87 octane vs. 93 octane

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biker dash I read your comments and you need to do a lot more research on what you say. You have no clue. First in bring displacement and of course you can build a monster motor low compression and make 450. But the piston to rod ratio so far out motor won't last unless you idle the thing all the time that is why all top fuel engines are just 500 cubic inches. Nitro is the most explosive period. The problem is you have to compress like a diesel does which the blowers depending on where in the U.S. they are run around 60 to 1. Basically when you keep saying its pistons cams and so forth part truth but anyone can build a motor but its how you build it. I too am tired of people not knowing what they are talking about any engine running 110 octane over 92 will make more power if tune for the fuel. Finally when talking about 87 or 93 the actaul rating is the same the 93 besides moonshine it has additive to surpress detonation. I won't even begin with you math comment. Also your fuel consupmtion of nitro is the same as a small block chevy in the eighth mile 5 gallons. Go study up on nitro cars and come back to me with some real information. Also nitro motors don't have a cooling system the nitro keeps the motor cool and the 5 gallons is just enough to do burn out and run 1/4 mile run. Motor basically runs till it blows it just where on the track the motor goes. That is why the have to rebuild after every race the sheer energy released from the Nitro the motor will only last for seconds. Last comment 2013 mustang 5.0 motor runs strictly on 92 octane with 11 to 1 compression tuned to do so.
 
biker dash I read your comments and you need to do a lot more research on what you say. You have no clue. First in bring displacement and of course you can build a monster motor low compression and make 450. But the piston to rod ratio so far out motor won't last unless you idle the thing all the time that is why all top fuel engines are just 500 cubic inches. Nitro is the most explosive period. The problem is you have to compress like a diesel does which the blowers depending on where in the U.S. they are run around 60 to 1. Basically when you keep saying its pistons cams and so forth part truth but anyone can build a motor but its how you build it. I too am tired of people not knowing what they are talking about any engine running 110 octane over 92 will make more power if tune for the fuel. Finally when talking about 87 or 93 the actaul rating is the same the 93 besides moonshine it has additive to surpress detonation. I won't even begin with you math comment. Also your fuel consupmtion of nitro is the same as a small block chevy in the eighth mile 5 gallons. Go study up on nitro cars and come back to me with some real information. Also nitro motors don't have a cooling system the nitro keeps the motor cool and the 5 gallons is just enough to do burn out and run 1/4 mile run. Motor basically runs till it blows it just where on the track the motor goes. That is why the have to rebuild after every race the sheer energy released from the Nitro the motor will only last for seconds. Last comment 2013 mustang 5.0 motor runs strictly on 92 octane with 11 to 1 compression tuned to do so.





Ok, Now, I have to ask myself this; WHY am I even thinking of arguing with someone whose writing is on par with a 5th grader with a love for War and Peace length paragraphs. also, would you learn to think out your posts into something that is a little more readable? PLEASE!

Now, as I explained in my last reply to you, comparing a dedicated race car engine designed to burn a fuel completely different than what is found in any sort of car you would drive on the street is utter nonsense. It is an Apples to "What kind of meth laced crack are you smoking" comparison. And yet, you're still harping away on this. The rest of your reply to me was just as bad, being run-on and nearly impossible to read. It seriously hampers any intelligent conversation.

What little bit I have been able to pull from your reply, it just tells me you know a lot about nothing at all. I have seen more intelligent conversation at a convention with a 9 year old pest who has watched a grand total of four episodes of Dr. Who, and now has to tell me every single reason why David Tenant is his personal God and Savior.

PLEASE, For the love of Luna and all her Creation, PLEASE write your next reply with ALL of your brain cells engaged.

https://www.youtube.com/watch?v=5hfYJsQAhl0
 
There are oodles and oodles of "typical", normally aspirated, small block Chevrolets, that will spin to 6500-7000 making 450-500 crank on 87 octane, it's been done for decades without doing anything weird to get there.........

I would like to know what small block Chevrolet burning gasoline consumes 5 gallons in a 1/4 mile...Really, I do, my curiosity is killing me on this one...:rofl_200::rofl_200::rofl_200:
 
This is beginning to look like one of those "best oil" threads... :rofl_200:
 
Look you blend the fuel 2 gallons 93 to 1 gallon 110. The reason you burn up the 02 is motor runs more efficient timing & fuel make the motor too lean because the 87 dakota computer set to run poor gas not good stuff. Your max will run better but don't run straight 110 octane your jet setting are not right to run really good gas. Look go to drag strip & go by the cars running in the pit the motors that run really good 110 octane and higher will be cleaner. Your old 68 was carbed just like you max. Just don't run pure due to the little motor not getting ready of the heat fast enough but your max will run better than it ever has. Don't run all the time either because if you go say 2 gallon 110 to one gallon 93 you bike will run hotter and if your cooling system is weak you will over heat your bike. Other than that you should be fine.

my 87 dakota was carb. as well, no computer on it. 2.2 liter inline 4. 2 barrel carb. worked like a 4 barrel, push it to the floor the 2nd barrel opened up, not sure why they put an 02 sensor on a carb. engine.:bang head:
 
2013 mustang 5.0 motor runs strictly on 92 octane with 11 to 1 compression tuned to do so.

Actually it's dual rated for 87 or 91, with separate horsepower ratings for each.

The engine is BUILT, not TUNED to utilize 91 octane.

