Diesel tow rigs and EGT’s

[rockyota83]

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.

fwiw typically nothing wrong with running 1250

example

If everything is working properly, 1250º to 1300º F. is a safe turbine inlet temperature, even for sustained running, mile after mile.

Why EGT is Important

Keeping an eye on exhaust gas temperature can save big money The exhaust gas temperature (EGT) pyrometer can be one of the most important gauges on a

official.bankspower.com

 

[OHV Wildcat]

fwiw typically nothing wrong with running 1250

example

Why EGT is Important

Keeping an eye on exhaust gas temperature can save big money The exhaust gas temperature (EGT) pyrometer can be one of the most important gauges on a

official.bankspower.com

This makes me feel better. The Cummins 8.3 in my RV is bone stock, a 2011 model, so DEF and all that. With my small trailer, I’m at about 30k total, and in mountain grades it runs right up to 1300, and will hold it all the way up a climb. I’ve always wondered if i should do something to drop that, but I know jack shit about it, so…all I ever do is downshift and pull a bit of throttle.

 

[JR4X]

Thats nuts that they last that long running like that

The Gas Transmission Northwest pipeline (according to google) runs right near town here. There is definitely more to them than just pipes in the ground like most of us think 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?

The process of compressing it into the pipeline heats it a lot. It actually has to be cooled post compression before it goes through the meter. The compressor can make the discharge gas temp as high as 300° but it has to be less than 125° before it goes the meters. The gas coolers are so big they are a full semi load by itself. A little derail never hurt anybody.

 

[TrailTamer]

Pistons are cooled by oil squirters on back side.

Turbochargers don’t have a way to cool it’s fins, so I can see why it’ll fail first.

 

[TrailTamer]

There are pistons to solve all of your problems. But they’re spendy.

Mahle’s extreme duty monotherm pistons. They’re all steel. The 1,200* egt rule go out of the window

An In Depth Look At Mahle’s Extreme Duty Diesel Monotherm Piston - Diesel Army

We take a deep dive into MAHLE Motorsports’ Monotherm pistons. These steel pistons are designed to handle the most extreme performance applications for extended durations. Find out more here!

www.dieselarmy.com

 

[YotaAtieToo]

The process of compressing it into the pipeline heats it a lot. It actually has to be cooled post compression before it goes through the meter. The compressor can make the discharge gas temp as high as 300° but it has to be less than 125° before it goes the meters. The gas coolers are so big they are a full semi load by itself. A little derail never hurt anybody.

I kinda figured. I've heard locals say that they're heated, but I figured it was a by product, not actually heated.

 

[JR4X]

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.

You’re not going to hurt that thing hitting 1300°. If it levels out around there and doesn’t continue to climb your in good shape to stay in it.

 

[JR4X]

This makes me feel better. The Cummins 8.3 in my RV is bone stock, a 2011 model, so DEF and all that. With my small trailer, I’m at about 30k total, and in mountain grades it runs right up to 1300, and will hold it all the way up a climb. I’ve always wondered if i should do something to drop that, but I know jack shit about it, so…all I ever do is downshift and pull a bit of throttle.

Sounds like it’s tuned about perfect. Most amount of power without self destructing. I wouldn’t be backing out unless that temp is creeping up on you.

 

[JR4X]

If your truck is stock and does not have a egt gauge do you worry. Asking for a friend.

If it’s still under warranty and you don’t mind the down time there’s no reason to think about it

 

[JR4X]

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

We live in the mountains so always high elevation. It’s a 17 crew cab short bed and he’s usually either towing a 38 foot fifth wheel camper, or a rock crawler on a equipment trailer. I followed him from Durango Colorado to Grand Junction co a few weeks ago over Red Mountain on highway 550. You go from 7,000 to 11,000 feet, 3 times. The speed limit for part of it is 65 so we were going 70, him towing about 9,000 pounds and me towing 10,000 pounds. When he could uninterrupted go 70 he never had to back out of it. But if some slack jawed moron tourist slowed us down he can’t re accelerate to our previous speed without getting into the red on EGT’s.

