EGT tempretures what they mean

[Terrano-saurus]

I would suggest setting your EGT as the first step in improving economy and performance, below is a quide to EGT and what they mean. (all EGT are post turbo)

EGT at idle should be approximately 150c

EGT at cruising between 315c and 365c

Normal running between 260 to 482c.

Max EGT's 600c

Above 370c the engine gets wasteful with the fuel, due to load demands.

Below 315c and you lose efficiency (Power and Torque).

With EGT's at 315 degrees c, most engines are operating at or close to peak efficiency. Complete combustion is being achieved and converted into usable horsepower and torque as efficiently as possible. Maximum fuel mileage is achieved at this point.

Hope this info helps :D

[fatboyvncalaisv]

Is there any variations from engine to engine?
Ie should my Nissan be running those temps, and my Rocky 2.8 Isuzu also?
or is this a rough guide?

[Terrano-saurus]

It can be used for all diesel engines, I set mine up for great ecenomy and good power, figures are approximately; at 60km in 4th gear 320c to 350c, at 100km in 5th gear 340 to 375c. This allows me to get great fuel econemy at the sacrifice of a small amount of power. If I increase the EGT then I would get more power but the fuel economy would decrease.

Is there any variations from engine to engine?
Ie should my Nissan be running those temps, and my Rocky 2.8 Isuzu also?
or is this a rough guide?

[fatboyvncalaisv]

But doesn't a turbo Diesel have different EGT's than a N/A(non turbo) one?
thats what my tuner told me, and he is quite reputable in modifying diesel engines.
is he misguided?

[Nullack]

Nice, any how tos on installin an EGT gauge the right way?

[Terrano-saurus]

install the sensor approximately 100mm to 150mm below the flange (exhaust flange that bolts to the turbo) all other instructions should come with the EGT/Pyro gauge.

Nice, any how tos on installin an EGT gauge the right way?

[Terrano-saurus]

Power/economy relates to combustion chamber tempretures, so if the temps are keep within the spec's as stated above, you will get the results. :truck:

But doesn't a turbo Diesel have different EGT's than a N/A(non turbo) one?
thats what my tuner told me, and he is quite reputable in modifying diesel engines.
is he misguided?

[HDJ105]

I would suggest setting your EGT as the first step in improving economy and performance, below is a quide to EGT and what they mean. (all EGT are post turbo)


So what qualifications do you have to qualify these figures?

(Anyone in the know wouldn't be recommending post EGT measurements, unless they stipulated them for a specfic model ;) ).

[Terrano-saurus]

You have asked me a simular question in the past and it was a lengthy process to quantify myself, I am not going to go through this process again with you, if you do not wish to believe my statement then simply dont. :crazy:

So what qualifications do you have to qualify these figures?

(Anyone in the know wouldn't be recommending post EGT measurements, unless they stipulated them for a specfic model ;) ).

[fullmetaljacket]

all of the pryos that I have fitted have been pre turbo, with the execptions of 2nd units being installed post (to allow observation of the turbo actual temps). Fitting post only on a turbo'd vehicle will give false readings as the turbo will cool EGT's conciderably.

from my experiances EGT's of around 450degC are average operating temps, and temps as high as 550-700degC during inclines (pre turbo).

Decreasing EGT's will have more of an impact on fuel cosumption (more fuel = lower temps at exhaust)........EDIT:- corrected by shonky VVV:thumb:

Note:- this is from my experance only, and should not be used as a guide, differant weighted vehicles, differant sized turbos, intake size, and exhaust diameter will all cause temps to differ.

[Shonky]

(more fuel = lower temps at exhaust)

For a petrol engine this is true, but not on a diesel, more fuel on a diesel = higher temps.

[Patrolling Paddy]

install the sensor approximately 100mm to 150mm below the flange (exhaust flange that bolts to the turbo) all other instructions should come with the EGT/Pyro gauge.

With my Denco A/M kit the port for the pyro was cast into the dump pipe about 1-1 1/2" from the turbo and when I had the custom 3" dump made the port was put back in the same place.
If these temps you specify are for a pyro at 100-150mm from the turbo then how much temp drop would be expected from the turbo to the pyro and does this mean that I could in theory have my temps higher then what you have stated?

Not trying to be a pain but what qualifications do you have? or could you send me the link to the previous discussion. Not that I am saying your not qualified but it is my engine that I am trying not to blow up.

