EGT temp, post turbo ?

[Dean Upson]

I also agree with Keith, if you are going to tow or otherwise work the truck, a pre-turbo probe is the way to go.



Dean

 

[Forrest Nearing]

I'll 2nd (4th?) what Keith said... a post-turbo pyro just doesn't give you the information you need to keep your investment safe. You can get EGT's in the danger zone well under the 400hp level! and by the time that post-turbo tells you you're too hot, you've been too hot for a while...



it really doesn't take much more effort to go pre-turbo... just grease the drill bit and the tap and go slow... and realize that if you do get a flake or two of iron in the manifold, it's just blow right past the turbine...



Forrest

 

[Dean Upson]

I think many are antsy about putting the probe in pre-turbo because of possible damage to the turbine. I have never heard of a probe "going south" although it has probably happened. I have always been amazed at how fast both the boost and egt gauges rise and fall.



Dean

 

[Bertram65]

I have a stock truck and plan on keeping it that way, I use the pyro to monitor the temp of the turbo for cool down purposes and while towing. Having my pyro post meetsmy needs. You cannot measure the temp of the turbo (by measuring the air that passes through it) without having the pyro after the turbo.

 

[Dean Upson]

If my egt is less than 300* pre-turbo, I feel confident the turbo has cooled suffiently to shut down. Normally, I shut down around 250-275*.



Dean

 

[Forrest Nearing]

I'm willing to bet that more damage happens on stock trucks from high EGT's than from people shutting down without cooling down...



Forrest

 

[rbattelle]

Originally posted by Forrest Nearing

a post-turbo pyro just doesn't give you the information you need to keep your investment safe. Forrest

Which investment? The engine, or the turbo?



And I've heard that most OTR trucks use a post-turbo EGT probe. Is this true?

 

[Forrest Nearing]

Originally posted by rbattelle

Which investment? The engine, or the turbo?



And I've heard that most OTR trucks use a post-turbo EGT probe. Is this true?

investment? the engine... an engine rebuild is a LOT more expensive than a turbo rebuild... and turbos are REALLY tough... we idle the trucks down because we're obsessed with them, but I promise you that we're in the minority as far as turbo owners. I know tons of people who don't idle their turbocharged cars down before shutting them off. It takes a long time before this causes a problem, and if you run synthetic, it'll probably never cause a problem... but it only takes one time getting the EGT's too hot to destroy the engine.



now... I do think a lot of people freak out about their EGT's more than they need to as well (did I just say that?!) I believe our engines are rated for a continuous 1250*F... as in, run it at 1250* all day every day and not cause any pre-mature damage. plenty of guys on this site routinely get up in the 1600++ range without worry. They don't run it at those temps for extended runs up a big hill, but their engines don't instantly disintegrate when they go over 1400* either...



but, bottom line is you can get a turbo rebuilt for a couple hundred bucks... you'd be lucky to get an engine rebuilt for a couple grand... (double or more would be more like it)



so, I'll continue to use my pyrometer to keep tabs on the engine in real time vs. getting the information 2nd hand after it passes through the turbo's ass.



Forrest

 

[KLockliear]

Originally posted by Dean Upson

I think many are antsy about putting the probe in pre-turbo because of possible damage to the turbine. I have never heard of a probe "going south" although it has probably happened. I have always been amazed at how fast both the boost and egt gauges rise and fall.



Dean

Perhaps early on in thermocouple technology, probe failure may have been a problem; however, in the past 5 years, I have not seen one break.



The FAA is known as being a pretty anal group... and they allow pre-turbo thermocouples in planes. And one would think that a failure at 10k feet would be more of a problem than driving on the road. If it's OK for them, it's OK for me.

 

[evldsl]

I second that thought because I know how the FAA think due to the fact I am a aircraft mechanic for A. A. .

 

[rbattelle]

Originally posted by Forrest Nearing



but, bottom line is you can get a turbo rebuilt for a couple hundred bucks... you'd be lucky to get an engine rebuilt for a couple grand... (double or more would be more like it)

An excellent point.

 

[LPChristensen]

Well, thanks to all that replied to my original post. I bit the bullet and drilled into the manifold and put the EGT probe pre turbo! I was very careful with the shavings, went and bought a extra small pencil magnet, lots of grease. After installation I felt a little foolish for worrying so much about it, once I heard my turbo work without any unusual noises, I felt fine. I was surprised at how fast the EGTs rise and fall. I would have thought that when it got up a few hundred degrees, it would stay there, but as soon as you slow down or stop it cools down real quick. Long and the short of it all, I'm happy, project is done, seems to work (fingers crossed) and I appreciate all the help and advise.

 

[KLockliear]

What will suprise you more is how hot it will get on an extended pull, even stock. The itty bitty stock turbo does a good job of keeping the heat in the manifold.

 

[JHardwick]

Hey Keith,



Sell me a bigger compressor wheel for my itty bitty turbo?



What will it do exacly? I'm already hitting 40 PSI with the stock configuration and I wont be doing any other mods until the new Edge box comes out. Once I have the new box on, I'll be looking at "whats next"!

 

[Forrest Nearing]

you gotta uncork the turbine side too... all the compressor in the world isn't gonna do much if you don't give the exhaust side some room to breathe.



Forrest

 

[JHardwick]

I'll do all the required machining, I figure I can spend a day machining the housing easier than I can send it off for a couple weeks, and have nothing but time and a compressor wheel invested

 

[Forrest Nearing]

you'll need to machine the center housing as well... it doesn't have to be super precise on the center, but you'll want a good cut on the compressor housing. not sure what kind of clearance spec you'll need, but I guess you could just measure the factory clearance and shoot for that.



once you're that far into the turbo, you might as well put a rebuild kit in it ('course, your turbo probably doesn't have many miles on it!!)



get a 16cm turbine housing to replace your stocker, and you'll have yourself a nice little turbo without too much investment...



Forrest

 

[KLockliear]

The stock HY will never support the power potential of these trucks. The turbine housing is way too small, as is the compressor.



Put your EZ back on setting 4 before you sack out the relief, and get ready for a bigger turbo. If you want to add more power to what you have, you have to go with a larger turbo... something like the kit we offer for the 03/04. You just can't do it with the HY, not and keep EGT's manageable anyway.

 

[Forrest Nearing]

Keith, what is the difference on '03/04's? I'm assuming the boost curve has to be similar to stock to keep the computer happy?



thanks,



Forrest

 

[JHardwick]

Kieth,



"Put your EZ back on setting 4 before you sack out the relief, and get ready for a bigger turbo. "



I assume this is the relief valve you are referring to?



I'm planning on stepping up to the next Edge when it is available, I've already got the EZ sold to a friend. Maybe I should wait and see what this thing does for EGT's. I am happy with EGT's as of now.



Injectors and turbo after the new Edge??Oo.