knock q

[pwhite]

How much knock is bad ? I am running 14-15#boost (stock reading was 11#) and when i stick it at 55 mph i get a knock reading of any where from 6.3 to 1.2 but only for about 1 or 2 frames on the scanmaster. From speeds lower or higher than 55 its fine just on a 55 mph punch for about 1-2 frames after that its fine> thanks

JUST INSTALLED\
42.5 inj
307 wb fp with hot wire
adj fpr.
adj. waste gate
k&n 9"

 

[WarpSpeed]

Are you sure your boost gauge is correct? Stock setting should be about 14, which is @3 off, sooo 15 + 3 is 18 which is pushing it on pump gas..

 

[Steve Wood]

Momentary knock indication such as you describe is often false knock...the sensor hears something banging when you hit it...often the downpipe hitting the control arm or pinchwheel on the lower firewall.

It can happen because of a bad driver's side engine mount.

If you turn the boost down to say 12# and it no longer happens, it could be real. A better test is to add some more octane to the tank and leave the boost where it is....if it goes away, then it is most likely real.....It could be a little bit lean and knock when the load first hits.

 

[pwhite]

How much knock is consitered to be a problem. my car knocks at 15-16# on 93 pump gas . goes away with in 2 frames on the scan master. the milivolts at wot are like in the 850s could this richness be the cause of my knock. how do i achieve the opt. 750 to770 on the milivolts. car knocks any where from 1.2 to 12.6 but only for one frame ?

 

[Fred 86 GN]

I'd be careful...

I have lost two headgaskets with these 009 injectors by running the car with knock over 5 degrees. If you are seeing 3 or less, and not running over about 17psi, then it will probably survive. But if you see more than 5, and certainly more than 10, get out of the gas!

Like Steve said -- find if anything is banging when the engine twists over and try running high octane gas to see if the KR goes away. Or turn the boost down and see if it goes away.

I am presently chasing a lean-out problem with the 009 injectors that occurs right during throttle tip-in. Either it is lean out or way too rich at tip-in...regardless it seems to be dumping the O2's in a big way for a couple frames in DirectScan and then the KR shows up. Only 1-2 degrees for me, but it still is a problem.

HTH