compression and fuel

[waggl1]

I'm wanting to run 12.5:1 compression in my 383 maro. Goals are mid 10 second 1/4 miles. What grade/style of fuel should I be looking at to make this work. Many people say E85 and others say vp1xx any help out here would be much appreciated.

[Featherburner]

93 super.

[MeanTA]

What is your cam specs? knowing what cam your running can give us the dynamic compression.

May i ask why such a high static comp? 10.5 1/4 is more then capable with a lower comp.

[waggl1]

Well honestly I'm being pessimistic on e.t I usually act like that so not to truly dissapoint myself lol (I'm odd).

As for cam I cannot remember the specs off my head

[Chopstix]

if you have access to 93 unleaded it might be all you need...I ran 12.2:1 on a 246/254 .613/.590 112lsa in my 396 for several years

[Blackbird96WS6]

Is 93 unleaded that uncommon for you guys? It's at every gas station I've ever seen here in TX o.O

[waggl1]

its fairly uncommon here...i think the highest i have here is 91 unfortunately. I dont even see any E85, its very saddening to see.

[popo8]

Wow...we have 93 and 94...like everywere.


Larry (Popo8) Co-owner
LTXtech.com

[Chopstix]

on 91 you could probably drop to 12:1 or so and not have any issues and still run the numbers you are looking for...but many other factors go into ET than just CR and fuel choice

[waggl1]

Yea unfortunately Im in south dakota and we dont have the awesome fuel you guys do. We still carry #1 diesel though which is a rarity lol.

[waggl1]

Yea for sure i mean after factoring in the engine and suspension etc etc details details...i hope to get it dialed in my poor car has been neglected to long and its time i put my foot down and start doing something about it.

[MeanTA]

Yea unfortunately Im in south dakota and we dont have the awesome fuel you guys do. We still carry #1 diesel though which is a rarity lol.

Sounds like me here in Kansas. All i got is 91 and one station in town has E85. Closes 93 is 50 miles away. And next E85 is 26 miles away.

[Blackbird96WS6]

I've never seen E85 at any stations around here. We have 87, 91, 93, and diesel (not at every station, but common enough). Can get race fuel at a track though.

[waggl1]

we have 85 88 and 91

[popo8]

Looked it up...i was wrong. We have 91 & 93


Larry (Popo8) Co-owner
LTXtech.com

[CALL911]

The E85 and race gas stuff really wouldn't benefit you. This is more for guys running REALLY high CR or a slightly higher CR with boosted applications to keep them further away from detonation. Or for boosted applications that want to run more timing or higher boost and wanting to again stay away from detonation.

Most N/A cars run best just on whatever premium is in your local state. For 91 Octane, I would also say 12:1 would be the best CR.

[waggl1]

The E85 and race gas stuff really wouldn't benefit you. This is more for guys running REALLY high CR or a slightly higher CR with boosted applications to keep them further away from detonation. Or for boosted applications that want to run more timing or higher boost and wanting to again stay away from detonation.

Most N/A cars run best just on whatever premium is in your local state. For 91 Octane, I would also say 12:1 would be the best CR.

Yea with all this talk about high CR and what not i should just drop it down to 12:1 and save myself the headache of a detonation on the track later.

[1QUICKZ28]

Do you have an airport near by? I have a small one near by that I get airplane fuel from. 100 octane and it smells good. I get asked if I'm running cam 2 all the time. I mix 5 gallons to every tank of 93. I can say the car seems to hit harder at an idle and definitely runs better. They usually won't let you put it in the car while there due to no road tax. I take several 5 gallon cans to get filled. No ethanol in it either and has lead. Usually runs $5.50-$6.00 a gallon right now. Just another option.

[CALL911]

Do you have an airport near by? I have a small one near by that I get airplane fuel from. 100 octane and it smells good. I get asked if I'm running cam 2 all the time. I mix 5 gallons to every tank of 93. I can say the car seems to hit harder at an idle and definitely runs better. They usually won't let you put it in the car while there due to no road tax. I take several 5 gallon cans to get filled. No ethanol in it either and has lead. Usually runs $5.50-$6.00 a gallon right now. Just another option.

