View Poll Results: what type of gas do yall use?
cheap shit
47
67.14%
midgrade
7
10.00%
expensive stuff
16
22.86%
other
0
0%
Voters: 70. You may not vote on this poll
what type of gas do yall use?
#26
Never Follow
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Originally posted by 85RX7GS
Must be one of those safety issues.
Must be one of those safety issues.
#27
standard combustion
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Ok here we go. Lower the octane, the least demanding the engine is in a way. Lower the octane, the more easily the fuel is ignited, but there are drawbacks to having such a easily ignited fuel.
Heres what I mean by this: A normally asperiated engine that has reasonably moderate compression will have no problems what-so-ever unless you have it too far advanced and improper air/fuel mixture. A rotary is hard to get to a compression ratio that will nessessiate anything above 87octane. I am uncertain what the renesis engine will need, since its supposively a higher then previously N/A rotaries. But it will probably still be a 87octane engine.
Some V8's or any piston engine with above 10:1 or 11:1 will need higher octane since lower octane will pre-ignite like a desiel engine. Most automakers want higher compression if possible since its more effiecent at using the fuel and making more power.-why high hp pistion engines usually need it and operating cost isn't a major concern to the buyer. But a lower compression engine is a cheaper operating engine since its requires a fuel that is slightly cheaper to make.
Have you ever heard a carb'd rotary have run-on/desieling after shutting it off like a pistion engine does? I think not! Its design makes that pretty much impossible.
Anyway, when it comes to igniting a mixture. All the gasoline out there whether it is 87 or 110octane will run about the same on a normally asperated engine with compression below 10:1. Which all rotaries are right now with no boost at least. Now when we are considering the higher compression engines and boost and putting a fuel in with lower octane then recommended, you risk making it a deseil engine and detonation by igniting the mixture before the spark plug ignites the mixture and then igniting the rest of the mixture by the spark plug causing the two combustion starting points running into each other(detonation). Deseil fuel is much lower then 87octane for the reason it is ignited by just compression heating and is given really high compression ratios for this reason to make certain its ignited by compression heat.
It has to do with cylinder of a piston engine or chamber pressure generated in a rotary being above a certain compression PSI and temp(before ignition) which is what determines what type of fuel will be required. In a rotary, realisiticily the only time a psi will be too high for 87octane is when usable boost is appied.
Heres what I mean by this: A normally asperiated engine that has reasonably moderate compression will have no problems what-so-ever unless you have it too far advanced and improper air/fuel mixture. A rotary is hard to get to a compression ratio that will nessessiate anything above 87octane. I am uncertain what the renesis engine will need, since its supposively a higher then previously N/A rotaries. But it will probably still be a 87octane engine.
Some V8's or any piston engine with above 10:1 or 11:1 will need higher octane since lower octane will pre-ignite like a desiel engine. Most automakers want higher compression if possible since its more effiecent at using the fuel and making more power.-why high hp pistion engines usually need it and operating cost isn't a major concern to the buyer. But a lower compression engine is a cheaper operating engine since its requires a fuel that is slightly cheaper to make.
Have you ever heard a carb'd rotary have run-on/desieling after shutting it off like a pistion engine does? I think not! Its design makes that pretty much impossible.
Anyway, when it comes to igniting a mixture. All the gasoline out there whether it is 87 or 110octane will run about the same on a normally asperated engine with compression below 10:1. Which all rotaries are right now with no boost at least. Now when we are considering the higher compression engines and boost and putting a fuel in with lower octane then recommended, you risk making it a deseil engine and detonation by igniting the mixture before the spark plug ignites the mixture and then igniting the rest of the mixture by the spark plug causing the two combustion starting points running into each other(detonation). Deseil fuel is much lower then 87octane for the reason it is ignited by just compression heating and is given really high compression ratios for this reason to make certain its ignited by compression heat.
