Boostn Donating Members 116 Member For: 20y 3m 28d Gender: Male Posted 19/09/06 02:02 AM Share Posted 19/09/06 02:02 AM Hey guy's....With all this talk about people running Lean mixtures and pinging. A lot people been bagging certain tuners about how lean they run there tune to produce more power.What are safe AFR's???At wot and during cruise???Would love to hear opinions of our sponsors and public...Paulie.. Link to comment Share on other sites More sharing options...
coach3062 Member 91 Member For: 18y 11m 26d Gender: Male Location: North west NSW Posted 19/09/06 02:26 AM Share Posted 19/09/06 02:26 AM I also would like some answers to these questions too, plus what effect altitude (say 1300metres above sea level) has on the AFR's? Link to comment Share on other sites More sharing options...
rboksic Donating Members 514 Member For: 20y 9m 3d Posted 19/09/06 10:09 AM Share Posted 19/09/06 10:09 AM I also would like some answers to these questions too, plus what effect altitude (say 1300metres above sea level) has on the AFR's?← leaner due to thinner air less O2 having said that 1300 mt is on that high so it may only be slight change in AFR's at WOT Link to comment Share on other sites More sharing options...
Romulus Donating Members 1,279 Member For: 20y 28d Location: Perth Posted 19/09/06 10:21 AM Share Posted 19/09/06 10:21 AM (edited) 11.5-12.0:1 AFR at full boost. I'm not a fan of lean mixtures and high boost. Edited 19/09/06 10:23 AM by M6 XR6T Link to comment Share on other sites More sharing options...
MYWPN Donating Members 554 Member For: 19y 7m Gender: Male Location: Bendigo Posted 19/09/06 10:24 AM Share Posted 19/09/06 10:24 AM 11.5-12.0:1 AFR at full boost. Anything higher than that during sustained load is dangerous, in my opinion.←if you have a CAT yeah, if not I would be happy running at 13.2 Link to comment Share on other sites More sharing options...
Fat-Tony Member 5,364 Member For: 18y 10m 11d Posted 19/09/06 10:29 AM Share Posted 19/09/06 10:29 AM 11.5-12.0:1 AFR at full boost. Anything higher than that during sustained load is dangerous, in my opinion.←if you have a CAT yeah, if not I would be happy running at 13.2←Even if you do have a cat you can still quite safely and realiably see mixtures of 12.5 Link to comment Share on other sites More sharing options...
jetute Donating Members 4,553 Member For: 21y Gender: Male Location: brisbane Posted 19/09/06 10:33 AM Share Posted 19/09/06 10:33 AM I dont know... everyone has different versions... hpf tuned a car that peaked at about 13.2 or thereabouts and they said on this forum that the tune is fully safe... so go figure.I consider 11.5 rich... and bloody expensive to run Link to comment Share on other sites More sharing options...
RAP1D Member Donating Members 3,739 Member For: 18y 8m 12d Gender: Male Location: Sydney NSW Posted 19/09/06 10:54 AM Share Posted 19/09/06 10:54 AM Dont forget that timing/detonation has a massive effect on how safe the AFRs are... High 12s with timing advance to the edge and high boost can be very risky, where as 13s on lowish boost and not so overly advanced timing can be happy sailing... Link to comment Share on other sites More sharing options...
tupperware Member 113 Member For: 22y 1m 5d Location: South Brizzy Posted 19/09/06 11:03 AM Share Posted 19/09/06 11:03 AM Stoichiometric AFR is 14.7:1 which is controlled in closed loop by the factory narrow band O2 sensor. AFR control is in closed loop mode for realistically all normal driving. This is to maintain an economic drive.Max power is made at 12.8:1, but blown & turbo'ed motors often run richer mixtures to help cool the air charge. Same principle as water injection. The extra fuel doesn't burn so it's similar to adding water to the charge, but with a lower latent heat of vapourisation.It is also prudent for tuning shops to add a little fat to the tune to allow for fouling injectors & filters & the pump performance decreasing. If you don't monitor your AFR with your own reliable meter I'd run a bit rich, otherwise keep the intake charge cool, use sensible timing & run the AFRs at mid 12:1 Link to comment Share on other sites More sharing options...
RAP1D Member Donating Members 3,739 Member For: 18y 8m 12d Gender: Male Location: Sydney NSW Posted 19/09/06 11:07 AM Share Posted 19/09/06 11:07 AM Totally, but richening it up to lower combustion temps is a little old school these days Link to comment Share on other sites More sharing options...
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