detonation detector

[madkaw]

Wasn't sure what forum to put this in, but I thought it was interesting to say the least. In pursuit of the perfect tune requires a lot of tools or track time it seems. I thought this would be an invaluable tool in regards to tuning-especially our engines and detonation. With a noisy valve train and my loud exhaust I am not sure I am hearing or deciphering properly detonation. I plan on making this tool to help me seperate noises and troubleshoot. I want to get the most out of my engine without hurting it(timing advance), so I would think this tool would be a no brainer. It's much cheaper then the LM1 I would love to have, and the LM1 won't detect detonation. Of all the reading I have done about our problematic #5 cylinder, I want to be sure that I am not advancing my timing to the point of damage. I am suprised I have not stumbled upon a thread of someone using this tool with all the work that has been done trying to remedy the #5 cylinder issue.

 

http://autoweb.autospeed.com/cms/title_DIY-Detonation-Detection-Part-2/A_0353/article.html

 

Love to hear some feedback on this

[azcarbum]

As much as we put into our motors, I wouldn't leave it to chance.

 

The best option in my opinion was brought to me by RTZ........... J&S SAFEGAURD KNOCK RETARD SYSTEM!

http://www.jandssafeguard.com/

 

This system is bullet proof, and in my opinion the best bang for the buck.

Basicly it senses through a single Bosch knock sensor that you can place anywhere on the block ( solid mount ). Then it senses knock on a "per Cyl. basis"..... Thats whats cool. So it know's what cylinder knocked on the last rotation of the crank. It then tailer adjust ( per your settings ) how much it will the timing for that cylinder on the second pass after the knock was detected. It does this automaticly, and will do so for every individual cylinder.

 

As much money and time we put into our motor builds, this insurance is awesome!!......... and it beats trying to set and adjust your own timing, as alot of times that just get you an expensive engine bill later!!

 

Check out the site, and read on it.

Edited August 13, 2010 by azcarbum

[madkaw]

That would be great for a fuel injected motor with an ECU, but I am just an NA guy with SU's. From what i read in articles this device is more reliable then the expensive gadgets you can buy. The experiments done showed that the human ear was more reliable in deciphering engine knock(if you know what you are hearing) then almost anything you can buy. At 30$, it is a good start to avoiding damage to your motor. To say you are taking a chance on hurting the motor by relying on your senses I think doesn't take into account that you are actually trying with this device. What's nice about a device like this is that you could diagnose or pinpoint almost any noise on your car in any place while your driving. For me it will help diagnose a rear end noise from my diff(I think it's my diff).

 

IMHO

[azcarbum]

Yesw, it is cheap, but as you said, what is it your listening too?? The J&S allows you to set its sensitivity, thus tuning out chatter from the drivetrain. I'm pretty sure you can use this with carbed motors as well... They have several different versions.

 

Anyway, each to his own, just thougth I'd throw that out there for you.

[madkaw]

I was looking for feedback and I truly appreciate it. Like i said, i was impressed to read that some tuners prefered this method over the more costly versions saying that the human ear was very good if not better in picking up the detonation. It a lot of cases you get what your pay for, I think in this example I think you can get away cheap in a trouble shooting or tuning device.

[Sam280Z]

I built one. You can really hear everything going on in the engine. I have not used it to tune with yet and therefore have not heard any knock. Right now, I'm running a pretty conservative tune.

Before I built it I found a video on youtube demonstrating what knock sounds like. It is pretty discernable.

 

I thought about the JCS unit, but in researching it there were two things that concerned me.

1) Characteristic engine sounds that must be filtered from knock sounds are different for every engine.

2) For the JCS, you should have a good timing curve to begin with. You shouldn't just max out the timing and let the JCS control the curve.

 

FWIW,

Sam

Edited August 17, 2010 by Sam280Z

[madkaw]

Sam,

you will have to update this thread if you get around to using this device to tune. I'm going to get one this week-end and try it out.

[thehelix112]

Related I guess, http://forums.hybridz.org/index.php/topic/43865-tutorial-the-best-value-detonation-detectors-on-the-planet/ (sorry the pics don't work, trying to find them to rehost) I used these to tune my car. Its very, very obvious when it is detonating, its like intermittent sharp pings (as you'd expect) when its detonating. Ran 21psi on a stock L28ET short block and GT3582R with no issues (after getting a L28ET not L28E head gasket!). I just like it as it costs basically $10 bucks and an afternoon. Plus you end up looking like an alien (got a pic of that somewhere).

 

Dave

[Sam280Z]

Will do. Should be tuning soon. I will say that with the whisperear setup, you can hear everything. You can hear just putting the keys in the ignition and the throttles turning with the key off. After you shut down, you can hear what sounds like little trolls hammering away inside the engine as the parts cool and contract at different rates. I do get a little noise from the ignition, but not a lot. Make sure you get the microphone cord from radioshack.

[RB26powered74zcar]

Those Wispers are hard to find now... I located a used, but never used one on eBay for $15.00 last week. I followed the instructions in the link posted above. It turned out great, and talk about sensitive!

 

This think will blow your ear drums if your not careful.

 

 

[Snailed]

I'm a big fan of using your brain as a signal processor for knock. Modern wideband knock sensors are very good but I know for a fact that I can "out hear" the few factory knock systems I have tested against, and those are tuned to for each specific engine (where the J&S isn't). Once you know what to listen for, it's a great way to tune out knock on whatever your particular setup is.

[rossman]

Did any of you guys end up tuning with the DIY knock detector? I'm interested to hear how well it works.

 

I went with the J&S Interceptor unit. It has a built-in audio out jack. It would be interesting to compare the two.