How much knock is too much?

[RandyRhydah]

i rewired my knock sensor because my power fc was picking up no knock at all. i have it working now and im getting knocks up to 58 ish with +2 degrees all over on the stock base map on bp ultimate. i did a quick google search and some people say they get up to 90 all the time and its fine some people say anything around 50 is bad and some people say they get knocks up to 160ish!

so this is really just a question to the people familiar with tuning not just what they read on google. what knock do you aim for with our engines (b18c for me)? also whats a relitivly safe knock rate and whats a good number which is a do not exceed and if it does back it off straight away.


thanks guys

Roy

[RandyRhydah]

Also just then i found out first and second is fine i can rev past vtec with only getting a knock of around 30.. but in third gear as soon as i get 4500+ its knocking 70ish..(ofcause i back off as soon as i see the c.e.l) why would it be different with different gears?

[seihoa]

I would say 30ish would be ok.
Then again what is your warning set at?

Knocks on different gears because of the timing map and depending on the load you give the car.

My car use to knock arnd 30ish and then went past 60 one time so got it checked out and did a road touch up tune.
Now knock is at 13-20 at WOT.

Then again is there anything such as safe knock?


Oh just read only for b18c?
this was for my Forged wrx motor so guess it could take more beating

[RandyRhydah]

By safe knock i mean how the knock sensor picks up other noises too.. i was told that it is always going to pick up some reading.

the power fc sets the warning to 60 stock i think. and yeah when i was getting knocks of 50 ish the warning wasnt coming on but at 70 it did so it sound about right..

i dialled the ignition down -2 over the whole map (so back to stock) and it was still knocking at the exact same moment as when it was +2. i have also upped the fuel maps so its a little on the rich side aswell to be safe. just for a little more info

[seihoa]

If its still knocking that means the tune is out more then 2 degrees in 3rd and on that certain load...try putting the whole map out by 4 degrees see if that helps....but seems like you need a touch up tune my friend. Best to do a road tune as the tuner will be able to load it up n fine tune it.

anything under 30 at wot is good to me.

forgot to mention , could be a bad batch of fuel. ( which has happened to me )

[nigs]

Could be a lot of things, as the name implies it just detects knock. So that could be anything.

In a straight line under WOT I only get 12 knock max and that's limiter bashing. 7,200rpm + 20psi.

[TODA AU]

Check/set your valve clearences & try again

[RandyRhydah]

thanks for the help guys i reset the map to stock and problem isnt there anymore... weird but will keep an eye on it

[IEVAQ8]

not sure if this is of any help, but with milans itr when we tuned it on the dyno, didnt see a knock at all, the whole time (6hrs of tuning or so)

as soon as we took it on the street the power fc was showing knocking often, so we hooked up knock box and headphones and went for a drive and it was as quite as a mouse.........

from what i know, power fc is very sensitive to any knock, or what it thinks to be a knock but in fact could be road noise or a stone or something else..

good luck with it

[VTECMACHINE]

Jesus, 90... 160! That sounds crazy. I was scared when I saw 40 from my first tune. Few weeks later, Ben from Touge Tune drew the line for Knock on the PFC at 20 and retuned it. The highest it ever saw once was a massive 28 at WOT touching rev limit at 7802rpm, lol. Even though we went easier on the tune and peak power was decreased according to butt dyno, it was faster around the track.

[RandyRhydah]

thanks for the info gents, talked to my tuner and he said it doesnt do it in first and second because the ramp rates so once my intake manifold comes in its time for a full dyno tune. i defiantly feel the butt dyno change with +2 ignition over the whole map.. but a safe engines a happy engine so i better not tempt fate and keep it safe untill it goes to the dyno

[Chr1s]

Yep, you can't really do it for second gear, it all happens a little too quick for the ecu to correlate.

I'm a little hesitant with your experiance Ricki, if you pull timing and power drops, your no where near MBT and on your due way to knocking. If you were knocking and you pull a few degrees, the power shouldn't change, in some cases it goes up! If you keep reducing, THEN you will loose power.

That's just my 2cents :)

Randy, it really depends on whats going on, being one of the smallest bore hondas, it should be able to handle the extra timing, however being 10+yrs old alot of things change. Theories that should work, don't.

[RandyRhydah]

understood, thanks for the words of wisdom :) stoked to get it onto the dyno

[Chr1s]

Are you tuning it on the dyno?

[RandyRhydah]

im not tuning it on the dyno but the local tuner is. just once i get my intake manifold and throttle body on (waiting for fking edelbrock to ship out their new batch.. its been 2 months so far). im just doing a street tune on it really for fun and a bit of education/experience..

ive done alot of reading up and research and its really just an area of interest for me.

Of cause im keeping it on the rich side and have sorted out my knock problem now (just took out 6 degrees of timing and its not throwing the CEL warning anymore).. i never heard or felt anything from the knock that the knock sensor picked up, some people tell me they can hear and that you will feel a loss of power. but im staying on the safe side and keeping knocks below 30 and will let my tuner go from there.

[Chr1s]

Making things rich won't exactly help with knocking, your simply demanding something the fuel cannot deliver. Unless it's a heat issue thats the probelm.

Mmm..street tuning with up to 6 degree's difference sounds like a disaster, if you went 6 degree's further from where you were that is.

Just remember, fuel = thermal management, ignition = power. More is not always better.

Ahhh..it's complicated and there is always something different to throw into the mix, theres alot more behind it, but the real real basics is above what I just said. Don't always rely on knock sensors as such, there is too many noises when it comes to an engine, changing the material the piston is made from will change the frequency, etc. Universal knock sensors are meh.. especially ones that need calibration. The knock box is a unit I like, it's audible, leaves it up to the user to distinguish what is knock and what is not.

[RandyRhydah]

thats exactly what i was saying, i know the knock sensors arnt always reliable but atleast if i go by how much its knocking its safe untill i get to the dyno where the tuner has a knock box.

By keeping it rich i mean im not leaning out the engine leading to disaster.

with the 6 degrees difference that was from the stock map, i only added 2 degrees which made it alot more snappy in first and second but never tested out third untill the other day when i posted this thread.

but thanks for all your info its helping me out and opening my eyes some more

[VTECMACHINE]

Chris... it got alot torquier, knock went down by half, and I used ALOT of fuel. haha. But man was it good. Temps were beautiful aswell. My first tune was a one lap wonder tune, way too lean, lasted 2 laps and then dropped power and slowed by half a second a lap. Ben's tune, 10 laps straight with in 0.3 seconds of each other. So what would have he done? I don't understand, please teach me. :) - Bit late as my car will be going soon though haha.

All of Ben's Honda tunes are awesome. For what the cars are, they get pretty good times. The S2K he's tuning is down to 1.09's on street tyres and stock engine.