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Diesel tow rigs and EGT’s

JR4X

wheeler
race
Joined
May 20, 2020
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Farmington NM
How many of you tow by watching your EGT’s? My brothers have Cummins Rams and they both have to back off pulling trailers up steep hills to keep from melting them down. Is there a fix for that? My one bro has an 07 with a 5.9 and a 6 speed manual. He got the truck cheap because the previous owner torched the engine pulling a trailer with no pyrometer and galled two cylinders breaking the piston rings. Brother rebuilt the engine put a pyro in while he was at it. It’s got all the power it needs to do it’s thing but he has to mind his overall speed pulling because the EGT’s will hit 1500~1600 pretty easy.

Other brother has a 17 6.7 and it’s same same on the EGT’s. If he has to slow down pulling a mountain pass because of traffic he can’t get his speed back because of the high EGT’s while trying to accelerate.

My truck will motor at 40 psi boost all day and never hit 1200°. If you sequential twin turbo a Cummins would you lose the EGT issue on them? Yes I tow in performance mode in the 250 hp over stock tune.

6357DBC8-A66F-40C0-87CE-1BA2BA8EE18E.jpeg
 
I'd think high egt's are a product of bad tunes with a small turbo.

The only time I really had to watch egt's with my 7.3 and 12v were with no i/C :laughing:

Is the 17 tuned?
 
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Those are common tuned CTD problems. A proper tow tune or no tune will fix that.
 
They need a bigger turbo and/or the fuel turned down in their tunes. A proper tow tune should not be over fueling at any RPM and causing huge EGT spikes. A properly sized compound setup is ideal and relatively easy to do on a Cummins since the packaging is a lot simpler on an inline.

EGTs are kind of a primitive way of tuning diesels now that air-fuel sensors compatible with the ranges diesels operate in have been available for a while. In fact, many European diesel cars have air-fuel sensors from the factory. I don't know why the aftermarket diesel scene still clings to pyrometers. 18:1 is about the lowest sustainable A/F ratio in a diesel, and 20-22:1 is about the limit for being smoke free.
 
They need a bigger turbo and/or the fuel turned down in their tunes. A proper tow tune should not be over fueling at any RPM and causing huge EGT spikes. A properly sized compound setup is ideal and relatively easy to do on a Cummins since the packaging is a lot simpler on an inline.

EGTs are kind of a primitive way of tuning diesels now that air-fuel sensors compatible with the ranges diesels operate in have been available for a while. In fact, many European diesel cars have air-fuel sensors from the factory. I don't know why the aftermarket diesel scene still clings to pyrometers. 18:1 is about the lowest sustainable A/F ratio in a diesel, and 20-22:1 is about the limit for being smoke free.

Every time I dive into diesel performance, I always end up with the consensus that 90% of the companies and people involved are really not that knowledgeable. "more fuel and more air, then upgrade parts that break" seems to be the extent of most of their experience :laughing:

It also seems like most of them just have diesel play toys and really don't know shit about towing.

I'm not a big fan of banks but he really seems to be on the leading edge of diesel performance. He's been building pretty much smoke free fast shit for a long time and the diesel monster truck engine is flat out impressive.
 
My truck will motor at 40 psi boost all day and never hit 1200°. If you sequential twin turbo a Cummins would you lose the EGT issue on them? Yes I tow in performance mode in the 250 hp over stock tune.

6357DBC8-A66F-40C0-87CE-1BA2BA8EE18E.jpeg


Where is your probe? Pre or post turbo?
 
If your truck is stock and does not have a egt gauge do you worry. Asking for a friend.
 
If your truck is stock and does not have a egt gauge do you worry. Asking for a friend.
we have a fleet of F550's dead stock All of them weigh at or near 20k every day of their lives, the guys drive them on the mat and not an EGT gauge anywhere to be seen.

Stock trim I would not worry.

probably 300 trucks.
 
I’d say normally I don’t drive by the EGT gauge. The first time I really did was at 29k lbs gross, high elevation, and hot outside. I was also a dumbass and drove in a medium tow tune when at 29k I should be in a heavy tow tune.

It’s common to hear guys driving my EGT gauges with stock trucks minus a tune. Not enough air from a stock turbo, too much fuel from the tune.

I never hear a bad thing about compound turbos for towing heavy with hotter tunes. Not to sound like a dumbass but I assume your “sequential twin turbo” setup is the same thing as “compound” turbos?

On the topic of EGTs I’ll admit I let out at around 1100 EGT. I’m told I can go higher then that.
 
I’d say normally I don’t drive by the EGT gauge. The first time I really did was at 29k lbs gross, high elevation, and hot outside. I was also a dumbass and drove in a medium tow tune when at 29k I should be in a heavy tow tune.

It’s common to hear guys driving my EGT gauges with stock trucks minus a tune. Not enough air from a stock turbo, too much fuel from the tune.

I never hear a bad thing about compound turbos for towing heavy with hotter tunes. Not to sound like a dumbass but I assume your “sequential twin turbo” setup is the same thing as “compound” turbos?

