UTEC's Knock Detection
 

Hey Guys...

I need to know how good the UTEC's Knock Detection feature?

I know for a fact that when the check engine lights flahes the UTEC detects knock.

Anybody here experienced hard knocking? How does it feel like? Is it like loosing power or stumbling when the engine is experiencing heavy knock? The car jerks around?

Any info is very much appreciated...

Thanks

when i tune and the car knocks, you can feel a slight loss of power/almost hesitating engine on a 3rd gear pull. Sometimes if i wasnt sure if it was knock, i would put in some 106 octane and do the same pull. If the seat of the pants dyno didnt feel the loss of power like feeling then i knew i was pulling timing because of knock. I had that same feeling with a leaky BOV too. I Also almost always tune at night, you can REALLY see the CEL blaring in your face. During the day, its impossible.... I found that datalogging at nite was best.....

FWIW I too have experienced some knock, but I never could "feel" it. I have only experienced knock when I am in 5th and punch the gas at around 2k rpm. I ran a log and saw some 2 to 9 counts on the knock, but never "felt" any knock.

you dont literally feel knock, you feel the loss of engine power when timing is pulled. At least i do.

Yes, the power loss is from the ECU pulling timing when it senses knock. This is where you need to check your tune. If AFR is good and there isn't a huge boost spike where you get knock, back off the timing at that point. Backing off timing in a tune is much smoother, and better for the engine, the getting knock and having the ECU pull timing.
The way I set up my last timing map for water injection was;
I datalogged after a good afr/boost tune. Then I entered ECU in all the load sites in the timing map.
I went RPM vrs Load down the data log and entered what showed up under the ECU column, (ei. 3500 rpms at 80% load was xxdegs of advance under the ECU timing column) .
I filled in from from 2750 - redline (8K in my case). Then I used the UCC timing map feature to "fill the map".
Now it's very close to optimal. I am tweaking around touchy areas, (5500- known knock area).
Now I have a great water injection tune. AFR's around 12.2:1, boost 22psi dropping to 20psi at redline and max timing at 20.5deg at redline...ON 91 OCTANE, WITH NO KNOCK!!
Did I mention...I love this UTEC! {thumbup}

from tuning wrx's with the utec (which are very very knock sensitive) i know that the EVO is pretty knock resistant. The wrx flashes the cell light whenever the ecu senses knock much like the evo's however, the evo ECU doesn't flash for every stupid thing and pull timing (like the wrx).. ANYWAY, enough said about that.. the UTEC knock perameters can be adjusted (if i'm not mistaken) and are infact very good. The stock ECU should prevent your car from knocking by pulling timing when it "thinks" it will knock; however, if you are doing something entirely wrong, you will KNOW that it is knocking... the sound is horrible and it feels like someone tapped the brakes going 50mph (and no i haven't done that with my car ahhaha) the Utec is safe if used correctly.. dont worry about that feature.. ;)

On the subject of knock.

I have a pretty good tune in the car right now but I am seeing some strange knock between 5800 and 7000rpms in 1st gear. What I dont understand is why it only happens in first gear not in 2nd, 3rd, or 4th. The other odd thing is only the UTEC is detecting the knock. The stock ECU isnt pulling timing at al and anything I do in the map doesnt change the knock situation. The knock is also very inconsistent. Only occuring on maybe 3 out of 5 pulls, but once again no timing adjustment. Very odd. Anyone else doing first gear pulls? I am really big on trying to hit all load cells for smoothness so I dont just sit in WOT in 3rd or 4th.

if you already have a SES light from running catless will the utec still flash the SES if it detects knock?

Yes, it still flashes.. However I noticed when my CEL is on, and the knock light flashes, I don't seem to notice it as easily.. You can turn off the CEL light from the UTEC configuration so you don't have the light on all the time if you always have a CEL code..

Thanks MJ.

My check engine light flahes in high rpm's around 5500 and above, I also dont' feel any loss in power or timing being pulled or any misfires due to high boost. I'm using the stock Iridium plugs from the factory, it already has 12k miles on it. Anybody know what causes that check engine light to flash?

