• We’re currently investigating an issue related to the forum theme and styling that is impacting page layout and visual formatting. The problem has been identified, and we are actively working on a resolution. There is no impact to user data or functionality, this is strictly a front-end display issue. We’ll post an update once the fix has been deployed. Thanks for your patience while we get this sorted.

The new WRX

Page 3 - Seeking answers? Join the AnandTech community: where nearly half-a-million members share solutions and discuss the latest tech.
There is no way the mirrors, exhaust, or wheelbase will survive the transition to production, but yeah...please take my money.

neither will the carbon fiber roof. Actually, I think a lot of the concept won't make it to production
 
neither will the carbon fiber roof. Actually, I think a lot of the concept won't make it to production

I wouldn't expect a carbon fiber roof for the WRX. Wheelbase I hope stays, but the mirrors/exhaust/diffuser can all be added via aftermarket.
 
Off the top of my head, the Pontiac Solstice, the new VW Beetle, the Porsche Boxster, and the Chevy Camaro were nearly identical to their concepts.

Don't forget the Viper (both RT/10 and GTS).

Yes many cars get totally butchered by the time they reach production (Volt anyone?) but a few make it through relatively unscathed.

Viper GTS
 
I'm pretty sure getting decent boost would require an effing starter motor bolted to the compressor. One capable of many tens of thousands of RPM.

And you couldn't 'regenerate' with it for multiple reasons that I really don't want to try to get into. Most importantly is the lack of mass...braking the compressor wheel with electromagnets would...well, probably break the compressor wheel. It would be like compressor surge from hell, I would think.

Yes energy density is an issue (they wouldn't be able to offer limitless electric boost), its just used to improve it (just spinning up the turbo faster so that the engine pressure can take over as the force). It needs to be well integrated and designed to offer advantages but that's pretty true in general.

That's why it wouldn't be done when you need the power but rather when you're letting off the power or when there's an overabundance of boost pressure so that you wouldn't be hitting it when you actually need the compressor boost. I don't really get what your argument is, this already exists, but there are issues that make it not feasible for mass production in cars yet. IIRC BMW, Porsche, and Ferrari are all working on it and I'm sure others are as well.

They wouldn't likely replace an alternator with it, but it could conceivably do that with improvements.

http://www.autospeed.com/cms/articl...ution-The-Coming-Technologies-Part-2&A=110994
 
Haha, Subaru concept car... they show us cool drawings that looks like this:
2014-Subaru-WRX-C-Carscoop.jpg


But then the actual production car looks like this:
2009-toyota-corolla-s-photo-401908-s-1280x782.jpg

LOL that cracked me the hell up. :biggrin:
 
Yes energy density is an issue (they wouldn't be able to offer limitless electric boost), its just used to improve it (just spinning up the turbo faster so that the engine pressure can take over as the force). It needs to be well integrated and designed to offer advantages but that's pretty true in general.

That's why it wouldn't be done when you need the power but rather when you're letting off the power or when there's an overabundance of boost pressure so that you wouldn't be hitting it when you actually need the compressor boost. I don't really get what your argument is, this already exists, but there are issues that make it not feasible for mass production in cars yet. IIRC BMW, Porsche, and Ferrari are all working on it and I'm sure others are as well.

They wouldn't likely replace an alternator with it, but it could conceivably do that with improvements.

http://www.autospeed.com/cms/articl...ution-The-Coming-Technologies-Part-2&A=110994

Will mark article for later.

Just wanted to explain that what I mean is that the drag from electricity generation seems like it would do little to nothing. If the throttle closes and you're under decel, there isn't going to be anything of significant driving the turbine, and the compressor wheel will have forces pushing against its typical direction of travel (surge). Adding a generator to such a lightweight part is just going to make it stall.

Spooling the turbo might be a more valid use, but that seems like a 'performance only' kinda thing...you're not getting economy from that; you're using stored energy to keep the turbine spinning at a reasonable RPM, which would be for throttle response, not efficiency.

You could make the turbo spool faster, I guess, but I'm not quite seeing how it would spool earlier in the RPM range...I guess it would be like increasing the efficiency of the turbine relative to the exhaust pressure/heat. I would think you'd need some kind of overrunning clutch to let the turbo/electric motor connection freewheel once it hits a certain speed.

Trying to maintain spool under closed throttle seems like a lost cause, though. You're just be pumping air against the throttle plate and wasting energy. But yeah, thinking about it more, I can see how it would make for overall quicker spool. I.e. you're going to start at the same absolute pressure as you would without the electric assist; it'll just build faster. Initially I was thinking in terms of actually keeping the turbo spinning like an anti-lag system.
 
I still find the overall styling rather 'cookie-cutter'. But it does look good.

The rear haunches are a nice touch that I don't seem to see much (lot of 'sab-sided' cars out there). And I actually am really digging the lights. ATTN: luxury carmarkers- light tubes are how you use LEDs. At least I assume that's how the front of this is done.

