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Old Apr 30, 2022 | 11:37 AM
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Something interesting.

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Motor Trend did n experiment with just adding oct will it increase hp.. With 87 oct 29* As the oct increased it went from 12.5 af to 13 af but didnt change because they were proving a point will adding oct and no timing added nothing. i guess back n the day when we use to fill up with 112 oct we were tossing r money out considering it was 100 x more expensive.but i swear r cars and bikes went faster. but it turned r exhaust pipes white. so we had guys come up to us and ask about what fuel we were running. That was cool when 16 ,17 yrs old.
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Old Apr 30, 2022 | 12:09 PM
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That is interesting! Thanx for posting.
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Old Apr 30, 2022 | 02:53 PM
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Best power and mileage usually are obtained with regular, 87 octane fuel. Not necessarily on Corvettes, though. My point is, any increase in octane over and above what an engine actually requires reduces power and efficiency! Think about it. Regular gas has a lower flash point than premium. Some would say it's more volatile/explosive. But if you're running a lot of compression, it will cause detonation/spark knock. Premium isn't as volatile. It burns a bit slower, which is why you need to advance the timing a bit. But there's less chance of spark knock/detonation......
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Old Apr 30, 2022 | 08:20 PM
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I forget which brand, maybe Chevron, used to have a “white pump” that was 100 octane. That was in the late 60’s, maybe very early 70’s. For our hp street cars it was either that, or drive into the Torrance airport and pull up to the fuel truck for avgas. Hard to image these days, but we would just drive right in and cruise down the tarmac, back up to the truck and fill ‘er up with leaded 100.
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Old Apr 30, 2022 | 11:18 PM
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Originally Posted by vette4fl
I forget which brand, maybe Chevron, used to have a “white pump” that was 100 octane. That was in the late 60’s, maybe very early 70’s. For our hp street cars it was either that, or drive into the Torrance airport and pull up to the fuel truck for avgas. Hard to image these days, but we would just drive right in and cruise down the tarmac, back up to the truck and fill ‘er up with leaded 100.
Man u just brought back a memoir. my bubby had station wagon as a sleeper and 525 cubic if i remember with carzy compressions. The ******* thing tore *** with 6 guys in it cruising the weekend looking for some meat to burn up . When we found guys to race they laughed at us but all they saw was the tail light and the empty beer cars we threw out the window at them ( 16, 17 yr) what happen to this ******* world. Like u said it was funny driving into a airport and filling up with fuel. That was the good old days when there wasn't 100 ft electric fence and sniper ready to take u out for a gallon of gas,
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Old May 1, 2022 | 10:58 AM
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Originally Posted by vette4fl
I forget which brand, maybe Chevron, used to have a “white pump” that was 100 octane. That was in the late 60’s, maybe very early 70’s. For our hp street cars it was either that, or drive into the Torrance airport and pull up to the fuel truck for avgas. Hard to image these days, but we would just drive right in and cruise down the tarmac, back up to the truck and fill ‘er up with leaded 100.
The good old days.......Too bad all that gas is gone forever. Remember Sunoco 260? The pumps had 260, 240, 220, etc, all higher octane than premium. In our state, there's a company named Clark. They used to advertise "Super 100", which was their premium. More telling was their regular grade, which was "only" 95 octane!!! Yup, regular at most stations 45-50 years ago was 95 octane-2 points higher than today's "premium." Yup, colored red, with lead, and very powerful aroma. Good stuff........
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Old May 1, 2022 | 04:18 PM
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E85 is cheaper still the best option in my opinion it’s gonna get just a shitty mileage . Better for the environment also .. if tuned right makes more power. I’ll be making some shine after I get this federal fuel license
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Old May 1, 2022 | 06:54 PM
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Originally Posted by Speedy007
E85 is cheaper still the best option in my opinion it’s gonna get just a shitty mileage . Better for the environment also .. if tuned right makes more power. I’ll be making some shine after I get this federal fuel license
LOVE IT!!!
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Old May 1, 2022 | 06:57 PM
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Originally Posted by vette4fl
I forget which brand, maybe Chevron, used to have a “white pump” that was 100 octane. That was in the late 60’s, maybe very early 70’s. For our hp street cars it was either that, or drive into the Torrance airport and pull up to the fuel truck for avgas. Hard to image these days, but we would just drive right in and cruise down the tarmac, back up to the truck and fill ‘er up with leaded 100.
it was Amaco. Claimed 100 octane and lead free. Must have had something worse than lead. It disappeared when lead free was required. It did smell different.
I’m currently using 90 octane no ethanol. Costs about same as 93 octane corn gas. Seems to perform fine.
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Old May 2, 2022 | 09:56 PM
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I agree No benefit from higher OCT fuel than needed
These engines have low 9.1 to 9.5 compression ratios No need for anything higher than 91-- 87 will work but remember it is cheap crap gas---and I would not run it in a Corvette
Leaded gas will foul your 02 sensors so I would never use it
One more thought if you want to run higher than 91 is if you run lots of timing However the LS heads do not require lots of timing and at some point will make LESS HP/TQ because of too much timing Look at the data logger and NOT the tuned timing tables The data logger shows ACTUAL timing not commanded timing There can be several reasons for timing to be removed--hi IAT readings / knock /Burst knock etc
Typically I see the best results with about 23-25* of actual timing at WOT
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Old May 3, 2022 | 12:04 AM
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These engines run 10:2:1 btw
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Old May 3, 2022 | 06:56 AM
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That looks like the graphs from Engine Masters. That was a good show on octane results.
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