A/F ratios....what should i be tuning for?
07-23-01, 12:36 AM
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A/F ratios....what should i be tuning for?
hi guys.....
Currently (i got it back from a shop like this)
it will idle at 12.1 when i start to slowly rev (no boost) it will slowly climb up to a high point of 14.7.....and in data logging i have recorded a highest measurement of 15.9
What should i try to keep the A/F at, on cruise, idle, and on WOT.
btw, its a Microtech MT8
s4, stock turbo
Currently (i got it back from a shop like this)
it will idle at 12.1 when i start to slowly rev (no boost) it will slowly climb up to a high point of 14.7.....and in data logging i have recorded a highest measurement of 15.9
What should i try to keep the A/F at, on cruise, idle, and on WOT.
btw, its a Microtech MT8
s4, stock turbo
07-23-01, 01:05 AM
#2
inteligent extratarestril
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on boost over 5000, no leaning than 11.5:1, its the stock restricter opps i mean turbo, which is you biggest bottle neck at the moment.
14:1 crusing without idle sounds a tad too lean aswell.
14:1 crusing without idle sounds a tad too lean aswell.
07-24-01, 03:30 PM
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>14:1 crusing without idle sounds a tad too lean aswell
No, that's fine, although he said 14.7, not 14.1. If you have closed loop operation, cruising should be close to 14.7:1 (average, it'll bounce above and below that). If it's open loop it doesn't matter much, but making it richer than 14.7:1 just wastes fuel. You can lean it out up to the point that it begins to misfire, then that's too lean.
No, that's fine, although he said 14.7, not 14.1. If you have closed loop operation, cruising should be close to 14.7:1 (average, it'll bounce above and below that). If it's open loop it doesn't matter much, but making it richer than 14.7:1 just wastes fuel. You can lean it out up to the point that it begins to misfire, then that's too lean.
07-24-01, 05:02 PM
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update...
after data logs i found this out :
On idle its averaging around 12.9-13.5
On cruise its 14.7 (closed loop i guess)
On boost its 12.5-13.0
Im guessing THATS why its blowing black smoke..
Im going to get some new plugs, take it to my tuner d00d guy, actually ill get two sets of plugs =D and we will get it running better....
thankyou for ur help
oh ps, i really need that intercooler, i had a 100 degree celcius intake temp on a big burnout =D
(simulated burnout of course.....
)
after data logs i found this out :
On idle its averaging around 12.9-13.5
On cruise its 14.7 (closed loop i guess)
On boost its 12.5-13.0
Im guessing THATS why its blowing black smoke..
Im going to get some new plugs, take it to my tuner d00d guy, actually ill get two sets of plugs =D and we will get it running better....
thankyou for ur help
oh ps, i really need that intercooler, i had a 100 degree celcius intake temp on a big burnout =D
(simulated burnout of course.....
)
07-25-01, 02:30 AM
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If you are going off the reading of your Microtech I would not trust them for even one second. They are a guesstimation on a non-temp corrected O2 sensor. You should only trust the figures from an accurate and dedicated wide band Air Fuel ratio meter.
Microtech MT-series do not do closed loop, nor is it programmable for closed loop features to select a target voltage from the sensor to aim for under different conditions.
If you run true 12.5 to 13.0:1 under boost at WOT it should not blow smoke and would infact be hours away from needing a rebuild. :-) Being a Microtech you should be aiming for at least 11.5:1 as HWO has said correctly. Idle around 12.6:1 and cruise at 13.8 to 14.5:1
Microtech MT-series do not do closed loop, nor is it programmable for closed loop features to select a target voltage from the sensor to aim for under different conditions.
If you run true 12.5 to 13.0:1 under boost at WOT it should not blow smoke and would infact be hours away from needing a rebuild. :-) Being a Microtech you should be aiming for at least 11.5:1 as HWO has said correctly. Idle around 12.6:1 and cruise at 13.8 to 14.5:1
07-27-01, 02:58 PM
#6
Banned. I got OWNED!!!
Originally posted by The_HITman
If you are going off the reading of your Microtech I would not trust them for even one second. They are a guesstimation on a non-temp corrected O2 sensor. You should only trust the figures from an accurate and dedicated wide band Air Fuel ratio meter.
Microtech MT-series do not do closed loop, nor is it programmable for closed loop features to select a target voltage from the sensor to aim for under different conditions.
If you run true 12.5 to 13.0:1 under boost at WOT it should not blow smoke and would infact be hours away from needing a rebuild. :-) Being a Microtech you should be aiming for at least 11.5:1 as HWO has said correctly. Idle around 12.6:1 and cruise at 13.8 to 14.5:1
If you are going off the reading of your Microtech I would not trust them for even one second. They are a guesstimation on a non-temp corrected O2 sensor. You should only trust the figures from an accurate and dedicated wide band Air Fuel ratio meter.
Microtech MT-series do not do closed loop, nor is it programmable for closed loop features to select a target voltage from the sensor to aim for under different conditions.
If you run true 12.5 to 13.0:1 under boost at WOT it should not blow smoke and would infact be hours away from needing a rebuild. :-) Being a Microtech you should be aiming for at least 11.5:1 as HWO has said correctly. Idle around 12.6:1 and cruise at 13.8 to 14.5:1
I love the screwdriver adjustable series of computers, I think they were on a good thing back then.
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