"Optimum" EGT's?
03-08-05, 05:23 PM
#26
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Originally Posted by eViLRotor
I've noticed the low EGT's on the highway with my TII as well.
AFR in the 14's, timing around 32-34* BTDC, EGT around 650-700C (1200-1300F).
Probe is about 6" down the DP.
Tuned by Steve Kan.
AFR in the 14's, timing around 32-34* BTDC, EGT around 650-700C (1200-1300F).
Probe is about 6" down the DP.
Tuned by Steve Kan.
Are we talking about high cruising?
If it's light load stuff (all in vacuum), advance the **** out of the ignition.
I run like 40 degrees+ of ignition timing in vacuum areas at high RPM's.
This burns more cleaner, and the big ignition doesn't hurt the motor in the vacuum ranges.
In your set-up, you should be getting EGT's easily over 700C...try more like 750C is ideal.
-Ted
03-08-05, 05:25 PM
#27
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Originally Posted by jreynish
I am currious what are you guy's seeing at iddle I seet between 400 and 500 deg C, and then when I step on it even when I start to boost .5 bar I only see tepms as high as 600 Deg c. is my timming advanced too much?
Idle EGT's are almost dead on 480C on most of the cars I've messed with.
Once engine temps (i.e. coolant) is warm, I typically see 480C.
If you boost the engine hard and let the EGT's come down, it will sometimes stabilize at 500C to 520C - this is still okay.
This is ignition timing set as factory specs - leading firing at -5, 15 degree split, wastespark'd leadings.
-Ted
03-08-05, 06:19 PM
#28
Originally Posted by RETed
WOT = redline?
What kinda ignition timing advance are you running at those points?
If you're getting 600C @ 4k - 7k, the EGT's are too low.
Since AFR's are ok, I think you're ignition timing is too retarded.
I would run about 25 to 30 degrees of total ignition advance at 7psi.
-Ted
What kinda ignition timing advance are you running at those points?
If you're getting 600C @ 4k - 7k, the EGT's are too low.
Since AFR's are ok, I think you're ignition timing is too retarded.
I would run about 25 to 30 degrees of total ignition advance at 7psi.
-Ted
at 5000 rpm at .5 bar boost, timming is 23 degrees
at 6000 rpm at .5 bar boost, timming is 23 degrees
at 7000 rpm at .5 bar boost, timming is 23 degrees
at 8000 rpm at .5 bar boost, timming is 23 degrees
and arround there I am seing 650 Deg C MAX that is with the probe located 4 inches behind the turbo outlet in the DP.
what is the max retarted for timming 15 deg for high boost? I haven't tuned above .5 bar yet.
03-08-05, 08:05 PM
#29
Racing Rotary Since 1983
iTrader: (6)
steve kan did not tune my car but loaded a map he thought might work when it was able to run.
i have since logged 79 runs and of course have changed almost everything but have retained. untouched, the ignition map. i will only look at it when i refire in a couple of weeks and will have 2 loggable egts.
comparing your IGL w mine at .5 bar and considering that you are running cold i would conclude that there is a good chance your ignition at .5 bar has too much advance.
i run:
4000 15
5000 17
6000 18
7000 20
8000 23 all w a conservative 14 split.
your combustion may be happening too early and the heat is being disapated thru the engine's interior surfaces. if this is the case you are going to be down on torque.
as Ted Sed
, be careful w ignition or you will be motor shopping.
good luck,
howard coleman
i have since logged 79 runs and of course have changed almost everything but have retained. untouched, the ignition map. i will only look at it when i refire in a couple of weeks and will have 2 loggable egts.
comparing your IGL w mine at .5 bar and considering that you are running cold i would conclude that there is a good chance your ignition at .5 bar has too much advance.
i run:
4000 15
5000 17
6000 18
7000 20
8000 23 all w a conservative 14 split.
your combustion may be happening too early and the heat is being disapated thru the engine's interior surfaces. if this is the case you are going to be down on torque.
as Ted Sed
, be careful w ignition or you will be motor shopping.good luck,
howard coleman
03-08-05, 08:24 PM
#30
would you mind shooting me a copy of your map so that I can compare your ignition map with mine? Either Ted or Howard?
