false knock, ECM compensates,

[EVIL]

So I am getting false knock. Yes I'm really positive.

When the ECM detects knock it will compensates by adding fuel and such to protect the motor.

So when it detection detects False knock the ECM will still react the same way.

My questions are, if this is happening and you can't find where the false knock is coming from, how much are you losing in power and how can you fix the issue?

D

 

[fastblackracing]

So I am getting false knock. Yes I'm really positive.

When the ECM detects knock it will compensates by adding fuel and such to protect the motor.

So when it detection detects False knock the ECM will still react the same way.

My questions are, if this is happening and you can't find where the false knock is coming from, how much are you losing in power and how can you fix the issue?

D

False knock can come in many forms and can be a real pita to find. As far as i know the ecm only pulls timing and there are ways to address this, reduced torque on the sensior itself where it screws into the block, the chip can be commanded for less knock reaction in degrees that it pulls how fast it gives the timing back and even a delay when the throttle is matted to begin pulling giving things a chance to quiet down if you will ......im sure there are many new tricks as i gave up on mine long ago....depending on how aggressive the sensitivity is it can cost you big in the power department easily pulling 50-100 horsepower or more......sometimes there is no rime or reason as to how it works as i did a stage 2 headed sollid roller cam deal for a guy that should have had all kinds of false knock And it worked great on his car.....yes i verified that it did work, made no sense to me.

 

[EVIL]

So a good tuner can adjust accordingly.

Thanks for clearing it up. That was some good info.

D

 

[fastblackracing]

So a good tuner can adjust accordingly.

Thanks for clearing it up. That was some good info.

D

A good tuner/chip guy can do do certain things in the parameters but if there there are metal to metal contact between pipes, rattling pullies and other sources of mechanical noise if you have not all ready done so do all you can to eliminate them.....

 

[GNVenom]

One of the tricks we used to apply to the chip programming was to modify the "recovery rate" in the chip. Knock under load would take away timing, and the stock-program rate of recovery to put the timing back to normal was pretty lengthy. Shortening that value still allows for timing pull, but gives it back quickly, so the overall timing loss is minimal. That simple change equated to a considerable difference in HP/TQ.

 

[TurboBob]

as others have stated, the stock ecm only adjusts timing. most modern aftermarket chips have "false knock ignore" algorithms that attempt to handle these situations.

under what conditions is this happening, perhaps your chip author can adjust the chip to help.

also, if you are getting false knock all the time, the knock sensor is not really doing anything to help/protect you. you might as well just unplug it....

Bob

 

[0-60n4]

Another old school trick to desensitize the sensor is to wrap the threads with Teflon tape and as said above, don't tighten so much.

 

[EVIL]

I tightened the sensor to specs. 14Lb if I'm not mistaken. I was getting knock at 10psi to 18 and other times non. .9 to 3 degrees. Even with 109 unleaded. Car is running great. The other day I had 4 people in the car and it registered 19.9 knock. Enough to blow things up I'm sure. The car is fine. So the weight helped trigger the knock. Didnt hear any significant bangging and definitely did not near any noticeable knock. I know what it sounds like.

The motor purrs and
The Trans shifts perfect.

D

 

[EVIL]

I also changed the Oil and it's clean.

D

 

[GNRick]

When I had a passenger my driveshaft was hitting the loop.

 

[EVIL]

I guess a GoPro set in different select locations may acquire some results.

Thanks for all the great information and advice gentlemen.

The car pulls hard and has scared the shit out of a few people.

I’ve even gotten a few “JEEEEEEESus” from a few non believers.

I need to install my Alky kit and bring it to be properly tuned.

I believe I’ve reached my limitations. I’d also like to be taught tuning as well.

D

 

[GNRick]

The added weight from the passengers is giving you a clue. I would put the car on a 4 post lift and have one person rock it up and down while someone else examines it from underneath. Good luck.

 

[Pronto]

My exhaust pipe was rubbing my hr bar clamp. When the car was on the lift and the suspension hanging, clearance looked fine. When on the ground it was flat up against the clamp. Had to flatten the pipe to clear.

 

[dynoman]

Did you check torque converter bolts ? Did this just start happening and did you make any changes in the car recently ? Sam

 

[Chuck Leeper]

When I had a passenger my driveshaft was hitting the loop.

300# mother inlaw in the trunk, will do that!

 

[EVIL]

Another good reason to never get married.

D

 

[B guz]

I had this 90 corvette that the half worn out belt tensioner would hit the stop and cause the knock sensor to go nuts.

The car had a whole host of problems making it run like crap, when I silenced the tensioner the car ran decent , it let me go on to find the other problems.