The new twin scroll 2.0 turbo
04-24-14, 11:56 PM
#91
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A good engine with good real world MPG is the GM V8. Particularly the 6.0L
It also sounds very nice with awesome performance.
It also sounds very nice with awesome performance.
Last edited by yowps3; 04-25-14 at 12:03 AM.
04-25-14, 06:47 AM
#93
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seems like the definition of turbo lag... now what takes "seconds" is probably combination of both - throtle input lag and turbo spooling to the maximum boost - it is not instant and while faster than before, it will never be instant. In modern turbo cars, throttle lag is more apparent as thats they way they "cheat" on MPG, so throttle is their way to limit the turbo initially as when using turbo, car spends a lot of fuel. In the end, it doesnt matter what it is really, you feel the lag, so wheather we call it turbo, throttle or turbo+throttle, it doesnt matter. So they could make it always responsive if they wanted to, but it would spend too much fuel then.
seems like the definition of turbo lag... now what takes "seconds" is probably combination of both - throtle input lag and turbo spooling to the maximum boost - it is not instant and while faster than before, it will never be instant. In modern turbo cars, throttle lag is more apparent as thats they way they "cheat" on MPG, so throttle is their way to limit the turbo initially as when using turbo, car spends a lot of fuel. In the end, it doesnt matter what it is really, you feel the lag, so wheather we call it turbo, throttle or turbo+throttle, it doesnt matter. So they could make it always responsive if they wanted to, but it would spend too much fuel then.
When this Lexus 2.0T comes out I'm expecting to hear two things. How much faster it is than the 4GR-FSE, but that it doesn't sound as good and maybe isn't as smooth. And also that they actually got better mileage with their 4GR!
If you've got your foot down and are making 260 ft-lbs of torque, you're burning MORE fuel than the 4GR at 185 ft-lbs or whatever it makes period. But the new 2.0T will definitely make 185 ft-lbs of torque more efficiently than the 4GR. But who on this board of enthusiasts will have the driving discipline to do that? LOL Regular people who baby their cars around will probably get both better mileage, and have a lot more power on tap when they need it. 
04-25-14, 07:03 AM
#94
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My only worry is refinement. I have never driven a 4cylinder where my hands weren't tingly from all the engine vibrations felt through the steering wheel. Sounding bad is one thing, but harsh vibrations is another and not very tolerable after a while.
04-25-14, 07:06 AM
#95
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^ Don't think you need to worry. In the case of the BMW 2.0T they've gone all out with dual balance shafts and active motor mounts, and even have active noise cancellation in the cars to cancel out some of the harsher noise. With Lexus' reputation for refinement, I'm sure they'll do no less. It'll still sound like a 4-cylinder though is the only thing.
04-25-14, 09:41 AM
#96
101
seems like the definition of turbo lag... now what takes "seconds" is probably combination of both - throtle input lag and turbo spooling to the maximum boost - it is not instant and while faster than before, it will never be instant. In modern turbo cars, throttle lag is more apparent as thats they way they "cheat" on MPG, so throttle is their way to limit the turbo initially as when using turbo, car spends a lot of fuel. In the end, it doesnt matter what it is really, you feel the lag, so wheather we call it turbo, throttle or turbo+throttle, it doesnt matter. So they could make it always responsive if they wanted to, but it would spend too much fuel then.
I would guess that small engines with big big turbo's get affected more, where N55 likely has 100hp more than that 2.0 4cly, without turbo's.
My 2GR-FSE had instant response when in PWR mode, to the point where it was too fast to drive like that unless you are on the open road.
I have also driven Polo GTI with 1.8T and that car never felt like it had any lag... that was combination of light car, short gearing with manual transmission, powerful engine + turbo.
On the other hand, small 3cly turbo's in small cars like Polo have plenty of lag as the underlying engine is so weak that it could not power the car properly without the turbo.... so combination of that, big turbo with more lag, weak engine, throttle lag, those never feel as fast, no matter what their HP rating is. I have just read comparo between 2 small suv's - Captour and 2008, where one had 0.9 turbo with 20% more torque but ended up being significantly slower 0-60 and actually spending more fuel (despite showing less on EU cycle).
Of course, it might end up being more drivable because it will likely be happy a 1800 rpm, unlike weak 4cly engine but still, it seems like bad application as you pay more for that turbo and end up getting less.
so in the end, tech is there, it is application that matters. Putting turbo on strong 4/6/8cyl engine will always be much faster than N/A engine, especially if same engine. Lag comes from trying to make it more efficient.