And yes, I know a WRX is not a luxury car. I just don't understand when/why stupid-ass light dots became 'classier' than properly-done lighting.
 
Efficiency for high power applications. You're decoupling a direct kinetic link between the engine (belt/exhaust gas turbine) for an electric generation method of some kind (regenerative braking? bigger alternator?) to produce the additional necessary power to spin the turbo up.

Extra complexity for limited / no gain at high HP. Why?

It's fine for low pressure, high efficiency engines maybe. But it's not an enthusiast level solution by any means.

Why don't we instead work on superchargers with gearboxes or something for more low end variable grunt then?

You obviously have absolutely no idea how much power is required to provide a meaningful amount of boosted intake pressure. Ideal power values for the compressor side of the turbo on a typical car are around 10-30hp. My MS3 usues roughly 25hp to compress intake charge air at ~300bhp and ~16psi of boost (31psi absolute). Feel free to examine various power/boost pressure values with this calculator: http://www.engineeringtoolbox.com/horsepower-compressed-air-d_1363.html assume ~1.5 CFM of flow for every 1bhp.

What does 25hp mean in a 12vdc eletrical system? About 1550A of current. That is a serious alternator and wiring, which is totally impractical. Only a high-voltage system like those used in hybrid cars could possibly supply this level of power in a reasonable way, but now you're lugging around a hybrid system (more or less) with no regenerative braking capabilities, so all the recharging comes from what? Another alternator? dc-dc converter? The bottom line is that the electrical systems required to support any meaningful level of electric supercharging is heavy, expensive, and possibly dangerous with a possibly minor gain in performance. Let's leave aside the fact that you'd have to try to interface an electric motor and/or geartrain with something that is spinning at 100,000-200,000rpm.

Need I go on?

Sequential turbochargers, twin-charging (turbo and supercharger together), and variable pitch turbochargers all do what you think an electric supercharger should do for less weight, money, and complexity. Yet we rarely see these systems on production cars because the benefits rarely outweigh the costs.

Do not forget: anything is possible if you have no idea what you're talking about.
 
You obviously have absolutely no idea how much power is required to provide a meaningful amount of boosted intake pressure. Ideal power values for the compressor side of the turbo on a typical car are around 10-30hp. My MS3 usues roughly 25hp to compress intake charge air at ~300bhp and ~16psi of boost (31psi absolute). Feel free to examine various power/boost pressure values with this calculator: http://www.engineeringtoolbox.com/horsepower-compressed-air-d_1363.html assume ~1.5 CFM of flow for every 1bhp.

What does 25hp mean in a 12vdc eletrical system? About 1550A of current. That is a serious alternator and wiring, which is totally impractical. Only a high-voltage system like those used in hybrid cars could possibly supply this level of power in a reasonable way, but now you're lugging around a hybrid system (more or less) with no regenerative braking capabilities, so all the recharging comes from what? Another alternator? dc-dc converter? The bottom line is that the electrical systems required to support any meaningful level of electric supercharging is heavy, expensive, and possibly dangerous with a possibly minor gain in performance. Let's leave aside the fact that you'd have to try to interface an electric motor and/or geartrain with something that is spinning at 100,000-200,000rpm.

Need I go on?

Sequential turbochargers, twin-charging (turbo and supercharger together), and variable pitch turbochargers all do what you think an electric supercharger should do for less weight, money, and complexity. Yet we rarely see these systems on production cars because the benefits rarely outweigh the costs.

Do not forget: anything is possible if you have no idea what you're talking about.

I completely agree with this, and it's pretty much what I thought of when someone combined the words 'electric' and 'turbo'. However, where did you get 1.5cfm per 1hp?

For one, that doesn't seem to agree with the linked site (looks more like 10cfm/hp at lower pressure levels)...but also, should it be lb/min per hp? As in, you'd want to measure air by mass, not volume, which will constantly vary?

Your hp estimates seem good, though. If I use some basic assumptions to go from cfm to lb/min and look at compressor maps for some smaller turbos (like what would be on many factory boosted four cyls), it's gotta be solidly in the 10-15hp range just to get into the turbo's efficiency range (but far below maximum boost pressures).

I think that's more the idea- getting into the territory where spool is occurring quickly. And (playing devil's advocate here) the electric motor would not be accomplishing this task on its own. As RPM builds, the exhaust is obviously going to act on the turbine more and more, giving it inertia and decreasing the load on the electric motor. It seems like it would be a pretty complex relationship.

Basically, if the motor is capable of the speed, can accelerate fast enough, I can see it working. You'd still need a good 5hp or more, I'm guessing. That's starter motor territory.

The speed just seems unfathomable, though.
 
Electric turbo. LOL

I remember a guy who seriously tried to make a electric blower and learned the hard way.

Ended up with like 3 x 20 HP electric motors or something like that turning an Eaton blower and could only make like 3 psi.

People just dont realize how much mechanical power even a small gasoline engine produces.
 
