Post Turbo EGT install

[Vaughn MacKenzie]

Pre post temp difference is 200 Degrees as a rule of thumb.

No, make it at least 400, preferably 500!



In my 5-1/2 years and 4800+ posts on TDR I have seen ZERO probe failures, not one person I've seen has damaged a turbo by a faulty probe.



It's either take a chance on hurting the turbo, or hurting the engine, your pick



Vaughn

 

[Bertram65]

No, make it at least 400, preferably 500!



In my 5-1/2 years and 4800+ posts on TDR I have seen ZERO probe failures, not one person I've seen has damaged a turbo by a faulty probe.



It's either take a chance on hurting the turbo, or hurting the engine, your pick



Vaughn

How many stock trucks have you seen where the engines were damaged due to high EGTs?

On a stock truck you are way more likely to have a turbo problem due to shutting it down hot than melting a piston because of percieved high EGTs while towing or high elevation or both.

 

[Badunit]

How do I install a post turbo pyro in a truck with no elbow? I have a Banks exhaust, and it mounts to the flange on the turbo. It seems the 4" tubing is too thin to hold a NPT fitting too well.

The probe may come with a clamp for holding it on the exhaust pipe. I'd just put it pre-turbo and drill and tap the manifold.



Post turbo - better monitoring of cooldown temps. Those with pre-turbo have to guess and/or wait extra time just to be sure.



Pre turbo - more accurate monitoring of EGT. Those with post-turbo have to estimate and it's not a precise thing to do so they should be more cautious and can't really use the full power of the engine (unless they throw caution tothe wind).



To each his own. Where you mount it depends on what you're trying to accomplish.

 

[Cattletrkr]

No flame intended

No, make it at least 400, preferably 500!

It's that kind of advice that had me flippin' out for a few months thinking something was wrong with my STOCK truck. Even at the much touted 300* difference, I should have been hitting 1400*+ quite often. That's why when I got my attitude I put the probe before the turbo and found out that I'M NOT RUNNING ANYWHERES NEAR THAT HOT.



The higher I set the Juice the broader the diference is. I wouldn't doubt for a second that bombed trucks really do see a 300* difference or more, but at least on my previously stock truck, the difference is not that much. I don't pull any long mountain climbs so maybe that factors in somewhere too.



Of course I may be way off base on all of this. My attitude has to go back for a reflash of some sorts. Not everything works the way it should. Maybe the EGT readout is FUBAR'd as well.



I forgot who oroginally started this mess, but I hope you found the answers you were looking for.



DISCLAIMER: I'm no mechanic nor am I even remotely close to being an expert on these or any other engine. I'm simply stating what I see happening on my truck and my truck alone.

 

[p-Bar]

Tell me why every Big Rig I have seen has it post turbo all these engine manufacturers can't all be wrong or are they???

 

[TCrawley]

Wasting your time as load on engine differs and thus egt will not be accurate post turbo. It is not a simple equation.

 

[DPKetchum]

Have no clue or facts if all big rigs are post turbo. I do know that in the last 5 years or until the 3rd generation forum I never read were any one on any diesel site ever installed post turbo. Its always been pre turbo and thats were I installed mine on previous trucks. 300 degrees was the goal for shut down and 1200 degrees plus was considered heading to the unsafe zone.

 

[Bertram65]

Tell me why every Big Rig I have seen has it post turbo all these engine manufacturers can't all be wrong or are they???

Easy answer. the TDR "experts" know more than Cummins or any other diesel engine manufacturer.

It's just a miracle the 98% of Dodge trucks without EGT gauges and all the over the road trucks with post turbo EGT gauges have not melted pistons and siezed engines due to either no information or inacurate information from a post turbo EGT gauge. :-laf :-laf

 

[klenger]

I personally feel that if you want to insist on having accurate pre-turbo EGT readings, the only way you can do it is to install one probe for each cylinder, otherwise, you are just guessing.

 

[ceaman]

I personally feel that if you want to insist on having accurate pre-turbo EGT readings, the only way you can do it is to install one probe for each cylinder, otherwise, you are just guessing.

Ok im all for that but how do we do it without spending big $,$$$

 

[testraub]

PLEASE! I already decided on a POST turbo install..... All I really wanted to do is get a few pictures and info/tools needed for the install! PRE Turbo guys I respect your decision, please respect mine. Please! Pictures and tool info for POST turbo installation only beyond here!



I _KNEW_ this would happen (tho I wish it hadn't!)

 

[RM]

PLEASE! I already decided on a POST turbo install..... All I really wanted to do is get a few pictures and info/tools needed for the install! PRE Turbo guys I respect your decision, please respect mine. Please! Pictures and tool info for POST turbo installation only beyond here!



