Making the stock knock sensor reliable and accurate...

[cbrfrenzie]

I am currently in the process of developing an electronic knock sensor conditioning unit. This will be able to tune the center frequency, bandwidth and sensitivity of the knock signal before it goes into the stock ECU. It will also have the capability to run 2 knock sensors into this module, so that you can see knock from each cylinder pair (1,4) and
(2,3).

There would be to re-locatable LED outputs, one for each sensor that you could mount anywhere... i.e. one on the left side of the instrument cluster for cylinders (1,4) and the other on the right side of the instrument cluster for cylinders (2,3).

The technology built into this device would be very sophisticated... where there are blanking times where knock is completely ignored... except when inside a crank angle "window" where knock CAN occur, such as the compression stoke... this would greaty reduce the effects of valve train noise, being the valve would be closed and not slamming open or shut.

The reason for this post is to see if anyone would be interested in a product like this, specific for our DSM's. There would be a model for the 2.0L, 2.3L stroker, and the 2.4L 4g63 engines, given they have different engine harmonics. I know how much it sucks ass to loose 20+ WHP due to some valve train noise on some of our higher horsepower setups... especially those with stiffer valves prings.

Please clobber me with your inputs and suggestion on what would be desired as far as a user interface for knock indication.... i.e. the LED idea blows, or the LED idea sounds sweet...

Extensive R&D will be done on my personal car to ensure correct operation for ALL ranges... as I have 2 AWD dynos at my workplace and can simulate ALL engine loading conditions with the load control features...

Please and thank you!
Chad

 

[cbrfrenzie]

x2, Did all the theories turn out to be just theories? I was getting all excited as I was reading through this post and then bam! nothing. Updates?

I'm waiting to get my car back on the road so I can test my two prototypes out on it. The bad thing about living in my location is there are very little DSM enthusiasts here, hence no cars to test with except my own. Before I feel comfortable releasing anything for sale I would like to PROVE my theory on cars with bigger displacement.

It would be nice to take measurements from 2.0L, 2.1L, 2.2L, 2.3L and 2.4L engine configurations so I can record the "range" i will need to cover with the adjustments. I have calculated values to use, but I need actual measurements to verify my findings.

Sorry this is taking so long to all you where are eagerly waiting, my car is taking much longer then expected to get up and running.... again... So the project is not dead, just waiting for a test subject

If anyone has access to a spectrum analyzer, could you probe the knock signal with both knock present and no knock present? I need the measured frequency of the second harmonic of the knock signal, as well as your engine displacement.

 

[EGuenther]

Well it's great to hear it's still in progress! Would a datalog with rpm and knock be useful to you from me? I'm running a 2.3, wiseco .020over, eagles, ARP's etc.. I don't actually have any datalogging stuff installed right now, still running stock ecu and injectors. What would be the cheapest way to datalog with a labtop? What free software, if there still is, would be the best/ would you prefer?

 

[EGuenther]

x2, Did all the theories turn out to be just theories? I was getting all excited as I was reading through this post and then bam! nothing. Updates?

 

[EGuenther]

x2, Did all the theories turn out to be just theories? I was getting all excited as I was reading through this post and then bam! nothing. Updates?

 

[turboAWDfanatic]

Just found this thread. *subscribing*. Keep us updated! Thanks

If you need, I can provide you with some more logs of severe knock/phantom knock.

 

[Team Addiction]

You know this product alreasy exists right?!

Phormula - Engine Knock, Detonation and Pre-Ignition Detection and Monitoring Systems

 

[dsmfa9nutter]

If you feel like paying $600+ for a standalone knock detector, sure it already exists.

 

[the_mork]

This thread provides quite a bit of information about the evo8/9 knock control system which is built differently but designed similarly. A much easier project for safely eliminating phantom knock would be to find the same tables in the H8 ecus (98/99) and eprom ecus and then just adjust our knock thresholds. Those of us running evo8 ecus already have to do this in the low range and sometimes very slightly in the mid range too. Individual cylinder knock metering is also available just through messing with the software.


Knock control - load vs RPM table found - evolutionm.net