Individual turbos per cylinder as engines shrink.

[Tomioka]

https://blog.caranddriver.com/engines-wi...ize-downsizing/

Quote:

The first element of the design, which they call “synergistic induction and turbocharging,” is to place individual throttles—two per cylinder, one for each intake port—right next to the cylinder head. “Between the throttle and the intake valves, the typical engine has an intake-manifold volume roughly equivalent to the engine displacement,” Clarke says. “That takes time to fill when you open the throttle.” His configuration allows the cylinders to fill much more quickly, rapidly generating full torque and a maximum dose of high-energy exhaust gas. Exploiting that exhaust is the next key idea.

 

[Brad_C]

There is a reason individual throttle bodies have been the thing in high performance for years. Complex, fussy and sometimes awkward to set up and balance, but a much snappier throttle response.

 

[Claud]

Motor bikes have been doing this for years. Brac_C has nailed it, good throttle response, but tricky to set up correctly. However this is the era of fly by wire throttle, so a computer constantly monitoring things might take care of keeping everything spot on?. Claud.

 

[Shannow]

Back in the day "split pulse" separated the individual exhaust events to provide more impulse to the turbines...made lots of sense over the log manifold early turbo days. But this concept has flaws...4 tiny turbos, with 4 radial clearances on a small diameter wheel, 4 moments of inertia combined, and 540 degrees of engine rotation before each impulse make me feel that the original "throttle plate near the cylinder" is marketting speak for give me funding. Yes, keep the turbo close to the exhaust port...it's basic physics, on a thermo and retained energy basis.

 

[eljefino]

So if you have an engine's displacement of vacuum in the intake that needs consuming, that should get sucked in in two to four revolutions (one to two power strokes). At 1500 RPM that's 1/375 minute or 1/6 second. Can you really nail the gas that fast and feel it?

 

[bigj_16]

An engine I dealt with in the past had 4 turbos and two blowers for 16 cylinders. Detroit 16V149TI.

 

[E150GT]

Yeah I can see that getting pretty expensive.

 

[Schmoe]

What about the heat???

 

[StevieC]

I was thinking what about weight. You know automakers and their reductions everywhere possible.

 

[DoubleWasp]

Originally Posted By: Claud

Motor bikes have been doing this for years. Brac_C has nailed it, good throttle response, but tricky to set up correctly. However this is the era of fly by wire throttle, so a computer constantly monitoring things might take care of keeping everything spot on?. Claud.

When the E39 debuted, it did so with 8 throttles for 8 cylinders, able to move 100% independently from each other for maximum performance and drivability. Of course, the thing now is to simply have no throttle at all. On topic, a series of smaller turbos is pretty much never as efficient as a single larger one.

 

[OVERKILL]

Originally Posted By: DoubleWasp

Originally Posted By: Claud

Motor bikes have been doing this for years. Brac_C has nailed it, good throttle response, but tricky to set up correctly. However this is the era of fly by wire throttle, so a computer constantly monitoring things might take care of keeping everything spot on?. Claud.

When the E39 debuted, it did so with 8 throttles for 8 cylinders, able to move 100% independently from each other for maximum performance and drivability. Of course, the thing now is to simply have no throttle at all. On topic, a series of smaller turbos is pretty much never as efficient as a single larger one.

I believe you are incorrect. I, up until recently, owned an E39 M5 and my recollection of how that system operated was as follows: There are two banks of linked throttles, each bank of 4 sharing a single TPS with a centre link to the electric motor in the valley, which actuates both banks of 4 together.

 

[JohnnyJohnson]

Originally Posted By: Kibitoshin

https://blog.caranddriver.com/engines-wi...ize-downsizing/

Quote:

The first element of the design, which they call “synergistic induction and turbocharging,” is to place individual throttles—two per cylinder, one for each intake port—right next to the cylinder head. “Between the throttle and the intake valves, the typical engine has an intake-manifold volume roughly equivalent to the engine displacement,” Clarke says. “That takes time to fill when you open the throttle.” His configuration allows the cylinders to fill much more quickly, rapidly generating full torque and a maximum dose of high-energy exhaust gas. Exploiting that exhaust is the next key idea.

No thanks cars already have enough problems without introducing more of them.

 

[StevieC]

Originally Posted By: OVERKILL

Originally Posted By: DoubleWasp

Originally Posted By: Claud

Motor bikes have been doing this for years. Brac_C has nailed it, good throttle response, but tricky to set up correctly. However this is the era of fly by wire throttle, so a computer constantly monitoring things might take care of keeping everything spot on?. Claud.

When the E39 debuted, it did so with 8 throttles for 8 cylinders, able to move 100% independently from each other for maximum performance and drivability. Of course, the thing now is to simply have no throttle at all. On topic, a series of smaller turbos is pretty much never as efficient as a single larger one.

I believe you are incorrect. I, up until recently, owned an E39 M5 and my recollection of how that system operated was as follows: There are two banks of linked throttles, each bank of 4 sharing a single TPS with a centre link to the electric motor in the valley, which actuates both banks of 4 together.

Dealer to Customer: We reccommend cleaning your throttle bodies. For only $349.95 we can do this for you.

 

[SilverFusion2010]

I think the twin scroll design on the headifold that ford is using on the I4 turbo engines is about as efficient as it gets. Think tri-y but pushing a turbo plus scavenging.

 

[DoubleWasp]

Originally Posted By: OVERKILL

Originally Posted By: DoubleWasp

Originally Posted By: Claud

Motor bikes have been doing this for years. Brac_C has nailed it, good throttle response, but tricky to set up correctly. However this is the era of fly by wire throttle, so a computer constantly monitoring things might take care of keeping everything spot on?. Claud.

When the E39 debuted, it did so with 8 throttles for 8 cylinders, able to move 100% independently from each other for maximum performance and drivability. Of course, the thing now is to simply have no throttle at all. On topic, a series of smaller turbos is pretty much never as efficient as a single larger one.

I believe you are incorrect. I, up until recently, owned an E39 M5 and my recollection of how that system operated was as follows: There are two banks of linked throttles, each bank of 4 sharing a single TPS with a centre link to the electric motor in the valley, which actuates both banks of 4 together.

It seems you are correct, and the matter is that BMW marketing material supplied to potential customers as well as the media claimed independent control of each throttle body. The brochure BMW mailed me back in 99 claimed it, and Road and Track had the same information. Jalopnik still has it. But there's no denying the schematics. That sure does not look like individually controlled throttles to me.

 

[OVERKILL]

Hey no worries, marketing material is.... well, you know.

 

[Claud]

I'm pretty sure for an engine to run at its best each cylinder would require an equal fuel/air mix, as well as identical compressions and timing. Not forgetting equal exhaust flow as well. Carburetor engines have come very close to this ideal, modern fuel injected engines closer still. This could be approaching the cost and complexity is aproaching not enough gain for the expense. The law of diminishing returns I guess. Claud.

 

[Shannow]

Originally Posted By: Claud

I'm pretty sure for an engine to run at its best each cylinder would require an equal fuel/air mix, as well as identical compressions and timing. Not forgetting equal exhaust flow as well. Carburetor engines have come very close to this ideal, modern fuel injected engines closer still. This could be approaching the cost and complexity is aproaching not enough gain for the expense. The law of diminishing returns I guess. Claud.

Every cylinder on every engine is different to a greater or lesser degree (for e.g. look at the ports on a Big Blcok Chev, or Early Holden V-8. In the absolute extreme, they can be tuned as 8 individual engines, cam, fuel and timing.