Thanks again,
jeffrey
clockstick@shaw.ca
Thanks again,
jeffrey
clockstick@shaw.ca
03-09-05, 11:45 AM
#31
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23 degrees timing is fine for 7psi (.5bar). I have ran as much as 29 degrees before w/o any issues. If anything, I would be careful more on the split timing than the actual advanced timing. There're two basic method of timing map, step timing and flat timing. either will be fine. The difference between the two is that one will retain more heat for more higher rpm hp while the other will have faster response but trailing off top than the other.
Originally Posted by howard coleman
steve kan did not tune my car but loaded a map he thought might work when it was able to run.
i have since logged 79 runs and of course have changed almost everything but have retained. untouched, the ignition map. i will only look at it when i refire in a couple of weeks and will have 2 loggable egts.
comparing your IGL w mine at .5 bar and considering that you are running cold i would conclude that there is a good chance your ignition at .5 bar has too much advance.
i run:
4000 15
5000 17
6000 18
7000 20
8000 23 all w a conservative 14 split.
your combustion may be happening too early and the heat is being disapated thru the engine's interior surfaces. if this is the case you are going to be down on torque.
as Ted Sed, be careful w ignition or you will be motor shopping.
good luck,
howard coleman
i have since logged 79 runs and of course have changed almost everything but have retained. untouched, the ignition map. i will only look at it when i refire in a couple of weeks and will have 2 loggable egts.
comparing your IGL w mine at .5 bar and considering that you are running cold i would conclude that there is a good chance your ignition at .5 bar has too much advance.
i run:
4000 15
5000 17
6000 18
7000 20
8000 23 all w a conservative 14 split.
your combustion may be happening too early and the heat is being disapated thru the engine's interior surfaces. if this is the case you are going to be down on torque.
as Ted Sed
, be careful w ignition or you will be motor shopping.good luck,
howard coleman
03-09-05, 02:57 PM
#32
Originally Posted by RETed
Again, what RPM's?
Are we talking about high cruising?
If it's light load stuff (all in vacuum), advance the **** out of the ignition.
I run like 40 degrees+ of ignition timing in vacuum areas at high RPM's.
This burns more cleaner, and the big ignition doesn't hurt the motor in the vacuum ranges.
In your set-up, you should be getting EGT's easily over 700C...try more like 750C is ideal.
-Ted
Are we talking about high cruising?
If it's light load stuff (all in vacuum), advance the **** out of the ignition.
I run like 40 degrees+ of ignition timing in vacuum areas at high RPM's.
This burns more cleaner, and the big ignition doesn't hurt the motor in the vacuum ranges.
In your set-up, you should be getting EGT's easily over 700C...try more like 750C is ideal.
-Ted
My timing advance is 34* there.
03-09-05, 05:18 PM
#33
Lives on the Forum
Originally Posted by eViLRotor
I my case we are talking about 5th gear 70mph so around 3200 rpm(?).
My timing advance is 34* there.
My timing advance is 34* there.
We're not talking under boost or WOT?
If it's light load in vacuum, you can run more ignition advance there.
I typically run around 40-degrees or even more.
I've had ignition maps run up to 50-degrees there just to see what it would do.
So as a rule of thumb, around 4kRPM, most of my vacuum ranges are running around 40 - 46 degrees of ignition advance.
Keep in mind, stock ignition maps (at least for a Cosmo) runs about 40-degrees of ignition advance in the high RPM / vacuum ranges.
-Ted
03-09-05, 05:20 PM
#34
Lives on the Forum
Originally Posted by pluto
23 degrees timing is fine for 7psi (.5bar). I have ran as much as 29 degrees before w/o any issues. If anything, I would be careful more on the split timing than the actual advanced timing. There're two basic method of timing map, step timing and flat timing. either will be fine. The difference between the two is that one will retain more heat for more higher rpm hp while the other will have faster response but trailing off top than the other.
Once of the variables that's been pretty much ignored is the split ignition timing.
Small changes in split timing can affect EGT's and power significantly.
