I Tried Race Fuel This Weekend At $6.50 Per Gallon, The Hemi Screems With 104 Octane. Worth It??????? I Am Going To Buy Heads And A Cam From The Fastman Next.
goathead75
02-22-2005, 06:23 PM
Hmmm, so....roughly $180 to fill the tank. For that price it better do more than scream. It better screw, do my taxes, mow my lawn, take the trash out and balance my checkbook....which would be easy being at $0.00 after running that stuff. I think I'll pass. :D Probably be fun to try once or twice though....still tough to justify the price.
Monkey Bus
02-22-2005, 07:18 PM
I don't think the ECU could possibly be programmed to advance the timing enough to enjoy anything over 94.
DSW
02-22-2005, 09:17 PM
That's About All I Wanted To Do, Try It Out. Not Anything I Plan On Doing Again Soon.
RoadKill05
02-22-2005, 10:40 PM
I Tried Race Fuel This Weekend At $6.50 Per Gallon, The Hemi Screems With 104 Octane. Worth It??????? I Am Going To Buy Heads And A Cam From The Fastman Next.
All in your head. People think that high octane gas is like nitrous or something. Your rig actually got slower. If your computer is programmed for 89 octane then what would the point be to run a gas that burns slower. The computer would have to advance the timing about 6-10 degrees to take advance of the 104. Sorry dude, you totally wasted your money. Now getting a tankful of 104 and then putting a 100 shot of nitrous on it, that is another story :rck:
DSW
02-22-2005, 11:56 PM
don't speak of what you haven't tried. extra boost is not imagined. i know how the truck drives pre mods and post. there was an extra boost without fail.
JamesJ2525
02-23-2005, 12:01 AM
I ran 220 octane aviation fuel one time in my lawn tractor. It will make a difference. Now rather or not for better or worse is to be determined. This thing detonated like no other because the timing was off, BUT, becuase of such a high octane rating when it burned it put off a buttload of energy. I am not kidding you when I say I was popping wheelies with this 14 hp lawn tractor. Now, I did burn a hole in the piston and bent a connecting rod, but it was worth it for the 10 minutes it ran.
07HEMI09
02-23-2005, 12:03 AM
My uncle tried it on his chevy. Took it to the track and it did help out. Not sure about the numbers though.
RoadKill05
02-23-2005, 12:03 AM
don't speak of what you haven't tried. extra boost is not imagined. i know how the truck drives pre mods and post. there was an extra boost without fail.
Unless you have a SC on your rig then it was wasted with no performance. You just have to understand what octane is. BTW, if that was real race fuel then you just took a chunk out of the lifetime of your O2 sensors. O2 sensors hate race fuel. Alot of people know that super high octane fuel without time advance will do nothing. The only time you can benefit from 104 is either: lots of time advance, high compression ratio, or some time of forced induction ie supercharge turbo nitrous.
07HEMI09
02-23-2005, 12:06 AM
Unless you have a SC on your rig then it was wasted with no performance. You just have to understand what octane is. BTW, if that was real race fuel then you just took a chunk out of the lifetime of your O2 sensors. O2 sensors hate race fuel. Alot of people know that super high octane fuel without time advance will do nothing. The only time you can benefit from 104 is either: lots of time advance, high compression ratio, or some time of forced induction ie supercharge turbo nitrous.
Thats true, He had to replace some things after using the fuel several times. :crazy:
JamesJ2525
02-23-2005, 12:08 AM
Geez, you people need to chill. Its not even your vehicle and you are so quick to jump on the fact he is lying. There are 3 people here who can verify gains as I did. So, I don't think all 3 of us are lying.
DSW
02-23-2005, 12:09 AM
funny how any chip or programmer tells you operation is best at 92+ octane. it's just something i wanted to try but is cost prohibitive. one thing was gas milage went down quite a bit or so it seemed, hard to tell when gunning it all over.
RoadKill05
02-23-2005, 12:23 AM
Geez, you people need to chill. Its not even your vehicle and you are so quick to jump on the fact he is lying. There are 3 people here who can verify gains as I did. So, I don't think all 3 of us are lying.
Geez, maybe you need to chill. I never said he was lying and if it sounded like that then I'm sorry. I just meant that sometimes the butt'o'meter is somtimes not the most accurate. I just try to tell people sometimes things I have learned in the course of my automotive schooling and the racing I have done.
