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what makes diesels so special???

1663 Views 22 Replies 13 Participants Last post by  carterbeauford, 
G
WHy don't they put turbos stock on other engines? Does the diesel NEED a turbo or something??? How much power would a diesel put out without a turbo? Seems it would be game over for say the D-max if GM put a turbo on the 8.1
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Stealthdump
They should put twin turbos on the V-6.
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H
they do not need a turbo. but they produce a TON of exhaust at low RPMs so they can really put a turbo to use well.

diesel fuel contains many many times the power per particle than gasoline. it is simply more efficient.

but it also is kinda dirty, so its not as widely used as gasoline.

turbos on a gas motor dont really kick in till you hit 3k rpm or higher. so most all of the time in a truck its doing nothing at all.
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W
Jeff said:
they do not need a turbo. but they produce a TON of exhaust at low RPMs so they can really put a turbo to use well.

diesel fuel contains many many times the power per particle than gasoline. it is simply more efficient.

but it also is kinda dirty, so its not as widely used as gasoline.

turbos on a gas motor dont really kick in till you hit 3k rpm or higher. so most all of the time in a truck its doing nothing at all.
Click to expand...

17% more energy per pound I think .. .
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H
thats it :crazy: i cant remember the exact number, but also, diesel motors run with double the compression of gas motors. 20:1 :rocking:
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J
Diesels are also a long stroke motor, that's why they always have alot of torque.
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Hit Man X
That Dmax is nearly square (bore and stroke equal), the Cummins is way under square...BIG stroke as opposed to bore. Not sure about the ol' Stroke but I think it's similar to the Dmax.

The Diesel motor is also an open manifold, where there is NO throttle body. The pedal on the floor just injects more fuel. The turbo rams in more air, so you can stuff in more fuel :D Just there for more power...a NON-turbo diesel is quite slow.

They can run such high compression ratios as the fuel is injected when the piston is pretty much at the top unlike a gasser where it's pulled in early on. So think like 30psi (more on a Cummins!!) avg and liek 20:1 compression!!!

Also, they do not rev high as the combustion is slower pushing the piston down all the way vs a gasser that pops and throws it down. Think of hitting a golfball with a club vs pushing the ball with the club.
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K
diesel fuel tends to be cheaper than gasoline, is less flammable, but isn't as "pure" as gasoline.
Diesels (especially non-turbo) don't really like to be changing rpm all the time and smoke more while changing those rpm...mind you once they are holding steady rpm...they can be set up to burn very clean...however there are several studies that claim the particulate matter from diesel burning is extremely bad for us....

but diesels do tend to be built into high torque setups...
Think about the typical 18 wheeler...needs to have as high as torque as possible (got to get 20 tons rollin) and do it as cheaply as possible...and its good if they can run as long as possible without requiring constant repair...

If I was buying a truck for serious hauln...big boat trailer or 5th wheel...I would seriously consider a diesel...
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Hit Man X
OH yeah, a diesel motor is a lot more efficient on the fuel when cruising about too. All that black shit from the tailpipe underload is just unburned fuel from what I recall, it's cleaner than the crap from my gassers still.

Yup, that diesel fuel needs to be compressed that much to ignite! Recall there are no spark plugs...these bitches work off compression ignition. The air charge is so hot that's what ignites the fuel once warmed up and the GlowPlugs turn off.

