Engine/Transmission (1998.5 - 2002) EGT's whats normal?

[Roadhogz]

Installed my pyro gauge today. What's normal for a 24v auto with a 4" catback and K&N air filter? Did a test run today at 80 degree weather. 400F at 70 mph. Is that right.

 

[Motorhead]

Sounds a little low to me. Is this pre or post turbo? Is your truck stock? is it an automatic or standard shift?

 

[Roadhogz]

It's post turbo on the elbow. It has an Afe style air filter and a 4" catback, no fuel mods. 98. 5 24v automatic. And its an isspro gauge.

 

[Motorhead]

My readings are PRE turbo and I run about 685 to 700. They say that there is about 300 degrees difference between pre and post temps.

 

[Roadhogz]

Hey motorhead, are you running stock or bombed?

 

[Roadhogz]

I know there's more CTD freaks out thier that can help me out. Give me some input on temp. stock or bombed. I just need to know if my gauge is accurate. Thanks.

 

[Motorhead]

Ck my signature as it will tell you. I am running DDII's and a Edge EZ.

 

[dlange]

700 in the exhaust manifold,with an isspro guage. at 65 mph.

 

[Josparkz]

700* post turbo @ 70 mph.

 

[CAT 385]

with my comp off I can hit 1500 degrees pulling hard. This is basically stock except for the exhaust and intake and 275 injectors.



With the box on I never let it go above 1300. I have a buddy who runs an EZ and the rest stock no gauges has ove 50,000 miles with this setup and pulls a JD 310sg that wheighs 17,000 lbs and he has not burned anything up yet. He can out pull me because I back out at 1300 degrees and he doesn't. (cause he has no idea how hot it is)



Running about 80 I run about 800 degrees empty

 

[GeneralMachine]

Exast Temp

Loaded 800 - 1000 post turbo, empty 600-800 just depends if im leaning on the go pedal. Harv

 

[Roadhogz]

Thanks for the replies. Does anyone know the temp difference between pre turbo and post turbo?

 

[Motorhead]

As I said above... It is about 300 degrees

 

[Roadhogz]

Cool, just trying to get someone to back you up on that to make sure. Thanks.

 

[Josparkz]

I have heard that about the difference being 300*. I have also heard it as 10* per pound of boost .

A lot of people seem to think that is not accurate, because you can heat up the manifold too quickly to register on the elbow , and have a meltdown.

One of these days I am going to tap my manifold and either move my thermocouple or add another one that I can switch back and forth , and then really have a good idea what it is (plus something else to play with Oo. . )

 

[Roadhogz]

I think I'm going to have to do the same. I just didn't want to have to take the turbo off to drill the manifold. But if that will give me a more accurate reading, then I'd better do it. Should've done it right the first time!



Another reason why I wanted to know if my gauge was accurate, was because I dropped the gauge pretty hard on the driveway when I was doing the installation. I had to take the gauge cover off to realign the needle.

 

[Motorhead]

First off, you do not have to remove your turbo to drill and tap the EX manafold. You grease the drill and the tap. You then start the engine before you put the fitting in the manafold and the chips will blow out the hole and/or go through the turbo harmlessly.

Second... To ck your egt guage for accuracy to about 375 degrees, pull the probe out and if it is long enough, CAREFULLY!!!! heat some clean motor oil in a pan with a hot plate next to the truck and with a candy thermometer in the hot oil and your EGT probe also in the hot oil, turn on the key and compare temps.

 

[BFC]

300 * used to be thought off as the "difference" between pre on post turbo temp. However, over the last few years many people have observe that to be not that simple or even plain wrong. We use to assume 300 and we all know what assume means... ... .



If you want accurate, pre turbo is the way to go. period.



Glenn

 

[JohnMcIntyre]

reading sounds a bit low?

Truck details in profile below. I concur with the ballpark figures of 300 deg F difference between pre and post turbo readings. Just remember that there are so many variables involved and don't lose any sleep over the "discrepancies" with different members' installations.



From what you've said, it does seem a little on the low side, and it might be worthwhile trying another thermocouple. Is the gauge itself also doing what it's supposed to? How fast does it respond to temperature rate change at the thermocouple?



Generally speaking, 70mph, flat road and empty and it's anywhere between 600 and 800 deg F post-pyro and (in my case) the range is 150 deg F pre-pyro. Most of the time I keep things below 1,000 deg F but under WOT hard acceleration, it's easy to peg it at 1250 deg F. My SPA post-pyro gauge peak has an all-time high of 1,747 deg F stored in memory, but that was more than 10,000 miles ago and I don't recall the circumstances.



HTH

 

[Roadhogz]

I think I'll take motorhead's tip on drilling and tapping the manifold. I mounted on the elbow to avoid taking the turbo off, but I think I'll try motorheads tip.



I didn't cut the wires and have about 3-4 ft more than I need. Will that make a difference? My gauge responds pretty quick within 2 seconds. Is that right?