Rumor: New M3 to get newly developed 3.2L inline six turbo

[hotrodalex]

There's definitely lag in the 2.0T, but I'm not sure that any similar NA engine (size and output) would be making any more power in the band where the 2.0T is below the boost range--which kicks in around 2000.  I mean, people talk about "throttle response" on NA engines like they make peak power from idle to redline. 

Mine is close, if you set the redline to 4500-5000.

[MX793]

There's definitely lag in the 2.0T, but I'm not sure that any similar NA engine (size and output) would be making any more power in the band where the 2.0T is below the boost range--which kicks in around 2000.  I mean, people talk about "throttle response" on NA engines like they make peak power from idle to redline. 

My car makes >90% of peak torque from 2200 to 6400 RPM.

Also, turbo lag is somewhat RPM independent.  It's not like an NA engine where you know if you're above or below a certain RPM, the engine is going to be in or out of its power band.  If you take off from a stop aggressively in something like a 2.0T, the turbo will spool up pretty quickly and by 2300 RPM or so (IIRC, those make pretty good torque on the bottom if you're WOT), you're at full boost and hauling ass.  But if you're cruising along at partial throttle at 2800 RPM, the turbo won't be fully spooled and if you suddenly floor it, there will be a little lag while the turbo winds up.

Another issue with turbos is heat soak.  I always have to laugh at the autoX when you see all of the guys with turbo subies (which last year was like half of the group) in the staging line with their hoods up, hopping out of their cars every 2 minutes to spray their intercoolers down with water.

Of course, if you live at altitude, like Colorado, it's hard to beat a turbo.  They adapt well to altitude and air density changes.  They don't lose nearly as much power in thinner air and boost pressure is typically controlled by pressure, so the various control valves simply stay closed longer in thin air so that you maintain closer to your design boost level.  Superchargers don't adapt as well, but if they are designed so that the bypass valve has to open pretty much all the time at lower altitudes, they'll maintain pretty close to their normal boost level as the air gets thin.

[sportyaccordy]

You can get decent torque from basically idle to redline w/o a turbocharger OR VTEC if you work at it.







And with all that fancy VTEC VVT stuff forget about it. Yea an N/A engine won't make peak torque from idle to redline. But when effort is made they have way flatter torque curves than turbo engines. W/a turbo engine you have to choose between low end or top end, or go with a super complex sequential turbo system (that they don't even do anymore outside of diesels).

Plus even if you choose low end, you don't always get it, because unlike an N/A engine a turbo engine needs time to spool. Even if its a tiny ass turbo. So in first gear, where you generally actually need that off-idle torque, physics dictate you won't get it. For a given displacement, its better than nothing I guess. But I would rather the displacement, and none of the turbo sorcery.

[Vinsanity]

Turbos rule. 

moar pistons > turbo

[S204STi]

I much prefer a supercharger too, if someone sticks a gun in my face and makes me choose F/I that is...

The supercharger is simpler, more robust, less complicated (in control), and lag free. Audi has done a great job with it.

Any power booster that is effectively parasitic seems less desirable to me, hence my preference for Turbos which basically make use of otherwise wasted energy.

[S204STi]

You can get decent torque from basically idle to redline w/o a turbocharger OR VTEC if you work at it.



And with all that fancy VTEC VVT stuff forget about it. Yea an N/A engine won't make peak torque from idle to redline. But when effort is made they have way flatter torque curves than turbo engines. W/a turbo engine you have to choose between low end or top end, or go with a super complex sequential turbo system (that they don't even do anymore outside of diesels).

Plus even if you choose low end, you don't always get it, because unlike an N/A engine a turbo engine needs time to spool. Even if its a tiny ass turbo. So in first gear, where you generally actually need that off-idle torque, physics dictate you won't get it. For a given displacement, its better than nothing I guess. But I would rather the displacement, and none of the turbo sorcery.

First gear is usually the last place you'll notice turbo-lag; it's usually in transient response in a taller gear that you notice it.  At any rate, as Raza pointed out, even out of peak boost most turbo cars still make more power than their NA counterparts.

[SVT666]

Any power booster that is effectively parasitic seems less desirable to me, hence my preference for Turbos which basically make use of otherwise wasted energy.

