Aftermarket knock sensors

Oliver Sedlacek · Post by **Oliver Sedlacek** » Mon Aug 13, 2012 9:15 pm

I'm going to try adding a knock sensor to my Ford XFlow engine and I was wondering if anyone here has done it. The offerings at http://www.phormula.co.uk/ look worth a go, but has anyone tried them?

Post by **brentp** » Tue Aug 14, 2012 1:04 am

That looks fascinating. Not sure how it compares to the J&S Safeguard system: http://www.jandssafeguard.com/safeguard.html

Let us know how it goes. What is your primary goal? tuning the engine to the edge of knock threshold? Is it boosted?

Oliver Sedlacek · Post by **Oliver Sedlacek** » Tue Aug 14, 2012 7:28 pm

High speed knock is just too damaging to be worth the risk. It also lets me be braver with my tuning experiments.

Oliver Sedlacek · Post by **Oliver Sedlacek** » Sat Oct 27, 2012 2:08 pm

I can now report that I'm pretty pleased with the Phormula knock sensor kit. I fretted for quite a while about the retrofit sensor mounting, but in practice the solution was pretty obvious. There is a boss on the left hand side of the block high up and at the front of the engine. It's as close as you are likely to get to the combustion chambers, so I decided not to worry any more about whether it could hear all the cylinders. The boss has a tapped hole in it which I assumed would be 5/16" UNC but turned out to be 3/8" UNC. This was actually the biggest headache as I had to make a custom stud for the sensor, which has an 8mm hole down the middle. I turned down some 3/8" UNC studding, leaving enough thread to engage in the hole and then re-tapped the plain end to M8. This lets me screw the stud to the engine, slip the sensor over it and then clamp it down with an M8 nut.

After installation I consulted the knock frequency calculator on the Phormula website and configured the unit to a 7kHz knock frequency. A gain of 7 then seemed to give sensible numbers, and I left the alert threshold at 40. A few runs showed that the unit was flagging up knock reliably, so all in all I consider that a sucess.

damunk · Post by **damunk** » Tue Aug 26, 2014 9:38 pm

where do you install these? can you install them where the oil pressure gauges screw into the engine.

i just need an addition knock sensor. knocklight g4 looks good to me.

Oliver Sedlacek · Post by **Oliver Sedlacek** » Mon Sep 01, 2014 1:36 pm

I don't think the oil pressure sensor is a good place as it's too far from the combustion chamber.

crossflow · Post by **crossflow** » Wed Sep 10, 2014 8:07 pm

This is not from me, but
I saw some photos here:
www.lathyrus.eu

than click on:
Special tools and parts

than click on:
Knock detection circuit

damunk · Post by **damunk** » Sun Sep 14, 2014 5:42 pm

In back of my engine I have already a knock sensor connector which is wired to the ECU that was removed.

Can I use the same connector and have a knock gauge in the car?

The connector looks like the one from the above link (previous post)

Is it the case of two wires: positive and negative through shielded sound cable with 3.5 jack into amplifier microphone socket. And use normal headphones from output of microphone?

Want to do it on cheap because the project has totally skinned me so far.

crossflow · Post by **crossflow** » Tue Sep 30, 2014 9:07 pm

@ Oliver

I had a look at the site you mentioned.
There are 4 different products.
Which one have you bought and used ?

damunk · Post by **damunk** » Sun Oct 05, 2014 10:57 am

I'm going the whisper 2000 diy way. Bought one for £10 off ebay. Need some good headphones now.

http://www.autospeed.com/cms/article.html?&A=0353

I've heard knock detection units sometimes flash (indicate knock) at high rpm's where there is not a knock. So people turn down the sensitivity.

When I heard this I thought I will do it the cheap way and actually hear what noises you get while driving.

Autosport Labs

Aftermarket knock sensors

Aftermarket knock sensors

Tuning

Good results with Phormula knock sensor

Re: Where to install the knock sensro