Rogeyboy

iTrader: (2)

Made myself some today from a peice of copper pipe with a pushfit plumbing end on, a hole drilled through the pushfit end and a 6mm o/d airline hose running to an old set or ear defenders. I havn't tried them on the car yet, but when i put them against things that vibrate or make noise i can bearly hear anything... Is this right? How loud will they be in the car?

Karlos G

iTrader: (4)

This is how I made mine Rog...









If you've not used them before you have to kind of 'tune' your ear to what your hearing/listening for, you'll hear the valve train mostly and the best way I can describe Det is it sounds like someone clicking a pen on and off with their thumb, the faster you hear the clicks the worse it's detonating, this is slightly louder and higher pitched than everything else you hear.

Rogeyboy

iTrader: (2)

Good man... I think im using too small a bore hose its only 6mm and into 1ear.
How did you route the hose from under bonnet into car?

Karlos G

iTrader: (4)

I think my ID is 8mm, I take a bonnet vent out and in through the passenger window.

Rob_DOHC

iTrader: (4)

Lol, thats actually a pretty good idea!

Roger - this only adds to our argument, Orion vs. RS turbo.... instead of poping a vent out you'll have to take your bonnet off

Maybe some temp bonnet raisers so you can get the hose out the back?


Rob,

Karlos G

iTrader: (4)

Yeah it's only three screws! lol
If not I'd imagine you can squeeze it through above the battery and out, never tried it though.

series_one_rst

lokk easy enough to make i got some ear defenders as work that never get used.

wheres best to fix on the engine, back of the block??

dug112y

iTrader: (1)

i had a well known mapper up here mapping an evo once and he used and old car stereo/headphones/knock sensor bolted to block.

Karlos G

iTrader: (4)

I fix to one of the coil pack bracket bolts, have also fixed to the inlet manifold (EFI) FPR bolt I think it was.

Karlos G

iTrader: (4)

Might need some form of amplifier to do this as I think a knock sensor is just a piezo 'microphone' so would have a very low voltage signal.

Rob_DOHC

iTrader: (4)

A car radio would do that Karlos, i think the voltage output from the knock sensor would be roughly equivalent to radio signal, which a car stereo amplifies fine.

The more important part is what type of knock sensor to use. There are two types each giving very different results.

It wouldn't be ideal though, proper signal filtering makes hearing light det sooo much easier.

Rob,

Rogeyboy

iTrader: (2)

Hey Rob, theres no need for that...
I can't do that vent out malarky - mmm I'll find someway of doing it, gonna try my smaller hose again.
I bolted to an exhaust manifold stud, but i'd rather go inlet mani tbh as its a shorter length for the hose and sound to travel.

Rob_DOHC

iTrader: (4)

Knock sensor output (is a googled) 3-500mV so i take back the radio voltage comment (which is much much smaller), however a cd input on a car stereo could manage an input of 500mV i think, most amplifiers have an input sensitivity of around 0.2-2V (ish), you definitely want to be listening with head phones rather than car speakers though!

Rob,

Rob_DOHC

iTrader: (4)

Might be able to squeeze the hose through your wiring loom grommet on the bulk head?

Karlos G

iTrader: (4)

It will fit out past the headlight and then back to the passenger window, just remembered I've done that before.

Karlos G

iTrader: (4)

Yeah 100% through headphones, you need to eliminate ambient noise.

Rogeyboy

iTrader: (2)

Tried it with a shorter peice of copper tube and a shorter length of 6mm airline and it works a treat, not very loud tho and only in 1 ear but it'll do to start with!
The engine sounds very tappy from inside lol!