I am going to do a no no on the forum and double post as I have not gotten any answers in the 3rd gen post but here's the situation

Well I have for the first time logged my EGT's via my Datalog. I am using a Redline guages exposed tip probe on my stock 13b-rew with my own 60-1 turbo kit. The probe is located maybe 2" from the turbine. Anyway, I'm a bit concerned about the temperatures I'm seeing. It maybe the exposed tip probe is reading higher but not sure. Here are some of my readings.

Idle 530 C 12.7 AFR 4 deg
Cruise 700 C 15.3 AFR 30 deg
16.5 psi 730 C raising to 840 C 11.3 AFR 15-17 deg with split of 12 deg

Let me know what you think. I know my temperatures are high for after turbo temperatures but I was thinking maybe my probe or measurements are off.

 

simple, take your probe out and get a bottle fed gas torch, unscrew the probe out of the exhaust and test it..... the maximum you should be able to get it too *orange cherry red trasition* is about 950 to 970deg C.

if it reads quickly over 1100deg C your probe is fucked

to get over 1000deg c on this test you need to use insulated bricks to shield the back end of the probe and retain more heat into it, Highest i have ever managed on bench test was around 1150deg C.

My probe reads to within 1 deg C so if at the start of the test its 8 deg C it generaly will show 8 deg C, as will my IR temp gun, and also the two other digital ref instruments I have

When looking at a color chart for steel you will see the colors correspond well to the temp you should be seeing so if its out to this basic test then you have problems and either need a better probe or a temp compensated electronics that condition the signal before it goes to your display or ECU logging channel.

So far as fitment goes the temp profile gets hotter as you go further away from the pipe wall , in short a legitimate temp of greater than 750deg c to 800deg C in the DP after a to the top of 4th or 5t gear is a worry. pre turbo 950deg C is getting up there on gasoline alone, but if your turbo is good enough 1100deg C can be tollerated with the right materials

hope that helps you?

 

Most turbo rotaries run 950deg C pre turbo at that power level, you only need look at the header after a very short dyno pull see the color and the temp is a give away hold that power for 10 seconds (simulate up a hill) and watch it go translucent you can actualy see the gas currents in the pipes ! *I kid you not 1* when that happens your normaly well over 1100deg C

Your timing is normal, extra AFR can cool things down if your concerned, but water injection is proven to take 100deg C off the EGT with little/no power loss when done right, and then you can step the power up and up and still have lower EGT than what you were getting on the far lower boost/power.

 

"A picture is worth a thousand degrees C"

 

I will check what your talking about tonight with the oxy torch. I almost wonder if my egt is offset due to a voltage somewhere. Not sure whether those EGT's at idle and cruise were normal at the downpipe. They seemed a bit high to me, I guess that's why I included those numbers. Also would a divided verses undivided turbine housing make any difference? I am running undivided.

 

Everything in the system has an effect.

housing and wheel can be viewed as a bottle neck, but the more obvious and often overlooked is post turbine exhaust (pressure sensor mounted here reveals lots), EGT is an interesting measure, in thermodynamics HEAT is one of the hardest concepts to grasp and follow and as you will find with your experimentation temperature is a given on the gas torch flame cones, its when you restrict the escape path of the HEAT that all of a sudden the temperature can go up alot even though the contributing factor has not realy chaged or is not the root cause of the problem.

all that aside, your trends look ok to me, its prob maybe the offset is off on the probe or something else (which you will test) or you have a restriction somewhere or you have bad sealing which is known to increase the egt too. pick the easiest less scary options and work your way through it you will enjoy the learning experience

 

forgot to add I personaly for your figures run a split of 8 degree's, cant comment on effects it will have in your case though.

 

This is too hot.
Any reason why you're running so lean also?


-Ted

 

I never considered 11.3:1 to be lean. I can add some fuel into the 11 flat range and see what happens. To much lower though and I'll probably get into break up.

 

Most people street tune for 11.2-11.1 for 14psi and in the high tens for about 16.