The reason they say it works best on 92 is cuz one of the ways the chip companys get more hp's from the engine is to advance the timing. And when you advance the time past a certain point you have to raise the octane of gas you use, to take full advance of the tuning they did.
JamesJ2525
02-23-2005, 12:28 AM
Yes wth proper timing it will work better, I agree. Go dump in a few gallons in your ride and make some 1/4 mile runs. It may not run right on a stock setup, but the times will go down a little.
My lawn mower was damn good verification of this, LOL.
goathead75
02-23-2005, 11:56 AM
Dude, I just want to try the aviation fuel in my tractor now. :rck:
JamesJ2525
02-23-2005, 12:00 PM
When I sold and serviced power equipment I worked with a retired navy seal who had access to the stuff at the local airport. I can't imagine how much it costs if you were to pay. He brought me 2 gallons to play with. Pretty potent stuff. I would love to build up a lawn tractor motor to run on it.
bbodyguy
02-24-2005, 09:18 AM
Ah, comeon guys!
I'm raising a big BS flag here!
A) More octane does not equal more performance. Actually, there are FEWER BTU's per gallon as octane increases. If the engine is setup with 89 octane timing, increasing it DOES NOT, WILL NOT, CAN NOT make you faster. You may THINK your faster, but your not. Octane is only a number that defines how fast fuel burns/flame front propagation/vs. pressure. Thats it. And things that are added to reduce the detonation and raise octane, such a lead in av fuel, HAVE NO NUTRITIONAL VALUE towards making your D faster.
B) No such thing as 220 avaition fuel. It does go to 100, and that has lead in it. Go ahead, put some in your D and see how long your O2's last.
C) Small engines have VERY LOW compression, maybe 6 or 7 to 1, and will see NADA from a higher octane. Could'nt tell if that poster was yanking or not, but it's pure, unmitigated BS. Maybe if he added some oxidizer (NOS), and richened it up via a plate, you could get some serious power out of a lawn engine. I always fantasize about this with my snowblower!
You will never convince me that 106 racing fuel in an engine not set up for it made you go faster, because it won't. Period. Perceptions are a hard thing to divorce from wish's subscribed to in the name of performance. Get it on a dyno and PROVE it to yourself.
Monkey Bus
02-24-2005, 12:00 PM
yeah...the 5.7L Hemi Magnum is only 9.6:1--so you don't need anything higher than 89 to prevent knock--and knock prevention is the only thing you need a higher octane rating for.
The race fuels like Sunoco GT Plus (light blue) 104, GT Standard Unleaded (purple) 110, and suchlike are for use when your compression ratio is high enough such that you get knock or pre-detonation with lower octane fuels--like if you have a HEMI crate motor that you worked over.
I had a 1972 Dodge Demon with a worked over 340 Six pack--had about 10.5:1 and I only ever had to use Sunoco 94 in cooler weather, and Sunoco GT 100 (clear) in hotter weather.
ECU Chips that require premium fuel (even then only 91 or 92) often simply advance the timing a bit to change the power/torque curve. With factory tuning on a 9.6:1 engine, you're just wasting money with anything over 89.
Unless you're boosting, increasing the compression ratio, or advancing the timing, stick with what the book says.
JamesJ2525
02-24-2005, 12:43 PM
Ah, comeon guys!
I'm raising a big BS flag here!
A) More octane does not equal more performance. Actually, there are FEWER BTU's per gallon as octane increases. If the engine is setup with 89 octane timing, increasing it DOES NOT, WILL NOT, CAN NOT make you faster. You may THINK your faster, but your not. Octane is only a number that defines how fast fuel burns/flame front propagation/vs. pressure. Thats it. And things that are added to reduce the detonation and raise octane, such a lead in av fuel, HAVE NO NUTRITIONAL VALUE towards making your D faster.
B) No such thing as 220 avaition fuel. It does go to 100, and that has lead in it. Go ahead, put some in your D and see how long your O2's last.
C) Small engines have VERY LOW compression, maybe 6 or 7 to 1, and will see NADA from a higher octane. Could'nt tell if that poster was yanking or not, but it's pure, unmitigated BS. Maybe if he added some oxidizer (NOS), and richened it up via a plate, you could get some serious power out of a lawn engine. I always fantasize about this with my snowblower!
You will never convince me that 106 racing fuel in an engine not set up for it made you go faster, because it won't. Period. Perceptions are a hard thing to divorce from wish's subscribed to in the name of performance. Get it on a dyno and PROVE it to yourself.
