eke_zetec_RWD Posted January 21, 2015 Share Posted January 21, 2015 I'll PM keltik but in the meanwhile, I'm wondering where to obtain a solenoid valve for this purpose and how large should/would I go on my 2L 4 banger. Also have the option for stepper motor control so would love it if anyone has any plans/info on either of these options. Many thanks. Oh and if none of that makes sense, it's regarding Idle Control with a TB bypass. Solenoid or stepper motor and sizing. I used a valve from a 1990s 320 BMW, it's 2 wire and just has like 16mm Hose in and out. Works a treat. 2 Quote Link to comment Share on other sites More sharing options...
0R10N Posted January 22, 2015 Share Posted January 22, 2015 So what is the OS consensus on safe cruise AFRs for turbo vehicles? After a few sessions of road tuning the TX3 on my own, it now hovers between 13.2-13.4 at motorway speed/3200rpm in 5th, but it's dipping into the 14s very briefly when I open the throttle to accelerate (I have tweaked the AE but perhaps more compensation may be needed). Quote Link to comment Share on other sites More sharing options...
slacker.cam Posted January 22, 2015 Share Posted January 22, 2015 You can go way more lean during low load cruise. 15-16 sort of range. 1 Quote Link to comment Share on other sites More sharing options...
mjrstar Posted January 22, 2015 Share Posted January 22, 2015 13's is a total waste of fuels, but hey it's cheap at the moment, I aim for mid 15's but in really light throttle leaner than that doesn't get my heart racing. Quote Link to comment Share on other sites More sharing options...
Testament Posted January 22, 2015 Share Posted January 22, 2015 Don't fret over instantaneous numbers high or low when stabbing the throttle, tune AE by getting it so it runs best acceleration wise. At steady state cruise below 80kpa around 15:1 or leaner if it still runs OK Quote Link to comment Share on other sites More sharing options...
0R10N Posted January 22, 2015 Share Posted January 22, 2015 Cool, thanks guys. Sounds like I can safely pull a bit more fuel out of the total map then. I retarded the timing 2 degrees after last Sunday's scorcher because it started to feel wrong when accelerating even though the AFRs were in the 11s. Sort of wish I had a knock link or similar. Quote Link to comment Share on other sites More sharing options...
eke_zetec_RWD Posted January 22, 2015 Share Posted January 22, 2015 At cruise just go as lean as you can before it stops 3 Quote Link to comment Share on other sites More sharing options...
Bangbug Posted January 22, 2015 Share Posted January 22, 2015 Well apparently 16.1 - 16.5 is the best ratio for economy. Just not so good for NOx production I'm going to be doing this shortly. I agree, having knock detection would be great I'm just going to set the closed loop to running and listen Quote Link to comment Share on other sites More sharing options...
downtrail Posted January 23, 2015 Share Posted January 23, 2015 Its all motor dependent some will behave well at cruise in the mid 15's some won't. also depends on your cam and if theres large overlap its'll be reading aftifically rich as some of the mixture escapes before the exhaust valves close. dosn't mean its acutally rich but it you try to tune it out it'll be extra lean and probably stumble and fart around. I normally go for 14.7 -15 at cruise on most motors creates a clean burn plugs last a little longer and you know your on the money. There is no easy way to listen for knock. knock sensors are good but some are slower than others and some are super sensitive and theres also a bit of false knock to watch out for. theres also a diffrent frequency for diffrent sized motors diffrent strokes no of cylinders so there is no simple sensor than can incorporate this all for you unless its oe equipement but then again slow. Most effictive method is to physically listin to the motor know what your listing for and know how to combat it with the data you are collecting. understand why it happens and what its doing. you can see it start on a dyno. as you add timing at say half a degree at a time at a certin load point you'll see torque incress as soon as it starts to not incress enough its getting close to the knock threshold. 5 Quote Link to comment Share on other sites More sharing options...
