Knock sensor and knocksense

itguy · Post by **itguy** » Thu Aug 17, 2006 10:17 am

Hi All

I've got a knocksense unit installed and hooked upto my MS but currently I've got knocksensing disabled as I'm having trouble actually getting the sensitivity right on it.

I've got a ford zetec engine on individual throttle bodies and even when I set the sensitivity really low I still get a knock sensed when on the overrun at high revs (5krpm+ for eg).

Now yes, I've got a shedload of retard in my map there but I'm also using fuel cut in MSnS-E so it can't be knocking....

Anyone else got this problem or able to suggest a suitable location of where I can fit the knock sensor to on the block to get the most accurate reading?!?!

Thanks

Will

jonny5_6977 · Post by **jonny5_6977** » Thu Aug 17, 2006 3:13 pm

im not to sure if this helps but i read something about engine noise will make it seem like their is knock. its like 10 paragraphs down http://www.megamanual.com/ms2/knock.htm i guess their is a way to adjust it at high rpms hope this helps

bluetrepidation · Post by **bluetrepidation** » Thu Aug 17, 2006 3:21 pm

Yeah it is prob engine noise above 5k.

bluetrepidation · Post by **bluetrepidation** » Thu Aug 17, 2006 3:22 pm

Otherwise does the unit work well? I was thinking of getting one?

A.J.

itguy · Post by **itguy** » Thu Aug 17, 2006 10:57 pm

That is a really good point actually - forgot that the code will allow a 'block' of all knocks above a certain rev limit, this may cure my issue.

In terms of how well it works, not really sure - I haven't tried to make the car knock yet to test the device, I'm a bit scared to to be honest!

Any suggestions as to how much advance should do it under load?

I currently run something like 19 degrees at 100kpa/2000rpm and 24 degrees at 100kpa/>=3500rpm. 16v 4cyl engine, pent roof head design.

What sort of advance would I need to add to expect a knock?

Thanks

Mad Professor · Post by **Mad Professor** » Fri Aug 18, 2006 1:39 am

I have not long brought mine for my car, but not yet fitted as the engine is being rebuilt at the mo.

So I also would like to know how you get on.

ae1969 · Post by **ae1969** » Fri Aug 18, 2006 10:24 am

You will definitely get engine noise over 5K rpm as we found on the dyno. It may be specific to engines but mine developed engine noise that could not be avoided at 5800 rpm.

We dynod the car with a nice conservative tune and had no knock except the engine noise described at 5800 rpm.

SO then I set the sensitivity to detect knock/noise at 3000 rpm and then pulled the sensitivity back and left it there...

I now run my knocksense with a range from 1500-5000 rpm at the moment.

I have recently spiked up my boost to much higher levels and the knocksense pulled back timing around 3500 rpm. I could not hear anything but I am assuming it is the first signs of knock.

SO I adjusted boost/timing and fuel accordingly until there was no indication of knock.