Roman Posted January 27, 2015 Share Posted January 27, 2015 Hahahah oh man I had a hearty LOL at this thread, worth a read: http://z4.invisionfree.com/lexusaltezzaclub/index.php?showtopic=14381&st=0 EDIT: Posted in wrong thread but you get the idea 4 Quote Link to comment Share on other sites More sharing options...
downtrail Posted January 27, 2015 Share Posted January 27, 2015 Lol wtf is wrong with people how does gearbox temp magically make it grow another cog lol Now if it made things hotter or cooler then ratios could change, though you would be talking about less than 0.08mm on diameter depending on the size of the gear and the temperature difference, (which would be absorbed by backlash in the gears). Quote Link to comment Share on other sites More sharing options...
CorollaGT Posted January 29, 2015 Share Posted January 29, 2015 Hahahah oh man I had a hearty LOL at this thread, worth a read: http://z4.invisionfree.com/lexusaltezzaclub/index.php?showtopic=14381&st=0 EDIT: Posted in wrong thread but you get the idea That's brilliant! I wonder if I put crapper oil in my gearbox I could shorten the gearing up for more acceleration? 2 Quote Link to comment Share on other sites More sharing options...
Roman Posted January 29, 2015 Share Posted January 29, 2015 The fact that he speaks so authoritatively about is what makes it funny. I'm sure some people will buy into his bullshit though. It's a pity that often there's a financial incentive for sales people to either not know what they are talking about, or just spout some bullshit that they know is false. 1 Quote Link to comment Share on other sites More sharing options...
Bangbug Posted January 29, 2015 Share Posted January 29, 2015 Lol wtf is wrong with people how does gearbox temp magically make it grow another cog lol Well you see.... the oil increases the operating temperature by 6750 degrees which you multiply by 0.0000072 (steel expansion ratio to temp) to give 0.0486 which you multiply by 4 cogs = 0.1944 * 100 = 19.4% increase in the volume of the steel gears which reduces your ratio. The idiot.... it's 19.4% not 20%, guess we can't all be perfect. 4 Quote Link to comment Share on other sites More sharing options...
downtrail Posted January 29, 2015 Share Posted January 29, 2015 I see so as temps rise the gears shrink and split into extra teeth to get a longer ratio sweet cool stuff lol. Wish i had a variable 5 cog gearbox lol Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted January 30, 2015 Share Posted January 30, 2015 Hahahahahaha. Everyone is so polite in that thread. David do u have a registration there? Please invite him to oldschool Quote Link to comment Share on other sites More sharing options...
Roman Posted February 1, 2015 Share Posted February 1, 2015 Nah that post was a year old, so hopefully come to his senses since then. Hey question/ramble, people... I'm looking to calibrate some sensors. Initally an air temp sensor, water temp sensor, and a MAP sensor. They're currently 'good enough' but I want them to be more accurate. I just need a two point reading for each, at each end of the scale more or less. What's the easiest way I would be able to go about this? Finding current atmospheric pressure is easy, as I just read the kpa output on the ECU's Barometric pressure sensor and then measure voltage output from the map sensor. But I'm wanting to accurately generate a given amount of vaccum at the other end of the scale. Need a magnehelic gauge I guess? For the temperature sensors I'm thinking that perhaps a thermometer will do the trick, and then put the water sensor in hot water and watch it as it cools. And for the air temp sensors, make a box that I can heat up or cool down (blow a hair dryer in, or put it in the fridge) that the thermometer is in too.Anyone got any better ideas than as per above?I'd like to calibrate the MAF sensor too, but I think that's in the too hard basket. Another thing is.... Hmmm if I wind my window down and the internal pressure of the car changes... Is the ECU going to adjust fuel slightly or not. Heh. Quote Link to comment Share on other sites More sharing options...