On the topic of EGTs I’ll admit I let out at around 1100 EGT. I’m told I can go higher then that.
Sequential and compound are the same thing. “Twin turbo”but Twin Turba can be either each bank Y’d into the intake or compound/sequential both banks into one turbo, then directly into another turbo then the intercooler then the intake.

Edit. What I know from work. 1400 is bad prolonged threshold. 1400 + degrees for very long will “tulip” valves and drop the valve head off the stem. 1200~1300 is sustainable
 
I’d say normally I don’t drive by the EGT gauge. The first time I really did was at 29k lbs gross, high elevation, and hot outside. I was also a dumbass and drove in a medium tow tune when at 29k I should be in a heavy tow tune.

It’s common to hear guys driving my EGT gauges with stock trucks minus a tune. Not enough air from a stock turbo, too much fuel from the tune.

I never hear a bad thing about compound turbos for towing heavy with hotter tunes. Not to sound like a dumbass but I assume your “sequential twin turbo” setup is the same thing as “compound” turbos?

On the topic of EGTs I’ll admit I let out at around 1100 EGT. I’m told I can go higher then that.

Sequential and compound are the same thing. “Twin turbo”but Twin Turba can be either each bank Y’d into the intake or compound/sequential both banks into one turbo, then directly into another turbo then the intercooler then the intake.

Edit. What I know from work. 1400 is bad prolonged threshold. 1400 + degrees for very long will “tulip” valves and drop the valve head off the stem. 1200~1300 is sustainable
What what I hear compounds are the way to go and it sounds like your experience and your brothers experience proves that.
 
My work truck is at 38k lbs every day and hits multiple 6% grades every day.
In stock trim? I was commenting on stock without an EGT gauge.

Ours are a fleet of utility bucket trucks. In stock trim unless something is seriously wrong I don't think you can hurt a modern truck. I've seen guys try:homer::homer:
 
I used to drive by egt or boost with old engine. Ran HOT when towing with cruise control uphill. I had to either turn CC off or give it a bit of throttle to get a head start uphill, to stop the CC from applying heavy throttle to regain and maintain speed.

New engine with minimal mods, performance wise; AFC LIVE, advanced timing and the big stick cam.
I don’t need either boost or pyro gauges anymore. I took them out, actually. Towing 20,0000-22,000 GCW with cruise control no problem.

12v p-pump Cummins. FWIW.
 
I can hit 1300 fairly easily on a grade towing. 7.3 with a riff raff wheel in the stock Garrett. Power hungry tune on 25 horse tow tune.
 
Sequential and compound are the same thing. “Twin turbo”but Twin Turba can be either each bank Y’d into the intake or compound/sequential both banks into one turbo, then directly into another turbo then the intercooler then the intake.

Edit. What I know from work. 1400 is bad prolonged threshold. 1400 + degrees for very long will “tulip” valves and drop the valve head off the stem. 1200~1300 is sustainable

I've always heard that high egt's will kill turbos first. 1400* at the turbo isn't necessarily 1400* inside the engine.

Although, maybe that's why they say sustained is what hurts the engine.

In stock trim? I was commenting on stock without an EGT gauge.

Ours are a fleet of utility bucket trucks. In stock trim unless something is seriously wrong I don't think you can hurt a modern truck. I've seen guys try:homer::homer:

Yes, sorry, that was kind of a bone head post :homer:

19 F550, goes up the 6% grades at about 45 mph floored. :laughing:
 
I've always heard that high egt's will kill turbos first. 1400* at the turbo isn't necessarily 1400* inside the engine.

Although, maybe that's why they say sustained is what hurts the engine.



Yes, sorry, that was kind of a bone head post :homer:

19 F550, goes up the 6% grades at about 45 mph floored. :laughing:
Granted, different fuels possible totally different deal. At work we almost never lose turbos but we lose 1 to 2 engines a week to melted valves. Go see my pictures in the stupid stuff you see at work thread. We can run the engines 24 hours a day with turbo’s glowing red and as long as the EGT’s before the turbo don’t exceed 1350° the heads will last 25,000 hours. If the EGT’s hit 1400 for even a short amount of time the (minutes) exhaust valve melts. The valve stem will part right at the valve dropping it into the cylinder and cratering the engine. On our biggest engines there’s a pyrometer in each exhaust port and there’s 16 cylinders with individual kills set at 1360°. Those temps are monitored constantly, the most crucial number to run time next to oil pressure and engine jacket water temp.
 
Granted, different fuels possible totally different deal. At work we almost never lose turbos but we lose 1 to 2 engines a week to melted valves. Go see my pictures in the stupid stuff you see at work thread. We can run the engines 24 hours a day with turbo’s glowing red and as long as the EGT’s before the turbo don’t exceed 1350° the heads will last 25,000 hours. If the EGT’s hit 1400 for even a short amount of time the (minutes) exhaust valve melts. The valve stem will part right at the valve dropping it into the cylinder and cratering the engine. On our biggest engines there’s a pyrometer in each exhaust port and there’s 16 cylinders with individual kills set at 1360°. Those temps are monitored constantly, the most crucial number to run time next to oil pressure and engine jacket water temp.

