Sunoco Racing Fuel
#81
Melting Slicks
Nobody cares about, "testing BTU", nobody said anything about, "heat value", I didn't say anything about, "stored energy". People only care about how their car is going to run when they fill up their tank, and not listen to all the BS.
#82
Pro
Making more power from different fuels. That's an entirely different discussion than using the correct octane for the application.
#83
Instructor
My god there is some crazy BS in this thread. There is no way that running 100 octane fuel in a engine designed for 93 is going to make more power. The only way it would make more power in that situation is to increase timing or boost. And a stock engine, SC or is going to be less efficient with increased octane over what it was desigmed for. These engines do not ADD timing, they will pull timing if detonation occurs but but will not increase timing beyond the max timing reference in the tune wether it is stock or custom tune.
And before all the internet gurus start taking shots, I do know a little something about engines and octane. I run a 632 big block in my dragster with 16.8 to 1 compression that makes 1225 hp with a single carb and 116 octane leaded race fuel. If I could run 112 safely I would do that and guys that run the same combo at elevation do run 112.
And before all the internet gurus start taking shots, I do know a little something about engines and octane. I run a 632 big block in my dragster with 16.8 to 1 compression that makes 1225 hp with a single carb and 116 octane leaded race fuel. If I could run 112 safely I would do that and guys that run the same combo at elevation do run 112.
#84
Pro
My god there is some crazy BS in this thread. There is no way that running 100 octane fuel in a engine designed for 93 is going to make more power. The only way it would make more power in that situation is to increase timing or boost. And a stock engine, SC or is going to be less efficient with increased octane over what it was desigmed for. These engines do not ADD timing, they will pull timing if detonation occurs but but will not increase timing beyond the max timing reference in the tune wether it is stock or custom tune.
And before all the internet gurus start taking shots, I do know a little something about engines and octane. I run a 632 big block in my dragster with 16.8 to 1 compression that makes 1225 hp with a single carb and 116 octane leaded race fuel. If I could run 112 safely I would do that and guys that run the same combo at elevation do run 112.
And before all the internet gurus start taking shots, I do know a little something about engines and octane. I run a 632 big block in my dragster with 16.8 to 1 compression that makes 1225 hp with a single carb and 116 octane leaded race fuel. If I could run 112 safely I would do that and guys that run the same combo at elevation do run 112.
Higher octane only indicates more knock protection. It isn't an indicator of power potential.
#85
Team Owner
And a stock engine, SC or is going to be less efficient with increased octane over what it was desigmed for. These engines do not ADD timing, they will pull timing if detonation occurs but but will not increase timing beyond the max timing reference in the tune wether it is stock or custom tune.
#86
Pro
GenV engines will also pull power in order to stay below the torque value in the driver demand table. So the ECU has the ability to manipulate throttle plate position, fuel and timing if it's exceeding the torque delivered at a given gear + RPM+ driver pedal position. This is why a lot of folks would talk about the ECU "detuning" modifications.
Fake driver demand target: If say 1,000 rpm has a 100ft lb limit at 80% pedal. And this engine would make 120ftb at 80% pedal position, then the ECU will compensate in order to deliver less torque.
Fake driver demand target: If say 1,000 rpm has a 100ft lb limit at 80% pedal. And this engine would make 120ftb at 80% pedal position, then the ECU will compensate in order to deliver less torque.
#87
Instructor
GenV engines will also pull power in order to stay below the torque value in the driver demand table. So the ECU has the ability to manipulate throttle plate position, fuel and timing if it's exceeding the torque delivered at a given gear + RPM+ driver pedal position. This is why a lot of folks would talk about the ECU "detuning" modifications.
Fake driver demand target: If say 1,000 rpm has a 100ft lb limit at 80% pedal. And this engine would make 120ftb at 80% pedal position, then the ECU will compensate in order to deliver less torque.
Fake driver demand target: If say 1,000 rpm has a 100ft lb limit at 80% pedal. And this engine would make 120ftb at 80% pedal position, then the ECU will compensate in order to deliver less torque.
