Josh B

I normally run around with the boost set to 16 or 17. Just pushed it up to 18-19 to see if the knock counts would go up.

If my air to fuel ratio is good at higher boost levels (19 psi) and the knock count is low then what other factors do I need to be looking at to know if i am still safetly pushing the motor?

samluke

I just rebuilt my motor over the winter, having thrown #2. I have rebuilt my motor a couple of times there has never been any indications of knock problems. I was hoping the rebuilt motor (I actually rebuilt my spare motor) would behave differently, but it doesn't. I think my car is seeing false/ghost knock, which is why the boost backs off and the power is down. I don't see any evidence of actual knock. I don't think its real. I just can't figure out why it does it.
I almost believe that its something in the main harness/car thats doing it, but I can't imagine what. It all stared when I keyed the car off at the track, with the car at speed, to reset the ABS. Its never been the same since. It drives me nuts.

fast951

If you are monitoring knock 100% of the time, and you have the way to react "fast" enough, you are fine. However, all it takes is a bad tank of fuel, heat soaked IC or higher IAT (mainly the variables that will directly affect knock) and you are in trouble.
On the street you get away with plenty, on the track a different story. However, your car being a street car, you will get away with a few spirited runs, but you are still taking a chance.

I think 15psi on pump gas is a safe bet. Anything higher and you are reducing your margin for error (not use error, but external elements that the use has no control over).

333pg333

Is anyone hearing these knock events like pinging? Or are they inaudible when in the car?

fast951

For those running the knock counter, have you tried to induce knock by tapping on the engine block? If so, please explain in details what you did.

My main concern with any knock display (or control) system is how do you test and verify the proper operation of such system.

333pg333

Exactly?

evil 944t

There is also a difference between knock and mechanical engine noise. With the right tool, you can dial out the engine noise and listen for true knock. You can google knock detection and a few will pop up.

Van

Out of curiosity, I've wired KLR wire #15 to a digital input on my Traqmate data acquisition. We'll see if it counts anything.

On a stock setup, is it likely to detect knock?

Rogue_Ant

Yes - most likely low load counts, typically during shifts...


-Rogue

ilikemy944

On a fully stock 86 951 I got 0 counts under boost, but I did get counts around town, while shifting and other situations.

333pg333

How were you measuring this?

ilikemy944

Knock counter wired in as described previously in this thread (I think its this thread).
The little counter hooked into the test port behind the glove box.

V2Rocket

where does the knock sensor mount on the 951? and without searching this thread, whats a good standalone knock monitor? (for a car that didnt have one before)

JohnKoaWood

Knock sensor is under the intake, on the head I believe

http://www.skycraftsurplus.com/index...OD&ProdID=1001

wired to KLR pin 15

Rogue_Ant

A good standalone knock system:

J&S Safeguard


-Rogue