Yowzer Posted January 23, 2015 Share Posted January 23, 2015 Overlapped valves make it appear lean as 02 sensors measure oxygen, not hydrocarbons so they give zero fucks about unburnt fuel in the exhaust. A missfire will appear lean, which is fun when it's misfiring due to over fueling. Quote Link to comment Share on other sites More sharing options...
eke_zetec_RWD Posted January 23, 2015 Share Posted January 23, 2015 Overlapped valves make it appear lean as 02 sensors measure oxygen, not hydrocarbons so they give zero fucks about unburnt fuel in the exhaust. A missfire will appear lean, which is fun when it's misfiring due to over fueling. This man speaks the truth Quote Link to comment Share on other sites More sharing options...
downtrail Posted January 23, 2015 Share Posted January 23, 2015 Yeah sorry lean extra air duh lol. But anyway you get the point the afr is a guide to go off but theres no set in stone method of what number is universally correct. Many other factors including egt and actually watching your torque incress untill it wont any longer is going to net the specific setup its best performance. Fuel is only there to control the egt the response and power is made else where. Quote Link to comment Share on other sites More sharing options...
japawagons Posted January 23, 2015 Share Posted January 23, 2015 I want to believe what your saying... But do you mean increase?? not incress... Kinda throws everything else out the window... Quote Link to comment Share on other sites More sharing options...
Roman Posted January 23, 2015 Share Posted January 23, 2015 A typo is just a typo man. But yeah this topic is relevant to my interests because I'm trying to figure out how the VVTI is going to be setup best on my engine. From the basemap it basically turns on at about 3500rpm, advances a shitload (40 degrees) by 4000rpm and then tapers off slowly to 6500rpm where it turns off again. I dont think there's any meaningful way I can measure whether advancing or retarding the cam more or less helps or hinders. I think 4,000rpm or 4500rpm is the rpm range where my intake runner lengths are working 'against' airflow, my fuel map is all up the shit at this RPM range! Smooths out nicely either side, but a big dip in fuel for a given KPA at that range even when VVTI is off. For figuring out best VVTI setting I cant go off the AFRs as a measure of anything. As if I add lots of cam overlap then unburnt air/fuel goes out the exhaust so it shows as leaner than it actually is, rather than being indicative of more air ending up in the cylinder. I remember someone saying that you need to get the exhaust manifold you plan to use sorted before you worry about the intake. This never made sense to me but I see why when you think about cam overlap. The tuned rpm of the exhaust runner length means you're either going to get a high pressure reflected wave arriving during overlap (which tries to prevent exhaust gas from exiting the engine) or a low pressure wave arriving (Yanks exhaust gas out, and pulls some intake in, with some going straight through while being unburnt) So it looks as though matching the resonant frequenies etc of both intake and exhaust (or making sure they offset from each other?) is part of getting some good zing out of an NA car. VVTI on the inlet side means I can shift the cam around to avoid the negative parts of high overlap (and resonance of intake runners) and benefit from the good bits. Dyno is only good option I think. Same kinda goes for ignition, I dont really know how to road tune it apart from creeping timing towards knock.But that might already be well past best torque. Either way I'll be taking my basemap ignition settings and fuel map I've sussed over the last few nights to Hampton on Monday, will see if it results in an inrease of speed on the back straight or not! 1 Quote Link to comment Share on other sites More sharing options...
