I seem to think my cold start and normal driving EGT's are a little high, so I need someone to verify what theirs does at these same times:
Cold start - 30 sec's: 425, 60 sec's: 475, put in drive and with just slight throttle up to mid 600's. Then it seems to drop as I start accelerating on the road. After its warmed up, cruising on flat interstate at 70 it holds between high 600's and low 700's. (start up temps are with the exhaust brake on, also.)

I've been getting black smoke right on start up (cold start only), and have been trying to isolate the facts..but started second guessing myslef when I started looiking at the EGT's. It doesn't seem like leakdown at this time - no fuel in the oil, no white smoke at all, and no rough idle. Smarty is now on level 3, XZillaraider is off. Air filter has been cleaned. Power does not seem to be up to snuff.......but that could be in my mind also.

 

Idling egts seem normal with EB on. What's egt at idle, right after start, with EB off? 300+/- ?

Driving egts are so dependent on all other factors (mods, settings, conditions, etc.) it's difficult to make a good comparison. However, your interstate cruising egts seem in the normal range for a stock charger.

 

Depends where your EGT probe is too....

Mine reads mid 600's cruising. On flat roads it will be high 500's and up inclines upper 600's. Passing or big hills get me 700's to 800's.

 

Seems normal. Mine runs 600-800 on the flat highway 75mph (nothing is really FLAT around here though). Hits 900-1100 over the passes depending how hard I'm into it. 1300-1400 over the passes with a trailer 60-70mph.
Doesn't seem any lower or higher with Bullydog on stock or performance mode (75hp).

 

Mine used to hit 1400 stock.... With my Smarty it won't go above about 1250.

 

Sounds like perfect EGT's to me. Wish mine were that good on cold start.

 

Yeah mine'll hit 1400 deg if I plant my right foot going over a pass with a trailer hooked up. Bullydog does not make it run any cooler, but it overfuels more than some programmers I think. I can black out an intersection with the best of them if I lug it and punch it!

 

Hmmm Weird... Usually excessive unburned fuel cools the cylinders and exhaust. I don't know what the Smarty does, but it won't get as hot as it used to. I figured it was overfueling to keep temps down. I know with my foot in it the mileage sure falls flat!

 

i thought diesels ran hotter when running rich.....

the changes in timing is what cools it down?

 

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JThiessen:

I agree with what the other DTR members have already said,.....your numbers look fine to me. Your EGT numbers are pretty well in-line with what I see on my 2006 too.

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John_P

 

Thanks guys - makes me feel a little better that I dont need to worry about the turbo right now. Guess I'll just keep waiting on this black smoke at the start to either get worse, or maybe it's just what this truck is going to do.

 

Timing, the BullyDog doesn't use as much timing as what a lot of people run the Smarty on, same as the E\JA.

The timing doesn't cool anything down it just puts more heat into the cooling system and heat soaks the piston rather than spit it out the exhaust. X amount of fuel still gives Y BTU's, we just can't measure it when it is in the cylinder too long.

 

Yep, X fuel = Y BTU's, but UNBURNED fuel cools right? If it's not releasing BTU's it's drawing heat from the metal it touches.

 

That statement is true for gasoline, but diesel is a different story. If you put in more fuel without more air, you will have higher EGTS. (It may be the same for a gasser, but no one really measures EGTS for gasoline vehicles.) You need more AIR or WATER injection (Effectively creates cooler denser air) to cool EGTS in a diesel.

Increasing the timing will show lower EGTS, but as stated above is because more heat is being kept in the cylinder creating heat soaked parts.

 

Essentially yes, if you go so far off stoichiometric balance and massively over fuel it quenches the combustion and cylinder temps drop dramatically. Not so much from the fuel but from combustion not reaching temps. There is 15 times more air than fuel in a balanced combustion so you have to massively over fuel to make a significant difference.

Stoichiometric rich will also drop the temps and power as too much of the combustion heat is trying to heat the excess air.