Like I said heard :flipoff2:

I'm very surprised those engines run that hot of egt's in a constant duty application. I would have guessed way lower.
 
I can hit 1300 fairly easily on a grade towing. 7.3 with a riff raff wheel in the stock Garrett. Power hungry tune on 25 horse tow tune.
Mine runs a 25hp tow tune also. Stock turbo with a ww2 it would hit 1200 if you were really hammering on it. I switched the a turbo from KC turbos and the normal running EGT dropped 100*. Flat out I have yet to see over 1000. Guess I need more fuel now :homer:
 
Like I said heard :flipoff2:

I'm very surprised those engines run that hot of egt's in a constant duty application. I would have guessed way lower.
1250° is nice and forever reliable but the engine has a rated horsepower. To get all of it your going to be pushing higher EGT’s. The machines I work on have known outputs, and if they aren’t pulling their weight the engineers and big bosses in Houston want to know why. The only thing off the table for more production is turning up EJWT and EGT kill setpoints. We can fudge other things to keep the gas moving but turning up those two kills instead of unloading the driven equipment a little is a fireable offense. Do not under any circumstances turn the EJWT kill above 220° and the EGT kill above 1360°.

This is what the inside of our big compressor stations look like and sound like in the dark. If you have nat gas at your home, this is how it arrives to you.

 
Mine runs a 25hp tow tune also. Stock turbo with a ww2 it would hit 1200 if you were really hammering on it. I switched the a turbo from KC turbos and the normal running EGT dropped 100*. Flat out I have yet to see over 1000. Guess I need more fuel now :homer:
Yeah, but what are you pulling and what grade? Not trying to be an ass, but those are what situations I’m talking about.
 
Yeah, but what are you pulling and what grade? Not trying to be an ass, but those are what situations I’m talking about.
16-20k through Colorado. My toy hauler is 10 empty. Add water, rig, firewood, beer.......

It also has a 9' inside ceiling so it has the aero dynamics of a brick.
 
Apart from a custom tune, and keeping my foot out of it, what can be done to lower EGTs?

I have a 7.3 zf6, TS 6 chip on the lowest setting above stock, bellowed up pipes, straight exhaust, and a big ass air filter. Towing our 19' trailer, it'll get up to 1200 pretty easy, and I have to back off or ride 4th at 2500 to keep it around 1100.
 
Other brother has a 17 6.7 and it’s same same on the EGT’s. If he has to slow down pulling a mountain pass because of traffic he can’t get his speed back because of the high EGT’s while trying to accelerate.


What situation is your brother in here? What weight? What grades, elevation? Speed he can sustain?

Reason I ask is I had my first situation like you mentioned last month. 29k gross, 7k feet elevation, I believe a 7% grade in spots and 5-6% in others. Acceleration was miserable and forget shifting, rpm drops too much (only a 4 speed) and EGTs skyrocket. I bet compounds would have helped quite a bit there. Get air flow moving at a much lower rpm.

The scenario I was in isn’t something I plan to do so I’ll live with it but I’m intrigued to hear about his situation.

Enjoy reading the tech and opinions here as well as your thread on equipment and part destruction
 
Apart from a custom tune, and keeping my foot out of it, what can be done to lower EGTs?

I have a 7.3 zf6, TS 6 chip on the lowest setting above stock, bellowed up pipes, straight exhaust, and a big ass air filter. Towing our 19' trailer, it'll get up to 1200 pretty easy, and I have to back off or ride 4th at 2500 to keep it around 1100.
Turbo would help move more air. I don’t use a KC turbo but I hear good things about them and they are a drop in.
 
Apart from a custom tune, and keeping my foot out of it, what can be done to lower EGTs?

I have a 7.3 zf6, TS 6 chip on the lowest setting above stock, bellowed up pipes, straight exhaust, and a big ass air filter. Towing our 19' trailer, it'll get up to 1200 pretty easy, and I have to back off or ride 4th at 2500 to keep it around 1100.
😜 Well at least I know I’m not the only one with a 7.3 that runs hot!
 
1250° is nice and forever reliable but the engine has a rated horsepower. To get all of it your going to be pushing higher EGT’s. The machines I work on have known outputs, and if they aren’t pulling their weight the engineers and big bosses in Houston want to know why. The only thing off the table for more production is turning up EJWT and EGT kill setpoints. We can fudge other things to keep the gas moving but turning up those two kills instead of unloading the driven equipment a little is a fireable offense. Do not under any circumstances turn the EJWT kill above 220° and the EGT kill above 1360°.

This is what the inside of our big compressor stations look like and sound like in the dark. If you have nat gas at your home, this is how it arrives to you.



Thats nuts that they last that long running like that :laughing:

The Gas Transmission Northwest pipeline (according to google:laughing:) runs right near town here. There is definitely more to them than just pipes in the ground like most of us think :laughing: I was surprised to see that they are warm enough to keep snow from accumulating. Deer seem to approve.

Do they actually heat them? Or does the process just create heat?


What's this thread about again? :flipoff2:
 
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