kpr Posted January 23, 2015 Share Posted January 23, 2015 Its all motor dependent some will behave well at cruise in the mid 15's some won't. also depends on your cam and if theres large overlap its'll be reading aftifically rich as some of the mixture escapes before the exhaust valves close. dosn't mean its acutally rich but it you try to tune it out it'll be extra lean and probably stumble and fart around. I normally go for 14.7 -15 at cruise on most motors creates a clean burn plugs last a little longer and you know your on the money. There is no easy way to listen for knock. knock sensors are good but some are slower than others and some are super sensitive and theres also a bit of false knock to watch out for. theres also a diffrent frequency for diffrent sized motors diffrent strokes no of cylinders so there is no simple sensor than can incorporate this all for you unless its oe equipement but then again slow. Most effictive method is to physically listin to the motor know what your listing for and know how to combat it with the data you are collecting. understand why it happens and what its doing. you can see it start on a dyno. as you add timing at say half a degree at a time at a certin load point you'll see torque incress as soon as it starts to not incress enough its getting close to the knock threshold. you need a listening device to know if there is knock when tuning. anything else is just guessing. there is decent knock control out there, but only good for after the engine is tuned. engines can knock and carry on making more power. If you get to the point there are no gains in power from ignition advance, with no knock. that is best timing. doesn't mean its close to knock. you want to use minimum timing for best power. eg; if 25 degrees makes the same power as 30 degrees, set timing to 25 degrees. now if power is still climbing and runs into knock before you get to minimum best timing. you haven't reached your best timing and engine is octane limited. this will happen a lot of turbo engines running a decent amount of boost on pump gas. from here there are many options. without revising who engine setup, either; *Throw some better gas in the tank. keep advancing timing * On turbo engine, find the best compromise between ignition advance and boost * na engine can mess with the cam timing so engine makes more power at high rpm and less likely to knock in midrange ^ im talking full load stuff here 15's is usually good for most stuff at cruise. will feel power drop fairly quick if you go too far. no drama's running engine lean at cruise. will even run cooler. but no good for emissions if you care. need to find the compromise that works best if you care about every last drop of fuel. but somewhere 15-15.5 is usually a good starting point 3 Quote Link to comment Share on other sites More sharing options...
Roman Posted January 23, 2015 Share Posted January 23, 2015 Ahhh I just realised two things that might help my situation... I've still got the MAF sensor plugged in, has power just not a signal back to new ECU. Could plug that in and monitor its output voltage to see if VVTI changes mean more air consumed or just that there's overlap stuffing unburnt air out the exhaust. Hey KPR I've heard of the idea of just using an amplifier on the knock sensor signal then using that with headphones to listen to knock. Seem an alright idea? Isnt that effectively what the knock block thing does. Otherwise I've been thinking I could wire the knock sensor into the ECU and just datalog its output voltage. Might be a bit useless compared to the knock sensing add on though which is a lot more sophisticated. Quote Link to comment Share on other sites More sharing options...
kpr Posted January 23, 2015 Share Posted January 23, 2015 I don't think the overlap is going to effect the afr as much as people say. sure it will but should be able to use it, to compare to a point. when we had the starlet on the dyno with the 300degree cams. we advanced the cam timing on the inlet, increasing overlap. the afr went from 13 to 14afr and gained around 5kw. which was about 5% increase in power. 13-14 afr is about 10% more fuel. the numbers don't add up, and will likely get worse if you go too far. but indication going in right direction, do a run with vvt off, then do another run with vvt full on, the overlay the afr. if the vvt off run is leaner at very low rpm and high rpm. and the vvt full on run is leaner though midrange. may give you something to work from. a lot of dyno time is the only way you will get it spot on though Quote Link to comment Share on other sites More sharing options...
kpr Posted January 23, 2015 Share Posted January 23, 2015 gah replying at the the same time again haha yes your maf should be useful for that. do the afr thing and setup link to log maf as well, should give you some good data to compare yup thats what i used to listen for knock. just have a dounut style knock sensor hooked up to to a small amp and headphones. knock sensor is just a microphone don't bother logging it, you really need to listen in real time so you can back out of it if there is knock 1 Quote Link to comment Share on other sites More sharing options...
cute wee gem Posted January 24, 2015 Share Posted January 24, 2015 ^^ this Cheap as chips to make as well. I was surprised at how well mine worked for like 15 bucks +1 for 15-16 at cruise Quote Link to comment Share on other sites More sharing options...
yoeddynz Posted January 24, 2015 Author Share Posted January 24, 2015 Dyno is only good option I think. Yep- this^ I think I myself will only be able to tune so far especially as I am only newbie at all this stuff. Sometime I will have to throw it on a dyno and see what Im getting and how close I am to it actually running as well as it can. yup thats what i used to listen for knock. just have a dounut style knock sensor hooked up to to a small amp and headphones. knock sensor is just a microphone Donut style? Have you got a picture it? The mazda knock sensor in my V6 is like a solid lump of metal that screws dwon into the valley of the V and has a single wire sticking out. Would it be putting out a simple 0-5 volt signal? Quote Link to comment Share on other sites More sharing options...
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