same car, thus the same weight. You are actually codifying my point that more power, and better gearing is the way to get better mileage. Plus on a V8, you are magnifying the effect of increased power, and latent torque providing better mileage, by more than 2 times what the effect would be on a 4 cylinder with less than half the displacement.

 

I am not disagreeing with what you are saying, in the context you discuss. I am saying that the rumor says that they want to cut horsepower, not keep it the same, not increase it.

 

I think it is stupid that they want to do that, especially that way. I think they should keep the compression ratio up, keep the power level up, gear the car properly, and let this new sport coupe be sporty, and get the mileage it gets.

 

But, removing the context of the car, and operating SOLELY on the fact that they are talking about cutting 40 horsepower from "x" where x=a given 2.0 liter boxer 4-cylinder, which is not 2%, but 20%... not an insignificant amount, the easiest way to do that stupid thing, would be to cut the compression ratio.

 

Cutting the valve-train tech, cutting the number of cams, or choking off the airflow, or running the engine hyper-lean (and thus hot) all the surrounding stuff is not that quick to do, and makes those systems less efficient overall, not just lowering peak output, and makes the efficient part of the RPM band narrower and less efficient in total.

 

That doesn't help their supposed MPG goal much at all, and just strangles the engine so that it doesn't run as well as it could at any and all points.

 

Again, I agree with you that cutting compression is not the thing they should do. I am just saying that their goals are crazy, but those goals are best acheived by lowering compression.

 

Frankly, not only do I think they should keep the compression ratio up, keep the Dual Overhead Cams, and the Active Valve Control System variable timing in place, and put in Toyota's D4-S direct fuel injection technology...

 

I think they should ALSO put Toyota's Valvematic variable valve lift technology on the engine. You can see at this link, how it works, and how it compares to BMW's Valvetronic, and Nissan's VVEL.

http://www.autozine.org/technical_school/engine/vvt_5.html

 

Frankly I think they should throw the kitchen sink at this engine, and make it burn as much energy out of the gasoline it drinks, as absolutely possible, and move air through the engine as best they know how... THEN they can gear the car properly so that it is fast when you want it to be fast, and cruise at modest RPMS, with enough power not to bog down, or require a heavy throttle foot to change the vehicle's speed.

 

Under-powered engines don't do cars any efficiency favors if they require a heavy foot to do what the driver needs the car to do. An optimum or slightly under-stressed engine that burns it's fuel thoroughly at as wide an RPM range as possible is more efficient.

 

But appliance buyers tend to think that fewer liters, and fewer horsepower = higher MPGs... and it just isn't that simple, and can sometimes be counter-intuitive to that simplicity.

[Guest]

I think they should ALSO put Toyota's Valvematic variable valve lift technology on the engine. You can see at this link, how it works, and how it compares to BMW's Valvetronic, and Nissan's VVEL.

http://www.autozine.org/technical_school/engine/vvt_5.html

 

Subaru has it's own variable lift tech, AVLS, present on 2.5i since MY06. Legacy's EZ30R has both AVLS and AVCS, not sure about EZ36R.

 

http://www.drive.subaru.com/Spring07_whatmakes.htm

[sactojesse]

That is a fully loaded $60-80K aluminum chassis, mid-engined V6 lotus, with more than 250 horsepower, compared with a base configuration, no turbo, no options, maybe even no fuel onboard Impreza... but point taken.

"Curb weight" by definition includes all fluids and a full tank of gas. IMO, a NA EJ25 AWD Impreza is a better basis for comparison than a $75K Evora, especially given the similarities between the Impreza and the proposed NA EJ20 RWD Toyo-Buru 2+2.

[IwannaSportSedan]

Subaru has it's own variable lift tech, AVLS, present on 2.5i since MY06. Legacy's EZ30R has both AVLS and AVCS, not sure about EZ36R.

 

http://www.drive.subaru.com/Spring07_whatmakes.htm

 

That is interesting info, but it isn't as variable as the other systems.

 

That AVLS lift system is analogous to original VTEC valve timing adjustment with binary operation... one lobe or the other, based solely on engine RPMs, and only activated above a certain RPM.

 

Valvetronic, VVEL, and Valvematic are more infinitely variable across the rev range, and have the capability of negating a butterfly valve throttle, if implemented with that in mind. It is computer map controlled, not solely controlled by engine rpm, thus can act on the engine with influence, rather than being acted on by the engine.

 

AVLS is not as advanced, although it is something demonstrable to aid high RPM breathing.

[IwannaSportSedan]

"Curb weight" by definition includes all fluids and a full tank of gas. IMO, a NA EJ25 AWD Impreza is a better basis for comparison than a $75K Evora, especially given the similarities between the Impreza and the proposed NA EJ20 RWD Toyo-Buru 2+2.

 

True, I was just trying to think of a lithe little exotic 2+2 to use as a foil in the discussion, and Evora's aluminum construction came to mind.

 

As I said, I figured about the same as your 2800lb estimate, for a GR-based 2+2.

 

I just have a hard time thinking they will cut hundreds of pounds more out of that, and still keep a 2+2 GR-chassis car in sheetmetal and glass, and components as robust as Subaru's reputation for reliability and longevity expects. Even without AWD. a front diff, and front half shafts don't weigh THAT much.

[MarcusDubya77]

looks like its back on!! supposed to debut at Tokyo Auto Show

[SubieDriver]

looks like its back on!! supposed to debut at Tokyo Auto Show

 

According to SOA_Blog on Nabisco, it was never off. The press gets their stories wrong so often, probably jumping to conclusions based on the weather or something, that they imagined it was an off-again, on-again affair.

[cheerio]

i dont know if u guys knew about this but figured ill post it...

 

http://www.edmunds.com/insideline/do/News/articleId=126521#3

 

http://a332.g.akamai.net/f/332/936/12h/www.edmunds.com//media/il/news/2008/0527/subarufr.500.jpg

[elpete77]

i would buy that and drive it around the city for a while.

[Platinum_Racing]

I wonder if they will eventually offer an AWD version?

 

220 naturally aspirated horses for under $20,000... Not to shabby if you ask me! I think it will be a hit, but the styling could be a little better. I'm sure most of that article is still speculation, and much will change, but it seems like a good platform for a new model.

 

I'm just wondering what Toyota has against releasing sports cars in the US. Are they trying to sell cars to yuppies and soccer moms only or something? Where did all the fun to drive Toyota's go?

 

I heard somewhere else this would be the new AE86, but I could be mistaken.

[cheerio]

personally i would prefer mines RWD so I can slide it around and have some fun DD, and keep my 05GT as my weekend car haha, then again im not that rich

[ehsnils]

Hmmm.... This looks like it can be upgraded to an AWD version, and then maybe be the platform to a new incarnation of the legendary STi 22B.

 

Give the engine something well over 300hp, good suspension and you have a new icon. At 1300 kg (2866 pounds) it's a bit on the heavy side for really high performance, but strip out some sound dampening, lighter seats and no back seat and you may have a real killer!

[lawl]

article is from 2008?

[NSFW]

Two naturally aspirated liters are going to make 220 hp? Is that remarkable or have I not been paying attention for a while?

[wengermi]

i think Hyundai already beat them to the punch...

looks like the new genesis