roadranger

Here's what I've got; 2001 HO with EZ box and 300RV injectors (Pensacola Diesel).

Here's the problem; I'm at a fairly high altitude (6200 ft.) and with the stock HO injectors the truck smoked somewhat and towing mountain passes the EGT's would climb to over 1250*.

Now that I've installed the 300RV injectors the truck smokes pretty heavy during turbo lag and towing mountain passes the EGT hit 1500*+ pretty quickly.

I know I need a bigger turbo, but I do NOT want to get rid of my Cummins EBrake. Most upgrade turbo's I've looked at use a 4 inch downpipe that is not compatible with the 3.5 in. Cummins EBrake.

Anyone know of a larger turbo that will still allow the use of a Cummins EBrake on it's exhaust flange?

Any help is appreciated.

Jim B.
Colorado Springs

PaulDaisy

This is why I bought a 4" inline BD brake. I think you are stuck: all turbos you might need are 4" and the turbo mounted brake will not work. I think you will have to sell the brake (you don't lose a whole lot, they seem to be a desirable item) and buy a 4" inline setup, be it BD, PRXB or other.

braxton357

Go to a larger turbine housing?

HOHN

Jim, what boost pressures are you seeing associated with those EGT numbers?

For example, with a full load running up hwy 24 passing GotG, how hot are you running and how much boost? Can you make it to woodland park (~8500ft) without hitting meltdown?

A larger turbo might make things worse for you because you are trying to get faster and earlier response from the turbo.

One thing you could do that would help lower overall EGT will be to install a larger compressor on your existing turbo, therefore converting it to a 35/40 hybrid. This will allow you to keep your brake, some pretty decent response, and a little less EGT in the thin air.

The best way to conquer thin air is a compound turbo setup, but I assume that's far more than you're interested in doing.


Is this something you cannot drive around by downshifting and winding up the engine to 2700rpm or so? Don't be afraid to run it at 2700rpm for extended periods of time. You are NOT going to hurt the engine, and under heavy loads, the engine would much rather be pulling 2700rpm than 2000, espially if that's in a lower gear (5th) with the lighter loading.

Downshifting and revving up to rated power rpm should drop a good bit of EGT-- enough to where your problem might disappear if you're not already doing this.

Justin
(alumni of that school on the hill in your town with the fancy church)

haloman

x2 on your boost pressures?

Do you have a boost controller installed?

roadranger

Justin - thanks for the reply.

I'm getting 34-35 psi boost out of the HX-35 and hitting 1500* egt's easily.

If I pull that hill by GoG in 6th gear it hits meltdown pretty quickly.
Downshifting to 5th gear (2400-2600 rpm) it'll still hit meltdown and I have to let off the fuel pedal.

Same scenario pulling I-70 up to the Eisenhour tunnel.
Downshifting won't reduce EGT's by much, and I have to back out of it in 5th to stay below 1250*.

Seems to be WAY too much fuel with the EZ and RV300 sticks for the HX-35 to handle at altitude...

A hybrid sounds like it might work...and I get to keep my EBrake.
Is a Dodgezilla turbo like this?

Alumni of AFA? I can see that fancy church from my back deck.

Jim B.
Colo Spgs

Big Blue24

Sounds like you could either run water injection for the long grades, lose those injectors, or pay the bucks for a different turbo setup. By the sounds of it, you have that HX35 working at 100% of it's potential. You might gain 50* lower egt's by opening up the exhaust ports/port matching all connections such as the exhaust housing inlet to exhaust manifold connection.

Something that might make a substantial difference is to drill or grind a 3/4" hole through the center divider exhaust housing so all 6 cylinders can vent out of the wastegate. In stock configuration, when the wastegate opens, it significantly lowers the drive pressure in the back 3 cylinders but actually raises the drive pressure on the front three cylinders. Allowing all 6 to work evenly and get some exhaust backpressure relief may help egt's another 50 to 100 degrees.

busa

Talk to High Tech Turbo, they might have some ideas for you or make a hybrid(how do you spell hybrid?)turbo for ya.

roadranger

Thanks for the help guys...
I spoke with Rip Rook and he suggested my doing a EGT test without the BHAF paper filter intake. I borrowed a K&N setup and saw a 150*-170* decrease in exhaust temps over 20 psi boost. Rip said paper filters like the BHAF don't flow as much CFM's as a gauze type rewashable filter will.

I'm convinced! I ordered from Rip an AFE Stage 1 Magnum Force air filter/intake. I hope it gets here before a big road trip coming up next Friday - see how it does.

Oh yeah, I called Pensacola Diesel about their eBay RV300 injectors. They said they are really Bosch RV275's and they have the correct nozzle/spray pattern for 5.9 truck piston bowls, not the marine engine.

A Hybrid turbo will be the next step, probably a Dodgezilla, so that I can keep my Ebrake. At the cost of more lagginess because of the inertia of the larger compressor wheel- and more smoke on upshifts. But gaining over 50% more airflow at boost pressures, for EGT cooling.