This is a big misconception about running higher than premium octane. If the car is not setup/tuned for it, you'll gain nothing. And on his N/A setup, it would be a complete waste.

Running 100LL can do damage if your car is not setup for it. Aviation fuel is NOT the same as race gas. C16 race gas would still be completely uneccisary and a waste, but at least it wouldn't do any harm.

His setup will really run best just off of 91-93 octane.

[Chopstix]

This is a big misconception about running higher than premium octane. If the car is not setup/tuned for it, you'll gain nothing. And on his N/A setup, it would be a complete waste.

Running 100LL can do damage if your car is not setup for it. Aviation fuel is NOT the same as race gas. C16 race gas would still be completely uneccisary and a waste, but at least it wouldn't do any harm.

His setup will really run best just off of 91-93 octane.

yep

[1sickta]

12.2-1 here on 93 octane even on a 200 shot.

[1QUICKZ28]

Everyone is entitled to their own opinion. Aviation fuel has no ethanol (Which causes more damage than anything) lead additive (which is a lubricant) and is rated at a higher octane(usually around 100). I run it in my car, generator, boat, weed eater, leaf blower and lawn mower. Have been for several years with no issues. It doesn't contain all the crap additives that today's fuels have either. Comes recommended from my local Stihl dealership to run in all Stihl equipment. Some of the new Stihl equipment now have fuel injection and have no issues using this fuel. As far as fuel injection goes on a car, yes it can cause damage to your O2 sensors over time. As can ethanol based fuel. Anyone have to replace their cats on their vehicles lately? Yes ethanol is bad on them. Corrosion is the number one culprit of the ethanol based fuels. I was only stating a way to increase some of the lower octane fuel by mixing it with aviation fuel. No benefits of higher octane fuel? Then why not use 87 octane? My car is tuned for 94 octane that I can get at Sunoco and runs fine on it. I can tell you from my experience that my car runs better with aviation fuel mixed in it. He's building his engine which will have to tuned and any respectable tuner will ask what octane fuel you plan on using. I have several friends that have been running this fuel for years with no issues. I'm not trying to start an argument over fuel just offering my opinion from my experiences.

[MeanTA]

with the cam specs you gave me. I would say 93 would be fine.

since its hard to find local run E85. just remember you will need larger injectors for increase flow needed. And tout need to change your fuel filter religiously.

[CALL911]

Well, let me tell you from a military and civilian pilot there is a lot more in 100LL than just the led and no ethanol that makes it bad. Ever hear of prist? This is just one harmfull additive that they mix to keep the fuel from icing when flying at altitude. There is a lot more. Aviation fuel is formulated, mixed, and meant for aircraft for multiple reasons. Race gas is meant for cars for the same reasons. That doesn't mean it's also a good idea to throw some C16 in a Cessna and go hit the skies.

There are a plethora of ways to reach higher than 91 octane. Meth injection, octane booster, hytrate, ect. All those are proven and used. But all this is pointless. His setup will NOT gain jack squat from raising the octane. His car is setup for premium. 12:1 CR will do fine on 91 octane. Why not run 87 you say? For the exact same reason he shouldn't run e85, because the car is not setup for it.

If you have gotten away with running fuel from your local airport without having anything go wrong, good for you. But I can't in good mind let you reccomend it for others.

[MeanTA]

Well, let me tell you from a military and civilian pilot there is a lot more in 100LL than just the led and no ethanol that makes it bad. Ever hear of prist? This is just one harmfull additive that they mix to keep the fuel from icing when flying at altitude. There is a lot more. Aviation fuel is formulated, mixed, and meant for aircraft for multiple reasons. Race gas is meant for cars for the same reasons. That doesn't mean it's also a good idea to throw some C16 in a Cessna and go hit the skies.

There are a plethora of ways to reach higher than 91 octane. Meth injection, octane booster, hytrate, ect. All those are proven and used. But all this is pointless. His setup will NOT gain jack squat from raising the octane. His car is setup for premium. 12:1 CR will do fine on 91 octane. Why not run 87 you say? For the exact same reason he shouldn't run e85, because the car is not setup for it.

