High EGTs After Minor Upgrades

[IISV345]

Hey folks, been lingering around this forum for years. Best site for reliable info.

My truck: 2000 24V with 262K, Edge Comp Box(VP44 is Tapped), Airdog 150 Lift Pump, 4" Exhaust, S&B CAI, ATS 48RE(Don't Ask lol)

Upgrade parts in question: HE351CW and DAP VCO 7x0.009 Injectors. All on 265X75r16 tires.

 

Recently l purchased a used HE351CW off the marketplace for $50. It was in bad shape, I opted for a Spoologic billet cartridge instead of rebuilding. Along with the turbo, I purchased DAP VCO 7x.009 injectors to spin it.

Project went smooth besides the dozens of boost leaks giving me hell. Countless hours later, with all the boost leaks resolved, my EGTs are through the roof. 3 seconds at WOT nets me 1500+.

My first thought was too much fuel, but I can't top 32 PSI on the turbo and she barely smokes regardless of fuel level on my Comp Box. I thought I'd be able to spin 40+, not that I care too. The big caveat to all this; I'm running the turbo non-wastegated as the stock one wasn't functional. I have the flapper closed with steel cable and it seems very tight, but I'm aware this could be an issue.

I have gauges so I figured I'd turn fuel down or use mindful throttling to manage boost until I figured my wastegate solution.

I do plan on purchasing a spring wastegate, but this still isn't adding up for me. The truck runs great and I'd be content with the boost it's making if not for the EGTs. 

Am I overlooking something or is boost potentially leaking by the flapper due to my silly solution? 

Any advice or criticism would be greatly appreciated. Thanks in advance!

Edited September 30 by IISV345

[Mopar1973Man]

No timing and fuel control on the Edge Comp. I left the Edge Comp and went to a Quadzilla Adrenaline. Your running excessively advanced timing and not enough retard to build boost and control EGTs.

 

I'm running custom 7 x 0.010 +150HP DAP injectors popped at 320 bar. Stock HX35W turbo (54/60/12). No EGT issues all the way to 100 MPH.

 

Now switch to my tow tune I can stand on the throttle and never exceed 1,200°F EGT even towing my 31 foot RV.

 

I've gotta ask what size tires are you running?

[Tractorman]

1 hour ago, Mopar1973Man said:

I've gotta ask what size tires are you running?

 

On 9/30/2024 at 10:54 AM, IISV345 said:

All on 265X75r16 tires.

 

What was the engine rpm and boost pressure when the EGT reached 1500°?  I presume your observations were done with an empty truck. 

 

I am curious as to why the high EGT's.  I always thought that the HE351CW turbo was a good upgrade - just what I have read.

 

- John

 

Edited October 2 by Tractorman

[Mopar1973Man]

Yeah I missed that thanks. 

 

The tires are OK for size. With an automatic with a 0.68 final ratio might bring the cruising RPM too low and might create lugging and EGTs will rise sharply. Proper cruising RPM should be1,800 RPM or higher. 

47 minutes ago, Tractorman said:

I always thought that the HE351CW turbo was a good upgrade - just what I have read.

 

No, because HY35W is a 9cm2 turbine housing like the HE351CW (60/60/9) is also a 9cm2 housing choke point that comes in very low at about 30 PSI. Now an HX35W is (54/60/12) and then an HX35/40 Hybrid is a (60/60/12) which is good till about 35 to 38 PSI without going to deep in the choke point.

Edited October 2 by Mopar1973Man

[Tractorman]

38 minutes ago, Mopar1973Man said:

like the HE351CW (60/60/9) is also a 9cm2 housing choke point that comes in very low at about 30 PSI

 

That makes sense regarding the 9 cm2 housing and could very well be his problem.

 

- John

[IISV345]

Thanks for the replies fellas.

Tractorman - I did quite a bit of research and found the HE351CW would be an upgrade as well. The turbo feels a ton better than the HX, but the HX may have been tired.

As for RPM and EGTs, almost immediately past 2000 RPM, they skyrocket. That's at 33 PSI and empty.

Mopar - I was gonna mention the Quadzilla, but spaced it. In my research before the install, I found the comp box could be an issue. 