Would you like to go ride on my lawn tractor? Its easy to sit back like you are waive the BS flag, but the bottom line is you weren't there so you have no idea. So stop waiving your BS flag at me, IT DID HAPPEN. We never said we were going to put aviation fuel in a Durango. But you knew that, because you read the entire thread, right?
I think its sad how people will chime into a thread that is fun in nature and feel necessary to ruin it with posts like this.
marpol
03-10-2005, 12:26 AM
Octane is a simple measure of how much compression a gas can take without spontaneously combusting. In itself is has NO effect on the horsepower of an engine. It is strictly used to reduce knocking. It can on the other hand indirectly effect performance by allowing an engine to advance its timing (witch would normally produce knocking) and therefore improve the performance of the engine. It is my guess that the increase in performance experienced by putting avgas in a tractor was not the result for the higher octane (the tractor timing was probably not computer controlled and therefore could not advance itself) but the fact that jet fuel is made of Kerosene not heptane and octane (the chemical not the rating) like autogas is. Kerosene stores more energy per unit then autogas dose therefore giving you an increase in power (and in the process destroying the engine). Or it had to do with and additional additives in the gas. Here are some good links to learn more about gases.
science doesn't lie...i'm with the ney sayers on this one....higher octane DOES NOT equal more ponies under the hood!
JamesJ2525
03-10-2005, 12:49 PM
Octane is a simple measure of how much compression a gas can take without spontaneously combusting. In itself is has NO effect on the horsepower of an engine. It is strictly used to reduce knocking. It can on the other hand indirectly effect performance by allowing an engine to advance its timing (witch would normally produce knocking) and therefore improve the performance of the engine. It is my guess that the increase in performance experienced by putting avgas in a tractor was not the result for the higher octane (the tractor timing was probably not computer controlled and therefore could not advance itself) but the fact that jet fuel is made of Kerosene not heptane and octane (the chemical not the rating) like autogas is. Kerosene stores more energy per unit then autogas dose therefore giving you an increase in power (and in the process destroying the engine). Or it had to do with and additional additives in the gas. Here are some good links to learn more about gases.
This was not jet fuel like you are mentioning. High octane gasoline used for small propeller aircraft.
DamnYankee
03-20-2005, 07:43 AM
both sides of this arguement are right...and wrong. Having a chemistry degree with a minor in physics, here's the basic nuts and bolts of octane:
1. As we know, most automobile engines are four-strokers and the upstroke or "compression" stroke is where the air/fuel mixture ignites.
2. What Octane is: how much gasoline can be compressed before it SPONTANEOUS ignites. We all know "Knocking" occurs when lower octane fuels is used. How does that occur? It occurs when gasoline inside the cylinder is ignited by compression INSTEAD OF THE SPARKPLUG. The lower the octane, the more apt the gas will ignite by compression instead of the sparkplug (a bad thing!)...and that reduces the horsepower of your motor because exploding by compression is not as powerful as igniting the fuel.
Everyone clear on that?
3. What higher Octane CAN do is MAXIMIZE YOUR ENGINE'S HORSEPOWER CAPABILITY. It does NOT create horsepower. To maximize your engine's horsepower, you want the gasline in the cylinder to explode by spark plug and not by cylinder compression (knocking). Lower octane fuels WILL drop your motor's horsepower because lower octane fuels tend to have more explosion by compression vs. spark plug ignition.
OK so far???
Conclusion: Using higher octane fuel ONLY MAXIMIZES your engine's true horsepower. It does NOT add "extra" horsepower. It is true those engines will ran faster on the higher octane fuels, but that was because the higher octane gas exploded completely by spark plug ignition and not by compression - and that my friends maximizes the horses in your motor. HOWEVER, the downside of higher octane fuels: since explosion is caused by spark plug ignition (vs. compression), the chambers WILL GET HOT and WILL melt pistons!
As an FYI: Compression ratio is what dictates horsepower. The higher compression ratio you use, the higher octane you must use to prevent the "knocking" (compression causing fuel ignition). A 7.5:1 engine may run fine on 87 octane, but a 12.5:1 engine on 87 octane will probably knock like hell.