eke_zetec_RWD Posted February 1, 2015 Share Posted February 1, 2015 Another thing is.... Hmmm if I wind my window down and the internal pressure of the car changes... Is the ECU going to adjust fuel slightly or not. Heh. Lol that's awsome! 2 Quote Link to comment Share on other sites More sharing options...
downtrail Posted February 1, 2015 Share Posted February 1, 2015 Temp sensors air and water easy way to do is to put under your arm with a thermometer untill resistance stabilizes then take readings for one point. Then hang in freezer and read 2nd point etc. Map sensor youll need a decient vaccum gauge teed into it then check with motor running what its output voltage is at given point then use atmosphere preasure as your 2nd point. 1 Quote Link to comment Share on other sites More sharing options...
Testament Posted February 2, 2015 Share Posted February 2, 2015 Water temp put it in a pot of boiling water, 100deg c at 101.3kpa 1 Quote Link to comment Share on other sites More sharing options...
cute wee gem Posted February 2, 2015 Share Posted February 2, 2015 ^^ just make sure the kitchen window is closed as it may give inaccurate readings 3 Quote Link to comment Share on other sites More sharing options...
Roman Posted February 2, 2015 Share Posted February 2, 2015 In my car with windows up it goes from 101.7kpa when the car is still, to 101kpa at top speed on the straight.How much difference does this make in my case? fuck all, but its adjusting values in the opposite way it should. As air inlet would get slightly higher pressure at speed not lower. If you've ever been in an open seater where the airflow is trying to lift your helmet off... Could make enough of a difference to put off your tune a little bit perhaps.Ill do a trackday with windows down and see if my engine explodes haha Quote Link to comment Share on other sites More sharing options...
peteretep Posted February 2, 2015 Share Posted February 2, 2015 im getting an inlet backfire at most startups, what would cause this? Quote Link to comment Share on other sites More sharing options...
Roman Posted February 2, 2015 Share Posted February 2, 2015 Does it do an injector test fire when ECU is first turned on? If you've got wasted spark and there's fuel in the 'other' cylinder then it could bang out the intake perhaps if you've got lots of cam overlap. Quote Link to comment Share on other sites More sharing options...
peteretep Posted February 2, 2015 Share Posted February 2, 2015 I dont think it does a test fire. does running lean at start make it backfire? maybe I need to let the pump prime for the full time before cranking. I did notice that pressure drops away instantly as soon as the pump is turned off, not sure if this is correct or not though Quote Link to comment Share on other sites More sharing options...
Yowzer Posted February 2, 2015 Share Posted February 2, 2015 Yeap racecar at work would do that due to wasted spark and overlap. Retarding the timing on cranking lessened it a fair bit so give that a try. Also yeah being too lean on cranking meant heaps of backfires. Maxed out the cold crank enrichment and was also better. So try two things. Quote Link to comment Share on other sites More sharing options...
Yowzer Posted February 2, 2015 Share Posted February 2, 2015 It should maintain pressure for awhile with the pump off quite happily if your pressure regulator is working properly. I don't think it should be able to flow backwards through the pump, but then I suppose different pumps behave in different ways Quote Link to comment Share on other sites More sharing options...
downtrail Posted February 2, 2015 Share Posted February 2, 2015 im getting an inlet backfire at most startups, what would cause this? If its megasquirt then mostlikely a lost sync during cranking will cause this mainly due to volt drop whilst cranking. That or cranking advance set too high. Itll read advance from cranking settings not your table if youve set up like this. If not then set up cranking advance to lower than what the advance is set to on your table whilst cranking. Could be that or at say 500rpm 60-100 kpa on your advance table is set too high. But most likely a sync loss. 1 Quote Link to comment Share on other sites More sharing options...
Testament Posted February 2, 2015 Share Posted February 2, 2015 Megasquirt fires the coils when you turn the ecu on as part of powering them up. So Leaky injector maybe, or just residual fuel from rich idle at shutdown. Quote Link to comment Share on other sites More sharing options...
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