Higher EGT's while towing

[roadranger]

I haul 18,000 GCW towing thru the Rockies with an HO and EZ box... .



After putting on a BHAF (with the turbo heat baffle), and adding a Pac Brake, I've noticed a problem.



On long hard pulls (like I-70 E'bnd up to the Eisenhour tunnel) I can no longer maintain 65 mph uphill without the EGT's getting up past 1250*. I have to back out of the throttle some to keep the EGT's down.



Kind of pi$$es me off when my PSD buddy loaded approx. the same can pull past me uphill!



Will a 4 in. exhaust get rid of some of the EGT heat??



Or should I go back to the outside vented airbox??



FlowerPoked in Colorado



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[RustyJC]

See my response here on the other thread where you posted this question.



Rusty

 

[DiTrani]

I'm curious what gear you're in. I know my stock truck wouldn't pull that load/grade/speed in 6th, but perhaps with the fueling box, etc. it could. Even so, I think it would be a lot to ask.

 

[Gary - K7GLD]

Info from Banks olong with some of their stuff I installed on my '91 Dodge indicated that they recommended 1300 degrees as the redline for EGT - I wonder what the max is you can get too with your setup?



My own current truck, with about 15,000 gross, will not exceed about 1200 EGT over the Sierra with my Comp on 5x5 - and I have no concerns so far, and wouldn't, unless I was seeing lots of time well above the 1300 mark...

 

[rob10858]

we pull about 15000 with our 2001. 5 3500's with e brake and 275 injectors thru the applachian mtn range, up and down the east coast. our trucks may pull a 5 to 8 percent grade at 60 to 65 mph, but when the egt's climb we back off and gear down. who cares who beats the other up a hill? that is not a true definition of "pulling power" jmho

 

[Turbo Thom]

Now with mine, an old 96, my EGT's were runnin around 1300 and would go higher when ever I wanted it to. Now with a 14 housing and 4" RR exhaust I can tow my fiver,14K, on a 3-4 degree grade, maintain 68 mph and stay at 1000. I have installed the AFE but I don't know what if anything that would do. I dyno'ed at 405 HP at 1021 Lbs -O-Torque so the power is there but I think the main thing to me is the housing and 4" exhaust. Also cool down is a lot less now.



. . Preston. .

 

[clem]

We traveled I 70 this past summer had no problem with EGT's, but I have smaller wheeles and tires and a 4:10 rear end which lets my engine run in the power band in top gear at 60 mph. With your set up you do not turn 2000 RPM at 60 mph. Have you tried pulling down a gear or two to keep the revs up above 2000 ? The 24v's like to run higher than the 12v'ers Thats the way I sees it:-{}

 

[Steve St.Laurent]

What kind of boost numbers are you seeing? Did you install the elbow in the turbo that came with your EZ box? Without upping the boost you'll definately have higher EGT's with the additional fuel. I run a BHAF on my truck and my EGT's while towing definately went down with the BHAF instead of the stock airbox.

 

[roadranger]

OK, let's see...



I'm in 6th gear pulling the hill at 1850 rpm at around 24-25 psi boost.



When the EGT hits 1200* I downshift to 5th which hits 2400 rpm and lowers the EGT's to about 1100*.



BUT while pulling in 5th at 2400, the EGT's will climb to over 1250* if I don't let up on the throttle.



This does happen in summertime--do you think the BHAF is sucking hot air from the radiator/intercooler??



Is the Cummins e-brake restricting the stock exhaust even more??



Will a 4 in. exhaust help get rid of some of the heat??

 

[Boldt's Wagon]

My personal opinion is you need more boost, about 30 psi. I see a maximum of 850 post turbo with full throttle and 30 psi boost in direct (3rd locked).

 

[AggieJustin]

Did you install the boost elbow when you installed the EZ? The HO will get HOt if you add more fuel but no extra air.



With my HO and BHAF, I can hit 33psi pulling a grade with my travel trailer and the temps stay below 1200*. Granted I have the 4" exhaust, but that shouldn't make that big of a difference on the boost numbers.



If you're only seeing 24-25 there's something wrong. I could pass those numbers empty before the BHAF and 4".



JM

 

[mschoenheider]

Roadranger,

Keep in mind that to put out the same power, our engines at 5000+ feet elevation will have higher EGTs than the same truck at sea level. This is because atmospheric pressure at 5000 feet is about 2. 5 psi lower than atmospheric pressure at sea level. To obtain the same boost level at elevation as a truck at sea level, out turbos have to deliver a higher pressure ratio (work harder). A higher pressure ratio also means that they will heat the intake air more than at sea level. The end result of all of this is that your boost numbers will be lower, and your EGTs will be higher than a similar truck at sea level.

