I was wondering if anyone is using the SES light to flash when knock is detected.

It seems an obvious benefit to have a clear visual sign of knock and this route would look the most "factory".

I have had a look at an 8746 hac and its beyond me, but seeing the amendments to make the speed limiter into a rev limiter got me thinking.
as i do not use egr, could i use the routine for setting an egr fault code but trigger it from the knock count ?

It sure would help as my laptop only has 1 com port and swapping between the romulator and aldl link is a pain at 80 mph !

Thanks if anyone can point me in the correct direction.

 

Ive thought about it, either using the SES or a high intensity LED driven off of one of the outputs. Probably could squeeze it in place of some of the vats and fuel cutoff stuff in the portion of the fuel minor loop on the prom. When the knock counter has changed by the specified threshold for knock, turn on the light. Probably have to be careful with how much you execute since its pretty full already. Dont know about the 8746 but in mine theyll add 5 lines of code in to save executing 15 so it must be pretty packed to begin with.

 

Probably need to turn the light back off when knock stops so it flashes rather than just a one time ON.
The flash frequency would let you know loads.

wished they used visual basic :-)

 

this might be dumb but thinking outside the box, could the knock sensor be wired to the amp in the car audio so you can hear what the ecu hears through your car speakers....

 

did a search, found this.......

listening to an engines knock sensor

got to be worth a try.

 

did a search, found this.......

listening to an engines knock sensor

got to be worth a try.

 

You could also use a PIC microcontroller to read in the sensor and turn a pin on (to power an LED, bulb, or anything) when a certain frequency range is detected. At least this is my impression as to how the KS works...someone correct me if I'm wrong. The PIC will cost you about 7 bucks. I can help whomever with the C programming.

 

Why?.
Properly tuned, ie a street tune, your not going to be running up against it anyway, other then for the ocassional bad tank of gas.

Me thinks, some folks are putting way too much confidence in a knock sensor as being the only answer in how to keep a motor out of detonation.

And even with a poor tank of gas, your not going to see more then 3-4d of knock in the worst case anyway.

Not to mention the K/S is pretty much blind to pre-ignition anyway. And from the few .bin files I've looked at, guys usually don't ramp the timing out quick enough, as the engine gets into actually being under load.

 

Grumpy
I have read a few articles that suggest a way of timing for cruise speeds is to advance until knock, then back it off.

I wanted some way for the driver to quickly detect knock, cant be a bad thing, the more info the better surely ?

can you advise a better method. My VEs are all ok now and i want to sort out the timing tables. As ever i am a bit cautious and wanted to stay away from PE.
might need some help on how they all add up.

 

Cant do it that way on all motors, only if the motor goes into detonation before the point of optimal timing is reached. If you try to tune jsut by KS alone, you may end up running too much timing. Too much timing will cause harsh operation, excessive fuel consumption, lack of power, and overheating.

I personally like the idea of having the ecm call out when knock is detected. Even though teh KS cant be trusted entirely on its own, the information, taken in conjuction with everything else, is still usefull IMHO.

 

the plan is

find a flat part of road.

Set the car to cruise at 55 (or thereabouts) I will try and find a good speed to allow "narrow" winaldl data to be collected.

make sure BLM for that rpm/load is 128, or maybe just under, adjust if required.

Use a digital volt meter to measure the TPS volts required to maintain the steady speed.

using romulator, start advancing the timing (2degree increments) in that rpm/load area.

Check, after each increment, if the TPS voltage is dropping then continue incrementing till it starts to become less sensitve to the timing advance changes.

Monitor BLM throughout, adjust if required.
Monitor for knock throughout. (this is where the flashing SES or amped up KS would help)

Move up the rpm/load range and start again.