Yeah.  I mean, look at the GT500.  It makes 662 hp, but the supercharger alone requires 125 hp to operate.  That's a lot of unused power.  I prefer turbos to superchargers, but I prefer NA to everything.

[68_427]

I read at WOT the GT500's supercharger require 150hp.  So the engine+ supercharger are kinda almost making 800hp.. :P

[Soup DeVille]

Yeah.  I mean, look at the GT500.  It makes 662 hp, but the supercharger alone requires 125 hp to operate.  That's a lot of unused power.  I prefer turbos to superchargers, but I prefer NA to everything.

its not unused power: its used to turn the supercharger.

[SVT666]

its not unused power: its used to turn the supercharger.

If I understand things right, the engine is actually putting out around 800 hp, but 125-150 of it is being used to turn the supercharger.  That's horsepower not going to the road.  That's why supercharged engines typically don't get very good gas mileage compared to similarly powerful turbo or NA engines.  I could be completely off base, but that's how I understand it.

[Soup DeVille]

If I understand things right, the engine is actually putting out around 800 hp, but 125-150 of it is being used to turn the supercharger.  That's horsepower not going to the road.  That's why supercharged engines typically don't get very good gas mileage compared to similarly powerful turbo or NA engines.  I could be completely off base, but that's how I understand it.

Without the supercharger, the  engine could not make that 800 HP though, could it? You can't just regard the blower as a parasitic loss like you would an alternator or a power steering pump. Its part of the horsepower producing system.

Yes, its overall a lower efficiency design, but you can't really say the power used to turn the supercharger is unused: its used to make power!

[SVT666]

Without the supercharger, the  engine could not make that 800 HP though, could it? You can't just regard the blower as a parasitic loss like you would an alternator or a power steering pump. Its part of the horsepower producing system.

Yes, its overall a lower efficiency design, but you can't really say the power used to turn the supercharger is unused: its used to make power!

I've wrestled with the argument in my head and I understand what you're saying.  But a turbo wouldn't eat up all that power and it would be much more efficient at producing that 662 hp. 

[Soup DeVille]

I've wrestled with the argument in my head and I understand what you're saying.  But a turbo wouldn't eat up all that power and it would be much more efficient at producing that 662 hp. 

Yes, it would; and a key point is that that mechanical stress is NOT added to the motor's bottom end the way it is on a supercharger.

I guess a fair way to say what you're saying is that a supercharged engine that produces 650 HP at the flywheel and uses 100 HP to drive the blower is under the same strain at the crank as if it were producing 750 HP.

[Colonel Cadillac]

I do hope the ATS-V sticks with the Corvette V8, but I doubt it will. I'd rather have a similarly powered NA V8 than an turbo-6 in this type of vehicle

(On the other hand, I would probably go for the EcoBoost F150 vs V8 F150)

[sportyaccordy]

I've wrestled with the argument in my head and I understand what you're saying.  But a turbo wouldn't eat up all that power and it would be much more efficient at producing that 662 hp. 

Thats true. A turbo does essentially utilize waste heat to make power. But to do so it comes with a lot of caveats/compromises. Supercharger makes power like a normal engine.

I do hope the ATS-V sticks with the Corvette V8, but I doubt it will. I'd rather have a similarly powered NA V8 than an turbo-6 in this type of vehicle

(On the other hand, I would probably go for the EcoBoost F150 vs V8 F150)

Very interesting....

[LonghornTX]

Unfortunately the ATS-V will also be FI

Where did you hear that?

[sportyaccordy]

Unfortunately the ATS-V will also be FI

Says who????

[hotrodalex]

I would assume it's going to use the LSA, like the CTS-V.

[TurboDan]

VWAG 2.0T definitely has some lag; not huge but it's there (and of course M/T will accentuate this).

The 2.0 has a lot less lag than the 1.8T. Personally, I liked/like both engines a lot. The lag makes your car a sleeper, and it's tons of fun to accelerate on the highway to change lanes, blow past someone, etc.

[nickdrinkwater]

The only good sounding turbo 4s Ive heard are turbo DOHC VTEC Hondas. Turbod I6/V8s sound good, but N/A I6/V8s sound better. And I don't think BMW had a choice.

The BMW 2.0 turbo engine in the 528i sounds really good, at least the one I saw the other day did