-Ted
03-09-05, 07:27 PM
#37
Racing Rotary Since 1983
iTrader: (6)
one of the problems re finding the optimum ignition matrix is that most of us have tuned for afrs and do not as yet monitor egts.
i do think that egts are the essential missing part of ignition tuning and there is significant power and durability to be had by those that log egts while tuning.
i know steve kan has utilized egts to a great extent while on the dyno and ted has run an egt gauge for years. with the myriad of engine states of tune and turbos we are all wandering around as to our ignition maps til we start measuring/logging egts.
howard coleman
i do think that egts are the essential missing part of ignition tuning and there is significant power and durability to be had by those that log egts while tuning.
i know steve kan has utilized egts to a great extent while on the dyno and ted has run an egt gauge for years. with the myriad of engine states of tune and turbos we are all wandering around as to our ignition maps til we start measuring/logging egts.
howard coleman
03-09-05, 09:18 PM
#38
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Originally Posted by howard coleman
if you are firing early your egts will be low due to the increased time for the explosive force and temp to cool before heading out the exhaust.
firing too late creates the opposite effect: too much of the force rushes out the port instead of driving the rotor. result more exhaust temp. an early opening exhaust port also can be a cause of higher egts for the same reason.
howard coleman
firing too late creates the opposite effect: too much of the force rushes out the port instead of driving the rotor. result more exhaust temp. an early opening exhaust port also can be a cause of higher egts for the same reason.
howard coleman
Originally Posted by RETed
It's hard to say.
Get too much ignition timing (advance) - power will drop, but EGT's will rise!
Get too little ignition timing (retard) - power will drop, but EGT's will drop.
Get too much ignition timing (advance) - power will drop, but EGT's will rise!
Get too little ignition timing (retard) - power will drop, but EGT's will drop.
Cheers,
Lam
03-17-05, 05:39 PM
#41
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Originally Posted by LDawg
These seem contradicting to me. Anyone care to shed light on which is true?
Cheers,
Lam
Cheers,
Lam
"Extreme ignition retard will actually cause fuel to burn out the exhaust, which WILL cause EGT's to RISE - this one stumps a lot of people"
03-31-05, 09:35 AM
#42
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Peak at Stoich!
Highest EGTs are at stoichiometry mixture about 14.7-15.0 AFR. (www.sdsefi.com) Aircraft normally richen their mixtures to the cool side of peak for cruise. There is now a thought that they can lean the mixture to the same temperature on the other (lean) side of peak EGT for best fuel economy. My car has cruised at 16 AFR smoothly, but I am afraid to push this experiment. What are your thoughts?
Barry
Barry
04-01-05, 01:18 AM
#43
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Originally Posted by howard coleman
steve kan did not tune my car but loaded a map he thought might work when it was able to run.
i have since logged 79 runs and of course have changed almost everything but have retained. untouched, the ignition map. i will only look at it when i refire in a couple of weeks and will have 2 loggable egts.
comparing your IGL w mine at .5 bar and considering that you are running cold i would conclude that there is a good chance your ignition at .5 bar has too much advance.
i run:
4000 15
5000 17
6000 18
7000 20
8000 23 all w a conservative 14 split.
your combustion may be happening too early and the heat is being disapated thru the engine's interior surfaces. if this is the case you are going to be down on torque.
as Ted Sed, be careful w ignition or you will be motor shopping.
good luck,
howard coleman
i have since logged 79 runs and of course have changed almost everything but have retained. untouched, the ignition map. i will only look at it when i refire in a couple of weeks and will have 2 loggable egts.
comparing your IGL w mine at .5 bar and considering that you are running cold i would conclude that there is a good chance your ignition at .5 bar has too much advance.
i run:
4000 15
5000 17
6000 18
7000 20
8000 23 all w a conservative 14 split.
your combustion may be happening too early and the heat is being disapated thru the engine's interior surfaces. if this is the case you are going to be down on torque.
as Ted Sed
, be careful w ignition or you will be motor shopping.good luck,
howard coleman
)
04-01-05, 06:31 AM
#44
Racing Rotary Since 1983
iTrader: (6)
yes..
i will be up and running w a new engine, larger compressors and loggable fuel pressure and (2) egts by wednesday of next week. if i learn anything helpful i will post it.
howard coleman
i will be up and running w a new engine, larger compressors and loggable fuel pressure and (2) egts by wednesday of next week. if i learn anything helpful i will post it.
howard coleman
04-03-06, 12:44 AM
#46
Senior Member
Such good info. Such an old thread.
I noticed on that data log posted, a pattern of 5 spaces apears to be the delay or .6-.7sec for the sensor to pick it up. We need more datalogs of egts.
Is the base egt found by playing under vac then used as a max for wot?
I noticed on that data log posted, a pattern of 5 spaces apears to be the delay or .6-.7sec for the sensor to pick it up. We need more datalogs of egts.
Is the base egt found by playing under vac then used as a max for wot?
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