Adjusting MBC based on Knock count..how much knock is acceptable?

[Spoolin4Ever]

OK, so I have the MMCD and palm hooked up and working fine.

I have an EVO3 16G turbo, set at just 10 lbs. right now (Stock fuel system, Boost Gauge, Open K&N).

I want to turn up the boost, but stay within safe limits.

Right now, the highest knock I have seen is 3-4 counts (at partial throttle).

I believe at WOT, I see none.

Anyway, how much knock can I allow? I need to know the safe limit.

 

[GSX93DSM]

From those knocks are pretty good from what I have seen. I have seen about 12 counts. I know my friend tune his buddies car and his was at 22 count of knock. So you sould be safe it nevers hurts to try to tune more to get it as low as possible. With that EVO Turbo I would suggest a fuelpump upgrade and injectors. With having the evo I wouldn't run nomore boost till I got the fuel for it.

 

[crazyboost]

You really don't want any knock. Anything over 7 the ecu will pull timing. But try to tune for zero knock. A few counts are ok, but I would tune for zero just to be safe. ### on that extra hot day you might be knocking.

 

[crazyboost]

From those knocks are pretty good from what I have seen. I have seen about 12 counts. I know my friend tune his buddies car and his was at 22 count of knock. So you sould be safe it nevers hurts to try to tune more to get it as low as possible. With that EVO Turbo I would suggest a fuelpump upgrade and injectors. With having the evo I wouldn't run nomore boost till I got the fuel for it.

I wouldn't keep it at that tune if you and your buddy have 12 and 22 counts of knock at WOT. This is not good for the engine. Richen it up a bit if you can, not sure what you have to tune with but either lower the boost or add some fuel to that tune ### that much knock is slowing you down and not good for your 4g63

 

[GSX93DSM]

Thats what it was before he tuned it.

 

[crazyboost]

 

[Spoolin4Ever]

I can't tune; I have no fuel control, I am on a stock fuel system.

I need to know what the maximum allowable is, it sounds like 6 is the highest I should allow.

Thanks.

 

[crazyboost]

I would say you can raise your boost al ittle bit until you see knock then lower it down a little bit so you dont/barely have any. Yes anything over six is bad, timing starts going down. But just to be on the safe side you should try and keep knock at zero. ### if it is hotter than the day you checked your knock count or if somethign else goes wrong (boost leak, bad gas etc) then your 6 count knock could raise and start to do some damage

 

[JayRolla]

You really don't want any knock. Anything over 7 the ecu will pull timing. But try to tune for zero knock. A few counts are ok, but I would tune for zero just to be safe. ### on that extra hot day you might be knocking.

I thought the ecu pulls a 6 counts of knock not 7. I would tune to 0 or 2 counts at the most. If you have 0 at wot you should be fine

 

[crazyboost]

0-3 the ecu advances timing, 3-7 the ecu will hold timing, and after 7 it will take one degree of timing for every 3 knocks.

 

[nightspeed87]

ive seen someone with like 110 counts of knock or something stupid like that.
What is to the point that its causing damage? Basically as long as there is more fuel than air it wont knock though unless its extremely hot or something correct?
Unfortuantly I live in fl so my knock count is probably going to be worse, but I dont
drive my dsm too much in the day time anyways. Do front mounts help lower knock considerably? What about placing your KnN filter in a colder spot, any help there?
Is there a way to detect phantom knock vs. real knock? I get 93 octane here is that better than what some of you guys are gettin in the other states? Just trying to learn a little about it before my car is up and running again after the rebuild.

 

[MrBoxx]

Front-mount intercoolers and relocating the air filter to a "cold air intake" location can help decrease intake charge temps, which help to lower knock. But if there is still a problem with the fuel system not delivering enough fuel to meet the demands of the engine, that can cause lean conditions which will possibly create knock. Another condition that can create knock is hot spots inside the cylinder, on the head, piston, or the spark plug (usually carbon deposits). If the hot spot pre-ignites the air/fuel mixture, it may cause detonation and knock.

In my experience, phantom knock presents itself at partial throttle, at low rpms, and with lots of timing suddenly pulled due to knock. If there's no knock at WOT from 3-7k rpms, but if there's 43 counts of knock at 17% throttle and 2500 rpms at cruising speed, that's more than likely caused by phantom knock. That was what happened to me.

Do a boost leak check to make sure you're not leaking boost. If you think your engine has a lot of carbon build-up you can try to run half a bottle of SeaFoam through it to clean it out. Do a search for how to use this chemical, since doing it wrong can mess up your engine. Get your fuel mods in order before cranking the boost.

 

[SinaiTSi]

In my experience, phantom knock presents itself at partial throttle, at low rpms, and with lots of timing suddenly pulled due to knock. If there's no knock at WOT from 3-7k rpms, but if there's 43 counts of knock at 17% throttle and 2500 rpms at cruising speed, that's more than likely caused by phantom knock. That was what happened to me.

Exactly the same for me too.

Also, like mentioned a fmic and cold air intake will help combat knock but you will be rid of it most effectively if you upgrade all aspects that will cause it. My friend installed a nice big fmic on his GVR4 and when we took it out, it starting knocking crazy, like 19 counts or so at WOT and pulled timing etc. We then rewired the fuel pump and what a difference that made, no knock at all at WOT now and he definitely saw an increase in power from it since his car wasn't pulling timing anymore.

This is basically the way I see knock at WOT, you want to raise the boost to get more power right? Well, then you definitely want knock below 7 counts so your car won't pull timing, because that means a loss in power and even though you're running higher boost you won't see that much gain from it and it'll be hard on the engine. It will be even better if you are under 3 so that your car will continue to advance timing. My suggestion, shoot for as close to 0 as possible.

 

[90gst_sean]

On cooled winter days, I tune for 1 count of knock (dsmlink - 1 knockretard raw OR .4 knock deg)

During the warmer summer days, I shoot for a max of 2 counts raw (OR .7 deg).

Street tune on 91 pump w/ water/meth injection 70/30.