It has to do with cylinder of a piston engine or chamber pressure generated in a rotary being above a certain compression PSI and temp(before ignition) which is what determines what type of fuel will be required. In a rotary, realisiticily the only time a psi will be too high for 87octane is when usable boost is appied.
#28
Rotary Freak
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Originally posted by WackyRotary
Ok here we go. Lower the octane, the least demanding the engine is in a way. Lower the octane, the more easily the fuel is ignited, but there are drawbacks to having such a easily ignited fuel.
Heres what I mean by this: A normally asperiated engine that has reasonably moderate compression will have no problems what-so-ever unless you have it too far advanced and improper air/fuel mixture. A rotary is hard to get to a compression ratio that will nessessiate anything above 87octane. I am uncertain what the renesis engine will need, since its supposively a higher then previously N/A rotaries. But it will probably still be a 87octane engine.
Some V8's or any piston engine with above 10:1 or 11:1 will need higher octane since lower octane will pre-ignite like a desiel engine. Most automakers want higher compression if possible since its more effiecent at using the fuel and making more power.-why high hp pistion engines usually need it and operating cost isn't a major concern to the buyer. But a lower compression engine is a cheaper operating engine since its requires a fuel that is slightly cheaper to make.
Have you ever heard a carb'd rotary have run-on/desieling after shutting it off like a pistion engine does? I think not! Its design makes that pretty much impossible.
Anyway, when it comes to igniting a mixture. All the gasoline out there whether it is 87 or 110octane will run about the same on a normally asperated engine with compression below 10:1. Which all rotaries are right now with no boost at least. Now when we are considering the higher compression engines and boost and putting a fuel in with lower octane then recommended, you risk making it a deseil engine and detonation by igniting the mixture before the spark plug ignites the mixture and then igniting the rest of the mixture by the spark plug causing the two combustion starting points running into each other(detonation). Deseil fuel is much lower then 87octane for the reason it is ignited by just compression heating and is given really high compression ratios for this reason to make certain its ignited by compression heat.
It has to do with cylinder of a piston engine or chamber pressure generated in a rotary being above a certain compression PSI and temp(before ignition) which is what determines what type of fuel will be required. In a rotary, realisiticily the only time a psi will be too high for 87octane is when usable boost is appied.
Ok here we go. Lower the octane, the least demanding the engine is in a way. Lower the octane, the more easily the fuel is ignited, but there are drawbacks to having such a easily ignited fuel.
Heres what I mean by this: A normally asperiated engine that has reasonably moderate compression will have no problems what-so-ever unless you have it too far advanced and improper air/fuel mixture. A rotary is hard to get to a compression ratio that will nessessiate anything above 87octane. I am uncertain what the renesis engine will need, since its supposively a higher then previously N/A rotaries. But it will probably still be a 87octane engine.
Some V8's or any piston engine with above 10:1 or 11:1 will need higher octane since lower octane will pre-ignite like a desiel engine. Most automakers want higher compression if possible since its more effiecent at using the fuel and making more power.-why high hp pistion engines usually need it and operating cost isn't a major concern to the buyer. But a lower compression engine is a cheaper operating engine since its requires a fuel that is slightly cheaper to make.
Have you ever heard a carb'd rotary have run-on/desieling after shutting it off like a pistion engine does? I think not! Its design makes that pretty much impossible.
Anyway, when it comes to igniting a mixture. All the gasoline out there whether it is 87 or 110octane will run about the same on a normally asperated engine with compression below 10:1. Which all rotaries are right now with no boost at least. Now when we are considering the higher compression engines and boost and putting a fuel in with lower octane then recommended, you risk making it a deseil engine and detonation by igniting the mixture before the spark plug ignites the mixture and then igniting the rest of the mixture by the spark plug causing the two combustion starting points running into each other(detonation). Deseil fuel is much lower then 87octane for the reason it is ignited by just compression heating and is given really high compression ratios for this reason to make certain its ignited by compression heat.