#88
Instructor
This is VP 100 octane unleaded fuel, why in the world would you want to pay $25 a gallon for fuel that isn't going to have any benefit at all...
In your scenario 87 required and running 95? Why would you use it even if the performance is the same, it for sure won't be better. Your power to weight ratio may change since your wallet will be lighter.
https://vpracingfuels.com/product/c10/?c=219
This is my previous engine 632 9 degree heads, 1320 hp@7300 and 1000 ft lbs of tq with a single carb. Sunoco 116 fuel
#89
Team Owner
I don't truly know with these engines if using say 100 octane unleaded race fuel vs 93 will decrease power but I would not think it will be as efficient. I will ask my engine builder about this. He is one of the best sportsman builders in the country and also has worked on NASCAR and Pro Stock engines. I'm sure there has been some real world Dyno time testing fuels.
This is VP 100 octane unleaded fuel, why in the world would you want to pay $25 a gallon for fuel that isn't going to have any benefit at all...
In your scenario 87 required and running 95? Why would you use it even if the performance is the same, it for sure won't be better. Your power to weight ratio may change since your wallet will be lighter.
https://vpracingfuels.com/product/c10/?c=219
This is my previous engine 632 9 degree heads, 1320 hp@7300 and 1000 ft lbs of tq with a single carb. Sunoco 116 fuel
This is VP 100 octane unleaded fuel, why in the world would you want to pay $25 a gallon for fuel that isn't going to have any benefit at all...
In your scenario 87 required and running 95? Why would you use it even if the performance is the same, it for sure won't be better. Your power to weight ratio may change since your wallet will be lighter.
https://vpracingfuels.com/product/c10/?c=219
This is my previous engine 632 9 degree heads, 1320 hp@7300 and 1000 ft lbs of tq with a single carb. Sunoco 116 fuel
#90
Melting Slicks
Pro Mechanic
Member Since: Nov 2013
Location: Ex DPRK, now just N of Medford, OR
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Meanwhile....
The OP has (intelligently....) bowed out of the conversation.
The C6 gen was tuned for best performance on 93. Dunno about the C7, but one might assume that is also.
Below that octane, they'll pull timing, and that WILL cost performance. They will run on 87... But why would anyone do that?!
At 93, the timing will revert to the base map, and deliver performance as programmed.
Above that, there will only be benefit if some detonation is present and timing is still being pulled. Maybe GM cut the tuning right to the edge.
I've seen no hard evidence that octane increased above optimum costs performance, just rumors of 'spongy acceleration', with the explanation of 'slower energy release'.
Tough for me to imagine that running a couple of points over optimum would be measurable.
In CA, at the pump, we could only buy 91. Here in Oregon 92 is the norm. OP didn't say what his local premium was. If it's low, blending in some 100UL is of performance benefit.
Up to him to weigh the cost/benefit ratio...
The OP has (intelligently....) bowed out of the conversation.
The C6 gen was tuned for best performance on 93. Dunno about the C7, but one might assume that is also.
Below that octane, they'll pull timing, and that WILL cost performance. They will run on 87... But why would anyone do that?!
At 93, the timing will revert to the base map, and deliver performance as programmed.
Above that, there will only be benefit if some detonation is present and timing is still being pulled. Maybe GM cut the tuning right to the edge.
I've seen no hard evidence that octane increased above optimum costs performance, just rumors of 'spongy acceleration', with the explanation of 'slower energy release'.
Tough for me to imagine that running a couple of points over optimum would be measurable.
In CA, at the pump, we could only buy 91. Here in Oregon 92 is the norm. OP didn't say what his local premium was. If it's low, blending in some 100UL is of performance benefit.
Up to him to weigh the cost/benefit ratio...
#91
Team Owner
The C6 gen was tuned for best performance on 93. Dunno about the C7, but one might assume that is also.
Below that octane, they'll pull timing, and that WILL cost performance. They will run on 87... But why would anyone do that?!