Mark

 

[Wolfgang]

I have an EZ and DDII's with the BHAF. I run over Donner at 65 and 1250 degrees in the summer with a 10,000 lb 5th wheel. My boost is around 28psi. This is at half throttle. I believe I need more boost in order to cool down the EGT's. A better muffler or 4" exhaust will help as well as a new turbo with a bigger than stock housing. I will probably do both. Also keep in mind if he has a TT and you have a 5th wheel he has less wind drag (don't know if this is the case but something else to think about).

 

[LSMITH]

1250 is not a reason to back out of it IMO, 1350 for several minutes might be. The engine is not going to suddenly burst into a molten pile of slag. You can sit at 1300 for an entire tank of fuel without hurting a thing. Your PSD buddy must not have gauges that cause him to back out of it.



Personally unless over 1400 for a couple minutes and water temps over 220 I am keeping it pinned.

 

[roadranger]

OK, now it's making sense--



Yes, I've got the EZ boost elbow installed.



I've got a 11 ft 6 in tall slide in camper in the bed, towing a 7500 lb tandem trailer.



To run 65 mph up Loveland Pass I-70 I don't need full throttle- hence the lower than max boost press. But it DOES get hot EGT wise at that throttle setting.



I've never been able to get more than 29 psi boost--at this altitude.

Home is 6900 ft.

On a trip to the Calif coast, I noticed that near sea level I'd get 32-33 psi boost, with MUCH lower EGT's, and a LOT less smoke when spooling up.



So I guess it's the altitude--not the BHAF or the E-brake.

I AM going to put a 4 in. exhaust on before the spring trips begin.



And YES, that PSD driver in our club does not have any gauges, and would run over old ladies pushing shopping carts just for a chance to pass my Cummins!

I just don't want to give him the satisfaction...

 

[Steve St.Laurent]

You may want to talk with K_Arts before you get that 4" exhaust system. He experienced higher EGT's and lower power when he switched over to a 4" and he is at high altitude like you are. I will say that his experience isn't typical of what most say they see but not that many people are at high altitudes either. Check out this thread where he talks about it: https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=19759&pagenumber=1 .



Also, your pac brake is setup for a 3" exhaust. I believe you'd have to change that out to a 4" inline brake mounted under the truck instead of the turbo mounted brake. I'm not positive about that but it's something to research.

 

[Shooter]

See profile:



DD2's, EZ, PDR HX35 ( which lowered boost at top end but increased boost low end ), BFAC, PAC, 4",



With the GV OD and 3rd I run 75 @ 2175 rpm, can pull most any grade at 75, if not then 65 @ 2400 and not exceed 1250. That is why I stopped the performance bombs. I live at 6100ft and have over 50k miles towing in excess of xxxxx#'s mostly in the mts. The BFAF lowered exhaust so the DD2's could stay.

HO's stock in this area can hit 1200+ MT, bone stock . The first bombs are 4" and BFAC's.

Before you put a complete 4" on consider a resonator back 4". I personally think the 4" down pipe is not necessary for lowering egt's and from my and others experience know it will increase turbo lag at altitude, thus the PDR HX-35 to compensate.

MHO

 

[MCummings]

Originally posted by LSMITH

1250 is not a reason to back out of it IMO, 1350 for several minutes might be. The engine is not going to suddenly burst into a molten pile of slag. You can sit at 1300 for an entire tank of fuel without hurting a thing. Your PSD buddy must not have gauges that cause him to back out of it.



Personally unless over 1400 for a couple minutes and water temps over 220 I am keeping it pinned.

Amen LSMITH.



I tow heavy, and my cruising EGT's are OK, around 1100*-1200* at ~80, But when accelerating 30,000 or more pounds my EGT's are above 1200* from 2K RPM in 2nd gear, from there they get higher, 3rd gear is 1400*, 4th holds a steady 1500* and 5th climbs slowly to 1600* (with 40-41PSI boost). When I hit 6th gear My Water temp is uaually at the top of safe, and EGT won't go below 800*, I then cruise at 2K RPM in 6th for a little while, and when water temp cools a little I cruise on up to whatever spped the trailer/road/truck is comfortable with.



Like LSMITH said, your motor isn't just going suddenly turn into a pile of melted Cummins, and my truck is a testament to that.



Merrick Cummings Jr

 

[roadranger]

Shooter- My HO comes with the HX-35. . what's the difference with PDR's HX-35?? Turbine size?



Steve- I read K-Arts posts...

my HO already smokes like a locomotive with the EZ and 3 in. exhaust on it in the summertime- but only at these high altitudes.

I don't want to dump $400+ into an exhaust system that'll downgrade performance.



Now I'm REALLY confused.



SO--how do you go about reducing towing EGT's at high altitudes??

 

[roadranger]

Originally posted by MCummings

But when accelerating 30,000 or more pounds my EGT's are above 1200* from 2K RPM in 2nd gear, from there they get higher, 3rd gear is 1400*, 4th holds a steady 1500* and 5th climbs slowly to 1600* (with 40-41PSI boost).

Merrick Cummings Jr

DANG, Merrick!



It's a wonder you don't have a thermonuclear meltdown under your hood!