I _KNEW_ this would happen (tho I wish it hadn't!)

like been said before use the small bushing eighthinch. you can go up but not down if something happence. if youre using dipricol gauges and putting them in the cubbyhole check the length of youre cable you could come up short. its a very easy job i took off the exhaust elbow theres a dowel in it to line it back up that is a little tricky but doable. and i hope you dont mind but i got a question for all the preturbo guys. how do you know what all six cylinders are doing if you put the probe in preturbo the exhaust at the turbo is siamesed? sorry i just want to know ive worked as a mechanic for 30 years and never seen a oem put it preturbo except very large engines and there in the head

 

[NIsaacs]

I have three CTD Pickups, all with post turbo pyro's, it works for me. I have always liked to monitor all 6-cylinders rather than two or three. In the old days, before split manifolds, pre turbo was ok. I also like the probe, no further down stream of the turbo, to be more than two or three inches. Isspro, one of the oldest makers of pyros have a color coded dial. Pre turbo red lines at 1300*, post turbo red lines at 1050*. I run all my trucks at 1000* towing with no problems. I am not sure where the temp. estimate comes in, they are accurate post turbo.





"NICK"

 

[ceaman]

PLEASE! I already decided on a POST turbo install..... All I really wanted to do is get a few pictures and info/tools needed for the install! PRE Turbo guys I respect your decision, please respect mine. Please! Pictures and tool info for POST turbo installation only beyond here!



I _KNEW_ this would happen (tho I wish it hadn't!)

Im sorry to assist in the hijack. I have had 2 post turbo... and offered my input about tapping the elbow. If you need direct info pm me, I will call you, but i dont have pictures.

But after my past issues my new truck will be pre... .

 

[Vaughn MacKenzie]

It's that kind of advice that had me flippin' out for a few months thinking something was wrong with my STOCK truck. Even at the much touted 300* difference, I should have been hitting 1400*+ quite often. That's why when I got my attitude I put the probe before the turbo and found out that I'M NOT RUNNING ANYWHERES NEAR THAT HOT.



The higher I set the Juice the broader the diference is. [/COLOR]

EXACTLY, and that's part of my point. . . the more you crank the power, the greater the temperature gradiant across the turbo, but without a pre-turbo probe, you don't really have much of an idea what you EGTs truly are.



On a stock truck I agree, you will likely be under 300F difference across the turbo, but EGTs are not as much of a concern.



Where the concern is the guys running a lot of fueling and run a boost elbow, now you're talking 500-600F difference pre vs post turbo. It varies so much it's like a guessing game. . . take the guesswork out of it and go with a pre-turbo probe.



BertRam65, I haven't heard of too many meltdowns running excessive EGTs, and a certainly the 3rd Gens can take more heat than the previous 24v due to greater piston cooling. But high EGTs will take their toll over time in increased piston wear and reduced engine life. You may think you're getting away with it so to speak since the motor sounds fine and you're ready to go the next time, but the laws of physics don't go on vacation . . . high heat = accelerated wear. I have seen posts on the 24v forum by guys who've run the EGTs high and bummer, at 125,000 miles they're puking oil out the blowby and the rings are done for.



The reason I bring this up is many seem to throw caution to the wind anymore, possibly without understanding fully the potential consequences in doing so



Vaughn

 

[Tim]

I'm still wondering how a big rig is set up has anything to do with a pickup.



Post turbo is a waste of a thermocouple in my opinion.

 

[Bertram65]

I'm still wondering how a big rig is set up has anything to do with a pickup.



Post turbo is a waste of a thermocouple in my opinion.

Big rigs have diesel engines just like our trucks only larger.

 

[DPKetchum]

A friend of mine with Sterling dumps and Cats says its the same guide lines with them. 300 degrees or so for shut down and 1250 or so for the getting worired factror. I would assume that the probes then are not post turbo.

 

[p-Bar]

Go hang out at a truck stop you will see that they are all "post". My friend has a fleet of trucks all are post.

 

[InThinAir]

It is threads like this one that makes me visit this site less and less. I understand that people have strong opinions. But that doesn't make it any more correct in my mind... to say that all 2nd gens are Pre is wrong, use the search. This person asked a question regarding the install, if you don't have any input regarding his question then don't answer with your opinion that he is wrong... I am not usually the voice of reason, usually a hot head myself. But this is ridiculous!



Soon there will be just the members on this board that agree because they have beat up everyone to the point to be afraid to ask a question or have an opinion because they, like me, must be stupid.



---Doug

formerly "InThinAir"

Switching to just reading the magazine! and staying away from this site!