EGT, Pre or post turbo----Risk?

[RScharbach]

I'm having my guages installed, the mechanic tried to talk me into installing the thermocouple post turbo. His reason is that the probe could rust/break and wipe out the turbo and send turbo pieces through the engine ruining it also.



As I have not heard of this before I ask that he install pre turbo.



Is this a serious risk? Did I make a mistake?

 

[FATCAT]

Rust????????????

Rust out ... on the inside of the manifold? I highly doubt it. a minute or two of runing the engine will coat the probe with soot.



Rust could never happen to the probe on the inside of the manifold.



Don't worry ... your fine. I've had mine installed pre-turbo for years now with no problems (other then I'll never be able to take it out of the manifold if I install an ATS manifold).

 

[MCummings]

If you break/melt/rust a thermoucople, the Turbo will be one of your last worries anyway. Only some debris can break a thermoucople, rust means water,, and LOTS of it, and melting,,, well,, When the thermoucple is rated for 2K*F, a melted tip isn't of concern.



Merrick Cummings Jr



BTW: If you are going to be BOMBing your motor,, a T-couple is more dangerous post-turbo, because it responds to slow, and will easily let you run well into dangerous EGT before it reads high.

 

[zari]

Hmmm...

Not too big of an expert when it comes to truck diesel engines; as a somewhat experieced turbine pilot, however, I'd prefer to watch TIT (Turbine Inlet Temperature) over TOT (Turbine Outlet Temp) any day. My gauges watch TIT. .

 

[Ladders]

Da old "TIT for a TOT" game, eh???



I did both so I can cool it down or run heavy.....



SOTSU!!

\\BF//

 

[MCummings]

I'd do both too, but If I had a choice either for TITs, or TOTs,, I'd Go for TITs.



Maybe I'm young, but TITs are more fun to watch than TOTs.



Merrick Cummings Jr

 

[rashwor]

I think...

this thread is going down hill now!

 

[rashwor]

Now for my real post.

I think on larger rigs, if it comes equipped with a EGT gauge, it will most likely be pre-turbo. These are the most accurate measures of what is going on in the cylinders and it allows you to watch your pistons and head melt if you can get enough diesel in there. Some on here can!



Mine is pre-turbo. I heard of a guy driving a ford one time. His was mounted post turbo about 4 feet back. He ran the truck so hard that he saw 1400* on it regularly. Kept toasting turbos and could not figure out why... . I can't imagine what the temps were pre-turbo!:--)

 

[Fireman]

I went pre-turbo. The biggest worry might be not getting all of the shavings out and damaging the turbo. There should be no worries about your engine if the turbo ingested the thermocouple anyway, the pieces would just be spit out the exhaust, not into the intake. As of yet I can't recall anyone on these boards losing a turbo because of a thermocouple mounted pre-turbo. Take adeep breath... and drill!



Fireman



BTW Diesel Performance Products has some very good instructions on their web site. Just remember to wear safety glasses and remember that the exhaust gasses will be around 400 degrees or more when idling with the exhaust blocked off.

 

[Ladders]

Isnt the rule "within 6" of turbo" if post(ing)? Pre is usually where the most manifold and cyls can be got at. I went in at an angle for the pre and the post is in the short neck part (underside).



Had the brake before the truck so did it so it wouldnt interfer with anything (not knowing where the clearance was the greatest) The exhaust was at angle due to drill size - no clearance and was not going to buy another drill nor takeoff the manifold or buy a 90.



SOTSU!!

\\BF//

 

[ReevesRacing]

Our you guys installing it where all the runners come togehter befroe the turbo?



We install it on our race cars about 1. 25" from the head in one runner (usually the leanest by nature).

 

[bzingre]

Big Rigs

Pyros on Big Rigs (if they have one) are installed from the factory 8-14 in. post turbo. if you see 1200 you better shift or get out of it.

 

[BHaner]

EGT's for Pre Turbo

What is the normal max egt for a stock motor? Just installed my gauges today... and I was slightly shocked to see 1200*. My other truck (97) was a post turbo setup... and the max I ever had was 1100* and that was on a good hill with about 12k. Is 1200* normal no load WOT? I have 24 Lbs boost.

 

[Steve M]

Big rigs are post turbo.

I only use mine for shutdown temps. I glance at it on long uphills if I'm towing and haven't seen over 850*. The turbo retains alot of heat and a post turbo probe will give a more accurate reading for shutdown. So my vote goes for post turbo for shutdown temps. But... And I like big butts... I run my trucks bone stock for longevity. For bombed trucks, you probably want to know the temps coming out of the cylinders.