I had planned on 245s for tires, but a discount lured me too the 265s. At 70 I do cruise around 2100 RPM though.

It's also worth mentioning I also had EGT issues with the HX, but it was much more manageable and I could tow comfortably. I haven't had the courage to tow with the new setup.

 

Would the best advice be to suck it up and buy the Quadzilla?

[Mopar1973Man]

Yeah you could manage your fuel and timing better with a Quadzilla. I tend to add fuel AFTER turbo is spooled. Basically I'm running only +150HP injectors till 15 PSI Boost. Then I pour the fuel to the engine above 15 PSI.

[IISV345]

Awesome. I appreciate the advice.

I'll update this when I do/don't resolve my issues.

Thanks!

[IISV345]

Alright, back with an update. Got the Quadzilla installed, took a while due to a dead iQuad. Quadzilla got it diagnosed and replaced quick. 

 

I've spent the last week testing and tuning, very happy with the upgrade. I have a lot to learn about the various tuning variables though. Needless to say, EGTs are still too high. I'm more concerned that I'm just not knowledgeable enough yet. 

I've also dug back into boost leak issues as I still speculate I'm having an issue there. My leak tester is showing that I am losing boost somewhere now. Not a drastic leak, but a leak nontheless.ive installed brand new boots just in case, but no change. Can't hear or see a leak with soapy water. Think I might be due for a @Mopar1973Man custom tune and I'll just go from there.

[Mopar1973Man]

Boost leaks are not a cause for high EGTs. I've pull the boost hose off the wastegate and one bolt from the manifold still reached 43 PSI and EGTs still below 1200°F.

 

Excessive advancement of timing will create high EGTs especially if your final ratio is less than 3.55 calculating oversized tires.

Edited October 29 by Mopar1973Man

[Tractorman]

On 10/2/2024 at 7:51 PM, IISV345 said:

As for RPM and EGTs, almost immediately past 2000 RPM, they skyrocket. That's at 33 PSI and empty.

1 hour ago, IISV345 said:

Needless to say, EGTs are still too high.

 

What are the EGT's running at now? 

 

I believe the 2004.5 through 2007 Cummins engines use the HE351CW turbo (waste-gated at 32 psi) as a stock turbo.  These engines run stock 610 lb/ft torque and 325 HP.  I recall from reading many posts on the Turbo Diesel Register that these truck owners were concerned about 1400° - 1450° egt's when towing.  They were told that this is normal and not to worry about it.  I also read that the injectors, head, and pistons for this era of engine are designed to handle the additional heat. 

 

It is my guess that you may not be able to achieve 1200° or less egt's with that turbo and the power you want from your engine.  And, the 2nd generation 24 valve engine is not designed to handle the higher heat.

 

I have RV275 hp injectors, stock HX35W turbo (393,000 miles now on the turbo), and a Smarty S03 set with a mild tune and stock timing.  I can pull a 4 mile 6% grade at 50-55 mph (combined weight 20,000 - 21,000 lbs) and keep the egt's below 1200° - 5th gear 2,000 - 2,200 rpms.

 

I hope that you can accomplish what you want with the tuner, but I am having doubts. 

 

- John

[Mopar1973Man]

In cylinder EGR event is made possible by a shorter duration cam lobe for exhaust. This could be fixed by changing the cam out for a performance cam and ditch the in cylinder EGR event and then get a tuner to ditch the retarded timing. 

[IISV345]

I was seeing EGTs peak above 1700° on more sustained pulls empty. I've been backing off sooner recently as I've played with the timing. Seen 1598° at 90% throttle in the data logger this morning. I'll keep playing with timing and try to retard it more until I see lower EGTs. Just slowly learning the variables.

[Mopar1973Man]

Typically advancing timing makes the EGT's cooler but the boost will disappear.  The more retard the more boost and EGTs. 

 

I'm running on my 2002 Dodge Cummins 26 to 27 degrees for timing at 2,000 RPM (66 MPH) under 20% engine load. The boost is typically under 5 PSI in this mode. Now drop out of cruise timing (performance timing will engine load above 20%) I'll see about 19 degrees and an increase in EGTs and boost together being you need expanding/burning gases to spin the turbine on the turbo.