Question about Knock and maybe a course of action

[LaN-]

Hey guys recently did my first real mods to my DSM (UICP Intake and MCB) got everything installed right and got the boost set at 14 - 15 psi (i'm trying to follow the stage 1 tuning guide) after driving around for alittle while i started to go over my logs and i was hitting 15 - 19 hits of knock in the higher RPMS. I know what knock is briefly but my questions are.

1.) is this to much knock
2.) should i turn the boost down
3.) Would cleaning out my IC help alittle bit
4.) What can the effects of knock be if its to high
5.) a better expliantion of "knock"

i did try and search on this couldnt find a good concrete answer so i'm posting this thread

Thanks,
LaN-

 

[EclipseOwner95]

Hey guys recently did my first real mods to my DSM (UICP Intake and MCB) got everything installed right and got the boost set at 14 - 15 psi (i'm trying to follow the stage 1 tuning guide) after driving around for alittle while i started to go over my logs and i was hitting 15 - 19 hits of knock in the higher RPMS. I know what knock is briefly but my questions are.

1.) is this to much knock
2.) should i turn the boost down
3.) Would cleaning out my IC help alittle bit
4.) What can the effects of knock be if its to high
5.) a better expliantion of "knock"

i did try and search on this couldnt find a good concrete answer so i'm posting this thread

Thanks,
LaN-

1. Any knock is too much
2. Yes
3. Not really, unless its clogged with something
4. Blown up engine
5. Detonation is when the air/fuel mixture ignites before the spark plug ignites, pistons still on the way up and the explosion forces it back down. (In a nutshell)

If you couldn't find any answers on this topic you didn't look very hard.

 

[LaN-]

yeah i figured that much but i just wanted to make sure

thanks

 

[CanadianTSi]

My advice would be to clean out your IC and get an upgraded fuel pump.

 

[Quasimondo]

5. Detonation is when the air/fuel mixture ignites before the spark plug ignites, pistons still on the way up and the explosion forces it back down. (In a nutshell)

You have it backwards. That's preignition.

"Pre-ignition is defined as the ignition of the mixture prior to the spark plug firing. Anytime something causes the mixture in the chamber to ignite prior to the spark plug event it is classified as pre-ignition. The two are completely different and abnormal phenomenon. Detonation is the spontaneous combustion of the end-gas (remaining fuel/air mixture) in the chamber. It always occurs after normal combustion is initiated by the spark plug. The initial combustion at the spark plug is followed by a normal combustion burn. For some reason, likely heat and pressure, the end gas in the chamber spontaneously combusts. The key point here is that detonation occurs after you have initiated the normal combustion with the spark plug."

-From streetrodstuff.com's webpage, "Engine Basics: Detonation and Preignition"
Click here for the full article

Turning down the boost would help, but you should also try re-wiring your fuel pump to get a little bit more out of it, or replacing it with a 190 lph pump.

 

[dsm1kenobe]

1.) is this to much knock
LaN-

...yes

2.) should i turn the boost down
LaN-

...yes, but if you do and you're still getting relatively high knock, then either you're running lean, have too much timing, or it could possibly be phantom knock.

3.) Would cleaning out my IC help alittle bit
LaN-

possibly.. check your lower intake pipe for oil. If you see oil there, then it's likely that you have oil in your IC.

I'm not familiar with the "Stage 1 mods" lingo as I've been way past that stage a long time ago, but basically the major contributors to knock is running lean, having too much timing, too high of intake temps or any combination of the above. There are a few ppl that have knock from running too rich, but I've never experienced it.

-Turn your boost down to stock levels, or whatever the lowest setting your wastegate will allow for the sake of eliminating too high of boost. What octane fuel are you running anyway? Make sure you got some premium in there.
-Check your base timing. 5 dbtdc is the factory setting. try as low as 3 btdc.
-are you running lean? check your plugs. white with sprinkles is indicative of running lean. if you have fuel management, add some fuel at the RPM you start seeing knock.
-If you did the above, and you're still knocking, then you could have phantom knock.

The search button is your friend. Read up on all the knock posts and I'm sure you'll get this thing fixed. Good luck.

 

[90blacktsiawd]

1.) is this to much knock
Yes way too much

2.) should i turn the boost down
Absolutely

3.) Would cleaning out my IC help alittle bit
Doubt it will help with that but it will give you alittle extra power if its coated with oil inside.

A bigger fuel pump or at the very least rewire your fuel pump to get alittle extra fuel. You'll spend like $25 at radio shack getting all the parts. And have you done a tune up lately? Plugs, wires, fuel and air filters and such. If you haven't you really should take care of these things before you start to modify.

 

[LaN-]

I am running lean and i'll rewire my fuel pump this weekend mabye clean out the IC

also could an air leak cause any of this

thanks for the help so far