exhaust gas temperature...facts
#1
exhaust gas temperature...facts
Hi there,
1st of all, i hope i post in the right subforum
I post here not so often cause i'm from germany and often it's a bit difficult for me to understand this colloquial language in which the most posts are written.
well anyway...
I got some questions about egt's.
I searched around but can't find a good thread, where a lot of facts are posted.
Maybe first some informations about my car.
I still got a 1.6l stock engine from 1993.
I got a lot of gauges in my car, because i want to know, whats going on in my engine.
Some of them you can see here: https://www.youtube.com/watch?v=qTX6mBablZQ
This engine got fired by a DIY turbokit, with Begi S4 exauhst manifold, GT2560R, Begi Downpipe, Subaru WRX STI intercooler, 360ccm injectors, Emagage ultimate and ZT-2 wideband. Also 6th gear and 3.6 torsen axle.
I only use 102octan fuel.
At the end of my exhaust system I installed a Magnaflow-muffler with welded in silencer (diameter only 1,5748inch ~ 40mm).
At the moment, I think that could be the reason for my high egt's.
I measure my EGT's at the collector of the S4 manifold and also 2inch behind the turbo.
If I am cruising at german autobahn at around 4000rpm, -3psi and 14,7afr I measure around 1400 - 1470f before turbo yet.
While max. accelerating till 7100rpm/155mph it increases to 1850f before turbo and 1600f after turbo. While acclerating I measure 11.5afr and around 9psi.
I think all results should be fine apart from my EGT's. They are a bit high, aren't they?
So I would like to know, what egt's you all measured in your miatas (AFR and Boost data would be also nice to know).
To compare that it maybe would also nice to know, where you measure your egt and where you drive when you measure them.
I don't know the exact laws in the states, but I think it is not allowed to drive so fast like here in germany.
So maybe some of you measure some data at the race track?
What do you think is the problem for my high egt's?
I think my ignition should be ok...
Sorry for my bad english
Would be very nice, if this could get an interesting thread!
Regards from Germany!
Basti
1st of all, i hope i post in the right subforum
I post here not so often cause i'm from germany and often it's a bit difficult for me to understand this colloquial language in which the most posts are written.
well anyway...
I got some questions about egt's.
I searched around but can't find a good thread, where a lot of facts are posted.
Maybe first some informations about my car.
I still got a 1.6l stock engine from 1993.
I got a lot of gauges in my car, because i want to know, whats going on in my engine.
Some of them you can see here: https://www.youtube.com/watch?v=qTX6mBablZQ
This engine got fired by a DIY turbokit, with Begi S4 exauhst manifold, GT2560R, Begi Downpipe, Subaru WRX STI intercooler, 360ccm injectors, Emagage ultimate and ZT-2 wideband. Also 6th gear and 3.6 torsen axle.
I only use 102octan fuel.
At the end of my exhaust system I installed a Magnaflow-muffler with welded in silencer (diameter only 1,5748inch ~ 40mm).
At the moment, I think that could be the reason for my high egt's.
I measure my EGT's at the collector of the S4 manifold and also 2inch behind the turbo.
If I am cruising at german autobahn at around 4000rpm, -3psi and 14,7afr I measure around 1400 - 1470f before turbo yet.
While max. accelerating till 7100rpm/155mph it increases to 1850f before turbo and 1600f after turbo. While acclerating I measure 11.5afr and around 9psi.
I think all results should be fine apart from my EGT's. They are a bit high, aren't they?
So I would like to know, what egt's you all measured in your miatas (AFR and Boost data would be also nice to know).
To compare that it maybe would also nice to know, where you measure your egt and where you drive when you measure them.
I don't know the exact laws in the states, but I think it is not allowed to drive so fast like here in germany.
So maybe some of you measure some data at the race track?
What do you think is the problem for my high egt's?
I think my ignition should be ok...
Sorry for my bad english
Would be very nice, if this could get an interesting thread!
Regards from Germany!
Basti
#9
FWIW A stabilized (operating temp) turbo'd small engine aeronautical "turbine intake temp" is typically 1500-1600f. The problem with using EGT as sole indicator that something is wrong, is that there are many things that can cause higher EGTs: fuel, ign timing, cam timing, exhaust restriction... Anything that creates a trailing combustion as the exhaust valve is open is going to bring the EGT up: too much fuel, ign retard, cam timing.
I saw 1600f peak, single probe in collector ~1" from turbine flange, at 14psi 6500rpm with a .48 AR stage III t3 turbine housing, 3" exhaust which included a resonator, catalytic converter and muffler. I replaced the original ceramic cat with a high flow metal and the EGT didn't change. Timing did change the EGT. So the answer is not always obvious. You might looking over your ign timing and fuel compared to similar set ups.
I saw 1600f peak, single probe in collector ~1" from turbine flange, at 14psi 6500rpm with a .48 AR stage III t3 turbine housing, 3" exhaust which included a resonator, catalytic converter and muffler. I replaced the original ceramic cat with a high flow metal and the EGT didn't change. Timing did change the EGT. So the answer is not always obvious. You might looking over your ign timing and fuel compared to similar set ups.
Last edited by m2cupcar; 11-09-2012 at 08:10 AM.
#11
So here you can see my EMU map:
Uploaded with ImageShack.us
You have to know that my basic setup is !! 8 !! degree in front and not like usual 10 degree in front.
So do you think anything looks wrong?
Depending the question why a restrictive exhaust increase EGTs?
This is easy. If the exhaust gas can't flow out freely, it gets damed up and the temperature also rises up.
Regards!
Basti
Uploaded with ImageShack.us
You have to know that my basic setup is !! 8 !! degree in front and not like usual 10 degree in front.
So do you think anything looks wrong?
Depending the question why a restrictive exhaust increase EGTs?
This is easy. If the exhaust gas can't flow out freely, it gets damed up and the temperature also rises up.
Regards!
Basti