Being loaded with electronics, namely electronic spark control and detonation sensing electronics, it TUNES it self to operate at a lower octane at the cost of about 10hp according to the manufacturer.

It does this by retarding the ignition advance to keep it from detonating allowing you to run 87 in it.

But nonetheless it's BUILT, not TUNED, for 91, it's SELF TUNING to allow 87 at the cost of performance.....

You can't do this the other direction though, you can attempt to advance ignition on a lower compression motor to the point that you need higher octane to keep it from detonating. But you can only go a very small amount with this, basically taking up mfg. safety margins before the performance advantage becomes negative.....
 
rebeltaz83;371153not sure why they put an 02 sensor on a carb. engine.:bang head:[/QUOTE said:
Not for engine management, but for a tattle tell on the cats. Modern cars still do the same. The 02 sensor before the cats is for engine management, the 02 sensor after the cats is just a tattle tell on cat condition...
 
Not for engine management, but for a tattle tell on the cats. Modern cars still do the same. The 02 sensor before the cats is for engine management, the 02 sensor after the cats is just a tattle tell on cat condition...

all i know is that thing was burned right off to the threads nothing left, and it looked like it cut off with a torch. and the cat was..........well there but not working, like it supposed to...... 110 smelled good, but never saw any difference performance wise, and that was 12 years ago when i was in school.
i'm just baffled on my max, why everybody says they get great mileage and performance on 87.... i been using 87 with 10% ethanol...... i ran 4 tanks of 93 with 10% ethanol and i get more power, and better mpgs. i'm just baffled :ummm:
 
Agree.....and specifically with a Gen 2, 89 makes more power than 92 or 93.
I know you know your shit on the gen 2's but do you have track testing to support this? Again I'm not saying you'll gain horsepower with higher octane gas, I'm just saying that you won't actually lose any either unless it's a really lopsided case like I mentioned earlier. I like using a little more octane if it's not too much cost difference, a little more room for forgiveness on your tune and as I've said, I've NEVER seen it actually cost horsepower except in extreme cases.
 
I know you know your shit on the gen 2's but do you have track testing to support this? Again I'm not saying you'll gain horsepower with higher octane gas, I'm just saying that you won't actually lose any either unless it's a really lopsided case like I mentioned earlier. I like using a little more octane if it's not too much cost difference, a little more room for forgiveness on your tune and as I've said, I've NEVER seen it actually cost horsepower except in extreme cases.

That's what I was told by Tim Nash who has many, many dyno runs with Gen 2's under his belt and some track time with Jay Gleason as the pilot
It's not a huge difference, maybe a couple of HP.

I believe your results 100%. The difference I'm guessing is that he has the ability with an FI engine and access to all of the timing parameters, to tune for different octanes. Where as in your case the "tune" is pretty much staying the same and you are just changing fuels.
 
I don't doubt 5 gallons a run on a dragster that burns alcohol, methanol or nitromethane.


My doubt was for a GASOLINE burning V8 to consume that amount of fuel.
Maybe in the Pro-Stock class, but seeing as the 4-5 gallon per run is the number always thrown out there for Top Fuel and Top Alcohol classes that run in the 2:1-3:1 a/f range I doubt the gas classes, utilizing a much leaner a/f, burn that much??
 
That's what I was told by Tim Nash who has many, many dyno runs with Gen 2's under his belt and some track time with Jay Gleason as the pilot
It's not a huge difference, maybe a couple of HP.

I believe your results 100%. The difference I'm guessing is that he has the ability with an FI engine and access to all of the timing parameters, to tune for different octanes. Where as in your case the "tune" is pretty much staying the same and you are just changing fuels.
Very good point, in any case I believe it to be just as you said that there's so little change that it probably wouldn't even show up in the real world.
 
Speaking of octane, what's anybody's experience with higher octane running Vgas carbs? I'm curious to hear what octane other Vgas guys are running.
 
I guess I'll jump into this mess too. The lowest octane you can run makes the highest power. The reason is that Octane, a single component in a blend, burns slowly. The higher the percentage of octane, or the higher the octane rating, the more slowly the blend will burn. Burning slowly means that under some circumstances the fuel will still be burning as it exits the cylinder. After it's out of the cylinder and in the exhaust, it has almost zero impact on generating power.

So, you want the fuel to burn fast enough that it finishes burning in the cylinder, but not fast enough to detonate or ping severely. Anything more than that is wasted in the exhaust.
 
I guess I'll jump into this mess too. The lowest octane you can run makes the highest power. The reason is that Octane, a single component in a blend, burns slowly. The higher the percentage of octane, or the higher the octane rating, the more slowly the blend will burn. Burning slowly means that under some circumstances the fuel will still be burning as it exits the cylinder. After it's out of the cylinder and in the exhaust, it has almost zero impact on generating power.

So, you want the fuel to burn fast enough that it finishes burning in the cylinder, but not fast enough to detonate or ping severely. Anything more than that is wasted in the exhaust.

sooo hows that work with my case?? 3 gallons of 93 octane 10% ethanol at 98 miles compared to 87 octane 10% ethanol with almost a 4 gallon fill up at around the same mileage.... and like i said i noticed the power difference with the vboost, and the throttle response is so much more crisp. it was 3.1xx gallons with 93....... and with 87 it's right around 3.9xx gallons around the same miles... sometimes it's about 96 miles or 95. i don't go over 100 unless i really have to..... and i ride like a dick most of the time...... sometimes i putter around. depends on my mood.
 
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