downtrail Posted January 24, 2015 Share Posted January 24, 2015 Bosch make em. I have a simmiler setup but its a small mike in a cable lug. Use laptop as amp and a program called audicity to play though to headphones. As for the mazda sensor itll connect to either the factory ecu this will have its convertor thing in it or a knock unit thatll proces it then output to factory ecu. 1 Quote Link to comment Share on other sites More sharing options...
kpr Posted January 24, 2015 Share Posted January 24, 2015 2 wire will be better. as can isolate from ground. i run my amp of a 9v battery, as got alternator noise when powering off the car. best explanation ive heard re what knock sounds like, is someone flicking a sheet of tinfoil warped over top of a jam jar. some cars with noisy valvetrain can make it harder to hear, but usually comes over louder than everything else. when getting on the very edge of knock usually only here 1 or 2 ticks over the whole rev range. most likely to happen at max torque. when checking for knock engine needs to have as much as possible load on it. 1st and 2nd gear may not knock but higher gears will. loading engine up with the brakes works well, if you are doing it on the road and like your license 2 Quote Link to comment Share on other sites More sharing options...
Roman Posted January 24, 2015 Share Posted January 24, 2015 There are narrowband and wideband knock sensors. Most factory knock sensors are filtered to just hear the frequency of knock for that type of engine. But GM knock sensors pick up everything and then filter with software in ecu. So factory knock sensor is fine so long as you havent changed the bore or stroke. Theyarent 0-5v but output a higher voltage higher knock vibrations get. Think they output about 1 volt or 2 volts max? Quote Link to comment Share on other sites More sharing options...
kpr Posted January 24, 2015 Share Posted January 24, 2015 in millivolt range i would think. use shielded cable another option is detcans. which is some pipe and tube and earmuffs. no mic's or amps. Quote Link to comment Share on other sites More sharing options...
yoeddynz Posted January 25, 2015 Author Share Posted January 25, 2015 Yeah I've heard of using det cans and earmuffs. Not so tidy... but effective yeah? I'll double check the knock sensors. It might be that they have two wires. In other news I bought and fitted a new wideband sensor and all is happy again. I have pretty numbers to watch. 1 Quote Link to comment Share on other sites More sharing options...
kpr Posted January 25, 2015 Share Posted January 25, 2015 haven't used detcans myself. but guessing volume control maybe an issue Quote Link to comment Share on other sites More sharing options...
downtrail Posted January 25, 2015 Share Posted January 25, 2015 Neither but oldman used to have a doctors stethoscope thing with the tube extended to a lump of copper that he could bolt places for this pourpose He reckoned it worked fine in the 80s lol 2 Quote Link to comment Share on other sites More sharing options...
Roman Posted January 25, 2015 Share Posted January 25, 2015 Ahhh so back to the VVTI thing. I wired up the MAF Sensor so I could log its output voltage to help tune cam angles. Then did a run at 12 degrees VVTI (minimum) then 20 degrees, 30 degrees, 40 degrees. If the MAF sensor voltage goes UP at a given rpm it's stuffing more air in so that's probably the best setting. Turned out a little bit different to the basemap, maybe because of my extractors/head being a little different at a guess. Plotted a graph, because graphs are awesome: So full 40 degrees advance from 3000rpm, backing it off to 20 degrees, then back down to 12 degrees by 6000rpm onwards. Interesting to see that the 'VVTI still on' curve kinda matches the engine's MAF curve on the standard ECU. But fully retarded cam position is still ingesting the maximum amount of air right to 8000rpm. The MAP sensor shows that the KPA values drop a few below 100 from 6,000rpm onwards so if I freed up the intake a bit ahead of the throttle body it looks like it would doort pretty awesomely to 8000rpm or more. 3 Quote Link to comment Share on other sites More sharing options...
kempy Posted January 25, 2015 Share Posted January 25, 2015 A novice question here as a mate was talking about sticking one of those electric blowers onto his Mitsubishi Lancer (1.4L standard thingy) for fun and I suggested he should check it out before he goes ahead and does it. Question being: does the EFI automatically adjust for different air input pressure such as a few pounds boost or does the mapping cater for a generally fixed environment with some slight adjustments for cold/hot/knocking etc. expecting that it would probably lean it out far too much? Cheers K. Quote Link to comment Share on other sites More sharing options...
downtrail Posted January 26, 2015 Share Posted January 26, 2015 Tell him to buy a bag of chips a lolly pop an ice cream and some beers. Rent a movie and watch it insted of wasting his time. 6 Quote Link to comment Share on other sites More sharing options...
kempy Posted January 26, 2015 Share Posted January 26, 2015 I more or less said that, not quite so eloquently. Quote Link to comment Share on other sites More sharing options...
downtrail Posted January 26, 2015 Share Posted January 26, 2015 Lol those mitey car mods dudes tried one made less power from memory. Then they tried 3 leaf blowers with like a 1hp gain lol Quote Link to comment Share on other sites More sharing options...
Testament Posted January 26, 2015 Share Posted January 26, 2015 Yeah roadkill also did it, they needed 20hp or so of petrol leaf blowers (no surprise really) to get any benefit on SBC powered Monza Basically its a waste of time. Quote Link to comment Share on other sites More sharing options...
Yowzer Posted January 26, 2015 Share Posted January 26, 2015 If it's something like this it'd do more than nothing, but if it's one of those inline fan things then nah Edit: Damn that's a big pic Quote Link to comment Share on other sites More sharing options...
Testament Posted January 26, 2015 Share Posted January 26, 2015 anythings possible. whether its worthwhile or not is another story. Quote Link to comment Share on other sites More sharing options...
Yowzer Posted January 26, 2015 Share Posted January 26, 2015 This lol'd me 5 Quote Link to comment Share on other sites More sharing options...
sentra Posted January 26, 2015 Share Posted January 26, 2015 what is the backstory to that photo? Quote Link to comment Share on other sites More sharing options...
Popular Post kyteler Posted January 26, 2015 Popular Post Share Posted January 26, 2015 what is the backstory to that photo? Johnny spent his afternoons and indeed the majority of his days pondering his existence and how he could become part of the community, not just his local community, but a global community. On a somewhat grey and cloudy day, he found himself wandering down the street near to where he lived, bound for the local convenience store to grab perhaps a baked pastry good. He'd not made his mind up yet whether that good was to be of a sausage roll variety or perhaps something a little more filling in the realms of piedom. This aside, Johnny walked down the street, each footstep on solid ashphalt more laborious than the last, Johnny wan't too enthused by walking, nor by pastry. He pondered whether he needed to make the journey at all. He did not. Yet, onwards Johnny went. As he approached the store he saw a couple of local ruffians and though normally they would give Johnny a hard time they seemed somewhat pre-occupied with a snail upon the roughcast wall of the dairy storefront. This as it was, Johnny managed to slink into the dairy relatively un-noticed. He perused the pie warmer for his delicatessan treat only to be fronted with a sign taped to the right hand door of the warmer that read "Get fucked, Johnny. Go take a photo of some starter motors connected to a blower on an SR20" ...and that's just what Johnny did. Just what he did, Dave, just what he did. 14 Quote Link to comment Share on other sites More sharing options...
kempy Posted January 26, 2015 Share Posted January 26, 2015 Thought it was a waste of time but I never realised how much delivery rate was required to get any gains. Great pleasure in delivering the news though Quote Link to comment Share on other sites More sharing options...
yoeddynz Posted January 27, 2015 Author Share Posted January 27, 2015 Did Johnny ever get a pie in the end? Or did the other dave eat them all.. 1 Quote Link to comment Share on other sites More sharing options...
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