It has to do with cylinder of a piston engine or chamber pressure generated in a rotary being above a certain compression PSI and temp(before ignition) which is what determines what type of fuel will be required. In a rotary, realisiticily the only time a psi will be too high for 87octane is when usable boost is appied.
#31
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so basically i am waisting my money on 91 when i should be useing 87 witch if better for the car, **** ! i wish i known sooner. as long as i have NA i use 87? what if my engine was fully built, and still NA would i still use 87 or a higher octane??
#33
Newbie
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Originally posted by gamble302
the lower the octane the better in n/a's. too abd we dnot have mexican gas over here
the lower the octane the better in n/a's. too abd we dnot have mexican gas over here
The dreaded numbered list!
1)What is n/a?
2)What models were out in 82? (do I have a GSL?)
3)Doesn't it "run cleaner" to use a higher octane? Wouldn't that be a reason to use higher octane?
4)Does anyone know what octane Premium gas at Chevron is?
Thanks
EDIT- oh yeah, and what is the number included in the model? (maybe that doesn't make sense...
Last edited by Shyft; 12-29-02 at 08:37 PM.
#35
standard combustion
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what if my engine was fully built, and still NA would i still use 87 or a higher octane??
N/A = normally asperated engine. Meaning the engine draws air/fuel in using vacuum. Were as turbo engine forces air/fuel into the engine with pre-compressed air under moderate to full load.
#36
I can has a Hemi? Yes...
iTrader: (2)
Originally posted by Shyft
Okay, a complete noob here. I just started to get into cars when I bought my 82 last month Got a few questions for you guys.
The dreaded numbered list!
1)What is n/a?
2)What models were out in 82? (do I have a GSL?)
3)Doesn't it "run cleaner" to use a higher octane? Wouldn't that be a reason to use higher octane?
4)Does anyone know what octane Premium gas at Chevron is?
Thanks
EDIT- oh yeah, and what is the number included in the model? (maybe that doesn't make sense...
Okay, a complete noob here. I just started to get into cars when I bought my 82 last month Got a few questions for you guys.
The dreaded numbered list!
1)What is n/a?
2)What models were out in 82? (do I have a GSL?)
3)Doesn't it "run cleaner" to use a higher octane? Wouldn't that be a reason to use higher octane?
4)Does anyone know what octane Premium gas at Chevron is?
Thanks
EDIT- oh yeah, and what is the number included in the model? (maybe that doesn't make sense...
#37
roadkill hats rock
Join Date: Jul 2001
Location: Austin, Texas
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Originally posted by Shyft
Okay, a complete noob here. I just started to get into cars when I bought my 82 last month Got a few questions for you guys.
The dreaded numbered list!
1)What is n/a?
2)What models were out in 82? (do I have a GSL?)
3)Doesn't it "run cleaner" to use a higher octane? Wouldn't that be a reason to use higher octane?
4)Does anyone know what octane Premium gas at Chevron is?
Thanks
EDIT- oh yeah, and what is the number included in the model? (maybe that doesn't make sense...
Okay, a complete noob here. I just started to get into cars when I bought my 82 last month Got a few questions for you guys.
The dreaded numbered list!
1)What is n/a?
2)What models were out in 82? (do I have a GSL?)
3)Doesn't it "run cleaner" to use a higher octane? Wouldn't that be a reason to use higher octane?
4)Does anyone know what octane Premium gas at Chevron is?
Thanks
EDIT- oh yeah, and what is the number included in the model? (maybe that doesn't make sense...
i mean come on, look at my avatar
just kiddin
all i can say is read and read and read, ive been readin since before i joined and im just now starting my turbo project
have fun
gamble
#38
Rotary Enthusiast
Join Date: Nov 2002
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Originally posted by specRX7_22
ok heres the thing about octanes.... this was a topic with the SRX7 guys last season...
a stock rotary engine runs best with 87 octane. YES, it makes a difference, and YES, WackyRotary is right in that your probably wasting your money on anything higher with a STOCK engine.
