Injection and turbo on G3

[sparks57]

Ok, I was reading the TDR magazine and a few questions came up in my mind:



First, why is there actually three injections? I know the first quiets the engine, but what other purpose does it have? I understand the primary injection, but what does the third injection do? I assume it has something to do with the new exhaust standards. It was partially explained in that exhaust article but it kind of confused me.



Second, why do these new trucks have such small turbo housings? How could they go from 18. 5 cm on my 93, down to 9 on an 03? I don't think my truck would run worth a crap with a 9cm housing.



Thanks for any answers!

 

[MCummings]

Originally posted by CB_Parker





First, why is there actually three injections? I know the first quiets the engine, but what other purpose does it have? I understand the primary injection, but what does the third injection do? I assume it has something to do with the new exhaust standards. It was partially explained in that exhaust article but it kind of confused me.



Second, why do these new trucks have such small turbo housings? How could they go from 18. 5 cm on my 93, down to 9 on an 03? I don't think my truck would run worth a crap with a 9cm housing.

1. Emissions.



2. spoolup from a 18. 5cm to a 9cm. Spoolup on the 9 is wayyy faster. If you spool faster, you can add fuel sooner while still burning clean. In other words,, Emissions.

The Common rail motors run very cool on EGT, so Dodge/Cummins could compromise and run a smaller Exh, housing on the turbo, and still maintain safe EGT.



Some members are running EZ's, and they still can't get 1,200*F EGT.



Hope this helps.

 

[sparks57]

I understand that the smaller the housing the faster the spoolup, but how do these new trucks run on the highway? I was told that when you go to a smaller housing you gain low end boost while sacrificing high end.



Also, how do these new trucks sound straight-piped? Are they very similair to any of the previous 24v CTD's?

 

[J DeMaio]

CB



These trucks don't sound like a 24 valve at all, they do not have the legendary 5. 9L sound. They sound somewhat like a Powerstroke without all of that whistling at idle. Similar to a duramax with more whistle I don't know how to tell you this. It's a deeper sound than usual and is real throaty. I like anything straight piped but I think it may sound a little better than the 12 and 24 valves myself.



John

 

[Steve M]

I was wondering why my EGT was so much lower than on my previous Dodge Cummins trucks. That makes sense...

Our motors sound similar to the PSD and Duramax but the exhaust is only similar to the Duramax. Our '03 Cummins and the Duramax have a very clear deep throaty sound with some turbo music. Drive next to a building slowly with the windows down and give it just a little throttle to wake up the exhaust note. I'm not sure if it was love or just lust but I sure liked what I heard!

The PSD sounds like a flutter. If it's straight piped, it sounds like a loud flutter. Like a rusted out collapsed muffler on an old gasser. If I was gullible enough to buy a PSD, I'd have to leave it quiet. The sound would be embarrassing. Even more so than the truck!

 

[sparks57]

Jeeze, that stinks. I hate the sound of straight-piped duramax's, but not as much as the sound of straightpiped powersmokes. I love the sound of my truck and the early 24 valve trucks.

 

[Blakers]

Originally posted by CB_Parker

Second, why do these new trucks have such small turbo housings? How could they go from 18. 5 cm on my 93, down to 9 on an 03? I don't think my truck would run worth a crap with a 9cm housing.



Thanks for any answers!

So, can you put larger turbo housings on them if you do get EGTs too high with bigger injectors, etc?

 

[krabman]

Diesel Dynamics has a turbo out now. I would guess there are more vendors with something in the pipeline.