PP

[fullmetaljacket]

For a petrol engine this is true, but not on a diesel, more fuel on a diesel = higher temps.

whoops my bad, was on a typing roll and stopped thinking

just had a look through some of my literature re:- temperature variance between having the thermocouple mounted turbine inlet (pre turbo) Vs turbine outlet (post turbo), average temp differance are

thermocouple mounted in inlet can be up to 250degC Hotter than a reading from post turbo under normal operating conditions, and 120degC hotter under full load conditions.

The reason that the temps vary more under low load conditions is due to exhaust gas flow, slower flow means the EG has time to cool as it flows through the turbo

[Peter @ Aawen4x4]

With my Denco A/M kit the port for the pyro was cast into the dump pipe about 1-1 1/2" from the turbo and when I had the custom 3" dump made the port was put back in the same place.


Hey PP, this is a Post Turbo port that you are talking about, isn't it? Or am I wrong in believing that almost all (if not in reality just plain ALL) aftermarket turbo kits sold for 4WD's these days usually come with Post Turbo Pyro probe ports? Why would they bother doing that if there was no benefit in putting the probe in post turbo and the EGT figures from a post turbo pyrometer were worthless?

[Patrolling Paddy]

Hey PP, this is a Post Turbo port that you are talking about, isn't it? Or am I wrong in believing that almost all (if not in reality just plain ALL) aftermarket turbo kits sold for 4WD's these days usually come with Post Turbo Pyro probe ports? Why would they bother doing that if there was no benefit in putting the probe in post turbo and the EGT figures from a post turbo pyrometer were worthless?

Yeah that's right. The thing that I was unsure of though was that a pyro port 100-150mm from the turbo will give a reading alot lower than a pyro port 25mm from the turbo so with the figures qouted at the futher distance does this mean that mine can be higher at the closer distance? I realise that there is a significant difference pre/post but the distance post would make a significant difference too wouldn't it?

I am happy with the way that mine is setup and feel comfortable with my post temp EGT, after all the figures pre and post would have been measured against the same vehicle at the same time at some stage and I don't believe that were just pulled out of thin air.
The only way to get a 'true' pre reading is to have a probe on each cylinder as with any two exhaust side by side you will get a high reading with the concentrated area, (eg TD42 3-4).

PP

[Terrano-saurus]

Ok all, this post has stired up some slightly heated discussions, and I apploigise for that, but if you look closely in my opening statement I say it is a "GUIDE", it is not set in concrete.

I put the figures post turbo because this is where I mount the probe and it is a common position to install probes. sorry for any confusion the infrormation was to help guide anyone that does not experience with EGT's and requires a guide to put them on the correct path.

If you require 110% performance out of your engine then it would be best to get it Dyno tuned. If you simply wish to set it up yourself for normal 4WD work, etc then the guide will be benifitial.

If you go back and read the GUIDE again you will notice a variance in tempretures (e.g. between 315 -365) this is because of different engine, exhaust, intake, etc setups effect the EGT's. so yes it is a GUIDE only.

[Peter @ Aawen4x4]

Yeah that's right. The thing that I was unsure of though was that a pyro port 100-150mm from the turbo will give a reading alot lower than a pyro port 25mm from the turbo so with the figures qouted at the futher distance does this mean that mine can be higher at the closer distance? I realise that there is a significant difference pre/post but the distance post would make a significant difference too wouldn't it?

It certainly does make some difference, but that's why, if you are gonna use Post Turbo EGT's, then you should work on Post Turbo EGT's that are either directly from your kit suppliers, or provided for your specific setup! And they are out there, you might hafta search a little, but every turbo kit will have a set of EGT's that are right for it on any engine it will work with!

And if you have a customised turbo outfit, rather than a kit from one of the 4WD Turbo kit suppliers, you know, one with all sorts of components assembled to make the outfit that works for you, then you simply go back to the base figures that Terrano has supplied, unless there's a turbo specialist that can provide a better set for your outfit!

It comes down to the basic fact that engines and turbo's don't melt until they reach a pretty specific temperature, and the transport/turbo/4WD industry has a helluva lot of accurate knowledge about that based on many years of research & experience, and by talking to almost any of the turbo specialists they will be able to fine tune those generic figures into a specific and very accurate setup for you!

Sure, Terrano's figures are only a pretty good 'ball-park' indicator, and like everything that's generic rather than specific, you've gotta be just a little wary of the potential differences between them and the 'good' stuff. Sometimes it's virtually nothing, sometimes it's a helluva lot! But at the same time, for most 4WDers out there, we don't use our vehicles to the extent or critical tolerances that mean we need anything all that much more accurate readings. Besides, the instruments that we use probably aren't any more accurate than the figures, and how much of your driving time do you spend watching the EGT guage??