If you have gotten away with running fuel from your local airport without having anything go wrong, good for you. But I can't in good mind let you reccomend it for others.

I agree with most of this. But i don't see why he can't run E85 if he chooses to stay at 12.5:1? he will be upgrading the fuel system anyways.

not trying to argue. Just wondering why you don't thank its a option?

[CALL911]

I agree with most of this. But i don't see why he can't run E85 if he chooses to stay at 12.5:1? he will be upgrading the fuel system anyways.

not trying to argue. Just wondering why you don't thank its a option?

Really for his setup, very little will be gained in upping the CR that little bit. True, if he upgrades the fuel fitting, lines, and pumps and gets it tuned for e85 it would be fine. But he already said e85 is not available for him in his area, and even if it was, all the PITA that he would need to go through, would not be worth the small bump in CR to use it.

Again, running e85, meth, or very high octane really is more for guys running boost that need to stay away from detonation.

[waggl1]

Wow lots of good information I appreciate it very much. I'm definitely going to be keep this in mind.

[Stephen Ertel]

I wouldn't even push 12:1 on 91 octane. I speak from personal experience. Every tank of gas is different, if you want to push it with inconsistent fuel then budget for a rebuild.

[1QUICKZ28]

I've researched this extensively and we have people on both sides of the fence. I gave my opinion and you gave yours. That's what makes America great....

[firebird_1995]

I think the "power boost" most people see from running avgas is because it makes the car run leaner.

[CALL911]

I've researched this extensively and we have people on both sides of the fence. I gave my opinion and you gave yours. That's what makes America great....

Show me 1 science proven fact from your "extensive research" that shows everything in 100LL would be good to run in a car. You won't find it. I have known people such as yourself that like how it smells, and believe that since its higher octane that everything in it must be beneficial to their car. But the truth is there are things in it that were never meant to run in cars, and can do damage. My whole point is, why the heck would you when there are MANY ways to get higher octane SAFELY (and most of them are cheaper too).

Here just ONE source showing what is going on and the damage that can occur> http://www.fuelexpert.co.za/canirunavgas.php

Unless theres a TON of ethanol in the blend, 12:1 should be fine on 91. I am running more than 12:5:1 in my Formula in my sig, and 91 octane was all I could get when I was out in the midwest for a few months. I beat that car sensless on it, and it never pinged or gave me any problems. I know that was a little much, but thats why I say 12:1 should be find on it.

[shownomercy]

Just as a FYI, for commercial aviation fuel, they are starting to add ethanol. Few of the guys who have planes at work were complaining bout it, this is NJ, not sure if its nationwide, but I would assume it will come to that.

[1QUICKZ28]

Show me 1 science proven fact from your "extensive research" that shows everything in 100LL would be good to run in a car. You won't find it. I have known people such as yourself that like how it smells, and believe that since its higher octane that everything in it must be beneficial to their car. But the truth is there are things in it that were never meant to run in cars, and can do damage. My whole point is, why the heck would you when there are MANY ways to get higher octane SAFELY (and most of them are cheaper too).

Here just ONE source showing what is going on and the damage that can occur> http://www.fuelexpert.co.za/canirunavgas.php

Unless theres a TON of ethanol in the blend, 12:1 should be fine on 91. I am running more than 12:5:1 in my Formula in my sig, and 91 octane was all I could get when I was out in the midwest for a few months. I beat that car sensless on it, and it never pinged or gave me any problems. I know that was a little much, but thats why I say 12:1 should be find on it.

