4 ms·

Haven't we been using electric motors and smaller turbos to get around lag? I drove a 3 cylinder MHEV EcoBoost that seemed to use the electric motor(s?) quite

Haven't we been using electric motors and smaller turbos to get around lag? I drove a 3 cylinder MHEV EcoBoost that seemed to use the electric motor(s?) quite well. It seems like a good idea in theory, though I can understand the negatives of electrifying the powertrain. Definitely an interesting topic. I remember hearing about the days of the early 911 Turbos (if my memory's correct) where you'd get a bunch of boost all at once... We've definitely come a long way!

aredox 1y ago
This plans for premptively spinning the turbo - which requires electric ones.
nubinetwork 1y ago
You could always do what race cars do, put an electric motor on the turbo so when you go back on the throttle, you get instant boost.
- westmeal 1y ago
  You can use antilag as well to achieve the same effect without electric turbochargers
  - lan321 1y ago
    Bad for emissions though so it'd never be OEM. Edit: Also bad for the valvetrain. 4T engines aren't really meant to be run as 2T..
  - tentacleuno 1y ago
    Isn't anti-lag (the type that invokes combustion in the exhaust, anyway) terrible for turbochargers, long-term?
    - westmeal 1y ago
      It's bad for everything but it's awesome
- Zak 1y ago
  Porsche is doing that on a road car now. It can also act as a generator to limit maximum boost instead of opening a wastegate. https://www.motortrend.com/news/2025-porsche-911-gts-t-hybrid-992-tech-everything-you-need-to-know https://www.motortrend.com/news/2025-porsche-911-gts-t-hybri...
  - rasz 1y ago
    Audi has been shipping electric compressor for 5 years now. They are prone to failures and they are on second revision now. https://en.wikipedia.org/wiki/List_of_Volkswagen_Group_diesel_engines#4.0_V8_TDI_310-320kW https://en.wikipedia.org/wiki/List_of_Volkswagen_Group_diese...
    - Zak 1y ago
      That's a different design; Audi uses a separate electric supercharger to fill in boost while waiting for its conventional turbochargers to spool up. Porsche is using a motor/generator built in to a turbocharger to spool it faster, and to recover energy at maximum boost.
- luma 1y ago
  F1 is getting rid of that system (MGU-H) for 2026 because it was costing the teams too much and it never seemed relevant to passenger vehicles. When a tech path costs too much for F1, that's a good sign you won't be seeing it in a GM product any time soon. OP system is just using a computer to get on the gas a little faster when the driver hits the pedal quickly.
  - jabl 1y ago
    Whatever F1 does or doesn't do has had extremely little relevance for passenger vehicles for at least the past 30 years.
- tentacleuno 1y ago
  I was thinking of that when I wrote the comment! I've heard of electric turbochargers, but I'm not sure how good they are under real-life conditions. Directly using heat energy from the exhaust (as opposed to introducing electric conversion losses) seems wiser to me. Part of me has always liked making use of what would otherwise be wasted to entropy. In theory (though not a mechanic, just have an interest in this), the best middle-ground would be to retain the same design but add a motor to the turbocharger shaft which would mainly be reserved for spool ups -- is that what they're doing?
  - luma 1y ago
    What you've described is exactly how the F1 MGU-H works (as I posted below). F1 is getting rid of it next year because it costs too much for an F1 team which should tell you a little bit about the complexity involved. GM is doing nothing of the sort, it's just an ECU map. Guessing here, but if driver presses on the gas quickly (throttle accel > some set value), juice the engine map to create extra exhaust pressure to spool up the turbo impeller. It's all software.
Peanuts99 1y ago
It all sounds quite complex when you can just drive the wheels with a motor directly.
- AtlasBarfed 1y ago
  Actually all of the car sounds really complex. How about we just pull it with a bunch of horses?.
  - littlestymaar 1y ago
    Horses are really complex beasts too, better just walking around.
    - SecretDreams 1y ago
      The human mind is complex as heck, we should give up on harvesting them for walking.
  - bluGill 1y ago
    Horses are very fuel inefficient. Sure they burn 100% renewable hay/oats, but they burn a lot of them. Worse they burn them even at idle so those who don't use their horse constantly still pay for the fuel. Horse emissions are really bad too.
- Reubachi 1y ago
  In your opinion, where does "the buck stop"? I feel similar to you in that complexity over time only locks out the user. However I certainly do not miss a choke or having to mess with a carb in general on my road going vehicle.
  - tentacleuno 1y ago
    I don't miss that either (in fact, I know the ECU can do a much better job), but I do enjoy engaging with the car, and thus drive a manual transmission. I'm fairly confident I can get better efficiency and control as opposed to the same transmission with a computer changing gears for me. From what I've heard, it's somewhat of a rarity in the US, but it's very widely used in Europe.