For instance, I cant even imagine how much faster this 2.0l turbo is than similar engine (3AR i guess) in Rav4... I guess I can, Rav4 with 3AR goes 0-62mph in 10.7s with S-CVTi. Turbo would probably go full 4.5-5 seconds faster.
Thats night and day difference. Not even night and day, more than that.
seems like the definition of turbo lag... now what takes "seconds" is probably combination of both - throtle input lag and turbo spooling to the maximum boost - it is not instant and while faster than before, it will never be instant. In modern turbo cars, throttle lag is more apparent as thats they way they "cheat" on MPG, so throttle is their way to limit the turbo initially as when using turbo, car spends a lot of fuel. In the end, it doesnt matter what it is really, you feel the lag, so wheather we call it turbo, throttle or turbo+throttle, it doesnt matter. So they could make it always responsive if they wanted to, but it would spend too much fuel then.
I would guess that small engines with big big turbo's get affected more, where N55 likely has 100hp more than that 2.0 4cly, without turbo's.
My 2GR-FSE had instant response when in PWR mode, to the point where it was too fast to drive like that unless you are on the open road.
I have also driven Polo GTI with 1.8T and that car never felt like it had any lag... that was combination of light car, short gearing with manual transmission, powerful engine + turbo.
On the other hand, small 3cly turbo's in small cars like Polo have plenty of lag as the underlying engine is so weak that it could not power the car properly without the turbo.... so combination of that, big turbo with more lag, weak engine, throttle lag, those never feel as fast, no matter what their HP rating is. I have just read comparo between 2 small suv's - Captour and 2008, where one had 0.9 turbo with 20% more torque but ended up being significantly slower 0-60 and actually spending more fuel (despite showing less on EU cycle).
Of course, it might end up being more drivable because it will likely be happy a 1800 rpm, unlike weak 4cly engine but still, it seems like bad application as you pay more for that turbo and end up getting less.
so in the end, tech is there, it is application that matters. Putting turbo on strong 4/6/8cyl engine will always be much faster than N/A engine, especially if same engine. Lag comes from trying to make it more efficient.
For instance, I cant even imagine how much faster this 2.0l turbo is than similar engine (3AR i guess) in Rav4... I guess I can, Rav4 with 3AR goes 0-62mph in 10.7s with S-CVTi. Turbo would probably go full 4.5-5 seconds faster.
Thats night and day difference. Not even night and day, more than that.
Your thinking is fundamentally backwards. Turbo engines are MOST EFFICIENT when they are ON BOOST. The bad fuel economy is due to the simple fact that torque is addictive, and people tend to accelerate faster without realizing it. Things like dynamic pedal resistance can help with this a lot, it gives the feeling you're pushing the throttle down more than you are, and once you stop paying attention to it work, you truly drive a bit slower and save some gas.
04-25-14, 09:52 AM
#97
Modern turbo petrol engines with direct injection and much higher compression ratios than in decades past, with quick spooling turbos that can make peak torque at under 2000rpm which enables them to turn very tall overdrive gears actually make their power very efficiently. That along with taxation and regulation is why the market is moving the way that it is, towards downsized turbocharged engines. The "inefficiency" has nothing to do with whether you're on boost or not. Modern turbo petrols are on boost any time the throttle is open.
a. turbo's are less efficient than non turbo engine. They always run richer. So at same rpm, they will do worse.
b. when you accelerate, they are much faster and they also spend a lot more gas.
So same engine will always be more efficient without turbo. It is not possible for them to be the same.
As to quick spooling, you dont reach full boost in 0.1s... I dont know how can you not understand that. It is not same if turbo just spins and when it works at full boost. It takes time to get there. This is why manufacturers are toying with the idea of electric turbos or why N54 had two - smaller one that can reach full boost much quicker than big ones.
As you said, it takes you few seconds to get real response from the turbo after cruising. This is lag. NA engine does not have this lag.
04-25-14, 11:22 AM
#98
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well,
a. turbo's are less efficient than non turbo engine. They always run richer. So at same rpm, they will do worse.
b. when you accelerate, they are much faster and they also spend a lot more gas.
So same engine will always be more efficient without turbo. It is not possible for them to be the same.
a. turbo's are less efficient than non turbo engine. They always run richer. So at same rpm, they will do worse.
b. when you accelerate, they are much faster and they also spend a lot more gas.
So same engine will always be more efficient without turbo. It is not possible for them to be the same.
As to quick spooling, you dont reach full boost in 0.1s... I dont know how can you not understand that. It is not same if turbo just spins and when it works at full boost. It takes time to get there. This is why manufacturers are toying with the idea of electric turbos or why N54 had two - smaller one that can reach full boost much quicker than big ones.
