a/f ratio
Thread Starter
Joined: 07-14-08
Posts: 12,039
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From: canada
a/f ratio
what a/f ratio u guys running on tune? and what would u say is safe? i know stock is running about 13 at wot, and on trifecta tune for 21 psi im running about 12. seems kinda rich to me.
Im reading all this busted piston stuff, and im thinking about just removing the select a tune and just leaving it stock and getting gm stage 1 later on. i think thats about the safest thing to do right now.
Im reading all this busted piston stuff, and im thinking about just removing the select a tune and just leaving it stock and getting gm stage 1 later on. i think thats about the safest thing to do right now.
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Joined: 07-30-08
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From: Gainesville FL.
12.0
what is with this trifecta is too rich thing?
both people in the other thread with trifecta tunes that popped a piston botht logged mid to high 12's for a/f ratio
and the person in the other thread stated he had hp tuners at 12.7 and he popped a piston.
when some posts online that the were at 12.0 or richer and pops a piston, then I will believe it's too rich for DI engines.
I even talked to two of my buddies who have DI 2.0 VW motors with APr tunes
apr is a well respected company and tuner and they logged a/f ratio on there flashed stage 2 cars(intake and DP) and both NEVER went leaner than 12.0, most of the time in the mid 11's. at 22psi
what is with this trifecta is too rich thing?
both people in the other thread with trifecta tunes that popped a piston botht logged mid to high 12's for a/f ratio
and the person in the other thread stated he had hp tuners at 12.7 and he popped a piston.
when some posts online that the were at 12.0 or richer and pops a piston, then I will believe it's too rich for DI engines.
I even talked to two of my buddies who have DI 2.0 VW motors with APr tunes
apr is a well respected company and tuner and they logged a/f ratio on there flashed stage 2 cars(intake and DP) and both NEVER went leaner than 12.0, most of the time in the mid 11's. at 22psi
26 psi max, tapering down to 19 psi @ 7200 rpm: 13.0:1, (.883 lambda) at WOT, 14.7 under 90% driver demand torque, (1.0 lambda). Tapers from 14.7 to 13.0 between 90 - 100% DDT. Stays at 13.0 all the way to 300% load. No cat overtemp protection that would drive it to 10.9 AFR (.74 lambda) like the stock tune. If your tune still has the COT in it, it gets ungodly rich trying to cool the cat at WOT during a long pull.
12.0
what is with this trifecta is too rich thing?
both people in the other thread with trifecta tunes that popped a piston botht logged mid to high 12's for a/f ratio
and the person in the other thread stated he had hp tuners at 12.7 and he popped a piston.
when some posts online that the were at 12.0 or richer and pops a piston, then I will believe it's too rich for DI engines.
I even talked to two of my buddies who have DI 2.0 VW motors with APr tunes
apr is a well respected company and tuner and they logged a/f ratio on there flashed stage 2 cars(intake and DP) and both NEVER went leaner than 12.0, most of the time in the mid 11's. at 22psi
what is with this trifecta is too rich thing?
both people in the other thread with trifecta tunes that popped a piston botht logged mid to high 12's for a/f ratio
and the person in the other thread stated he had hp tuners at 12.7 and he popped a piston.
when some posts online that the were at 12.0 or richer and pops a piston, then I will believe it's too rich for DI engines.
I even talked to two of my buddies who have DI 2.0 VW motors with APr tunes
apr is a well respected company and tuner and they logged a/f ratio on there flashed stage 2 cars(intake and DP) and both NEVER went leaner than 12.0, most of the time in the mid 11's. at 22psi
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Joined: 08-16-06
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From: hope mills NC
GM stage 1 and run mid 14s at wide open throttle i personally think thats very lean however im led to believe that DI is a different animal, gm is a bunch of vagtastic girls anyway i highly doubt they would release something thats gonna cause any damage cause they are not gonna wanna pay to repace it
Thread Starter
Joined: 07-14-08
Posts: 12,039
Likes: 156
From: canada
well i wanna know what is breaking the pistons, cause id like to lean it out and get some more power if thats not whats causing it. i think ill stay off tune for the time being till someone figures out why pistons are going up in smoke.
I watched all cylinders on my dashdaq, i get knock on all 4 as some as i even boost a little bit in either tune or stock. But knock spark retard always stays at 0.0 whats up with that?
is that dashdaq knock thing telling the truth or no?
I watched all cylinders on my dashdaq, i get knock on all 4 as some as i even boost a little bit in either tune or stock. But knock spark retard always stays at 0.0 whats up with that?
is that dashdaq knock thing telling the truth or no?
IF it is due to fuel getting between the #1 & #2 rings and igniting causing the lands to blow out, I'd consider the Cat Overtemp Protection running it very rich during long hard pulls. Just speculation from what I have read and how the pistons are failing. One member posted his blew out after a 5th gear pull.
When I still had the COT in there, it would kick in at the top of a 3rd gear pull and stay active all the way up from there. It's like a 10.9 afr when it kicks in. (.74 lambda IIRC)
It takes the ECU sensing knock for a half second or so before it actually retards the timing. What you are seeing is burst knock. I have the same when you give it a shot of throttle at times.