87 octane burns a little bit slower than midgrade or premium, so the theory is.... the 87 fuel burns in a streak as a the rotor is spinning, as opposed to the Premium which would burn up almost instantly. it will also burn slower and fill the long, thin combusion chamber of a rotary. Premium will burn in a short, fat explosion like the combusion chamber of a piston engine.
--eric
ok heres the thing about octanes.... this was a topic with the SRX7 guys last season...
a stock rotary engine runs best with 87 octane. YES, it makes a difference, and YES, WackyRotary is right in that your probably wasting your money on anything higher with a STOCK engine.
87 octane burns a little bit slower than midgrade or premium, so the theory is.... the 87 fuel burns in a streak as a the rotor is spinning, as opposed to the Premium which would burn up almost instantly. it will also burn slower and fill the long, thin combusion chamber of a rotary. Premium will burn in a short, fat explosion like the combusion chamber of a piston engine.
--eric
--eric
#39
Are you gonna shift?!
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My RX-7 is turbo'ed and I ALWAYS use anything higher than 94 octane to resist detonation. This is a must have for ANY turbo car. Everybody should know that by now..jeez.
#41
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Join Date: Mar 2001
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No Alcohol
No Alcohol here at the 'ol corncrib, or in the corral. Only have the cleaning, disinfectant kind. In other words, we only burn Shell fuel as it's the last brand left that isn't mixed with alcohol since Marathon took the plunge.
Denny,
From the 'ol corncrib..
Denny,
From the 'ol corncrib..
#42
standard combustion
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here in Colorado we can get 85 octane, what about that?
Absolutely. That is why they sell it. I am sure some of us could use it in lower altutides too.
The reason they make a even lower then 87octane for the mountains is the lower RAD - Relative Air Density. The higher you go up into the atmphere the less there is and thus the lower your max PSI you will reach before igniting the mixture. And that max PSI will undoubtibly be below the threshhold of detonation/knock problems then it would be 5000ft lower, so your even farther away from detonation so lower octane is fine and will ignite with less work and uses more of the cheaper components of gasoline.
OFcourse at 5000ft, you will make less power ofcourse unless you have a turbo that will force positive PSI into your engine. If you measure the RAD at sea level its 100%, were as at 5000ft, its about 79%. So at really high places like 10,000ft, you get RAD's below 70% which is why you make less then 70% of what you'd make at a much lower altitude. So if you went REEEAALLY high up a gas below 85octane would probably work also.
Oh, some of us are using carbs instead of a EFI, don't forget to lean it out as you go higher or you will be too rich as you go higher and higher or you will make even less power.
#43
Got Boost?
Yep, 85 works fine for us high-altitude boys, and would probably be fine for you guys at sea level.... I have used 85, 87, and 91 (thats the highest they sell, until race gas...)
#44
Never Follow
iTrader: (18)
Originally posted by fatboy7
Yep, 85 works fine for us high-altitude boys, and would probably be fine for you guys at sea level.... I have used 85, 87, and 91 (thats the highest they sell, until race gas...)
Yep, 85 works fine for us high-altitude boys, and would probably be fine for you guys at sea level.... I have used 85, 87, and 91 (thats the highest they sell, until race gas...)
#46
Senior Member
iTrader: (1)
Originally posted by Jinx099
here in Colorado we can get 85 octane, what about that?
here in Colorado we can get 85 octane, what about that?
And, if I remember correctly, the 787b also ran on 83 octane.
So in reality, we'd all be better off running lower octane fuel than is comercially available. (NA only)
#47
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Originally posted by WackyRotary
Have you ever heard a carb'd rotary have run-on/desieling after shutting it off like a pistion engine does? I think not! Its design makes that pretty much impossible.
Have you ever heard a carb'd rotary have run-on/desieling after shutting it off like a pistion engine does? I think not! Its design makes that pretty much impossible.