I am happy with the way that mine is setup and feel comfortable with my post temp EGT, after all the figures pre and post would have been measured against the same vehicle at the same time at some stage and I don't believe that were just pulled out of thin air.
The only way to get a 'true' pre reading is to have a probe on each cylinder as with any two exhaust side by side you will get a high reading with the concentrated area, (eg TD42 3-4).

PP

All very correct, and measured more than once! By the time a turbo hits the streets, then that sort of pre-post EGT comparison has been done to death and Terrano's EGT's will work fine! And you can spend as much money as you like on getting better and more accurate measuring and metering instrumentation, but it won't really add a great deal more 'protection' for most users, like I mentioned above! It all comes down to how much you want to spend, and really how critical is it to what you are doing.

So just enjoy the extra power, watch that the EGT's don't go too high and stay there, and if they do, ease off a bit, change down, do whatever it takes to bring them down into the 'safe range' and keep them there!

Cheers!

[azzad]

Thanks Terrano-saurus, I for one will find this information usefull.

Dazza

[Patrolling Paddy]

Terrano-saurus, I meant no dissrespect in any way, I just always try to learn what I can about as much as I can. I have a fair handle on what is happening with my setup and was just curious to learn more with different variations in probe locations etc....


Peter once again you have spent alot of time and effort to reply to members (this time me) and as always it is much appreciated.
The ruputable aftermarket kits (or all kits for that matter) would have been tested to death, and for a TD42 it is fairly common knowlegde that 550-600deg is the max allowable safe post turbo EGT as I'm sure it is for most 4wd diesels on the market.

I am thinking of getting mine dyno'd as recently a local workshop (who I have known for a long time and trust with my vehicle) has recently become the only dyno owner in about 1000km (that I know of). I set up my system myself with the boost and Pyro gauges and some road testing only and I think I am pretty much on the money (I had a dyno run without tune when I had the Gas fitted and was told it was pretty good), however it is hard to perfect a tune with nothing more then two gauges and a heavy right foot and enough knowledge to be dangerous so I might just spend a couple of bucks and get it 'right', who knows I might even squeeze some miniture ponies or a clydesdale or two out of it and heaven forbid if I get better fuel economy too.

Cheers

PP

[Terrano-saurus]

Patrolling Paddy, no worries mate. all is good. I think Peter has mastered the art of typing, I think I can type about 5 to 10 words a minute, so it takes a lot for me to explain in writting. If you have a really brave mate like those JACKASS guy's you may be able to tune it as good as a dyno fairly quickly, just get your mate to sit in the engine bay while you drive down the highway in 4th gear at 3000RPM and turn the fuel adjustment screw until the EGT's are good, LOL :D

[ol blu 40]

Every truck that I've ever worked on (we're talkin highway trucks here folks...) run a post-turbo pyrometer. If it's good enough for Cat, Cummins and the like, it's good enough for me!

Cheers, Matt

[Patrolling Paddy]

Every truck that I've ever worked on (we're talkin highway trucks here folks...) run a post-turbo pyrometer. If it's good enough for Cat, Cummins and the like, it's good enough for me!

Cheers, Matt

Here Here

[gmetzroth]

Patrolling paddy, what pyro temps do you get out of your denco kit? I have a denco kit fitted to my 2.8 and it is not uncommon for me to see 600 degrees and sometimes on a hot day can go slightly higher. If a back the fuel off it makes no difference to pyro temps it only makes the vehicle feel guttless. But if i put more fuel in the pyro temps go up.

[Terrano-saurus]

It sounds like you are at a point where you need to either, reduce the turbo boost or improve the air intake (K&N filter) or improve the exhaust flow (straight thru muffler bigger pipe) or cool the charged air further (bigger intercooler or bonnet scoop). Have a look at all of these things and see what you can do. Hope this helps

Patrolling paddy, what pyro temps do you get out of your denco kit? I have a denco kit fitted to my 2.8 and it is not uncommon for me to see 600 degrees and sometimes on a hot day can go slightly higher. If a back the fuel off it makes no difference to pyro temps it only makes the vehicle feel guttless. But if i put more fuel in the pyro temps go up.

[sudso]

Patrolling paddy, what pyro temps do you get out of your denco kit? I have a denco kit fitted to my 2.8 and it is not uncommon for me to see 600 degrees and sometimes on a hot day can go slightly higher. If a back the fuel off it makes no difference to pyro temps it only makes the vehicle feel guttless. But if i put more fuel in the pyro temps go up.
Is it going that high only at highway speeds or up hills under load etc?
There could be a deficiency in the volume of air that the snorkel can catch and a larger snorkel hat might fix it.
Like Terrano-saurus said improve the air intake.

