PDA

View Full Version : Diesel Aspiration



Doza
02-24-2004, 04:15 PM
When I research any car that is diesel powered, they (of the one's I've looked at) are always turbocharged if not naturally aspiriated, is there a reason for this?

Matra et Alpine
02-24-2004, 05:30 PM
When I research any car that is diesel powered, they (of the one's I've looked at) are always turbocharged if not naturally aspiriated, is there a reason for this?
Yep, they're gutless without the extra boost.
It was OK to sell the lower power when they were odd-ball cars.
Trying to make them mainstream, they have to increase the power from the engines - boosting does it.
Trucks have done it for decades.

Doza
02-24-2004, 05:41 PM
Yep, they're gutless without the extra boost.
It was OK to sell the lower power when they were odd-ball cars.
Trying to make them mainstream, they have to increase the power from the engines - boosting does it.
Trucks have done it for decades.
Sorry.... I was vague, when I said they were N/A or Turbo, I'm wondering why not supercharged.

Matra et Alpine
02-24-2004, 05:44 PM
Sorry.... I was vague, when I said they were N/A or Turbo, I'm wondering why not supercharged.
Diesels have high-pulse exhaust. So can likely provide boost even at lowish revs - not sure about that conclusion.
They also aren't raced in the same way, so the lag isn't an issue.
Having LOTS of torque probably helps mask the lag.
Personally I've been surprised how quickly a modern turbo diesel (Skoda) spins-up.

henk4
02-25-2004, 12:29 AM
Diesel technology has gone a long way, not only in the automotive industry. You'll be surprised to hear that modern marine diesel engines, (with more than 70,000 BHP) are also fitted with turbochargers and common rail systems. If you also take into account the fuel quality (not even a liquid substance under normal temperatures) you' ll realise what can be done these days.

I am glad that Matra noted the quality of the Skoda engine (a VW product), and my personal experience with PSA HDi engines only confirms this. The modern diesel comes very close to the traditional US philosophy of having big, low revving but very torquey engines, the benefit of the diesel being it's fantastic economy which with new filter technology can also be combined with very low emissions, not only of CO2 but also of the infamous particles.

NAZCA C2
02-27-2004, 01:34 PM
diesels make power ususlly by increasing the compression ratio. most diesels use a turbo wo that they can make more power without having to raise the compression ratio too high.