Peter Cobbold Posted June 23, 2011 Report Share Posted June 23, 2011 This cheap DIY approach to detecting detonation by listening to it appeals to me: http://www.autospeed.com/cms/article.html?&A=0353 But where is the best place to position the microphone on the TR6 head? (or block ?) Anyone had any experience of using proper kit? perhaps on rolling road? Quote Link to post Share on other sites
littlejim Posted June 24, 2011 Report Share Posted June 24, 2011 Did one years ago on the Camry (circuit from an electronics magazine) because the pinging was right in my hearing loss. The electronics fired a buzzer and light in the cabin which I could hear (and see). Because of my propensity to to make it slug I was ordered to take it out after a couple of days by she who rides shotgun. Anywhere on the head should be OK the metal conducts the sound pretty well. Quote Link to post Share on other sites
Guest ntc Posted June 24, 2011 Report Share Posted June 24, 2011 (edited) This cheap DIY approach to detecting detonation by listening to it appeals to me: http://www.autospeed.com/cms/article.html?&A=0353 But where is the best place to position the microphone on the TR6 head? (or block ?) Anyone had any experience of using proper kit? perhaps on rolling road? Peter The RR man I use always has a stethoscope on hand used on the first run Edited June 24, 2011 by ntc Quote Link to post Share on other sites
Peter Cobbold Posted June 24, 2011 Author Report Share Posted June 24, 2011 Peter The RR man I use always has a stethoscope on hand used on the first run Neil, Been searching for more DIY info and found mention of 'det-cans' - no electronics just a rubber hose plugged into ear protectors at one end and a metal pipe bolted to block at engine end: a 'stethoscope' for use on the road. All it will need is the TRR logo on the ear pads to look the business. On second thoughts bit of a boring sound-track. Peter Quote Link to post Share on other sites
Peter Cobbold Posted June 24, 2011 Author Report Share Posted June 24, 2011 Did one years ago on the Camry (circuit from an electronics magazine) because the pinging was right in my hearing loss. The electronics fired a buzzer and light in the cabin which I could hear (and see). Because of my propensity to to make it slug I was ordered to take it out after a couple of days by she who rides shotgun. Anywhere on the head should be OK the metal conducts the sound pretty well. Its triggering the warning light/buzzer that seems to be the DIY stumbling block owing to different frequencies of knock for different size cylinders. Human ear reckoned to be a much more discriminatory filter than electronics. (No mention of human ears with higher frequency cut-offs like mine.) I'm going to use hearing aid/earplug approach connected to knock sensor. And passenger can have a job to do as she is nbg with maps. Peter Quote Link to post Share on other sites
Denis Posted June 24, 2011 Report Share Posted June 24, 2011 I'd rather stick Cotton wool in me ears! Quote Link to post Share on other sites
rogerguzzi Posted June 24, 2011 Report Share Posted June 24, 2011 (edited) Hello All How about this to modify? http://cgi.ebay.co.uk/Hearing-Aid-Loud-Clear-Personal-Voice-Sound-Amplifier-/310272709793?pt=UK_Health_Beauty_Mobility_Disability_Medical_ET&hash=item483db1d4a1 I might give it a go having trouble setting my Spitfire(sorry)at the best point(I do have a TR2 awaiting a rub over with an oily rag which I have owned for 41 years) Roger ps or this one http://cgi.ebay.co.uk/Sound-Amplifier-Hearing-Aid-Listening-Gadget-/260791508457?pt=UK_Gadgets&hash=item3cb8629de9 Edited June 24, 2011 by rogerguzzi Quote Link to post Share on other sites
Tony Millward Posted June 25, 2011 Report Share Posted June 25, 2011 I remember reading an article regarding 'knock detection' and it recommended using Piezo buzzers wired as a microphone. These work in the same frequency range as the 'Knock'. Unfortunately, I can't remember where I saw this article. Cheers Tony Quote Link to post Share on other sites
smizgals Posted June 25, 2011 Report Share Posted June 25, 2011 This cheap DIY approach to detecting detonation by listening to it appeals to me: http://www.autospeed.com/cms/article.html?&A=0353 But where is the best place to position the microphone on the TR6 head? (or block ?) Anyone had any experience of using proper kit? perhaps on rolling road? http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=270763410103 looks like a candidate for conversion. Quote Link to post Share on other sites
alan atkinson Posted June 25, 2011 Report Share Posted June 25, 2011 Don't have practical experience using it, but I'm given to understand the knock characteristics of a Volvo are such that the frequencies are similar to that of those in the TR and the sensors should be cross swappable. I was looking to use one with an MS system. Take it for what it cost, but I would love to see one fitted and working. Quote Link to post Share on other sites
Peter Cobbold Posted June 25, 2011 Author Report Share Posted June 25, 2011 I remember reading an article regarding 'knock detection' and it recommended using Piezo buzzers wired as a microphone. These work in the same frequency range as the 'Knock'. Unfortunately, I can't remember where I saw this article. Cheers Tony Tony Ah yes - neat. I'll chase it up. Peter Quote Link to post Share on other sites
Peter Cobbold Posted June 25, 2011 Author Report Share Posted June 25, 2011 Don't have practical experience using it, but I'm given to understand the knock characteristics of a Volvo are such that the frequencies are similar to that of those in the TR and the sensors should be cross swappable. I was looking to use one with an MS system. Take it for what it cost, but I would love to see one fitted and working. Alan, From what I've read knock frequency is somewhat engine specific and the sensors ( piezoelectric) are tuned to specific engines, eg: http://www.performanceforums.com/forums/archive/index.php/t-67156880.html If someone has recorded data of TR 2.5 litre engine knocking frequency that would be a valuable first step in finding an appropriate sensor. My guess is knock charactrisitcs will be determined to some extent by the shape of the combustion chamber, so focus on centre plug/bathtub heads - whats the Volvo's? Peter Quote Link to post Share on other sites
Peter Cobbold Posted June 25, 2011 Author Report Share Posted June 25, 2011 (edited) Here are audio recordings of knock in TR6 engine: http://www.turbo-tr6.info/knock.htm (I can only juts hear the higher frequency tinkling- my age!) The blue graphs (FFT means 'fast Fourier transforms) show knocking at 6.8 and 9 kHz. So those are the frequency we need the piezosensor(s) tuned to. And here is a sensor off a 1988Toyota that resonates at about 6.8kHz: http://deviantmethods.com/bigmoose/pages/knock.htm - so thats the sort of info we need. More Toyota resonant 7kHz knock sensor info on page7 here: http://www.toyotapartsandservice.com/pub/pdf/TechCenterLibrary/ToyotaStarServiceNews/2004/2004_TSSN_Fall.pdf Anyone know which UK Toyota engines have/had the 7kHz sensor we need? Edited June 25, 2011 by Peter Cobbold Quote Link to post Share on other sites
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