[Glenn-BJ74]

Originally Posted by boogie74

Hello All,

I've been busy this week fixing up my BJ74. Just taking care of the little things that make the cruiser ride better.
I just got back from testing out my new Autometer Sport Comp Pyrometer. As you can see from my picture I went
post turbo on the install. Bag me out if you wish believers of pre turbo thermocouples.

Anyway after searching on mud and other places I need some clarification on exhaust temps.

After my drive this arvo I recorded the following stats:
Idling @ 95C (200F) before driving & 205C (400F) after driving.
Cruising at 70KMH @ 300C or 45MPH @ 600F
Gunning it from 70KMH to 90KMH @ 370C or 55MPH @ 700F
Up a steep hill 500m long got up to 800F or 426C going through 2nd, 3rd
& 4th gear. I was pushing it to see how high I could go.
Would have pulled out if it had got close to 1050F.
Seems like I still have 200F of headroom before I get into the red zone.

So how do these temps compare to other people's EGT temps? It would be good to see how mine compare to others findings.
I was worried about the depth of the probe but I have the standard 2.5" dump pipe with about 1.5-2" of probe going into it.
That much probe should give accurate readings shouldn't it? I pretty much screwed the themocouple in the dump pipe so the threads
on the thermocouple sat flush on the inside of the dump pipe. I thought if the threads were too deep inside they may burn up.
Don't know if I'm being too cautious here.

Cheers All
Time for a beer now or may be a turkey!!!!

Since your probe is post turbo your readings are low compared to if you had installed it pre-turbo. From memory my pre-turbo readings are as follows:

idling = 350 F
around town = 500 to 800 F
highway = 600 to 1000 F
climbing = 900 to 1200F+

As for depth of the probe I installed mine in approximately in the center of of the exhaust collection manifold (in the center of the chamber) where temperatures should the highest. During sustained climbing with the truck loaded for a trip the pyro temps increase VERY RAPIDLY. I have found the EGTs are more related to the amount of fuel the engine is using, rather than RPM. EGT's rise under hard throttle.When EGTs temperatures are high (over 1,100-1,200F) I often have to back off on the throttle and sometimes shift down. Shifting down only has a small effect of reducing EFTs. When under maximum load that is when the pyro is most usefull. Often when I am climbing with other 74's I advise them over the CB that I am backing off on the throttle. I have an after-market water temperature gauge in my truck and even when EGT are high, the water tempertaure gauge only increases a few degrees. EGTs are very sensivtive to the amount of fuel burning in the engine. I think post turbo you should add 200 to 300 F to estimate your actual pre-turbo EGTs. In a way, this imprecision defeats the purpose of the location of a post turbo pyro.