Truck is D word I don’t like to put in writing and just has an 80 hp tow tune.

 

[WaterH]

Good to read this. Mine will cruise around 1000-1100, but can get to 1300 pretty easy on a hill. I always get nervous above 1200. In fact I generally back out. I have to have my foot on the floor to hit 1400.

 

[bdkw1]

There are pistons to solve all of your problems. But they’re spendy.

Mahle’s extreme duty monotherm pistons. They’re all steel. The 1,200* egt rule go out of the window

An In Depth Look At Mahle’s Extreme Duty Diesel Monotherm Piston - Diesel Army

We take a deep dive into MAHLE Motorsports’ Monotherm pistons. These steel pistons are designed to handle the most extreme performance applications for extended durations. Find out more here!

www.dieselarmy.com

Those and some inconel exhaust valves.

 

[YotaAtieToo]

We live in the mountains so always high elevation. It’s a 17 crew cab short bed and he’s usually either towing a 38 foot fifth wheel camper, or a rock crawler on a equipment trailer. I followed him from Durango Colorado to Grand Junction co a few weeks ago over Red Mountain on highway 550. You go from 7,000 to 11,000 feet, 3 times. The speed limit for part of it is 65 so we were going 70, him towing about 9,000 pounds and me towing 10,000 pounds. When he could uninterrupted go 70 he never had to back out of it. But if some slack jawed moron tourist slowed us down he can’t re accelerate to our previous speed without getting into the red on EGT’s.

Truck is D word I don’t like to put in writing and just has an 80 hp tow tune.

Has he tried it without the tune?

Hard to imagine a tuned 6.4 out pacing a ln almost new cummins, but maybe some of these diesel war numbers aren't 100% accurate.

My buddy has a hot rod 08 6.7 and he's been fighting VGT issues for a while. He picked up a fleece performance VGT turbo and still has other issues like blowing manifold gaskets. He tried a 3 piece and then blew the turbo gasket.

I think it's the VGT tuning. He said it's usually after he's used the exhaust brake feature a lot. My guess is the tuner is closing the turbo too much and when he gets on the throttle, it can't open fast enough, so the drive pressure spikes.

Anyways, tuning is all over the place these days. For every tuner out there, there is 100 people who praise them despite them being any good or not.

 

[Weasel]

I can hit 1400 on mine pretty easily. Easy way to fix is to click it into manual mode and drop the trans a gear to get the revs up.

Duramax LBZ, tune likes to kick in the boost vs increasing the revs and boost. EGT drop instantly when kick down a gear. It has a big variable turbo thing and an air charger. Before I figured out the gear trick I understand a bigger air cooler or water injection can help as well.

 

[06h3]

I can hit 1400 on mine pretty easily. Easy way to fix is to click it into manual mode and drop the trans a gear to get the revs up.

Duramax LBZ, tune likes to kick in the boost vs increasing the revs and boost. EGT drop instantly when kick down a gear. It has a big variable turbo thing and an air charger. Before I figured out the gear trick I understand a bigger air cooler or water injection can help as well.

I always wondered what kind of gain or benefit you would get with water injection (no methanol) and if it could do engine damage.

 

[Weasel]

I couldn't say, start down the route as I was getting alot of EGT issues and then found out I had several leaks in the piping. A few loose clamps and bolts. Got all that sorted and with downshifting they EGT's are very much manageable now. Wasn't really looking forward to adding such a system, just more thing to keep up on.

I do have an edge though and have it alert at 1300F.

 

[CarterKraft]

If your truck is stock and does not have a egt gauge do you worry. Asking for a friend.

No worries.

 

[pvkj454]

My buddy has a hot rod 08 6.7 and he's been fighting VGT issues for a while. He picked up a fleece performance VGT turbo and still has other issues like blowing manifold gaskets. He tried a 3 piece and then blew the turbo gasket.

