EGT issue

[Zenki]

If I drive at the racetrack with 30 degree Celius (ambient temperature) my EGT goes up to 1000°C, after a few laps I have to drive piano, otherwise the EGT rise more under full load

With 22 degree Celius (ambient temperature) there is no issue with the EGT, about 950°C peak, pedal to metal for 30 minutes

In street use my peak EGT is about 910-920°C

Spec List:
SR20DET Blacktop
Stock cams
Stock manifold
Garrett GT2871r 0,64 Housing ported
HKS actuator
3 inch free flow exhaust
FMIC
Bosch 044 Fuel Pump
740cc Nismo injectors
Bigger oil sump
Oil cooler
52mm water cooler

Boost pressure 1,0bar

Under full throttle
Afr 11,0 (fuel 98 octane)

Timing [filtered value]
Rpm timing
4000 12
4400 12
4800 12
5200 12
5600 14
6000 15
6400 16
6800 17


More timing?
More fuel?
More timing+fuel?

Please let me now your experience with this topic.

[raddy]

for me it looks that you are using quite agressive timing compare to usual sr20det values...rest of configuration looks just right. 1000deg pre turbo is definatelly too much for any extended time of use. are you sure that timing advance isnt too big?

[unreal-]

Also, can you post a screenshot of the ENTIRE timing map? It will help with troubleshooting the issue.


From the looks of the info you already presented, your motor should be a heaping pile of aluminum at this point. Usually those EGTs are reserved for Rotaries! A SR is supposed to be in the 1600F range AT THE MOST under WOT conditions. Preferably in the low 1500 to 1400 range. (750-850C) with a maximum value of 900 for brief periods. I would stick to 850 as a safer maximum.

From a tuning point of view, you have pretty retarded timing and it keeps increasing past peak torque. From what ive seen on different maps, timing is supposed to stop increasing when you reach peak torque and remain constant. Otherwise you end up with overly retarded timing, and high EGTs. In my case, my map starts off in the single digits under low rpm/full boost, and slowly increases to 18* @ peak torque (4500rpm) and remains at 18* until redline.

[unex]

From what ive seen on different maps, timing is supposed to stop increasing when you reach peak torque and remain constant. Otherwise you end up with overly retarded timing, and high EGTs. In my case, my map starts off in the single digits under low rpm/full boost, and slowly increases to 18* @ peak torque (4500rpm) and remains at 18* until redline.

fuel burning speed is fixed (of course if we take fixed temp, fixed boost, fixed afr). So, as the engine rotating speed is increasing (increasing rpm) you have to increase timing, to get burned mixture at the same time. I have never seen a map with fixed ignition timing while increasing rpm!
btw, when you say retarded, you mean advanced.

btw2: getting back to problem, I would try leaning it to 11,5 and see how it goes. And for sure with knock monitoring.

[Zenki]

From what ive seen on different maps, timing is supposed to stop increasing when you reach peak torque and remain constant. Otherwise you end up with overly retarded timing, and high EGTs. In my case, my map starts off in the single digits under low rpm/full boost, and slowly increases to 18* @ peak torque (4500rpm) and remains at 18* until redline.

fuel burning speed is fixed (of course if we take fixed temp, fixed boost, fixed afr). So, as the engine rotating speed is increasing (increasing rpm) you have to increase timing, to get burned mixture at the same time. I have never seen a map with fixed ignition timing while increasing rpm!
btw, when you say retarded, you mean advanced.

btw2: getting back to problem, I would try leaning it to 11,5 and see how it goes. And for sure with knock monitoring.

Knock monitoring I do all the time
If I lean it knock values will increase
I have monitored during driving on the race track at 30°C that the EGT goes to a higher base level (750-840°C), and when you are pushing hard the EGT start increasing from the higher base level. (Street drive is complete different, base level from EGT is at 650-750°C)

So what do the guys with a similar setup if they are driving on the race track?

Or is the way to go for track use to increase the fuel level to AFR 10.0-10.5 with more timing to get a lower EGT?

[unex]

Knock monitoring I do all the time
If I lean it knock values will increase

I wouldnt call it "knock value". Its more like increased engine sound, but it doesnt mean its knock. You have to find where is knock and where is just increased sound because of more pressure in cylinder (more power), but not as much pressure as knock makes.

[Zenki]

Knock monitoring I do all the time
If I lean it knock values will increase

I wouldnt call it "knock value". Its more like increased engine sound, but it doesnt mean its knock. You have to find where is knock and where is just increased sound because of more pressure in cylinder (more power), but not as much pressure as knock makes.

You are right, the engine sound gets is increased.

We are talking about the same, I am using a knock analyser:
You can adjust the frequency band and the sensibility.
The knock analyser gives you then values between 0-95
It is adjusted that values from 30-45 are ok
A value of 60 is my personal limit
If you get a value from 95 it means knock (you hear it with your ears if you trained and sensible for this noise)

So that means if I say the values are increasing, the engine sound is increased.

At the moment I have values up to 40, if I lean, as suggested from you the values will grow up to my personal limit.

[raddy]

you are already on quite rich side of AFR, I would definatelly take off 2deg of timing to see influence to EGT on the track... Track use is allways quite different thermal stress on engine compared to street and you should tune it more conservative to get endurance....

