RAM 1500 Diesel Forum banner

21 - 31 of 31 Posts

·
Registered
Joined
·
229 Posts
The new VGT turbo's pretty much negate any need for compound turbo's, my older Ecodiesel would hit and hold 25 psi boost, that's enough. The older Cummins engines in heavy commercial trucks only produced 21 psi boost, the amount of boost is directly proportional to big problems, the higher the boost pressure the more likely an expensive problem will occur.
 

·
Registered
Joined
·
2,112 Posts
The new VGT turbo's pretty much negate any need for compound turbo's, my older Ecodiesel would hit and hold 25 psi boost, that's enough. The older Cummins engines in heavy commercial trucks only produced 21 psi boost, the amount of boost is directly proportional to big problems, the higher the boost pressure the more likely an expensive problem will occur.
Boost is only a tiny portion of whats going on vgt expands the usable range on a turbo but they do not negate a compound setup. If you have 25 psi of intake manifold pressure but 60 psi of exhaust manifold pressure performance well suffer one of the big advantages of a compound setup is balanced intake to exhaust pressure or delta. Older trucks pre vgt used a wastegate to help that but with vgt there is no wastegate. Also egr engines need a delta to flow if the egr is not used that delta just hurts performance.
 

·
Registered
Joined
·
13 Posts
No doubt turbo upgrades would be a performance boost, but I'm pretty sure that doesn't help lower egt, which is what this discussion is about. New turbo(s) is also a major modification, Which most people don't care to do. Along with that extra airflow you might as well do a larger exhaust, re do all the intake piping and get a higher capacity intercooler. Not to mention a custom tune. Expensive rabbit hole if you ask me.

I think water methanol injection is one of the only proven methods of getting more (safe) power while lowering egt.
 

·
Registered
Joined
·
229 Posts
Take it from me guy's you don't need more boost if so you should have bought a 3500, the technical engineering appears to be sound but then there is the real world test of course. More boost = More heat = more catastrophic engine failures from cracked heads blown head gsk you name it. I would love to have a 2020 Gen3 truck the engine is actually very much improved, more powerful, more max torque @1600 rpm instead of 2000 rpm. EGR intake has been moved down stream of the DPF where if it existed at all should have been.
 

·
Registered
Joined
·
13 Posts
Ran water meth for two years with no noticable difference in my intake manifold, even ran it so aggressive for a while I would go 8 gallons with every tank of fuel. At the end of it I came to the conclusion it adds 15 rwhp and helps lower egts a tiny bit but thats about it. Long term one is better off with a compound turbo setup.
sorry to hear about your experience, sounds like it wasn't really optimized for your truck. A 10% gain in power is very achievable. lets hear about your set up and maybe we can figure it out...

-kit you used
-nozzle size
-injection mixture
-injection boost pressure
-injection location
-other relevant mods
 

·
Registered
Joined
·
2,112 Posts
Went through a bunch of different setups three different nozzles, two different controllers, two different nozzle locations, different pressure settings, different mixtures, etc. These engines are limited by the small turbine housing and without adding more flow on the exhaust side the results well be minimal. Either a larger turbo or a compound setup well make the biggest egt reduction.
 

·
Registered
Joined
·
4,571 Posts
I haven't seen a reliable compound setup on one of these engines yet. Larger single turbo would be the only change I'd make to the turbo.

Motorgoat811, what tank are you using for the -40 fluid?
 

·
Registered
Joined
·
260 Posts
The key that your are missing is airflow. A bigger turbo flows more CFM for a given boost level. Even our little turbos can spin up to produce 30+ psi, but the efficiency falls off a cliff and you end-up generating less (proportional) airflow at higher temperatures. This is also why a bigger turbo lowers EGTs. Ideally you want to match a turbo where the volumetric efficiency is highest in the boost range you want to operate at. This will provide you the most airflow with the lowest EGTs.

To my knowledge, the main reason compound turbos were "more popular" is just because are turbos are a pain to access and typically requires at least lifting the cab a few inches. GDE had a turbo upgrade before the shutdown and there are a couple of shops in Canada offering upgrades. There was a guy on youtube that was rebuilding an ecodiesel and had parts to upgrade the exsiting turbine wheels, but had not done an update last time I looked.
 

·
Registered
Joined
·
13 Posts
I haven't seen a reliable compound setup on one of these engines yet. Larger single turbo would be the only change I'd make to the turbo.

Motorgoat811, what tank are you using for the -40 fluid?

I'm just using the 1 gallon tank that came with the AEM kit, mounted in the engine bay for now. Ive heard of people repurposing the def tank, I may try that out when I get time to do it. Unfortunately the GDE tune disables the def gauge...
 
21 - 31 of 31 Posts
Top