Knock Control

[plechtan]

Have you considered using something like the Intersil HIP9011 chip in the next version of your controller? Knock control would be great and since the cihip is only about $5.00 i think the added features would be well worth it.

Another idea would be to make a seperate tunable knock module that could be wired into the ignition controller. This could also be used with Megasquirt or other aftrmarket engine controllers. Intersil sells an evaluation kit that is pretty cool, but a little expensive.

[brentp]

Hi Peter,

Welcome to the forums- and thank you for the suggestion. With the Megajolt2 we are building in a spot for a pluggable knock control module, so we can develop knock control on a separate track relative to the main Megajolt2 project. This Intersil chip is a candidate for such an add-on board.

Keep an eye on developments, and follow us on twitter for the most recent news!

regards,

[brentp]

More information the TPIC8101 is a similar to the Intersil chip:
http://focus.ti.com/docs/prod/folders/p ... c8101.html

[plechtan]

the TI Chip Looks like the same thing,

if you decide to do a seperate unit , perhaps you could have several outputs,

1. A pulse output comaptible with the GM knock modules used the 80-90s
2. a 0-5V analog output or PWM ( it could also drive a dash guage)
3. A CAN intercace that would would work with aftermarket ECUs

[brentp]

Yes, a stand-alone knock sensing unit is definitely possible. It could also feed the Aux input of the current MJLJ V4.

We'd appreciate suggestions for a variety of OEM knock sensors as well!

Thank you,

[brentp]

Looks like this is a good candidate for a project on the short-list. The TI chip seems to be the likely candidate.

In the meantime it would be good to gather a list of OEM knock sensors. I'll add a page in the wiki where the information can live.

[plechtan]

I suggested the Intersil unit because they had an evaluation board and software that runs on a PC. it uses some pins on the paraell port to send data out to the SPI interface.

They want like $300 for the evel board and software though.

I will hunt up the part numbers for the Jeep Knock sensors for you.

[plechtan]

If you want a good list of Knock sensors, go to amazon.com, select automotive. search the term "Knock Sensor" I came up with a couple of hundred. It does show a picture of each one and a application guide for which vehicle it is used in. It would be good to get drawings with mounting dimentinons and the conector specification.

On a different subject, do you have any idea how to tune the unit for a specific application? I was thinking of advancing the timing to create a knock event, then let the knock box hunt around to see where the strongest signal was. Since different engines will generate different frequencies, this would seem to be an easy way to do it. The best would be if the tuning software had 2 usb interfaces and talked to the Ignition controller and the knock box. Once the knock event was detected and the optium filter determined, the timing could be backed off a little then hunt for the best filter again.

Some other suggestions would be to have an LED blink when a knock event occured, and have a audio output for headphones to help with the tuning.

[NITROPIXIE]

Now then i read on a certain speed of auto website that he made a knock sensor for tuning, but instead of your typical ecu controlled sensor, he used a small microphone epoxied to a battery terminal then bolted to the engine between bores 2 and 3, then connected the microphone to a small battery powered amplifier which went to a set of head phones in the car.

Once your MK1 ears are calibrated to the sound of pinking, valve train noise etc could be quite successful. Did go to try it myself but jiggered the microphone. May have to get it out and try it again.

[NITROPIXIE]

Something like this

http://maplin.co.uk/module.aspx?moduleno=220058

but with better headphones instead of the speaker.

I know its cheap and cheerful but its good for an experiment

[david jenkins]

Now then i read on a certain speed of auto website that he made a knock sensor for tuning, but instead of your typical ecu controlled sensor, he used a small microphone epoxied to a battery terminal then bolted to the engine between bores 2 and 3, then connected the microphone to a small battery powered amplifier which went to a set of head phones in the car.

Once your MK1 ears are calibrated to the sound of pinking, valve train noise etc could be quite successful. Did go to try it myself but jiggered the microphone. May have to get it out and try it again.

I've done something along those lines - if you go to my website (www.lathyrus.eu), click on 'special tools and parts' and 'knock detection circuit', you'll see my solution to the problem. The key thing is that the computer between your ears has many thousands of years-worth of evolution* in picking out strange noises from a noisy environment - something that's very hard to do with electronics.

Just one warning - listening to the noises made by your favourite engine is SCARY!

* Sorry if you have problems with the concept of evolution...

[NITROPIXIE]

Excellent read i enjoyed that. Will defo have to get it working now. Could you hear the knock way before you can normally hear it from the engine, i'm kinda guessing you did. Did you notice any better running once done and have you had it compared to a professional on a rolling road??

Sounds like fun anyway,will get my mate to drive it while i sit in the passenger seat listening for it and adjusting the timing.

[Salamander]

Hi all

I used this circuit to my MSII, it´s works for MJLJ v4?

[plechtan]

Anything going on with this?

[hendrik6073]

is knock control possible allready ?