how much knock is something to be concerned about

[18psiWhiteMS3]

in 5th and 6th gear i have been seeing between 1 and 2.3 knock flash a few times near the higher RPM. only in 5th and 6th. Is that something to be concerned about?? the temp was like 85 90 outside too.
when the air is like 70 degreese i see blips of .3

 

[MS3_KIDD]

how high rpm are you talkin? lol

i cant see how any "knock" would be acceptable

 

[Knox Joe]

What octane gas you using? How much boost?

 

[mrdouble99]

knock is always something to be concerned about.

Detonation want to push your piston down when the piston want to go up

This is the worst thing to do to an engine

 

[18psiWhiteMS3]

i tried lucas octane booster and my knock is completly gawn, im guna run octane booster at every fill up. i have never knocked in 1st through 4th on 93 octane witch is what we have here in PA. only 5th and 6th. boost is 20 peak tapering to 18 at 6000 rpm its only a weekend car anyway but damm does it run good now since its not knocking in 5th and 6th. Really strong now
octane booster really works

 

[MS3_KIDD]

Octane booster gets you speeding tickets lol.

 

[meicalnissyen]

i tried lucas octane booster and my knock is completly gawn, im guna run octane booster at every fill up. i have never knocked in 1st through 4th on 93 octane witch is what we have here in PA. only 5th and 6th. boost is 20 peak tapering to 18 at 6000 rpm its only a weekend car anyway but damm does it run good now since its not knocking in 5th and 6th. Really strong now
octane booster really works

mOST OF THOSE ADDITIVE USE A NASTY CHEMICAL WHICH bad FOR YOUR ENGINES LONG TERM HEALTH

 

[MS3_KIDD]

What would the name of this nasty chemical be? What proof do you have that it causes damage?

You don't help anyone when you make a statement like that. With no facts you don't sound like you know what your talking about

 

[clos561]

i see .4 and .7 alot (and in between shifts wot sometimes) the higher ones like you i only see at 5th-6th gears. Sometimes i think its just the knock sensor beiong too sensitive. I have trz delrin and when i see the knock its because im part throttle and accelerating under 3k which makes the car vibe alot in high gears.

 

[MSMS3]

What would the name of this nasty chemical be? What proof do you have that it causes damage?

You don't help anyone when you make a statement like that. With no facts you don't sound like you know what your talking about

+1.

I've used octane boost for decades in many different high compression engines with no negative side effects. Very curious about this "nasty chemical," that causes engine damage. Would that be methyl cyclopentadienyl manganese tricarbonyl (MMT) or ferosene? One or both of these are used in limited amounts in most of the off-the-shelf boosters. The majority of commercial boosters use MMT.

Tolulene is probably the best octane boost additive, if you can find it. It's already a component in 93 octane pump gas (up to 5%) and 100 octane race gas may have as much as 25% tolulene.

 

[MS3_KIDD]

You can pick up a can of tolulene at most hardware stores and add a few ounces into you tank with every fill and boost your octane more for less that with the off the shelf boosters

 

[Bravnik]

Here is a really good article that tested Octane boosters for the effectiveness. They utilized proper testing procedures and posted the results.

http://www.europeancarweb.com/tech/0503ec_octane_boosters_tested/index.html

 

[18psiWhiteMS3]

i cant read no more. so they are bad is what i got?

 

[MS3_KIDD]

not so much as bad as not economical as making your own brew at the pump

shelf boosters only give at most iv seen 1 whole octane point (ex 93 becomes 94) or slightly more when added to the specified amout of fuel

these boosters have a s*** load of other stuff in small amounts

you can get larger amounts of one thing and get more octane points for the same amount of the booster

http://www.gnttype.org/techarea/misc/octanebooster.html
http://www.gnttype.org/techarea/misc/octaneblend.xls

 

[MS3_KIDD]

good gas and less boost

(thumb)

 

[COBB Tuning]

There is always going to be some degree of engine noise which may be interpreted as "knock" by the ECU but that may not mean that there is "knock" in the engine. The knock sensor is essentially a microphone that reacts to engine noise by generating a electrical signal. That signal is then interpreted by the ECU with signal processing software that looks for a certain kind of noise or signal. Very low levels of noise my not be knock at all but just noise. When you start to see very high knock correction then you know you have an issue.

Travis
COBB Tuning

 

[MS3_KIDD]

yes the knock sensor is a piezoelectric sensing element that sees mechanical noise, and cannot tell the difference between knock and say a loose exhaust.


im not familair with specifics on the cobb product or "knock" levels at which timing begins to get pulled, but id say its getting pulled fairly early

being that the OP is only seeing the knock under heavy load and WOT conditions its a fair assumtion that what hes seeing is traces of knock and not just any mechanical noise

if he doesnt see it at normal driving conditions or under rough road conditions or no/low boost conditions
id say we can narrow things down pretty quickly

 

[714ms3]

I assume we are talking about the knock retard value on the AP yes? If so, when I am in 5th or 6th and get into boost I will also see a slight blip never higher than 2.3. This sounds more like Travis' explanation right? And I should not be concerned right? Sorry for my newbness but I just got my AP last night.

 

[djthom]

my knock sensor hits 5 or 7 sometimes...

it is usually in the morning after the car is cold and about 3 min into my morning drive. always 5th gear...

 

[nig3]

any knock is bad under load, its common to register some false knock between shifts sometimes but you dont want any in general especially in 4th gear up thats the worst time to be knocking.