I've seen no hard evidence that octane increased above optimum costs performance, just rumors of 'spongy acceleration', with the explanation of 'slower energy release'.
Tough for me to imagine that running a couple of points over optimum would be measurable.
In CA, at the pump, we could only buy 91. Here in Oregon 92 is the norm. OP didn't say what his local premium was. If it's low, blending in some 100UL is of performance benefit.
Up to him to weigh the cost/benefit ratio...
Below that octane, they'll pull timing, and that WILL cost performance. They will run on 87... But why would anyone do that?!
I've seen no hard evidence that octane increased above optimum costs performance, just rumors of 'spongy acceleration', with the explanation of 'slower energy release'.
Tough for me to imagine that running a couple of points over optimum would be measurable.
In CA, at the pump, we could only buy 91. Here in Oregon 92 is the norm. OP didn't say what his local premium was. If it's low, blending in some 100UL is of performance benefit.
Up to him to weigh the cost/benefit ratio...
I am low on gas and that's all I can get?
I've also heard of gains from a part that the dyno or track doesn't agree with. IMO, SOTP dynos are generally worthless at best and misleading at worst.
I honestly doubt it can be measured or if it could, probably not significantly different.
Maybe get a scanner and see what the ECM says?
#92
Melting Slicks
Pro Mechanic
Member Since: Nov 2013
Location: Ex DPRK, now just N of Medford, OR
Posts: 2,925
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93 is the available premium in alot of areas.
Since the KR strategy is so good, they're going for the best possible perf, and letting the ECU correct for any shortcomings.
I don't know how close to the edge factory maps are to detonation on 93, whether there is more performance to be gained with octane above that or not.
If I had a dyno and all the time in the world, I'd pass the info along...
Back in the E36 M3 days, the performance chips were mapped for 92, but they would run fine on CA 91.
Until they went to the track.
I cautioned my customers to add in some 100UL to bring the octane up a smidge if they were going.
I could tell who didn't listen by the blown headgasket!
Since the KR strategy is so good, they're going for the best possible perf, and letting the ECU correct for any shortcomings.
I don't know how close to the edge factory maps are to detonation on 93, whether there is more performance to be gained with octane above that or not.
If I had a dyno and all the time in the world, I'd pass the info along...
Back in the E36 M3 days, the performance chips were mapped for 92, but they would run fine on CA 91.
Until they went to the track.
I cautioned my customers to add in some 100UL to bring the octane up a smidge if they were going.
I could tell who didn't listen by the blown headgasket!
#93
Melting Slicks
Cars today are much more sophisticated. They do say in the manuals that it's ok to run a bit lower octane, and the higher octane. This is because the electronics have become much better at handling knock, and not do any damage, and not relying on the driver to keep his foot out of it. It's an advertising, sales thing. The car then seems cheaper to drive.
#94
Burning Brakes
NOPE!
The BTU/lb of energy of 91-93 premium is the same as regular 87. (within the margin of error) The heavy aromatic content is slightly different (same concentration) to get the higher octane value. Distillation, flame speed, burn rate, vaporization, etc... all practically the same.
The BTU/lb of energy of 91-93 premium is the same as regular 87. (within the margin of error) The heavy aromatic content is slightly different (same concentration) to get the higher octane value. Distillation, flame speed, burn rate, vaporization, etc... all practically the same.
#95
Team Owner
Cars today are much more sophisticated. They do say in the manuals that it's ok to run a bit lower octane, and the higher octane. This is because the electronics have become much better at handling knock, and not do any damage, and not relying on the driver to keep his foot out of it. It's an advertising, sales thing. The car then seems cheaper to drive.
#96
Melting Slicks
I also tried the E85. It does work but like you said, the milage is really BAD. Not worth it. I'm not as sure about using 87 vs 91, yes it will make a bit less power, but not sure the milage would be all that bad.
#97
Team Owner
Not sure since the only way to do that would be to measure it under heavy load to see the KS remove timing.