I see it on #3 and 4 more than 1&2 but have seen it on all 4 cyls, especially after loading a new tune before the ECU settles in.
When I still had the COT in there, it would kick in at the top of a 3rd gear pull and stay active all the way up from there. It's like a 10.9 afr when it kicks in. (.74 lambda IIRC)
I see it on #3 and 4 more than 1&2 but have seen it on all 4 cyls, especially after loading a new tune before the ECU settles in.
Last edited by Iam Broke; Jan 16, 2010 at 09:00 AM. Reason: Automerged Doublepost
IF it is due to fuel getting between the #1 & #2 rings and igniting causing the lands to blow out, I'd consider the Cat Overtemp Protection running it very rich during long hard pulls. Just speculation from what I have read and how the pistons are failing. One member posted his blew out after a 5th gear pull.
When I still had the COT in there, it would kick in at the top of a 3rd gear pull and stay active all the way up from there. It's like a 10.9 afr when it kicks in. (.74 lambda IIRC)
It takes the ECU sensing knock for a half second or so before it actually retards the timing. What you are seeing is burst knock. I have the same when you give it a shot of throttle at times.
I see it on #3 and 4 more than 1&2 but have seen it on all 4 cyls, especially after loading a new tune before the ECU settles in.
When I still had the COT in there, it would kick in at the top of a 3rd gear pull and stay active all the way up from there. It's like a 10.9 afr when it kicks in. (.74 lambda IIRC)
It takes the ECU sensing knock for a half second or so before it actually retards the timing. What you are seeing is burst knock. I have the same when you give it a shot of throttle at times.
I see it on #3 and 4 more than 1&2 but have seen it on all 4 cyls, especially after loading a new tune before the ECU settles in.
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Joined: 01-24-07
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From: Winchester, VA
wow i cant believe yall are running mid to high 12 afrs..... i run a strong 11.8-12.3 at 14 psi.... and 12.3-12.6 on 17psi..... man 12.6 aint even that safe.... i cant believe yall are being this dumb.... id be pissed if i took my car to get tuned... and i was running 12.8 afrs at wot
Yeah at wot a safe afr is about 11.3-11.8. And u can go richer if u want replace plugs all the time.I tune
my own car with hp tuners and I turn cot off and piston protection and tune with ve map and the pe table....... Tuning is easy but getting your afr right is not easy because of the weather but safe afra are 11.3-11.8 and anything leaner u r asking for knock and high egts.
my own car with hp tuners and I turn cot off and piston protection and tune with ve map and the pe table....... Tuning is easy but getting your afr right is not easy because of the weather but safe afra are 11.3-11.8 and anything leaner u r asking for knock and high egts.
Yeah at wot a safe afr is about 11.3-11.8. And u can go richer if u want replace plugs all the time.I tune
my own car with hp tuners and I turn cot off and piston protection and tune with ve map and the pe table....... Tuning is easy but getting your afr right is always easy because of the weather but safe afra are 11.3-11.8 and anything leaner u r asking for knock and high egts.
my own car with hp tuners and I turn cot off and piston protection and tune with ve map and the pe table....... Tuning is easy but getting your afr right is always easy because of the weather but safe afra are 11.3-11.8 and anything leaner u r asking for knock and high egts.
yea definitly going to be looking for some help.
Last edited by cmiller8006; Jan 16, 2010 at 12:46 PM. Reason: Automerged Doublepost
U might think a 11.3-11.8 is to rich but I have seen better results. More timing lower iat2 more safer boost and I also have a built motor with all mods I can have it does not matter of direct injection mpi, or anything else. A afr the is above 11.8 for a force induction car is to lean....... Time to say good bye to pistons cylinder walls and here comes a new motor. I have tuned supras to Honda and even the once in a while chevy lol j/k it is always the same for forced induction. If u can afford a new motor have fun.but as a daily driver I would rather be safe
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Joined: 05-14-08
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From: around the world
This is the lnf section, you need to keep your regular fuel injected theories out of here since they don't work on direct injected engines. Stock afr goes from 14:1 in the midrange down to 12.8:1 at 5000rpm, until you fully understand why its so lean don't go saying 11.5:1 afr is just fine. That afr was fine on my dsm too, but it just doesn't work on an lnf.
Some direct injection 101 is needed here.
Some direct injection 101 is needed here.
Becasue one a car that is stock will have a fr of say 13 becasue the manufactuar becasue the tune they give the car has litterally
no timing. Restrictive exaust a cat. Low rev limit. Small injector which are already maxed out from stock so going with bigger injectors gives you the opp to change wot setting for a much safer afr..... More boost with less restrictive exaust means faster flow which means lower egts if you have a afr that is 11.3-11.8. And it also depends on where u live.people with altitudes are differnet since at sea level the atmospheric pressure is 14.7 pounds per square inch. I'm pretty sure that is correct. And since I live around 500 ft above sea le el I have to compinsate
Air and fuel. The only way some one can tune is in open loop so u can change stuff without the computers looking at sensors. But still and always a safe afr is 11.3-11.8 ...... A tune with a afrnof say above 11.8 might be safe in some perspectives but your egts will get to high and that is where you get a hole in a piston a crack in the cylinder wall and blow by through the rings.
