I found something disturbing.

Whenever I do fast shifting, knock count goes over 23 counts. That makes ECU to switch to lower Octane map. And, even though low octane map is the same, ECU will still pull a lot of timing and stay there until you release the throttle.

May be this is why they all run stand alone when they do serious racing. Knock sensing is good for the protection but stock ECU isn't capable of spirited driving.

Someone got to find the knock sum decay algorithm in our ECU to fight this. Knock sum decay just takes too long and there is no way to prevent fast shifting knock unless you disable the knock sensor or knock sensor filter map. hmm....

 

Log ?

 

Here is the log when I downshifted hard from 4th to 3rd.

rpm TPS O2 Knock sum timing adv
2156 89. 0.819 0 40
2093 88. 0.780 0 32
2125 85. 0.838 0 14
3000 100 0.546 11 19
4906 100 0.838 23 10
4156 100 0.897 22 4
4781 100 0.897 21 1
4343 100 0.897 21 -1
4718 100 0.916 20 -1
4562 100 0.916 20 -2
4750 100 0.916 19 -1
4750 100 0.916 19 -1
4875 100 0.916 18 -1
4937 100 0.897 18 -1
5031 100 0.916 17 0
5093 100 0.916 17 0
5156 100 0.897 16 0
5250 100 0.916 16 0
5312 100 0.916 15 2
5406 100 0.916 15 2
5500 100 0.916 14 2
5562 100 0.9165 14 2
5625 100 0.9165 13 2
5718 100 0.9165 13 2
5750 100 0.9165 13 3
5843 100 0.9165 13 3
5906 100 0.9165 13 3
6000 100 0.9165 13 3
6062 100 0.9165 13 5
6156 100 0.9165 13 5
6187 100 0.9165 13 5
6250 100 0.9165 12 5
6312 100 0.9165 12 7
6375 100 0.9165 12 8

Edit: I get 1 or 2 knocks the most on just regular 3rd gear pull with granny style shifting. and my timing stays above 6 and ends 13 at 6300 rpm normally.

 

Are you sure the downpipe isn't hitting the crossbar when shifting?

 

Nope, You are supposed to get the knock when you do the fast shifting or free reving. Just do quick free rev and log it. you will see like 10 or more knocks.

Important thing is ECU pulls timing like crazy and stays there too long( due to the too conservative knock sum decay).

So, people at the drag strip with the stock ECU won't get the pull potential out of the car.
bouncing off the revlimiter with hard lunch and fast shifting = a lot lower timing with pig rich fuel.

I say, disconnect your knock sensor when you are at the drag strip .

 

I am not sure that that is correct. You are comparing a DOWNSHIFT to HIGH LOAD with the launch control, which I logged and showed there were only 8 counts of knock peak. Be careful about making blanket statements though while they may be true in certain situations arent always true in all situations. If it hurt you that bad, Mitsu would never have included it in the software.

 

You have to love phantom knock. This was a major problem for the 1G DSM's....some people even resorted to stacking washers on the knock sensor threads (to prevent it from hearing backround noise). However, just because your car is doing this doesn't necessarily mean all other Evo's are doing the same thing.

 

8 counts are still too much and good enough to pull down entire WOT run. knock counts should vary depending on the mod and how it is tunned. it varies from 5 counts to 25 counts on my car.

However, I am more concerned about knock sum decay problem with stock ECU. I think I have seen an article about DSM guys shortening this decay with the stock ECU. They actually reprogrammed that sub routine.

 

this is partially phantom knock but also includes real knock. This actually happens on all other cars too. It is known phenomena. Anything too sudden unexpected movement can't be compensated well by ECU's fuel map or anything.
Numbing down the knock sensor should help but you take away the ability detect the real knock.

 

91 octane
What boost level are you running?
What plugs are you using (what is their condition). 1 range cooler would be best.
Walbro?
Injector duty cycle?
Water injection problem solver

 

I am running only 19 psi now.
I use bpr 8 es.( 1 range colder)
injector duty cycle? I got 660 injectors!
yes Walbro.
well, this was on race gas.
Edit: oops!

 

Update your puny signature tough guy. Still have'nt gotten a hang of this "mind reader" thing. Can you elaborate on your ghetto exhaust?

 

Your car doesen't switch maps, or even change the octane value that fast. This is a VERY important distinction to remember. What it does do is real time timing pull proportional to the knock sum count.

 

I guess I have to update my signature.
This is not really exhaust or mechanical problem. I have a fine set up.
I eliminated all the rattles. I went through many stages for all this and I don't want to elaborate what I did but I assure you, my set up is rock solid. I went through many exhaust setups but my current ones are the best fit of them all. It is megan + HKS now. I will do the run without exhaust or with the stock one for you if you want, but the result will be the same. I have been testing this numerous times with different exhaust set up. I have many many logs and this is not one of those rattling problem. just do the free revving on your engine and log it. you will see the knock sum shooting pretty high around 7 if you car is well tunned.

 

yes, I agree to that. I just found that my low gas map has much lower timing for that load