Engine/Transmission (1998.5 - 2002) Expected EGTs?

[DonS]

Based on the mods in my sig, what kind of max EGTs should I see?



I just installed the 4" exhaust, because I'd seen 1200 degrees when flooring it, climbing a small hill, unloaded, at 70 MPH.



Fifteen minutes ago, I went out to see what, if any, decrease the new exhaust gave me...



Smarty on #8, Comp on 5x5. Cruising at 70 MPH in 6th gear, ~2000 RPM, level ground, empty. I floored it. I got the expected black cloud, and my boost gauge went to 35 psi. The unexpected part was when my pyrometer pegged at 1500.



I suppose it's time for a new turbo, but I really didn't expect these EGTs with my current mods.

 

[johncameron]

drag comp

M 4 injectors

Smarty





... ... ...



Stock turbo :--) :--)



Your lucky it hasn't gone BOOM yet!!!



John

 

[DonS]

I have the turbo wastegated at 35 psi. Prior to the 4" exhaust, the highest EGTs I saw was the 1200 mentioned above - and I'd tried. Until today, I was in pretty good shape (based on tests).



I know I have to be careful, but I was really surprised to see the EGTs climb so dramatically with the new exhaust.

 

[Cummins724]

That is alot of fuel for that turbo. I would get a super stock turbo from HT... . it works great for me. If you don't tow... maybe the 64 quick diesel would be a better choice. Hate to see you melt down & have to replace the engine. It doesn't take long to melt a piston @ 1500.

 

[DonS]

That is alot of fuel for that turbo.

Yeah, I know.

It doesn't take long to melt a piston @ 1500.

I won't be doing it again.



This was the first time I'd seen such a temp, and I'd actually been trying to get the EGTs up - just to see if I was in "danger". Until today, the highest I'd seen was 1200. I thought that was high (given that I was unloaded), and decided my next upgrade was the 4" exhaust.



My next upgrade is clearly a turbo.



EDIT: I guess what I should've asked up front is: Would the exhaust upgrade have contributed to a 300 degree increase in EGTs? Or was I just lucky in my previous "testing" that I only saw a max. of 1200 degrees?

 

[Joe Mc]

"Good God Man, give that engine some more air to go with all the timing and fuel!" :-laf



Yes an aftermarket turbo would be very desirable with those egts. I'm waiting to for 4s or 5s and a Super Stock Diesel to round things out for me.



Even with my present 1. 6 sticks and the comp on 5/4 those egts get up there with the stock huffer.



Best to ya!

 

[johncameron]

I know I have to be careful, but I was really surprised to see the EGTs climb so dramatically with the new exhaust.

Theres no way your EGT's were only 1200 PRE TURBO with thse mods before your exhaust. Do you have the pyro post turbo?

 

[Cummins Thunder]

Sounds like you need to check your pyrometer



You should be able to EASILY peg it!!!



BTW, dont get too worked up about touching 1500 for a second. I am a testament for these motors being able to take 1500+ degrees for 15+ seconds Ok, all you non-insane people, go ahead and tell me im an idiot...

 

[DonS]

Theres no way your EGT's were only 1200 PRE TURBO with thse mods before your exhaust. Do you have the pyro post turbo?

No. Pre-turbo in the manifold.



If 1500 degrees, with my mods, is not unexpected, then the only explanation I have for my prior 1200-degree maximum is that I may have "gotten out of it" when I saw 1200.



In any case, I do know that I have to be more careful until I can pump more air in.

 

[johncameron]

I am a testament for these motors being able to take 1500+ degrees for 15+ seconds Ok, all you non-insane people, go ahead and tell me im an idiot...

I agree, I am able to see 1450+ in the 1/4 mile. That takes me about 15. 8 seconds

 

[DonS]

Sounds like you need to check your pyrometer

Sounds like I just did this afternoon Looks like it's currently working just fine.

BTW, dont get too worked up about touching 1500 for a second.

I'm not in the least concerned about that temp for the second or two that it happened. I was watching the gauge during today's test, and let off as soon as I saw the gauge peg - which happened in less than 2 seconds. No sweat (until next time, of course - it's going to take some doing to lighten my right foot).

