Diesel gurus...question [Archive] - GrandAmGT.com Forum


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01-30-2004, 04:25 PM
So a curiosity question popped in my head at work today, maybe someone can answer it for me.

Boosted applications work best with low compression...so how can a turbo handle the rediculously high compression of a diesel engine?

just curious.

01-31-2004, 10:37 AM
Diesel engines do not have a throttle body. They are always drawing in the maximum amount of air that the engine is capable of at a given engine rpm. With that said, the same principle applies the them as it does gasoline engines. The more air you put in the more fuel you can burn in and the more power you get. Also keep in mind todays diesels run anywhere from 20:1 to 24:1 compression ratio roughly. They also run higher fuel pressure. The gm duramax is capable of 27,500 psi. And that is not a typo.

01-31-2004, 02:42 PM
dang took the words right outta my mouth:) and its kinda funny..last night at work i watched a duramax in the test stand blow a fuel line thats alot of hard a$$ spraying diesel

01-31-2004, 08:43 PM
I know how diesel engines work, that's not what I'm asking.

I'm asking how it is the turbo on a diesel can handle the high compression, when boosted cars need to be lower compression?

01-31-2004, 11:45 PM
Google is god of all searches.


Read that article, or just read this:

Easy turbo charging. Turbo charging a diesel is easier than turbo charging a petrol engine. One problem for a petrol engine is that if the compression ratio is too high, and the pressure in the cylinder gets too high during the inlet stroke, then the fuel/air mixture can start to burn too soon, while the piston is still on the way up. A turbo increases the pressure in the cylinder making this problem worse. With a diesel engine, there is no fuel in the cylinder during the compression stroke, so a turbo can be used to pack as much air in there as desired without causing problems.