THEGAME22193
03-20-2005, 06:21 PM
thank you for the lesson ( no disrespect ) but if someone tries something and they believe it made and improvement nothing people say will change that, until you do the same and prove that person wrong.
my .02c
DSW
03-20-2005, 10:14 PM
i made the original post. i have added every available mod to my hemi and since the electronics outfit recomends at least 92 octane per timming advance i thought i would try race fuel. that's it, i didn't make any wild claims. the truck ran better than it normally does. the fools who don't think octane is an issue are lost. try the 104 if you can afford it and see how much better the hemi runs. i have not fueled up with 104 since or plan it anytime soon. it was fun on the freeway!!!!!!!!!!
THEGAME22193
03-20-2005, 11:05 PM
i am glad you had fun with it . i did alot mod. to my D too and i run 93 even thru the false or true statements some people make here . bottom line is good or not i will keep doing what i am doing because that's what i believe even if I am flushing my money down te toilet. SO BE IT.
DSW
03-20-2005, 11:11 PM
if i knew it would cause the stink it did i wouldn't have posted it. everyone is an "expert" i am glad someone can relax. i use 91 with a booster and it flat out runs better!!!!!!!!!!!!!!
DaveLeg
03-20-2005, 11:44 PM
DSW, When you say "Better" does that include Better MPG ? On average I only drive a total of six miles in the city but at $2.25/gallon and rising my 9.8 mpg sucks.
DSW
03-21-2005, 12:07 AM
in ca 91 is about $2.50+ i get on average of about 12mpg hot rodding around. if i drive it per the law i have seen 19mpg. my next mods will be per the fastman, rebuilt heads, cam and intake. i am still waiting to hear if the new programers work or not.
DamnYankee
03-21-2005, 02:14 PM
What you say is true...
However when it comes to combustibles, the Law of Nature rules. Higher grades of gasoline is more explosive and burns hotter and that maximizes the engine's horsepower capability.
If you took a can of gasoline and compressed it in a hydraulic press, it'll explode. Take that same can of gasoline and put a match to it and it will explode. Common sense will tell you which method will cause the bigger, more powerful explosion.
The same thing occurs in a cylinder.
For those who are still non-believers:
1. Empty your gas tank, put Sunoco's 86 octane in your hemi and do a few 1/4 mile runs. Then...
2. Empty your gas tank and put in 93 or 100 octane and do a few 1/4 mile runs.
3. Compare the 2 sets of numbers...I can guarantee you they will *not* be the same.
Proof is in the puddin' guys...
DY :)
bbodyguy
03-21-2005, 07:08 PM
That's because 86 octane is significantly less than what is required for full hemi programing. It sure as he11 is gonna start pinging with 86 and full bmep.
When it starts pinging, the pcm is going to pull timing and reduce output.
I just doubt gains from going ABOVE 89 octane. This is where the engine and programing have been optimised.
Oh - Mr. Chemist: What has more BTU's per gallon? 86 octane or 100 octane?
DamnYankee
03-22-2005, 12:14 AM
Methanol has less than half the BTUs than Gasoline...but ya mix it's hydrocarbon structure with some oxygen and a little spark, yer gonna make a pretty damn big hole!
And computerization aside, the fact of the matter is: the higher the octane number, the more fuel explodes in cylinder by ignition vs compression.
Ya can't increase horsepower with higher octane, but ya sure can make your engine maximize what horsepower she has.
It ain't worth arguing over, Dude...we agree to disagree.
Monkey Bus
03-22-2005, 04:57 PM
Now, if we could all quit fapping about with regards to our scientific credentials, lawn mowers, and what Richard Petty told us over a beer at bar near Darlington and if someone would get a Dyno chart of RWHP/torque with 104 and one with 89, then the matter would be solved once and for all.
Until I see two jpegs/pdfs with said charts posted here, not one word of this thread means crap to me, and I'll use what the book says and hold the opinion that (without significant timing advance) the Hemi runs on 89 as it does on 104.
EDIT: Link 1 (http://www.rxp.com/Octane.htm) and Link 2 (http://www.hotrod.com/techarticles/72498/)
JamesJ2525
03-22-2005, 05:59 PM
Now, if we could all quit fapping about with regards to our scientific credentials, lawn mowers, and what Richard Petty told us over a beer at bar near Darlington and if someone would get a Dyno chart of RWHP/torque with 104 and one with 89, then the matter would be solved once and for all.
Until I see two jpegs/pdfs with said charts posted here, not one word of this thread means crap to me, and I'll use what the book says and hold the opinion that (without significant timing advance) the Hemi runs on 89 as it does on 104.
My lawn mower wont fit on a dyno genius. :thatfunny :crazy:
