Just wondering what my options are for knock detection il be planning to use the megasquirt standalone ecu.
is there a self build guide for det cans?
i read something about using a microphone and something about using a bosch sensor instead is there a guide somewhere?

 

for hearing knock im using a home made det can... and for det controll im using a standalone ecu but i dont know how well it all works cause i still have to get the car running lol... i had the det can on the motor when it ran and it works awesome! i could hear everything in the motor i recomend everyone to build one... im planing on making a "how-to" vid and posing it on youtube but i dont know if i feel like it lol...

 

For the lazy: I have 10 sets of electronic detcans sitting on my desk just waiting for final assembly (Now with battery holders and power buttons!!!). I'm also starting to a PNP knock input for MS1/2 with RPM based filtering ala TXS knocklite which will be taking priority as soon as I get my BMW finished up.

 

You mean 9 cough cough.

 

From what I understand, if you can't program a sample period prior to ignition event, then there is no point in spending a cent on knock control. For this reason I run lots less spark angle than maximum and my car still runs with no issues.

 

+






just kidding, i'd never hear it over the exhaust. i just guess and/or borrow other people's spark maps. i'm running lower compression than everyone here which helps

 

Meth, **** loads of meth.

 

ok Jeff il take a set off your hands! you have pm.

 

J&S Ultra Safeguard
('cos I have stock ECU and base Powercard)

http://www.jandssafeguard.com/safeguard.html

 

Det cans are king. If you run it through the ECU you must have frequency filtering and 2D noise filtering based on RPM in order to have any faith in it at all. Tune it conservative and fat, listen to the det cans, and check the plugs every 500 miles for pepper until you know it's not pinging. Set it up to pull timing in hot weather (high CLT/IAT).

 

Knock detection that alters your injection angle is fail as ****.

 

I thought J&S was spark control.

From http://www.jandssafeguard.com/tech.html

"Spark retard, within limits is the most powerful means of controlling detonation." and
"J&S Electronics has developed the SafeGuard which uses a knock sensor to provide feedback to it's microprocessor which, in turn, controls the timing for each cylinder on an individual, optimized basis." and
"the J&S SafeGurad can be set for up to 20 degrees of ignition retard."

Am I reading this wrong?

 

Not as fail as your reading comprehension I can't find anywhere on that site where it states the injection angle is altered.

Ignition yeah, but then that's a given surely

OP I quite like the KnockLite from TurboXS, I've tried the KnockSense and as it has zero rpm sensitivity you either end up with no detection or a shitload of false knock (confirmed with electronic detcans). YMMV in this case, but I definately prefer the KL.

KL also has an output wich is pretty easy to plumb into a MegaSquirt, this will give you a rudimentary amount of automatic knock retard. You won't get any advanced windowing ect, but for the price and installation effort required, it's a nice to have as a failsafe when on track etc.

 

The J&S alters the signal from the crank position sensor to do its job. If it controlled your coils directly it would be a different story.

 

Never mind, I looks like it can be wired into the coils directly.

 

I was under the same impression that aricjm was - the J&S intercepted the trigger signal and altered the spark angle -> fed to the ECU to trigger the coils. This would also alter the injection angle. After looking at their documentation though, that doesn't seem to be the case. I could have sworn that they had a version that did that at one point though...

FWIW- My reading comprehension is fine. Perhaps the guy who spells like **** shouldn't lecture

I stand corrected.

 

I apologise unreservedly for the typo's which missed out a 'h' in which and got the letters the wrong way around in 'etc'.

I never seem manage to spell, 'definitely' correct

 

Its all good man.

 

I bought a j&s for my Protege build before some asshat wrote off my car. It was very easy to setup and gave me confidence to play with the timing a bit while street tuning. It would also probably save your engine if your tuned for meth and ran her dry.

 

Here it is and works like a champ. I was able to detect the slightest knock, but nothing would have saved me from a oil pump failure, besides listening to others to remove the almuninum crank pulley.

http://autospeed.com/cms/A_0353/article.html



The picture above shows the unit from the website. The one that follows is the one I made with improvements.

- The wire coming from the alligator clamp is routed through the firewall and somewhere under the dash or glove compartment. The good thing about mine is it looks like a mp3 plug. The amplifier can be disconnected and stored, and the alligator clamp is strong enough to stay permanently on the engine bay or lets say for long periods of long time.



The alligator clamp is connected on the electronic oil sensor. Try to place is far or out of the radiator fan airflow.

http://autospeed.com/cms/article.html?&A=0348

If you dont like reading, at least review the conclusion of the link above...