Most boost with pump gas?
Dec 19, 2007 | 08:23 PM
#11
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From: Colorado Springs, Co/ Central, Ca
Detonation comes from a combination of 4 things:
1) octane
2) compression ratio
3) heat
4) spark advance
These 4 are locked in a dynamic relationship -- as octane falls, spark, heat and/or compression have to fall to compensate (assuming a static boost target). Are you running an intercooler?
I ran 15-16psi on pump before (with an intercooler and meth) on 16* advance -- in Florida and high 90s ambient.
1) octane
2) compression ratio
3) heat
4) spark advance
These 4 are locked in a dynamic relationship -- as octane falls, spark, heat and/or compression have to fall to compensate (assuming a static boost target). Are you running an intercooler?
I ran 15-16psi on pump before (with an intercooler and meth) on 16* advance -- in Florida and high 90s ambient.
-9.4:1 LQ4, 212/212, .527/.527, 114ls
-Intercooled trick front mount, T76, .96AR
-11~12psi
-WOT 16 deg timing(It jumps to 17 sometimes)
-91 octain(unless im getting screwed)
-30 deg ambient temp, 65 deg max IAT
-WOT AFR is 10.5-10.8. Max I have ever seen is 11.2 at the top of 2nd gear.
-7000' elevation, Air psi hear is 11.3, or 78kpa.
With 11.3 psi of atmospheric air psi, compaired to 14.7 @ sea level is like me only running 8.5psi. I really should be able to run at least 15-17psi no meth.
Dec 19, 2007 | 08:41 PM
#12
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From: Colorado Springs, Co/ Central, Ca
I was told by more than one person, there was a test done a few years back, which found premium pump gas taken from various stations, around colorado springs averages 87-88 octain(some stations were even down around 850. even though the pump says 91.
Who is stopping gas stations/ suppliers from doing this kind of thing. The gas station has no way of telling what octain gas is in there tanks. And we have no way of telling what gas we are really getting. I just filled up with 91 at a westorn convenience station. 87 is the lowest they go, they also are a E85 station. I got 3 gallons of E85 Im going to pour in and test tonite if I have time.
Who is stopping gas stations/ suppliers from doing this kind of thing. The gas station has no way of telling what octain gas is in there tanks. And we have no way of telling what gas we are really getting. I just filled up with 91 at a westorn convenience station. 87 is the lowest they go, they also are a E85 station. I got 3 gallons of E85 Im going to pour in and test tonite if I have time.
Dec 19, 2007 | 08:55 PM
#13
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From: colorado above 6000 ft.
I think you mean 85. colorado has 85 , 87, 91. never seen 84 in my 23 years here. I think i got som shitty gas a week ago after the cam install. Ran great the 1st night, next day kept getting det. top of second. dynoed the following day , no problems and still working fine. This is at 10 psi and 20 deg. timing
Dec 19, 2007 | 09:22 PM
#14
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From: Colorado Springs, Co/ Central, Ca
I think you mean 85. colorado has 85 , 87, 91. never seen 84 in my 23 years here. I think i got som shitty gas a week ago after the cam install. Ran great the 1st night, next day kept getting det. top of second. dynoed the following day , no problems and still working fine. This is at 10 psi and 20 deg. timing
Dec 19, 2007 | 09:28 PM
#15
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From: kansas
I was told by more than one person, there was a test done a few years back, which found premium pump gas taken from various stations, around colorado springs averages 87-88 octain(some stations were even down around 850. even though the pump says 91. Who is stopping gas stations/ suppliers from doing this kind of thing. The gas station has no way of telling what octain gas is in there tanks. And we have no way of telling what gas we are really getting. I just filled up with 91 at a westorn convenience station. 87 is the lowest they go, they also are a E85 station. I got 3 gallons of E85 Im going to pour in and test tonite if I have time.
Who is stopping gas stations/ suppliers from doing this kind of thing. The gas station has no way of telling what octain gas is in there tanks. And we have no way of telling what gas we are really getting. I just filled up with 91 at a westorn convenience station. 87 is the lowest they go, they also are a E85 station. I got 3 gallons of E85 Im going to pour in and test tonite if I have time.
Dec 19, 2007 | 11:29 PM
#16
here at 1000' 92 octane no intercooler i wouldn't go over 7psi.
add an intercooler and i wouldn't go over 10psi.
add 2 psi to that or whatever your corection is for the altitude and that puts you right at what i have found the limits to be for me. my timing is always in the 14-17deg range. i think you are right where you should be.
adding meth i was able to take it up around 15psi and gained something nuts like 200hp. it did complicate the tune but was worth it for that much extra power.
the cold does help with your iat's but then the air is just that much more dence so you get more power and more cylinder presure so i dont know if it really helps or hurts with the detonation.
add an intercooler and i wouldn't go over 10psi.
add 2 psi to that or whatever your corection is for the altitude and that puts you right at what i have found the limits to be for me. my timing is always in the 14-17deg range. i think you are right where you should be.
adding meth i was able to take it up around 15psi and gained something nuts like 200hp. it did complicate the tune but was worth it for that much extra power.
the cold does help with your iat's but then the air is just that much more dence so you get more power and more cylinder presure so i dont know if it really helps or hurts with the detonation.
Dec 20, 2007 | 06:26 PM
#17
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From: Colorado Springs, Co/ Central, Ca
Well I did some testing with the other gas, and truck still gets 8 deg of KR. So I turned the boost all the way down to 6psi, and still 6-8KR. So I tried 15LBS and same exact thing. KR was still 8deg. There is no sound, or sign of det at all. It even will KR in 1st gear before boost comes in. So I have to be getting false knock somere?
I think it may just be piston slap, or valve train. This engine along with most 6.0's I have heard have alot of engine noise, and that has to be what's going on.
I think it may just be piston slap, or valve train. This engine along with most 6.0's I have heard have alot of engine noise, and that has to be what's going on.
Dec 20, 2007 | 09:21 PM
#19
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From: colorado above 6000 ft.
here at 1000' 92 octane no intercooler i wouldn't go over 7psi.
add an intercooler and i wouldn't go over 10psi.
add 2 psi to that or whatever your corection is for the altitude and that puts you right at what i have found the limits to be for me. my timing is always in the 14-17deg range. i think you are right where you should be.
adding meth i was able to take it up around 15psi and gained something nuts like 200hp. it did complicate the tune but was worth it for that much extra power.
the cold does help with your iat's but then the air is just that much more dence so you get more power and more cylinder presure so i dont know if it really helps or hurts with the detonation.
add an intercooler and i wouldn't go over 10psi.
add 2 psi to that or whatever your corection is for the altitude and that puts you right at what i have found the limits to be for me. my timing is always in the 14-17deg range. i think you are right where you should be.
adding meth i was able to take it up around 15psi and gained something nuts like 200hp. it did complicate the tune but was worth it for that much extra power.
the cold does help with your iat's but then the air is just that much more dence so you get more power and more cylinder presure so i dont know if it really helps or hurts with the detonation.