I think it's the VGT tuning. He said it's usually after he's used the exhaust brake feature a lot. My guess is the tuner is closing the turbo too much and when he gets on the throttle, it can't open fast enough, so the drive pressure spikes.

My tuned 6.7 Cummins in the 09 F750 is blowing exhaust manifold gaskets and it has a 2 piece factory manifold. Sounds like a Kazoo on crack with the exhaust brake on. The EGT runs up to 1300 and holds on climbs and the boost holds at 28psi. The engine has a spark knock sound at part throttle. I replaced the blown gasket and it blew it again.

 

[GLTHFJ60]

6.0 here, tuned, 155cc injectors, atlas 80 ficm, stock turbo, ~26k gross going down the road. I have an analog pyrometer and keep an eye on it, but the towing tune with exhaust brake feature doesn't allow the EGTs much above 1200* on the steepest grades in my region.

I wouldn't want a modified diesel tow rig without a pyro, but a stock truck I wouldn't care about.

 

[YotaAtieToo]

My tuned 6.7 Cummins in the 09 F750 is blowing exhaust manifold gaskets and it has a 2 piece factory manifold. Sounds like a Kazoo on crack with the exhaust brake on. The EGT runs up to 1300 and holds on climbs and the boost holds at 28psi. The engine has a spark knock sound at part throttle. I replaced the blown gasket and it blew it again.

He described the sound almost word for word

 

[[486]]

I have an IDI, coolant temp is a problem before EGTs.

on the compound-turbo golf, I've never once lifted from the pyro reading. It kinda buries the needle and then you don't need to worry about looking at it any more. Though, I run outta balls in the speeding department after only like 10 seconds. It isn't a particularly fast car, it is for a diesel, but it'd get slapped around by a v6 accord lol

If you're running into EGT issues, you just need more (or another) turbo. You could also back off the fuel in the tune (or the go pedal) but that isn't the fun answer.
Artificial turbocharger-analogues can also be employed, such as a better intercooler, water injection, water nozzle spraying on your intercooler, nitrous will help drop your EGTs... Anything that jams more air through there.

I used to think intercoolers were a wasted effort before I started looking into the density ratios you can achieve across them. Pretty easy to double the density of the air just through dumping heat outta it. As an aside, this is part of why you'll sometimes make less power with your wastegate welded shut. You just start eating all the pressure ratio increases with temperature-based density ratio decreases.

Those and some inconel exhaust valves.

aren't all modern diesel exhaust valves inconel?

Can get away with a lot worse alloys in gasoline engines because the atmosphere is generally erring toward reducing rather than oxidizing.

 

[[486]]

If you sequential twin turbo a Cummins would you lose the EGT issue on them?

why sequential?
Only reason I can figure is so you can run a very wide spread (a little tiny one that'll come up near idle, and a more reasonable one for at freeway speed)
My experience in that world, you destroy HP turbos a lot unless you bypass the compressor and the turbine, you actually need to block off flow through both sides, or the shaft speed gets absolutely retarded. Tried just doing an HP compressor bypass (just a one-way flapper valve), had a 60mm interstage wastegate set up so that the HP would just idle along above 15 psi in the intake manifold, still, the HP would eat thrust bearings. When the turbo is just idling along choke-flowing with low/no pressure ratio and the wastegate totally open and not much of a restriction, it somehow can have a higher shaft speed than when it is working against a reasonable pressure ratio.

Just go with straight compounds if you're doing that shit.
You're carrying the HP turbo with anyways so why not scavenge some of that wasted exhaust heat into intake pressure?
Not really into the cummins world, but shooting from the hip, something like a mid-sized s300 under a larger-compressor s400 should do real well, run a big external interstage wastegate with the top chamber getting fed interstage boost and the bottom getting HP boost. Big LP external gate, too, mostly for redundancy's sake. I turned my fabricated intake manifold into a balloon when the interstage WG bottom chamber line fell off, wrapped the 60 psi boost gauge right back around to the zero stop pin.

 

[bdkw1]

aren't all modern diesel exhaust valves inconel?

