lleroyb

Does anyone know how quickly the DME pulls timing when the KLR senses knock? Does it just take one knock or many over time, say 10 in 20 seconds?

I am still getting four or five counts when I leave it at full throttle to 5k or so. I added some octane booster and still get one count in a run.

I have a portable knock counter I would loan to someone with a bone stock car to see if they get any counts. It just plugs in and has a padded clip to mount it on the air vents. It also has the blink code diode if that would interest you to see.

Lou

fast951

DME does not pull timing, the KLR does.

lleroyb

Thanks for the correction John. Do you know specifically how it decides when to do it? One knock?

Lou

hp18racer

When I've behaved badly, low octane, high boost, I'd see count go up by 10 in a single burst of full throttle, change gears and get another 10, never more than 10 per application of full throttle. KLR must be taking action at that point or I'd get more.

lleroyb

When you say "behaved badly" are you running MBC? I am a little concerned about the counts. I have no doubt it is pulling harder with the octane booster added, which tells me timing is being pulled without it. I would really like to know when the timing gets pulled, after one knock or ?

In basic terms is a few counts like we are experienceing OK? At 6000 rpm there would be 200 combustion cycles per second. At even 10 counts per "run" that is just a few, but it only takes one bad one to blow the head gasket, right?

Lou

hp18racer

I do run a black **** manual boost controller. When I set up the timing in my chips I was shooting for no knock at 17psi with 100 octane, 1650 EGT. When I went to more than 50% pump gas at 17psi (behaving badly), I'd get 10 hits as I went through each gear at WOT.

My opinion is that one every now and then is OK. I won't live with 10 per gear shift at WOT. Knock isn't really an all or nothing thing, very unlikely you blow your head gasket up with one event detected by the KLR.

Last year my car gave almost no knock events on the street. Now with the same A/F ratios, timing and fuel, but the addition of a breather tank, I get one or two events from KLR pin 15 per WOT burn through a gear, certainly nothing I can hear. I still think it's OK but like you I'm concerned. I'm watching my plugs now for signs of pitting and plan to borrow or make a bore scope to look for other signs of damage.

I'd like to hear from some more experienced folks out there what they do to verify their cars are knock safe.

lleroyb

You bring up a good point, when I first installed the knock counter I could not get a single count. It was cooler out, but other than that I don't know what has changed. It makes me wonder what is going on.

Lou

lleroyb

I went to see my mechanic today whom I trust more than I can describe. We hooked up a precision boost gauge and did a few glory runs. Boost was obviously being controlled to 1bar max. above atmosphere. He said the newer turbo cars with OBDC II will register a few knocks before a correction is made and not to worry about a few counts.

Lou

hp18racer

I got a total of 3000 events in 9 sessions at 14psi at my last DE. Hmm, 9 sessions, 8 laps each, 16 shifts per lap, less than 3 ticks per gear. Does that still qualify as 'a few counts' ?

Geneqco

Hey Ron,

Just a thought... when you put your breather tank in, have you set it up to vent to atmosphere? If so, did you enlarge the hole in the top of the AOS. Not sure if not doing this would cause the knock, but it does seem curious that you are getting knock only after adding the breather.

333pg333

Also how accurate are these knock counters and how influenced are they by their position? In other words can one sensor pick up more than another. Can the same sensor pick up more or less depending where it's put? Can they pick up Bogey signals?
Just a few questions that I don't know the answers to.

hp18racer

I did not enlarge the opening in the top of the AOS. It does vent only to the atmosphere. What are your thoughts behind the size of the opening in the AOS??

theedge

The ones ive seen people installing are ones that count the signal coming out of the KLR, thus using the KLR's own programming and the stock sensor. If theyre getting knock counts, its because the KLR is sensing knock...

Geneqco

LR site:

The oil separator has a nipple on the top in which our breather tank connects to. Inside this nipple the factory has a small hole only measuring .240" in diameter. You can enlarge the hole to .540" which is the inside diameter of the nipple and gain 500% in the volume of air that can pass through the orifice into the breather tank, fully utilizing the capability of our breather tank system. We recommend you remove the oil separator and drill or enlarge the hole while holding the tank up-side down so shavings will not be lost in the tank. The oil separator is hollow and can be flushed out if needed.

I spoke to Dave before installing mine because I didn't want to go to that trouble if not required. He suggested I enlarge the hole with a hot soldering iron.

I think without vacuum to help, the tiny orifice is probably too samll to allow proper crankcase ventilation and this could be the cause of your knock.

AI had a similar problem with an Audi a few years ago. I was not running quite right so I hooked up a test light and fault codes came up for the knock sensors - so I replaced them... but still had the problem. I had also noticed oil was leaking from the filler cap - I replaced the seal but it was still leaking... turned out the breather orifice was blocked. Once that was fixed, problem solved.

Hope this helps!

lleroyb

Well I am at 132 so far. I would really like to hear from someone who knows how the KLR and DME decide to pull timing etc. after sensing knock. As I stated above the boost control looks like it is working as designed with my chips.

HP18, were you running race gas or? My next experiment is to mortage the house and fill the car up with race gas to see if I get any counts. Last time I looked it was $8/gal when pump gas was $2.60 or so.

Lou