no timing. Restrictive exaust a cat. Low rev limit. Small injector which are already maxed out from stock so going with bigger injectors gives you the opp to change wot setting for a much safer afr..... More boost with less restrictive exaust means faster flow which means lower egts if you have a afr that is 11.3-11.8. And it also depends on where u live.people with altitudes are differnet since at sea level the atmospheric pressure is 14.7 pounds per square inch. I'm pretty sure that is correct. And since I live around 500 ft above sea le el I have to compinsate
Air and fuel. The only way some one can tune is in open loop so u can change stuff without the computers looking at sensors. But still and always a safe afr is 11.3-11.8 ...... A tune with a afrnof say above 11.8 might be safe in some perspectives but your egts will get to high and that is where you get a hole in a piston a crack in the cylinder wall and blow by through the rings.
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From: causapscal, qc
Becasue one a car that is stock will have a fr of say 13 becasue the manufactuar becasue the tune they give the car has litterally
no timing. Restrictive exaust a cat. Low rev limit. Small injector which are already maxed out from stock so going with bigger injectors gives you the opp to change wot setting for a much safer afr..... More boost with less restrictive exaust means faster flow which means lower egts if you have a afr that is 11.3-11.8. And it also depends on where u live.people with altitudes are differnet since at sea level the atmospheric pressure is 14.7 pounds per square inch. I'm pretty sure that is correct. And since I live around 500 ft above sea le el I have to compinsate
Air and fuel. The only way some one can tune is in open loop so u can change stuff without the computers looking at sensors. But still and always a safe afr is 11.3-11.8 ...... A tune with a afrnof say above 11.8 might be safe in some perspectives but your egts will get to high and that is where you get a hole in a piston a crack in the cylinder wall and blow by through the rings.
no timing. Restrictive exaust a cat. Low rev limit. Small injector which are already maxed out from stock so going with bigger injectors gives you the opp to change wot setting for a much safer afr..... More boost with less restrictive exaust means faster flow which means lower egts if you have a afr that is 11.3-11.8. And it also depends on where u live.people with altitudes are differnet since at sea level the atmospheric pressure is 14.7 pounds per square inch. I'm pretty sure that is correct. And since I live around 500 ft above sea le el I have to compinsate
Air and fuel. The only way some one can tune is in open loop so u can change stuff without the computers looking at sensors. But still and always a safe afr is 11.3-11.8 ...... A tune with a afrnof say above 11.8 might be safe in some perspectives but your egts will get to high and that is where you get a hole in a piston a crack in the cylinder wall and blow by through the rings.
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Joined: 01-12-09
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From: Illinois
Becasue one a car that is stock will have a fr of say 13 becasue the manufactuar becasue the tune they give the car has litterally
no timing. Restrictive exaust a cat. Low rev limit. Small injector which are already maxed out from stock so going with bigger injectors gives you the opp to change wot setting for a much safer afr..... More boost with less restrictive exaust means faster flow which means lower egts if you have a afr that is 11.3-11.8. And it also depends on where u live.people with altitudes are differnet since at sea level the atmospheric pressure is 14.7 pounds per square inch. I'm pretty sure that is correct. And since I live around 500 ft above sea le el I have to compinsate
Air and fuel. The only way some one can tune is in open loop so u can change stuff without the computers looking at sensors. But still and always a safe afr is 11.3-11.8 ...... A tune with a afrnof say above 11.8 might be safe in some perspectives but your egts will get to high and that is where you get a hole in a piston a crack in the cylinder wall and blow by through the rings.
no timing. Restrictive exaust a cat. Low rev limit. Small injector which are already maxed out from stock so going with bigger injectors gives you the opp to change wot setting for a much safer afr..... More boost with less restrictive exaust means faster flow which means lower egts if you have a afr that is 11.3-11.8. And it also depends on where u live.people with altitudes are differnet since at sea level the atmospheric pressure is 14.7 pounds per square inch. I'm pretty sure that is correct. And since I live around 500 ft above sea le el I have to compinsate
Air and fuel. The only way some one can tune is in open loop so u can change stuff without the computers looking at sensors. But still and always a safe afr is 11.3-11.8 ...... A tune with a afrnof say above 11.8 might be safe in some perspectives but your egts will get to high and that is where you get a hole in a piston a crack in the cylinder wall and blow by through the rings.
well i wanna know what is breaking the pistons, cause id like to lean it out and get some more power if thats not whats causing it. i think ill stay off tune for the time being till someone figures out why pistons are going up in smoke.
I watched all cylinders on my dashdaq, i get knock on all 4 as some as i even boost a little bit in either tune or stock. But knock spark retard always stays at 0.0 whats up with that?
is that dashdaq knock thing telling the truth or no?
I watched all cylinders on my dashdaq, i get knock on all 4 as some as i even boost a little bit in either tune or stock. But knock spark retard always stays at 0.0 whats up with that?
is that dashdaq knock thing telling the truth or no?
Last edited by mkriebs; Jan 16, 2010 at 02:41 PM. Reason: Automerged Doublepost