DIY knock detection, how?

[jaycos]

eliot the fart noise is the det yes

[eliot]

jaycos said:

eliot the fart noise is the det yes

Crikey, dont think you need a microphone to hear that!

[boosted Ls1]

I built the autospeed version and as Stevie says, it picks up everything. No way could I drive around for ages with earphones. It made the engine sound like a scrapper. When I connected it to some speakers instead of the headphones it was more beareable. It's a good iiagnostic tool though

Boosted.

[jaycos]

just brought this chaps . also going to wire it to my logger to show det hopefully

www.thor-racing.co.uk/KNOCK_BLOCK_-LNK_KNKB.asp

[stevieturbo]

Good stuff....let us know how it fairs.

Ive heard good reports about it from a couple of the Subaru guys.

[kickslop]

Greetings from the US.

Here's a $115us option.
www.turboxs.com/more_info.php?ID=212

And far from DIY:
www.turboxs.com/more_info.php?ID=196
www.jandssafeguard.com/

If you ask me, visual indicators are NOT enough (as someone's reiterated here in this thread already). Something with an audio jack is a must.

[stevieturbo]

The tuner pro stuff looks nice....

Would be better with some pics to give an idea of size of display etc.

[nicecupoftea]

Just found this - guys, 80s Saab Turbos had an APC system that controlled boost based on knock. It's an analogue system that is easily adjusted and independant of timing / fuelling, so can be (and has been) easily adapted for your own needs. Even if you don't use it to control boost it will detect knock (one of its pins drops to earth when knock is detected) and they can be picked up on ebay for 15 quid or so.

Got to be a cheap way of doing things....

Good write up on this site:

www.900aero.com/

Go to "tech" and then "APC Theory"

Edited by nicecupoftea on Tuesday 2nd January 10:28

[jaycos]

ive tested my knock box and yes it works .The earphones were crapi had to buy a stero set and looking at it through the data logger was strange as the graph climbs up withthe revsbut u can see a spike here and there . I have maneged to get 19 degree at 2 bar on a t34 ,im now on a emerald k3 ecu and the cars been off the road for 7 months as ive been adding more stuff to it so i do apologise for the very late reply folks

[stevieturbo]

I bought one myself...havent fitted it yet though.

Need to get it hooked up to log the 0-5v as well.

[Herman Toothrot]

stevieturbo said:

I bought one myself...havent fitted it yet though.

Need to get it hooked up to log the 0-5v as well.

Are you talking about the LINK knock block? Thinking of trying one, but want to know it works, a friend said he'd hook up his knock box http://www.theknockbox.com.au/content/view/5/5/ to check it out but that would involve me buying the knock block before knowing if its anygood.

[stevieturbo]

Ive heard good reports about the knockbox, and it does look like a nice piece of kit. Tad pricey though.

I have bought the Link Knock Block, but it has only made it from the house, to the floor of my car in the garage.
From what I understand, the audible section of it is quite good, although the 0-5v logging bit, isnt quite as good. Often displaying spikes, when perhaps there isnt detonation.

I imagine it will take a lot of fine tuning though, for you to interpret what is, or isnt detonation when logging.