I'm using Alcohol Injection and boosting 24psi on the stock turbo with 91 Octane.

Can someone enlighten me on this?

Thanks

with the UTEC, flashing CEL is knock.. You should change your plugs to a step colder and gap them tighter.

But a misfire (Combustion quench or just boost blowing out the spark) may not result in knock, but will result in a slightly richer Wideband reading..

I think Al (Dynoflash) had said at one point that 5000-5500 or so are RPM's prone to more engine noise, where the knock sensor may mistake engine noise for knock. You have no way of knowing this without listening to the engine with cans while your making these runs

You will probably need to alter your timing and fuel curve a little. Unless you can determine that its actually engine noise, then you have the option to set the UTEC to be a little less sensitive to that noise (if you have no way of telling then don't change it)

Alcohol injection won't guarantee not getting knock, but it will slow combustion rate just as if you raised the octane of your gas.

Hi, I cant seem to figure out if the run I made is safe or not?

I'm boosting 24psi stock turbo, stage 4 parts

Can somebody explain if this is safe? I can see knock count as high as 6-8 counts is that too high? I dont' feel any loss in power or misfires just a straight pull till redline boosting 24psi

Here is my UTEC Log File


2197 035 +27.4 10 +15.8 00000 <------ Knock Count
2427 037 +27.4 10 +15.8 00000
2606 042 +27.4 10 +12.7 00000
2913 050 +27.4 10 +7.3 00000
3156 050 +27.4 10 +6.3 00000
3486 051 +27.4 10 +5.4 00000
3926 054 +27.6 10 +13.9 00000
4426 072 +27.6 20 +11.8 00000
5073 100 +27.6 40 +11.4 00000
5688 100 +27.6 60 +14.2 00000
6422 100 +27.6 80 +14.2 00004
6958 077 +27.6 90 +15.5 00000
6207 002 +27.6 00 ECU. 00000
5707 001 +27.6 00 ECU. 00000
5257 001 +27.6 00 ECU. 00000
5224 050 +27.6 10 +13.1 00000
5012 049 +27.6 10 +12.7 00000
5042 050 +27.4 10 +12.8 00000
5359 068 +27.4 40 +11.9 00000
5707 100 +27.4 60 +14.8 00000
6049 100 +27.4 80 +11.7 00002
6397 100 +27.4 90 +9.7 00006
6574 073 +27.4 90 +10.8 00000
5858 002 +27.6 00 ECU. 00000
5402 001 +27.6 00 ECU. 00000
5012 001 +27.4 00 ECU. 00000
4616 001 +27.4 00 ECU. 00000
4852 056 +27.4 10 +13.5 00000
4830 066 +27.4 10 +13.6 00000
4909 088 +27.6 10 +13.2 00000
5050 100 +27.6 40 +11.3 00000
5224 100 +27.6 60 +7.7 00005
5411 100 +27.6 70 +7.6 00000
5592 100 +27.6 80 +8.8 00000
5777 075 +27.6 90 +14.4 00000
5184 003 +27.6 00 ECU. 00000
4789 001 +27.6 00 ECU. 00000

Thanks

Is the knock repeatable?
Anything over a 1 count for me is too much knock. Especially in the higer RPM ranges. I have also had times where the UTEC reports Knock but doesnt do anything about it (Meaning it doesnt throttle timing). I have asked this question before but got shut down pretty fast for some reason.
If you are shooting for a safe tune work on getting rid of that knock.

The big problem is your logs aren't full pulls in any particular gear, and the newer log you sent me has knock at a lower transition point.. Hopefully you'll be able to get some more data..

a run through the gears is good, but you have to tune through each gear first.. First gear won't sample enough data, second may not either.. But third and fourth usually give me enough data to do tuning with.. you have to go from 2000rpm through redline.. fourth gear you'll be going way too fast to do this legally on the street.. third gear is your best bet..