As you said, it takes you few seconds to get real response from the turbo after cruising. This is lag. NA engine does not have this lag.
As you said, it takes you few seconds to get real response from the turbo after cruising. This is lag. NA engine does not have this lag.
Like I said, I'd take a BMW or most any 2.0T over most mid-powered 3.5L class V6's including the Toyota 2GR-FE. Far better torque delivery when and where I need it. The 2GR has better throttle response, but when it always came up short for me in the torque department.
I took a pic for you coming back from lunch.
I actually tried to drive efficiently. Mostly highway, and lucked out and didn't have to sit at a light for two minutes.
Last edited by SteVTEC; 04-25-14 at 12:19 PM.
04-25-14, 12:16 PM
#99
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BTW the spool rates between the N54 and N55 are pretty much identical, as proven by the curves on this dyno. Biggest reason for the N54 is so that BMW could claim "twin turbos" because they knew it would be compared to past twin-turbo engines and especially the 2JZ-GTE. If it started off as only a single it'd have been poo-pooed. Wise marketing move by BMW. The architecture allows for a little more tuning on the N54, but it's not like the N55 doesn't have potential, and it is a lot more efficient. Valvetronic is crazy, basically closing the valves off at speed on highway when coasting. No other car I've owned coasts as well as this one does. It hardly loses any speed when you let off the gas. You're also not bleeding off energy as friction by lifting valves that don't need lifting either on the N55. Both are great engines, but the N55 in particular is exceptionally efficient, when you actually try to drive efficiently.
04-25-14, 12:43 PM
#100
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lol, i have a 2006 V8 that has 292 hp and 300 pound-feet of torque. 
but as you know it's more about the responsiveness/feel than interweb numbers, and the the excellent toyota v6 just doesn't compare in low end torque to the also excellent ford v8. (aside: both have 6 speed auto)
agreed.
but as you know it's more about the responsiveness/feel than interweb numbers, and the the excellent toyota v6 just doesn't compare in low end torque to the also excellent ford v8. (aside: both have 6 speed auto)
agreed.
Link for reference
http://www.caranddriver.com/comparis...uer-4x4-page-2
Motor Trend got 8 seconds as well
http://www.motortrend.com/oftheyear/...ford_explorer/
Highlander
-3.5 V-6 with 278hp and 248lbs of toque with a 0-60 time of 7.2 seconds getting 18/24 MPG (AWD)
So while your 2006 V-8 Explorer might "feel" faster, the Highlander is a far faster vehicle. The Highlander just won't feel at torquey or smooth being a V-6 vs a V-8.
04-25-14, 01:00 PM
#101
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Technically my old RAV4 V6 is faster than our X5d. Make sense, both have about the same peak power but the X5 is over a thousand pounds heavier. 425 ft-lbs of torque vs barely clearing 220 ft-lbs at the bottom end of the 2GR paints a vastly different picture in actual driving though. 425 ft-lbs of torque and 5200 lbs vs 220 ft-lbs and 3800 lbs out of a 2nd gear corner. Who's faster? X5 has practically double the torque, but not double the weight! Ditto with the V-8 explorer example. Doubt it's as heavy as the X5d is, and has 300 ft-lbs at the bottom end, way more than the RAV4 (or Highlander, whatever)
04-25-14, 01:45 PM
#102
Nope, nope, and nope. You're making gross generalizations that aren't necessarily true, and on part b you're not even talking about the engine. You're talking about the driver. As always, things are far more complicated than you make them out to be. If you compare the "same" engine one turbocharged and the other not, the torque advantage allows the turbocharged one to run taller gearing, for example. It could probably get away with 500 rpm lower cruising gears, as is the case with real-world examples.
...
Like I said, I'd take a BMW or most any 2.0T over most mid-powered 3.5L class V6's including the Toyota 2GR-FE. Far better torque delivery when and where I need it. The 2GR has better throttle response, but when it always came up short for me in the torque department.
I took a pic for you coming back from lunch. I actually tried to drive efficiently. Mostly highway, and lucked out and didn't have to sit at a light for two minutes.
...
Like I said, I'd take a BMW or most any 2.0T over most mid-powered 3.5L class V6's including the Toyota 2GR-FE. Far better torque delivery when and where I need it. The 2GR has better throttle response, but when it always came up short for me in the torque department.
I took a pic for you coming back from lunch.
I actually tried to drive efficiently. Mostly highway, and lucked out and didn't have to sit at a light for two minutes.Steve, same engine, one with turbo and another without, there is no chance turbo can do same mpg with same type of driving. Why are you so stubborn into trying to prove something that cant be proven? I would gladly always give out 10% mpg for 100hp more, it is not even a question.