 

[johncameron]

I think your best bet would be to turn your comp completely off and just run your M4's and smarty on timing (3-5-7-9) until you get a turbo. Even Without your comp I'm sure you will see over 1300 on hard pulls.

 

[EBung]

With my mods I can peg my gauge (1700) in the summer time heat and I can hit 1200 on injectors alone. I really cant see how an exhaust could have a negative effect on EGTs unless its plugged.

 

[Red Ram]

Based on the mods in my sig, what kind of max EGTs should I see?



I just installed the 4" exhaust, because I'd seen 1200 degrees when flooring it, climbing a small hill, unloaded, at 70 MPH.



Fifteen minutes ago, I went out to see what, if any, decrease the new exhaust gave me...



Smarty on #8, Comp on 5x5. Cruising at 70 MPH in 6th gear, ~2000 RPM, level ground, empty. I floored it. I got the expected black cloud, and my boost gauge went to 35 psi. The unexpected part was when my pyrometer pegged at 1500.



I suppose it's time for a new turbo, but I really didn't expect these EGTs with my current mods.

Check this out :



What To Monitor For . . .

PYRO:

Temperatures will vary whenever the throttle is moved or the terrain changes. The peak

number is the most important while towing, the ISB can be safely run up to 1450 for

short bursts and 1350 all day long. This number is strongly affected by modifications

weather it be Air flow or Fuel delivery. If air flow and fuel flow are increased equally, we

can increase power to very impressive levels with no increase in EGT or smoke.

Average temps for a stock truck

Idle - 250 to 450

Cruise no load - 400 to 700

Cruise with trailer - 500 to 800

Pulling hill no load - 500 to 1000

Pulling hill with trailer - 900 to 1250

Go too high and risk these...

exhaust gaskets

exhaust manifold

cylinder head casting

pistons

rings

cylinder bores

Cylinder #1 has an obstruction of the intake port caused by a casting boss for accessory

mounting bolt placement plus a forward facing valve port which causes the intake air to

run a maze to reach the cylinder. These reduce the airflow to the #1 cylinder, causing it to

run richer than the other cylinders. Often, the exhaust manifold gasket has been cooked

on cyl #1, while the others are fine.

Boost:

Boost pressure tells you how well your turbo is working, weather or not you have a boost

leak, and how your waste gate is adjusted.

Average pressures for a stock truck

Idle - 0

Cruising 70 mph no trailer - 5 to 10 psi

Cruising 70 mph with trailer - 7 to 15 psi

Pulling a hill no trailer - 10 to 20 psi

Pulling a hill with trailer - 15 to 21 psi

Go too high and risk these...

Turbo

Intercooler Boots

Head Gasket

Again this number will vary like EGT, with throttle position and load. Air flow and fuel

flow increases will make this gauge move much faster.

Fuel Pressure:

Pressure created by the electric fuel pump that carries the fuel from the tank to the filter

then on to the injection pump. This has become a very important gauge on the ISB with

all the fuel pump failures that have occurred and cause drivability issues. This gauge is

not very exciting but when there is a problem it becomes very important in diagnosis,

plus it can save a very expensive injection pump from failure due to lack of lubrication

and cooling.

Average Pressures on a stock truck

Idle - 10 to 14 psi

Cruising - 8 to 12 psi

Pulling a hill with trailer - 8 to 9 psi

Absolute minimum pressure is 8 psi; anything below that and you need either a new lift

pump on a stock truck or an upgraded fuel system on a modified truck

Automatic Transmission Temperature:

Temperature of the transmission fluid that leaves the torque converter and goes on to the

coolers. Again not very exciting be very important to the life of your transmission and or

torque converter.

Average temperatures on a stock truck

Idle in neutral or park - 140 to 160

Idle in gear - 160 to 260 depending on how long.

Cruising - 70 mph no trailer 150-170

Cruising - 70 mph with trailer 160-180

Pulling hill no trailer - 180-220

Pulling hill with trailer - 190-280 depending on load and how long a hill, or weather you

can pull the hill in lock up or not

Temps will always be higher when out of lock up, because 90% of the heat generated in

an automatic transmission is from the shearing of the fluid in the converter. Temps will

be lower when in lock up because the input shaft of your transmission is locked to the

crankshaft on the engine.