You have 11.3 AFR for 16.5psi, that is lean! That is what Ted means.

 

Well before my compressor incident I setup for 11 flat at 16 psi. During my runs I saw a max of 830 C. I will have to check the probe still as I was busy removing the turbo tonight.

 

Usually, post turbo, anything over 800C is iffy.
I'd be scared to run anything above 11.0 on the AFR's with that kinda boost.
You're not running some kinda supplementary injection?
Alcohol / water?

Also, it's a question of how stable the EGT's are?
If the EGT's are rock solid, then it might be nothing to worry about.
If the needle is still creeping, I would try and bring it down a bit.

Also, what kinda fuel are you running?


-Ted

 

Nope no AI or water injection. Trying to push it on pump gas and from the sounds of it I was... Running 94 octane pump gas. The egts I was seeing were rising until around 6k where they leveled off at around 800 and I would see a spike to 830 or so. The spikes I'm seeing I'm almost thinking is noise in the system as its level at just above 800 with one datalog point spiking up.

 

I strongly suggest you check your instruments, callibrate them if possible and check them against a known source.

I dont trust ANY of my *new* stuff untill its proven in every test, be it a AFR meter or EGT gauge etc..... once you have this locked down then you can be 100% about your figures *obviously only if you have any lingering doubts about the absolute number*

Being a knife maker and knowing alot about steels I can pick the temps very very close, but that skill comes with a bit of time. If you have an oxy set you prob have a good idea yourself, but pretending you dont (pls dont take offence) have a look on-line for a good temp gradient to color chart for steels (heat treatment,quenching etc) and this will help in the basic cross check of your device.

 

I use a stand alone EGT device that goes to 1200+deg c and its resolution is down to 1 deg C, its fully compensated so readings stay true despite changes in temp in electronics. The display takes centre stage in the dash just below the tach as I regard this as one of the most critical measures...... especialy during long haul extended use, if the EGT is too high then the power level needs to come down a bit so less boost is of order.

You can only drown the **** so much in fuel and water before it will cry enough and no amount of measuring of AFR (which I also have on a seperate display) will counter too much power and asociated heat

I'll be real interested to see how you go with this, as its one of the better thread topics that realy does not get discussed or understood enough. if you have a chance since you have the turbo off you should realy place the EGT probe where its meant to be (pre turbine) for only then do you realy know how hot things are (as you can see in the above photo I posted) its quite a big diff pre v's post.

 

If you have seen my other thread the car is now down as the turbo compressor shaft sheared for some reason and killed my compressor. I will work on trying to gauge how accurate the EGT is. I have an oxy fuel setup that I can work with. I may have to borrow an IR temp gauge. I am using my datalogit with the PFC to take a voltage and convert it to a temperature. I have a basic AD595 amplifier setup giving me the logged voltages.

 

Well with the MAP gas and the probe still in the downpipe I got the probe over 1000 deg but that is the maximum the amplifier and my datalogit was set to go. So I believe my probe is just offset in its readings on the high side. I guess when I get a new turbo I can figure it out. Not sure other than getting an IR gauge how to make sure of its offset.

 

Alright new turbo 62-1, have relocated the EGT and installed another 2 in's from the engine port. I am sitting at 11 psi 15 IGL and 10.5-7 AFR's at WOT. I am seeing a maximum of 935 C. Idle sits at 650C at 12.5-13 AFR and 12 IGL. Again I'm using open element probes. The runners are within 20C of each other. I am seriously wondering if the open element probes read higher than standard k-types with a metal sheath. It would also explain the instant response of the probes in my datalogs. I guess I am now wondering how long they will last. Let me know what you think still high in temperature but when you take into account the idle EGT temp maybe its alright. I have yet to see the manifold glow either.

 

I am also running a redline gauge with the exposed tip probes (excellent product).
I have it set to F. My car idles about 670* and going through the traps i read about 1530* at 7500.

Allen

 

Where are your probes located?

 

About 6" from the port. I am running a very large turbo for my application though.