aredox 1y ago

This plans for premptively spinning the turbo - which requires electric ones.

nubinetwork 1y ago

You could always do what race cars do, put an electric motor on the turbo so when you go back on the throttle, you get instant boost.

westmeal 1y ago
You can use antilag as well to achieve the same effect without electric turbochargers
- lan321 1y ago
  Bad for emissions though so it'd never be OEM. Edit: Also bad for the valvetrain. 4T engines aren't really meant to be run as 2T..
- tentacleuno 1y ago
  Isn't anti-lag (the type that invokes combustion in the exhaust, anyway) terrible for turbochargers, long-term?
  - westmeal 1y ago
    It's bad for everything but it's awesome
Zak 1y ago
Porsche is doing that on a road car now. It can also act as a generator to limit maximum boost instead of opening a wastegate. https://www.motortrend.com/news/2025-porsche-911-gts-t-hybrid-992-tech-everything-you-need-to-know https://www.motortrend.com/news/2025-porsche-911-gts-t-hybri...
- rasz 1y ago
  Audi has been shipping electric compressor for 5 years now. They are prone to failures and they are on second revision now. https://en.wikipedia.org/wiki/List_of_Volkswagen_Group_diesel_engines#4.0_V8_TDI_310-320kW https://en.wikipedia.org/wiki/List_of_Volkswagen_Group_diese...
  - Zak 1y ago
    That's a different design; Audi uses a separate electric supercharger to fill in boost while waiting for its conventional turbochargers to spool up. Porsche is using a motor/generator built in to a turbocharger to spool it faster, and to recover energy at maximum boost.
luma 1y ago
F1 is getting rid of that system (MGU-H) for 2026 because it was costing the teams too much and it never seemed relevant to passenger vehicles. When a tech path costs too much for F1, that's a good sign you won't be seeing it in a GM product any time soon. OP system is just using a computer to get on the gas a little faster when the driver hits the pedal quickly.
- jabl 1y ago
  Whatever F1 does or doesn't do has had extremely little relevance for passenger vehicles for at least the past 30 years.
tentacleuno 1y ago
I was thinking of that when I wrote the comment! I've heard of electric turbochargers, but I'm not sure how good they are under real-life conditions. Directly using heat energy from the exhaust (as opposed to introducing electric conversion losses) seems wiser to me. Part of me has always liked making use of what would otherwise be wasted to entropy. In theory (though not a mechanic, just have an interest in this), the best middle-ground would be to retain the same design but add a motor to the turbocharger shaft which would mainly be reserved for spool ups -- is that what they're doing?
- luma 1y ago
  What you've described is exactly how the F1 MGU-H works (as I posted below). F1 is getting rid of it next year because it costs too much for an F1 team which should tell you a little bit about the complexity involved. GM is doing nothing of the sort, it's just an ECU map. Guessing here, but if driver presses on the gas quickly (throttle accel > some set value), juice the engine map to create extra exhaust pressure to spool up the turbo impeller. It's all software.

Peanuts99 1y ago

It all sounds quite complex when you can just drive the wheels with a motor directly.

AtlasBarfed 1y ago
Actually all of the car sounds really complex. How about we just pull it with a bunch of horses?.
- littlestymaar 1y ago
  Horses are really complex beasts too, better just walking around.
  - SecretDreams 1y ago
    The human mind is complex as heck, we should give up on harvesting them for walking.
- bluGill 1y ago
  Horses are very fuel inefficient. Sure they burn 100% renewable hay/oats, but they burn a lot of them. Worse they burn them even at idle so those who don't use their horse constantly still pay for the fuel. Horse emissions are really bad too.
Reubachi 1y ago
In your opinion, where does "the buck stop"? I feel similar to you in that complexity over time only locks out the user. However I certainly do not miss a choke or having to mess with a carb in general on my road going vehicle.
- tentacleuno 1y ago
  I don't miss that either (in fact, I know the ECU can do a much better job), but I do enjoy engaging with the car, and thus drive a manual transmission. I'm fairly confident I can get better efficiency and control as opposed to the same transmission with a computer changing gears for me. From what I've heard, it's somewhat of a rarity in the US, but it's very widely used in Europe.