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Old 11-09-2012, 12:33 AM   #21
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Quote:
Originally Posted by Mazdaspeed_Miata View Post
So does anyone else would like to post his EGT's with AFR, before or after turbo, turbocharger, engine, boost pressure, exhaust system, and so on?

I really would be interested in a lot of results.

Thanks!
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Old 11-09-2012, 08:29 AM   #22
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The restriction of the very small exhaust will cause higher EGT numbers.

I have no EGT gauge but I know for example when a catalytic converter becomes clogged the exhaust pipe becomes red hot.

Offnen der exhausten und lieben der horsepoweren. lol.
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Old 11-09-2012, 09:08 AM   #23
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Quote:
Originally Posted by Leafy View Post
1.5x the exhaust port circumfrance as a maximum. Closer to the valves = better.
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Old 11-09-2012, 09:09 AM   #24
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Quote:
Originally Posted by Mazdaspeed_Miata View Post
So does anyone else would like to post his EGT's with AFR, before or after turbo, turbocharger, engine, boost pressure, exhaust system, and so on?

I really would be interested in a lot of results.

Thanks!
There is only one measurement that matters and it's not at the bumper.
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Old 11-09-2012, 02:17 PM   #25
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There is only one measurement that matters and it's not at the bumper.
funny...
I would like to know some different results, but it looks like that this is too complicated?

Of course I know, that there are different temperatures at different positions, thats why I want to know where anybody measured his tempertures.
Otherwise I can't get an opinion about his result.

The reason why I don't measure close to the head at only 1 pipe is that I want to measure the results of all cylinders.
And I don't think that the results of all cylinders at the collector of the exhaust manifold are so diffrent to the result 2" after head.

Again... I really just want to know which EGT's the mass of you got.

But looks like that nobody wants to tell that or otherwise nobody measures his EGT's.


So do I also understand your statements correctly that my ignition map looks ok so far and the reason for my high EGT's is the silencer at my exhaust with a diameter of only 1,6"?

So far!
Basti
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Old 11-09-2012, 04:34 PM   #26
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Why would anybody install EGT probes at all the wrong locations just to give you measurements that are useless?
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Old 11-09-2012, 05:22 PM   #27
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Quote:
Originally Posted by Mazdaspeed_Miata View Post
funny...
I would like to know some different results, but it looks like that this is too complicated?

Of course I know, that there are different temperatures at different positions, thats why I want to know where anybody measured his tempertures.
Otherwise I can't get an opinion about his result.

The reason why I don't measure close to the head at only 1 pipe is that I want to measure the results of all cylinders.
And I don't think that the results of all cylinders at the collector of the exhaust manifold are so diffrent to the result 2" after head.

Again... I really just want to know which EGT's the mass of you got.

But looks like that nobody wants to tell that or otherwise nobody measures his EGT's.


So do I also understand your statements correctly that my ignition map looks ok so far and the reason for my high EGT's is the silencer at my exhaust with a diameter of only 1,6"?

So far!
Basti
Go kill yourself you German ****
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Old 11-09-2012, 05:33 PM   #28
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Quote:
Originally Posted by Mazdaspeed_Miata View Post
And I don't think that the results of all cylinders at the collector of the exhaust manifold are so diffrent to the result 2" after head.
You're wrong
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Old 11-09-2012, 05:34 PM   #29
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Originally Posted by Faeflora View Post
Go kill yourself you German ****
You are my favourite! Why you answer, if you can't or don't want to help? Since beginning of this thread.
Know such guys like you of course from german forums, simply irritating.

Really don't understand, what the problem is!

I think I just ask a normal question?!?

Why I can NOT get some informations about measured EGT's in turbo miatas?
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Old 11-09-2012, 05:35 PM   #30
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Originally Posted by olderguy View Post
Why would anybody install EGT probes at all the wrong locations just to give you measurements that are useless?
It depends on what you want to measure. Do you want an idea of whats going on in the combo chamber? Do you want to know what your enthalpy across the turbine is (you got to be a ******* weirdo to want to know that but w/e)? Just because the data someone is gathering would be useless to you doesnt mean its useless data, unless its gathered incorrectly.
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Old 11-09-2012, 07:03 PM   #31
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Measure the exhaust backpressure just before the final muffler, and before the cat

Before the cat it should be < 7 psi (45 kPa).
Before the muffler, 1.5 psi of backpressure (10 kPa) is pretty bad.

To measure:
You can drill a small 3 mm hole in the pipe then insert ~0.5m copper tubing, a few cm sticks in the pipe. At the other end of the copper tubing you use some long rubber vacuum hose leading into the cockpit to a boost gauge.
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Old 11-09-2012, 07:15 PM   #32
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Originally Posted by olderguy View Post
Why would anybody install EGT probes at all the wrong locations just to give you measurements that are useless?
A lot of people have a lot of datapoints of EGT at the collector just before the turbo. It's a useful figure of merit due to the data available. And, the turbine may be a weaker link than the exhaust valves anyway, so measuring here may be more useful than at the exhaust port. At this location 1600*F seems to be the acceptable maximum. Maybe 1650*F.


The EGT measured right at the exhaust port will be lower than at the collector, due to the duty cycle of the exhaust flow (it's 1/4th as compared to the collector)

Also note that the OP says he gets his 1700*F reading approaching 155 mph (I wonder if he can really get up to 155 mph with his setup).

To the OP: What is your max EGT just accelerating, redlining, from about 100 to 180 kph?
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Old 11-11-2012, 11:58 AM   #33
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Quote:
Originally Posted by JasonC SBB View Post
A lot of people have a lot of datapoints of EGT at the collector just before the turbo. It's a useful figure of merit due to the data available. And, the turbine may be a weaker link than the exhaust valves anyway, so measuring here may be more useful than at the exhaust port. At this location 1600*F seems to be the acceptable maximum. Maybe 1650*F.


