Air-take verses direct hho injection into manifold

[cRiPpLe_rOoStEr]

Originally Posted by Isaac Zackary

just widening the intake or exhaust doesn't mean better efficiency. Everything in the intake and exhaust is pulsing with each intake and exhaust stroke. Harmonics become much more important here, which is affected greatly by runner diameters and lengths as well as resonate chamber designs. In other words, widening things can be just as bad as making them more narrow

Much like that Ford/Simca Aquillon engine, which had a truck version with narrower intake and exhaust in order to improve low-end torque. One could easily guess that engine in a Ford Vedette with a slightly higher rear-end to be likely to provide some better fuel-efficiency...

[teoman]

I wonder if a subwoofer would provide any benefit if installed on the airbox.

[Piotrsko]

PROBABLY. If you could empirically determine placement, might work the same as a resonator, like noise cancellation headsets.

[teoman]

I am thinking that you do not want to cancel it but have it in synch with the intake valves.

[Isaac Zackary]

Originally Posted by teoman

I am thinking that you do not want to cancel it but have it in synch with the intake valves.

The goal has generally been to sync the intake going in for years with tube length and width in order to improve performance. But I understand that Porsche is doing the opposite and is getting better fuel mileage results due to cooling of the intake charge (air cools as you stretch it). Which in combination of a turbocharger still allows for a better intake charge than a normal engine. In other words, it's compressed by the turbocharger then stretched back out through harmonics in order to cool the intake without using a restrictive source like a throttle valve for each intake runner. This allows for greater boost, lower NOx emissions and better power and fuel mileage.

[cRiPpLe_rOoStEr]

Originally Posted by teoman

I wonder if a subwoofer would provide any benefit if installed on the airbox.

I'm not sure to which extent it would be worth to place some "active" device like that to the airbox of a vehicle.

[teoman]

If porsche are noting an fuel economy benefit it could be worth it.

On the plus side it would be active and work for all rpm ranges and have an economy and power mode.

[cRiPpLe_rOoStEr]

Originally Posted by teoman

If porsche are noting an fuel economy benefit it could be worth it.

But at which cost? Anyway, if I would ever use some active device to improve the flow in the air box, I'd much rather resort to some flap instead of a loudspeaker.

On the plus side it would be active and work for all rpm ranges and have an economy and power mode.

Nowadays I've been prefering engines with a narrower useful RPM band and rely on a wider gear spread.

[teoman]

I am just curious.

If installing a subwoofer on the airbox can provide a benefit, that would something fun to investigate.

[cRiPpLe_rOoStEr]

Originally Posted by teoman

If installing a subwoofer on the airbox can provide a benefit, that would something fun to investigate.

Indeed. But even if it could be fun to try, I'm not so confident about the results.