I'd say a diesel would run 250-400K before anything weird happens to the bottom end on a stock/mild hop'd up unit.
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T
one reason that chevy doesnt use a turbo is because it makes the engine more efficient with out it. when you put a turbo on the exhaust it creates a TON of back pressure and kills effieiency. conversly, that increased back pressure actually increases torque so you have to decide which is more important to you.

and kryptonite...if you plan on serious hualin there is no alternative. just have to decide if you are gonna be doin enough hualin to offset that $4k more price tag :think:
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bggrnchvy
A deisel needs a turbo because w/o it it only puts one atmosphere of pressure into the chambers, where as a turbo can multiply that by many times and as hitman X siad a deisel is always sucking in the maximum amount of air, the only thing you control with the pedal is how much fuel the injectors dump in there, which is why when you floor a deisel or hit high RPM's they through out that black stuff (unburned fuel and carbons). There is no excuse for a diesel w/o a turbo.
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Hit Man X
Oh yes, don't forget you can use nitrous on a diesel motor also BUT since the fuel is introduced differently...you must have lots of black smoke (fuel) to utilize it! Nitrous works when it's atomized with extra fuel, otherwise it just makes shit cold lol

Propane is injected later on (post turbo I believe, it's been a while since I thought about it) and effects timing and detonation I think it is. That's because LP is another fuel. It's good for towing and some racing/performance apps.

Basically choose to run LP or Nitrous, not both. :D
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M
Lots of torque and low end power. You can tow pretty heavy loads and still get desent milage on the highway. Can also leave them running all the time and they dont waste very much fuel. I don't think I will every have a gas engine in a truck I use for towing, 10mpg vs 20mpg.
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G
tx marine said:
one reason that chevy doesnt use a turbo is because it makes the engine more efficient with out it. when you put a turbo on the exhaust it creates a TON of back pressure and kills effieiency.
Click to expand...

how can this be true? More air = more efficient burn = less fuel used.

Some guy on ls1tech put a t-60 turbo on his 6.0 2500 and gained 3.5MPG
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Hit Man X
GMCtrk said:
how can this be true? More air = more efficient burn = less fuel used.

Some guy on ls1tech put a t-60 turbo on his 6.0 2500 and gained 3.5MPG/QUOTE]



The vehicle also moves easier under turbo boost. My WRX rarely gets over 3200rpm unless I'm racing someone. That's still on wastegate boost (closed loop, 14.7:1 A/F) of about 8psi. Scooting about town it gets nearly 24mpg!

Basically, when you give it gas the turbo does the work instead of the motor...the compression ratio is raised also. 1 bar of boost (about 14.7 psi) will double your static compression ratio.

Also, forced induction creates over 100% volumetric efficiency. WTF does that mean? :think: Basically the deficiencies of the motor aren't there when the air is rammed in there.

:shake:
Click to expand...
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carterbeauford
if you have to ask... :D
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Hit Man X said:
GMCtrk said:
how can this be true? More air = more efficient burn = less fuel used.

Some guy on ls1tech put a t-60 turbo on his 6.0 2500 and gained 3.5MPG/QUOTE]



The vehicle also moves easier under turbo boost. My WRX rarely gets over 3200rpm unless I'm racing someone. That's still on wastegate boost (closed loop, 14.7:1 A/F) of about 8psi. Scooting about town it gets nearly 24mpg!

Basically, when you give it gas the turbo does the work instead of the motor...the compression ratio is raised also. 1 bar of boost (about 14.7 psi) will double your static compression ratio.

Also, forced induction creates over 100% volumetric efficiency. WTF does that mean? :think: Basically the deficiencies of the motor aren't there when the air is rammed in there.

:shake:
Click to expand...
that's what I thought....oh well, im a n00b on diesels and never desire to become anything but a n00b :D :pow:
Click to expand...
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nboylie
on trucks he put nitrous AND propane on a cummins? i think. not quite sure
but it hauled ass :rocking:
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bggrnchvy
Yes, he did put both. Nitrous indroduces more oxygen as its NO2 I believe and propane is a catylist that causes all of the deisel in the combustion chamber to get burned. Diesels only burn I think 85% of the fuel in the chamber stock. Propane reduces the black smoke in other words, improves MPG and gives more HP and TQ, its a great option for a deisel.
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J
Nitrous is hard on motors though, whether it be gas or Diesel, Propane Injection is the only way to go on a Diesel. I think you can do it to a Gasser too, but its real efficent on Diesels.
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