Last edited:
Right, but that would be unassisted. The turbo would have help from the exhaust. Plus, again, don't think in terms of building boost. To combat lag, the goal would mostly just be to remove vacuum and get into >atmospheric pressures.

(I still think it's dumb; I'm just trying to see some benefit. I don't think Subaru would be effing with it if it was truly a 100% useless endeavor.)
 
Well, that turned out looking worse than I expected. I wanted something to bring back the GC body style...
 
I completely agree with this, and it's pretty much what I thought of when someone combined the words 'electric' and 'turbo'. However, where did you get 1.5cfm per 1hp?

For one, that doesn't seem to agree with the linked site (looks more like 10cfm/hp at lower pressure levels)...but also, should it be lb/min per hp? As in, you'd want to measure air by mass, not volume, which will constantly vary?

Your hp estimates seem good, though. If I use some basic assumptions to go from cfm to lb/min and look at compressor maps for some smaller turbos (like what would be on many factory boosted four cyls), it's gotta be solidly in the 10-15hp range just to get into the turbo's efficiency range (but far below maximum boost pressures).

I think that's more the idea- getting into the territory where spool is occurring quickly. And (playing devil's advocate here) the electric motor would not be accomplishing this task on its own. As RPM builds, the exhaust is obviously going to act on the turbine more and more, giving it inertia and decreasing the load on the electric motor. It seems like it would be a pretty complex relationship.

Basically, if the motor is capable of the speed, can accelerate fast enough, I can see it working. You'd still need a good 5hp or more, I'm guessing. That's starter motor territory.

The speed just seems unfathomable, though.

The 1.5cfm/1bhp is for intake flow to engine output power, the calculator shows power required to actually compress the air. Yes, lb/min is more consistent, the assumption made is that cfm is at standard temperature and pressure and should only be used as a rough estimate.
Unless you really want to convert lb/min every time.
 
Electric turbo. LOL

I remember a guy who seriously tried to make a electric blower and learned the hard way.

Ended up with like 3 x 20 HP electric motors or something like that turning an Eaton blower and could only make like 3 psi.

People just dont realize how much mechanical power even a small gasoline engine produces.

That's a supercharger and yeah there's major energy density issues (being able to provide enough current) that make it very unfeasible.

Actually go read up on this ("electric" turbo), its not getting rid of the mechanical aspect of a turbo at all, its putting electric components in it so that they can manage the turbo spooling even better, thereby making the turbo more efficient/beneficial. This isn't pie in the sky stuff, they've already made this stuff and are working to make it feasible for production in cars (and trucks).
 
Last edited:
That's a supercharger and yeah there's major energy density issues (being able to provide enough current) that make it very unfeasible.

Actually go read up on this ("electric" turbo), its not getting rid of the mechanical aspect of a turbo at all, its putting electric components in it so that they can manage the turbo spooling even better, thereby making the turbo more efficient/beneficial. This isn't pie in the sky stuff, they've already made this stuff and are working to make it feasible for production in cars (and trucks).

Can you please link a published paper or article about this?
 
Saw the concept in person yesterday. It doesn't look that good in real life. Pictures are doing this car more justice than it deserves. It honestly looks like crap in real life, even though it's literally only a shell on wheels.

I was much more impressed with this beauty.

benz.jpg


Hell, even the IS250 looked nicer. And the IS250 looked rather...plain in person.
 
Last edited:
You obviously have absolutely no idea how much power is required to provide a meaningful amount of boosted intake pressure. Ideal power values for the compressor side of the turbo on a typical car are around 10-30hp. My MS3 usues roughly 25hp to compress intake charge air at ~300bhp and ~16psi of boost (31psi absolute). Feel free to examine various power/boost pressure values with this calculator: http://www.engineeringtoolbox.com/horsepower-compressed-air-d_1363.html assume ~1.5 CFM of flow for every 1bhp.

What does 25hp mean in a 12vdc eletrical system? About 1550A of current. That is a serious alternator and wiring, which is totally impractical. Only a high-voltage system like those used in hybrid cars could possibly supply this level of power in a reasonable way, but now you're lugging around a hybrid system (more or less) with no regenerative braking capabilities, so all the recharging comes from what? Another alternator? dc-dc converter? The bottom line is that the electrical systems required to support any meaningful level of electric supercharging is heavy, expensive, and possibly dangerous with a possibly minor gain in performance. Let's leave aside the fact that you'd have to try to interface an electric motor and/or geartrain with something that is spinning at 100,000-200,000rpm.

Need I go on?

Sequential turbochargers, twin-charging (turbo and supercharger together), and variable pitch turbochargers all do what you think an electric supercharger should do for less weight, money, and complexity. Yet we rarely see these systems on production cars because the benefits rarely outweigh the costs.

Do not forget: anything is possible if you have no idea what you're talking about.

Whoa whoa whoa, why are you railing on me? I said it was a horrible idea and outlined why.
 
I apologize. Your phrasing made it seem like you thought it was a great idea, though I may have been quite tired at the time.

😳
 
Back
Top