The EGT measured right at the exhaust port will be lower than at the collector, due to the duty cycle of the exhaust flow (it's 1/4th as compared to the collector)

Also note that the OP says he gets his 1700*F reading approaching 155 mph (I wonder if he can really get up to 155 mph with his setup).

To the OP: What is your max EGT just accelerating, redlining, from about 100 to 180 kph?
I logged 150mph at my navi with GPS. The position of the needle of my tachometer was approximately vertical.
The car still accelerates but in realtion to my EGT gauge I ease up on the acclerator.
I got a video from 0 to 120mph, there you can see its performance:

At 155mph I measured 1850*F at the collector of my exhaust manifold.
At 180kph it should be around 1700*F.

My car does its hibernation at the moment, till april or may.

I am pretty sure now, that I will change my exhaust system to a complete 3" one, before I get the car back on the street.

Yesterday I took this photos of my exhaust valves. Is this colour normal? They're pretty white...




Uploaded with ImageShack.us




Uploaded with ImageShack.us

I also checked my cat, it looked still good:


Uploaded with ImageShack.us

So the biggest problem should be really the 1,5" silencer at the muffler.
I got a Blitz NürSpec 3" system of a Subaru, maybe I adapt this on my miata.



Uploaded with ImageShack.us


Finally, I am still interested in EGT result's from other turbo miata's!
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exhaust gas temperature...facts-p1050059ooooooo.jpg   exhaust gas temperature...facts-p1050065oooooooo.jpg   exhaust gas temperature...facts-p1040833oooooo.jpg  
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Old 11-13-2012, 04:06 PM   #34
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It looks like maybe you're confusing 'mph', 'kph' and 'kPa'. Check your units and fix your posts where necessary.

Tachometer is 'Drehzahlmesser' and speedometer is 'Tacho'. You may have those confused too.

You likely won't get data on stable speed EGTs out of anybody who lives in a place where those speeds would exceed the speed limit. I certainly wouldn't publicly post that I was driving 200km/h for a few minutes in order to take proper EGT readings.

Wire your wastegate open, switch back to stock fuel and ignition and then record your EGTs at speed. That should give you an idea of where to be at 100kPa.
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Old 11-13-2012, 04:37 PM   #35
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Quote:
Originally Posted by stefanst View Post
It looks like maybe you're confusing 'mph', 'kph' and 'kPa'. Check your units and fix your posts where necessary.

Tachometer is 'Drehzahlmesser' and speedometer is 'Tacho'. You may have those confused too.

You likely won't get data on stable speed EGTs out of anybody who lives in a place where those speeds would exceed the speed limit. I certainly wouldn't publicly post that I was driving 200km/h for a few minutes in order to take proper EGT readings.

Wire your wastegate open, switch back to stock fuel and ignition and then record your EGTs at speed. That should give you an idea of where to be at 100kPa.
lol what?
he's not confusing anything. I have videos like that too. Finally, he has 6spd with 3.6 gears...
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Old 11-13-2012, 04:48 PM   #36
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With the mph/kph confusion I was mostly referring to the bit below. It's certainly confusing me- don't know what he's trying to say....

Quote:
Originally Posted by Mazdaspeed_Miata View Post
At 155mph I measured 1850*F at the collector of my exhaust manifold.
At 180kph it should be around 1700*F.
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Old 11-13-2012, 05:08 PM   #37
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Quote:
Originally Posted by hustler View Post
EGT probe is supposed to ~1.25" from the head on the header or manifold. Anything longer than that and you don't know the real temp of the gas coming out of the engine.
I would lean towards installing a manifold sensor during tuning, but moving it back to the downpipe after tuning. It's one less thing to break off and find its way through the turbo.
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Old 11-15-2012, 12:33 PM   #38
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Quote:
Originally Posted by stefanst View Post
With the mph/kph confusion I was mostly referring to the bit below. It's certainly confusing me- don't know what he's trying to say....
Originally Posted by Mazdaspeed_Miata View Post
At 155mph I measured 1850*F at the collector of my exhaust manifold.
At 180kph it should be around 1700*F.


Why not?
I could have also written:

At 155mph I measured 1850*F at the collector of my exhaust manifold.
At 112mph it should be around 1700*F.

How now, it is easier to understand?

"Tachometer is 'Drehzahlmesser' and speedometer is 'Tacho'. "
Ok, that's nice to know, my translation programm says
tachometer (eng) = Tachometer (german)

And soviet said it right: I got a 6speed with 3.6axle. Video shows the end of 5th gear.

And EGT raises so fast, that you have to accelerate only 1min or so on, to know which temperatures you got.
I also do not drive around with 150mph longer time, cause the miata should not be the first choice for such speedhunting. I would feel better in a Mercedes or BMW.

@savington: Don't think, that a piece of the egt sensor could drop to the turbo. Therefor I would be more scared about pieces of weld seam

So what EGtemps did you measure behind or in front of the turbo?
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Old 11-15-2012, 01:00 PM   #39
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Higher exhaust pressure and the mere fact of the heat not escaping quick enough will raise your egt's. Hence a clogged catylitic converter will will not allow the heat from the combustion to be released.
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Old 11-21-2012, 07:15 PM   #40
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My sensor is located about 15 cm in front of the cat flange.
At cruise, I see mid 500 to 700 C.
Under really hard acceleration - or during very aggressive driving conditions, the gauge reads about 820 C.
I' m pretty sure about these numbers because my gauge remembers peak values.

Hope this helps.
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