[unex]

We are talking about the same, I am using a knock analyser:
You can adjust the frequency band and the sensibility.
The knock analyser gives you then values between 0-95
It is adjusted that values from 30-45 are ok
A value of 60 is my personal limit
If you get a value from 95 it means knock (you hear it with your ears if you trained and sensible for this noise)

So that means if I say the values are increasing, the engine sound is increased.

At the moment I have values up to 40, if I lean, as suggested from you the values will grow up to my personal limit.

ok, at this point we know that knock analyzer should be adjusted ok. Btw what make knock analyzer it is ?

More timing?
More fuel?
More timing+fuel?

1. you will get more knock. So, NO.
2. I think you already have a lot fuel. Personally I think, that its to much.
3. My guess would be that you will have the same result or even worse.
So, if leaning it out makes it knock, I would remove some timing and lean it out a little bit and see how it goes. Not every time richer is better.
Forgot to ask: where your egt probe is installed?

[Zenki]

We are talking about the same, I am using a knock analyser:
You can adjust the frequency band and the sensibility.
The knock analyser gives you then values between 0-95
It is adjusted that values from 30-45 are ok
A value of 60 is my personal limit
If you get a value from 95 it means knock (you hear it with your ears if you trained and sensible for this noise)

So that means if I say the values are increasing, the engine sound is increased.

At the moment I have values up to 40, if I lean, as suggested from you the values will grow up to my personal limit.

ok, at this point we know that knock analyzer should be adjusted ok. Btw what make knock analyzer it is ?

-> Phormula KS4

More timing?
More fuel?
More timing+fuel?

1. you will get more knock. So, NO.
2. I think you already have a lot fuel. Personally I think, that its to much.
3. My guess would be that you will have the same result or even worse.
So, if leaning it out makes it knock, I would remove some timing and lean it out a little bit and see how it goes. Not every time richer is better.
My experince is that when I take some timing out the egt goes up. I was adding some timing until the egt had a "normal" level for street use.
(Maybe I have a fallacy)


Forgot to ask: where your egt probe is installed?
-> exhaust housing turbo very close to the t25 4 bolt flange

[raddy]

if you remove timing advance and EGT goes up, it should mean that:
1, timing was over advanced
2, timing was very retarded

in normal situation, when timing is just/about prior knock treshold, increasing advance will increase EGT, as peak pressure will increase....vice versa, remove few deg. of timing will decrease peak pressure followed by lower EGT (and lower torque).

[unex]

exhaust housing turbo very close to the t25 4 bolt flange

as I thought. As I said before, I think you are running too rich and your unburned fuel burns in exhaust manifold ant turbo housing, so thats why you see big temps. I would do following:
1. remove 4-5deg timing.
2. lean to 11.5-11.7
3. add timing until you see knock. Go back a little bit.
4. check EGT after that. I bet it will be lower.

[unreal-]

From what ive seen on different maps, timing is supposed to stop increasing when you reach peak torque and remain constant. Otherwise you end up with overly retarded timing, and high EGTs. In my case, my map starts off in the single digits under low rpm/full boost, and slowly increases to 18* @ peak torque (4500rpm) and remains at 18* until redline.

fuel burning speed is fixed (of course if we take fixed temp, fixed boost, fixed afr). So, as the engine rotating speed is increasing (increasing rpm) you have to increase timing, to get burned mixture at the same time. I have never seen a map with fixed ignition timing while increasing rpm!
btw, when you say retarded, you mean advanced.

I assume things are different for SR20's, but on the KA24DE its recommended to stop increasing timing right around peak torque. I got that from this thread: http://www.ka-t.org/forums/viewtopic.php?t=18784 and its helped me out a lot when tuning my setup. The post in question is halfway down the page. Ive noticed this same tuning philosophy when i retrieved the Enthalpy tune from my S13 ECU when verifying it against my current Nistune setup.


I do see this low timing at lower RPMs, and then ramp up towards redline in a lot of factory turbo, lower compression motors like on the EJ Series motors and the 4G63/4B11. So in certain situations it does help. Just depends how you tune it

Since this is getting a bit out of my zone, i'll let the guys who know more about it speak. I can only say from my experience and Street tuning/use.

[raddy]

I personally tend to keep fixed timing for turbo application as soon as max. boost/max. torque was reached. I found that increasing timing in high revs (past max. VE area) will lead to detonation situation, if max. torque timing was just below detonation treshold. I understand it as kind of heat soaking that promote det in high revs, even when engine is out of max. VE area. Also, I found that there was just little of power gain if I compensate revs with ign. timing, but safety window was much narrow...

[louiswun]

Boost pressure 1,0bar

Under full throttle
Afr 11,0 (fuel 98 octane)

Timing [filtered value]
Rpm timing
4000 12
4400 12
4800 12
5200 12
5600 14
6000 15
6400 16
6800 17


More timing?
More fuel?
More timing+fuel?

Please let me now your experience with this topic.

From my point of view, your timing and afr for 1 bar is little too retard, and little too rich.
I will use your timing at 1.2 bar
And for 98 octane pump fuel at 1 bar, I will not go richer than 11.5 if the fuel quality is good.