HOHN

Jim, a Dodgezilla is exactly this kind of hybrid turbo.

There's nothing wrong with backing out of it in 5th. Do you not have the power you need to pull the hill at 45-50 under load?

I've had my truck in thin air in summer heat, but it was not towing. I noticed it getting warmer, but nothing drastic.

But towing in thin air is a VERY different game, as you've discovered.

Are you *certain* that these injectors are actual Bosch RV injectors? If they are something else marketed as "300hp" injectors based on the popularity of the Bosch option, then some shady diesel shop might be marketing some offshore-made nozzles of lower quality.



One thing you can do that will reduce peak EGT is the slightly larger 14cm turbine housing. This will cause a slight reduction in response (which will make smoke control a little tougher and raise day-to-day EGT at low load). But in return you will have lower peak temps at high loads when towing.

The larger turbine housing will also lower the boost pressure, which should help. At 35psi, the compressor isn't as efficient as it is at 32psi or so. This means that you might actually get have less oxygen (by mass) getting to the engine, even at higher pressure. That same 35psi in the higher altitude would be almost 40psi at sea level, so your turbo is being pushed too far to cool effectively.

Normally, the intercooler would help to compensate slightly for reduced compressor efficiency, but in thin air the CAC is less effective due to the reduced mass of air flowing over it which would receive the heat it wants to transfer.

There's a good chance that you don't have any leaks if your truck is holding 35psi just fine, but it's worth checking if you have exhausted your options.

Hope this helps.

Justin

HOHN

I personally wouldn't be comfortable with a substantial loss of filtration to achieve a marginal improvent in airflow. But I trust Rip-- I just have as a personal soapbox a crusade against oiled gauze filters. That's for another thread, though.

I'm glad to see that your injectors are verified. That's one less thing to worry about.

If you are willing to to try and optimize the engine for high loads (heavy towing) by accepting the tradeoffs in spoolup and smoke control, then a slightly larger turbine (not just turbo, but specifically the hot side of it) is really what you want.

The 65mm turbine of the HTBG from hi tech turbo would be a good incremental upgrade. This turbo is very similar to the BD Super B turbo, which as a good versatile turbo upgrade that improves hp and cooling without any substantial reduction in spoolup. Towing performance should improve nicely.

You can narrowly tailor your turbo be to optimal for a limited range of circumstances, but since the range of operating conditions our trucks face is so large, it's tough to have a true "do it all" configuration of turbomachinery.

Even twins setups can't "do it all". They just come closer than any other currently used setup.

Please keep us posted on how your improvements and modifications change the towing performance your truck delivers.

Thanks.

Justin

PaulDaisy

Roadranger, I am in the same area and in the same boat. I have not tracked what my EGTs are but I am sure they are not cold. My pyro and boost gauges are on their way so I will know soon.
For the turbo I plan to first play with my stock wastegate and then upgrade to the 3rd gen turbo like Big_Blue24 did. Hopefully that will help out at high elevations. I did not see in your posts, are you using a boost elbow? What is your boost level?

roadranger

PaulDaisy - With the small fueling upgrades I've got (EZ box and RV275 inj.) the stock HX-35 turbo is putting out 34-35 psi boost on long hard pulls. This is at the outer edge level of efficiency for this turbo. I like the Dodgezilla because it flows more air, spools up about the same as stock, and I can use my Ebrake on it. All of the turbos HOHN mentioned have a 40 size hot end and can't run a turbo mounted Ebrake. I believe a 3rd gen turbo after 2004.5 will be the same way.

Hohn - I don't LIKE having to back out of it in 5th gear!
and have all of those lightly loaded Powerstrokes walk right past me!

I've got a road trip to South Dakota coming up next weekend.
It'll be interesting to observe how much the new intake will lower the EGT's.
Rip has already shipped it, and UPS predicts it'll get here in time.

PaulDaisy

I understand the e-brake concern! It is an expensive investment. Good luck with the intake and Dodgezilla turbo. I will be watching this thread to see what changes you will see. Please post updates.

AlpineRAM

Well, IMO, one thing to consider for all those guys suffering from high altitude EGT problems is the CAC efficiency. On most of the machines I have to fix with EGT troubles (excavators, wood processors etc) there are drastic EGT drops after cleaning the CAC and also the normal radiator, AC condenser etc. The CAC is obvious, but dirt in the other radiators will impede airflow through the CAC and therefore lessen the efficiency.
Another factor are small boost leaks in some cases. I also prefer to limit the boost to a maximum of 32 psig and increase the wastegate size and drill the divider.
This and a good cold air intake (I use the Scotty with the hole) make for very controllable EGTs even with bigger injectors than mentioned here towing at altitudes of more than 6k ft.

Just my 2c

AlpineRAM