[gmetzroth]

Terrano-saurus, I have already fitted a K&N air filter and also had a 2 3/4 beudesert exhurst fitted with a custom dump pipe. The only other thing is it has no intercooler at all, but on a cool night it has no affect on the pyro temps. I have also played around with the boost presures running it at the standard 7.5psi and running it at a max of 10psi with no affect to pyro temps.
Sudso, running on the highway at 100kph the pyro sits around the 400 degree mark. It is under load that the pyro temps go up. But also if i pull off the highway and accelerate hard the pyro will be at 500 degrees at about 90 kph.
The vehicle has a safari snorkel fitted and does not have the washer fitted in the snorkel top for a non turboed engine.
A water to air intercooler is on the cards.

[Terrano-saurus]

GMETZROTH - One possibility is that your timing is out slightly, allowing too much fuel to enter into the combustion chamber at the incorrect moment. I have my Harley setup to do this on purpose for more power (old school - it is called free fuel injection) but in a diesel it is not normally a good thing to be happening.

[bricat]

Thanks Terrano-saurus Was an informitive piece of information. cheers Brian

[gmetzroth]

I have tried the pump timing at both ends of the specifications and it made no difference to pyro temps, at the moment it is set to max advance.

[Patrolling Paddy]

gmetzroth
My normal no wind type conditions on flat ground at 100-110km/hr in 5th for my TD42 will see 300-350, I think this has a little to do with ambient air temp differences.
In most conditions other than strong head wind and steep inclines will see 350-450ish. If I am running into a bad head wind or up a long knarly hill I can see up to 500-550.
The only time I have seen it any higher was when I was driving in a way I can only describe as 'like it was stolen' and even then it topped out just under 600.

Air flow in and out will create temp problems but you seem to have that sorted. Timing is another thing but you seem to have that sorted. Have you looked at the injectors or the pump itself? How old are the injectors and pump and have the been serviced/overhauled?

What sort of Mech experience do you have to be able to make the adjustments or have you had someone do it? Are you sure you are making the right adjustments (not trying to insult you but maybe you have mislead yourself)? Maybe a dyno tune is in order to see what is going on.

Again not trying to sound like a smart a$$ but sometimes (especially diesels) you can know just enough to be dangerous, I think I fit in here most of the time.

PP

[gmetzroth]

Patroling paddy, the motor was rebuilt 20,000km ago by myself and at the same time i had the pump and injectors overhauled, i also got a boost compensator fitted. I know where you are coming from by saying that one can know enough to be dangerous, particulaly to a diesel engine.
I like yourself are a mechanic but sometimes it is good to recieve some good advise from others, as sometimes things can be overlooked.
I also have some pretty damn good training manuals from toyota about the diesel engine and also injection systems. I also got a fair understanding about it from the training schools i went to, to get them.
I have had this engine on a dyno before when it was fitted to my Ln106 hilux and they set the fuel according to pyro temps and the pyro temps i witnesed when it was on the dyno are alot less than when it is on the road up a steep hill under full load (hitting the hill at 100 in 4th and speed dropping to 80 by the top).
It has come down to the fact that it is a little engine working hard and was never entended to have a turbo fitted and in the 70,000km before the rebuild running at these temps had no affect on the engine at all. The only reason the engine was rebuilt is it tended to use a little amount of oil on a high speed run.
All the advise i have recieved on this post so far has been good and things i have previosly tried. Seeing lower pyro temps would be good but the design of this turbo engine combination I don't think it is going to happin.

[Patrolling Paddy]

Not had anything to do with boost compensators yet but is it possible that this could be restricting fuel or over fuelling at the wrong time? Is this something that is adjustable or is it purely on boost alone? Maybe the boost side is working but the mechanical control over the fuel needs adjusting??

PP

[hunterdive]

guys, very interesting discussions,

regarding Pyrometers, what do people think of the hose clamp type that fix around the exhaust? I assume you drill into the exhaust and then seal up the caps after fitting the pyro in.

I have the screw in plug post turbo ready to go on my DTS kit, I assume this type would be better than the above mentioned??

[azzad]

I just picked up an EGT for $199 from Autobarn, including probe. A bit hard to see in direct light (not to bad), its one of thoose backlit ones.

It came with everything needed to fit, had it fitted in about 30min, still waiting for my gauge pod though.

Have driven Patrol a bit and so far seems quite good, normal town driving sees just under 300°C after acceleration from lights and its been up to 450°C up a reasonable hill at 90-100kmh. Only running 10psi at the moment, hope to have a bit of a play on the weekend do the valve clearance, timing and get the fuel setup and maybe bump it up to 12psi.

Dazza