Look at new Honda 4cly engines, that are state of the art - they cruise at low rpm as well.
I was able to get 30+ mpg on my 3GS without any issues, and at the same time in the city if i gunned it, i could get 12 MPG. So of course that it is up to the driver. Turbo's are even more sensitive as when gunned their performance is usually worse than larger V6.
As to taking 2.0t over 2GR-FSE, all things being equal (no tax or mpg advantage), it would be pretty dumb to take small turbo. But you are always comparing apples and oranges - small economy SUV with sports sedan. You cant seem to understand that your experience in economy SUV with V6 is not equal to the one of latest V6 engine in sports sedan.
I would take turbo any time of day over NA 4cly engine. Nobody is even arguing that. Point was that they are still less efficient no matter what, if we compare it to the same engine without turbo.
Even comparing small capacity turbo's vs larger engines, they are less efficient. Just read any test ever made, as long as they are both on similar tech level (and not comparing 5spd vs 8spd, etc).
04-25-14, 02:50 PM
#103
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Steve, same engine, one with turbo and another without, there is no chance turbo can do same mpg with same type of driving. Why are you so stubborn into trying to prove something that cant be proven? I would gladly always give out 10% mpg for 100hp more, it is not even a question.
Look at new Honda 4cly engines, that are state of the art - they cruise at low rpm as well.
I was able to get 30+ mpg on my 3GS without any issues, and at the same time in the city if i gunned it, i could get 12 MPG. So of course that it is up to the driver. Turbo's are even more sensitive as when gunned their performance is usually worse than larger V6.
As to taking 2.0t over 2GR-FSE, all things being equal (no tax or mpg advantage), it would be pretty dumb to take small turbo. But you are always comparing apples and oranges - small economy SUV with sports sedan. You cant seem to understand that your experience in economy SUV with V6 is not equal to the one of latest V6 engine in sports sedan.
I would take turbo any time of day over NA 4cly engine. Nobody is even arguing that. Point was that they are still less efficient no matter what, if we compare it to the same engine without turbo.
Even comparing small capacity turbo's vs larger engines, they are less efficient. Just read any test ever made, as long as they are both on similar tech level (and not comparing 5spd vs 8spd, etc).
Look at new Honda 4cly engines, that are state of the art - they cruise at low rpm as well.
I was able to get 30+ mpg on my 3GS without any issues, and at the same time in the city if i gunned it, i could get 12 MPG. So of course that it is up to the driver. Turbo's are even more sensitive as when gunned their performance is usually worse than larger V6.
As to taking 2.0t over 2GR-FSE, all things being equal (no tax or mpg advantage), it would be pretty dumb to take small turbo. But you are always comparing apples and oranges - small economy SUV with sports sedan. You cant seem to understand that your experience in economy SUV with V6 is not equal to the one of latest V6 engine in sports sedan.
I would take turbo any time of day over NA 4cly engine. Nobody is even arguing that. Point was that they are still less efficient no matter what, if we compare it to the same engine without turbo.
Even comparing small capacity turbo's vs larger engines, they are less efficient. Just read any test ever made, as long as they are both on similar tech level (and not comparing 5spd vs 8spd, etc).
In your scenario, if there's a NA and FI engine and had the same exact same hp, I would take the FI engine because i can do a number of things to fine tune the performance as I see fit without having to redesign the engine. Remember, a turbo engine is just taking the wasted exhaust energy from the engine and "regurgitating" it back into power, thus will technically be more efficient.
My hope is that this new 2.0T will carry on as the spiritual successor to the legendary 3SGTE....
04-25-14, 05:45 PM
#104
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I think we have to get something clear. A 2.0L NA engine will always achieve better MPG than a 2.0T, assuming all variances are similar such as gearing, weight etc.
But the incentive is that your getting much more performance for a 10-20% MPG reduction.
But the incentive is that your getting much more performance for a 10-20% MPG reduction.
04-25-14, 05:51 PM
#105
it depends on the car the engine is in. For instance, the older models of the Infiniti M37 vs M45 several years ago, the M45 actually made similar mpg to the M37. That means the M37 was undersized for the car and it had to work harder and lose efficiency to move that car while the V8 had no trouble.
I have the feeling the 2.0 will be more efficient than the 2.5. That 2.5 V6 will have to work harder than the 2.0t
I have the feeling the 2.0 will be more efficient than the 2.5. That 2.5 V6 will have to work harder than the 2.0t