I have no idea. I don't see oems spending that much on valves though.

 

[ironman_gq]

Air in and air out is the best way to cool down EGT's, easiest way is to drop down a gear and let the RPM's get up a bit. With the V8 diesels try to keep them up around 22-2500, yes it's past peak torque but the engine is moving a lot more air.

 

[YotaAtieToo]

Since we've already de railed a bit.

Anyone run a monitor on an older rig? I really don't want pillar guages, but feel like putting a monitor on a 97 F350 with a 12 valve would be silly

 

[[486]]

With the V8 diesels try to keep them up around 22-2500, yes it's past peak torque but the engine is moving a lot more air.

peak hp is what you're looking for anyways when pulling a hill

Since we've already de railed a bit.

Anyone run a monitor on an older rig? I really don't want pillar guages, but feel like putting a monitor on a 97 F350 with a 12 valve would be silly

you know them stamped sheetmetal gauge holder dinguses? Stick it on top of the dash with some deck screws.
Bonus points for boost gauges that got a vacuum section of the scale labeled "well depth in feet"

 

[granitestatedestroyer]

Since we've already de railed a bit.

Anyone run a monitor on an older rig? I really don't want pillar guages, but feel like putting a monitor on a 97 F350 with a 12 valve would be silly

I had a steering column gauge pod on my super duty EGTs. Worked well.

Quick Google says the super duty pods work on older trucks.

 

[white-rhino]

May as well derail it a little more. I've got a 22 Duramax 3500, all stock. We did a trip yesterday, all highway, no trailer, cruising +/- 70, 140 miles each way. I tend to toggle through the menus while driving and was watching my instant mpg and the past 25 miles mpg. On the trip one way, average mileage was around 20. Same thing halfway home, then we stopped for dinner. Head out and my mileage was suddenly 12-13. This lasted about 45 minutes and then returned to 20.

I'm on my 4th Duramax and I've never seen this happen. Maybe regen and I've never caught it in the past? Sticky injector?

 

[ironman_gq]

May as well derail it a little more. I've got a 22 Duramax 3500, all stock. We did a trip yesterday, all highway, no trailer, cruising +/- 70, 140 miles each way. I tend to toggle through the menus while driving and was watching my instant mpg and the past 25 miles mpg. On the trip one way, average mileage was around 20. Same thing halfway home, then we stopped for dinner. Head out and my mileage was suddenly 12-13. This lasted about 45 minutes and then returned to 20.

I'm on my 4th Duramax and I've never seen this happen. Maybe regen and I've never caught it in the past? Sticky injector?

Regen, I think they run about every 1000mi on the newer trucks depending on driving conditions. Short tripping and they'll happen sooner, hauling heavy with high EGT's and they'll happen less frequently.

 

[cchambers13]

Anyone run a monitor on an older rig? I really don't want pillar guages, but feel like putting a monitor on a 97 F350 with a 12 valve would be silly

Ran pillar gauges on my OBS since stock because the whole no intercooler thing. Stock everything they run HOT with any hill or trailer... how they have been cruising all these years is a wonder. Putting a 6.0 intercooler on helped a ton and with "baby swamps" injectors it runs comfy in the below 1250 range even full tilt. Towing with a "60hp" tune and 8K behind it can still get warm in the WV mountains in OD but kicking out cools it right down.

The toasty part is probably 2 fold, I put a 1.0 exhaust housing on it when it got a new Garret turbo with billet wheel but its still a stock size turbo. Smaller housing helps spool up but not as good as a super duty .84 wastegated setup and even then you're not pushing big CFM of air without high wheel speeds because small compressor wheel. Then it still has the small intake plenums etc.. But its way better than it was and tows pretty well for the weights I pull.

Edit: Keeping things based on the stock turbo and small injectors was intentional. Going bigger on either of those would have cascaded issues for towing. More power puts the transmission in jeopardy, its all a balance. A stand alone controlled VGT turbo would be enticing if anything was to change.