Let me rephrase " extensive research" there are thousands of people out there running this with no issues whatsoever. I've only found where a couple of people blame the aviation fuel for some issues. Truthfully who knows. I work in the parts business as a manufacturer representative and when a part fails its always "the part's fault" and not the tech or improper installation. I've found some websites that say not to run due to the lead which may damage O2 sensors and cats in newer cars. (Most of these being companies that sell race fuel) The same applies to ethanol based fuels. I stated that already (I couldn't begin to tell you how many catalytic converters we sell a year since they have switched to fuel with ethanol in it). On a race engine with no cats or O2 sensors this wouldn't be an issue. You will need to re-jet to run richer due it having less density. Electronic Fuel injection would/should adjust for this. Some say the lead can leave deposits on the valves, ports etc. I've been a tech for many years in the past working on anything and everything and today's fuels leave deposits behind too. They all put additives in their fuel, good and bad, plus we also have winter/summer blends to deal with. Ever notice you get terrible fuel mileage in the winter (We all blame the cold, not the Winter blend) Any fleet can tell you when they make the switch from summer blend to winter blend. As far as higher octane being needed, as you know today's cars use a sensor to adjust timing when pinging starts which can make it hard to hear or know it's even happened. Throw some loud exhaust into the mix and well good luck hearing it before the computer adjust for it. The higher the compression ratio the higher the octane you need. High octane fuel burns slower so it won't ignite with the heat generated from the higher compression but rather with the spark plug. Hence where the pinging comes from with lower octane fuel in high compression engines, small explosions igniting before its suppose to. I'm in no way trying to be an ass here, I'm just sharing my experiences as do most on here and my opinion on what options are out there. If your cars runs fine on 87/91/92/93/94 then all is good. Everyone is entitled to their opinion and to make their own decisions in life. I do respect your opinions and concerns.

[JCzNova]

Let me rephrase " extensive research" there are thousands of people out there running this with no issues whatsoever. I've only found where a couple of people blame the aviation fuel for some issues. Truthfully who knows. I work in the parts business as a manufacturer representative and when a part fails its always "the part's fault" and not the tech or improper installation. I've found some websites that say not to run due to the lead which may damage O2 sensors and cats in newer cars. (Most of these being companies that sell race fuel) The same applies to ethanol based fuels. I stated that already (I couldn't begin to tell you how many catalytic converters we sell a year since they have switched to fuel with ethanol in it). On a race engine with no cats or O2 sensors this wouldn't be an issue. You will need to re-jet to run richer due it having less density. Electronic Fuel injection would/should adjust for this. Some say the lead can leave deposits on the valves, ports etc. I've been a tech for many years in the past working on anything and everything and today's fuels leave deposits behind too. They all put additives in their fuel, good and bad, plus we also have winter/summer blends to deal with. Ever notice you get terrible fuel mileage in the winter (We all blame the cold, not the Winter blend) Any fleet can tell you when they make the switch from summer blend to winter blend. As far as higher octane being needed, as you know today's cars use a sensor to adjust timing when pinging starts which can make it hard to hear or know it's even happened. Throw some loud exhaust into the mix and well good luck hearing it before the computer adjust for it. The higher the compression ratio the higher the octane you need. High octane fuel burns slower so it won't ignite with the heat generated from the higher compression but rather with the spark plug. Hence where the pinging comes from with lower octane fuel in high compression engines, small explosions igniting before its suppose to. I'm in no way trying to be an ass here, I'm just sharing my experiences as do most on here and my opinion on what options are out there. If your cars runs fine on 87/91/92/93/94 then all is good. Everyone is entitled to their opinion and to make their own decisions in life. I do respect your opinions and concerns.


With that being said, I think this thread might actually BELONG in the Area 51 section now. From the original post, that is no where near "Advanced Tech Only."

[waggl1]

To be quite honest jcnova I agree it could've been in another section but with as in depth and intelligent span of people we have on this site I felt that's why I should put this in the advanced tech because quite honestly when getting to the real grease and grime of it all so to speak its very hard choosing a good fuel and/or fuel additive when running a vehicle to its full potential. Yea bigger injectors larger fuel pump etc get ya going but without the right fuel the pumps underrated the injectors act like my neighbors. I maybe exaggerating but hey its a forum, embelishment is ok a little occasionally. But at least you've walked away with knowledge.

[JCzNova]

To be quite honest jcnova I agree it could've been in another section but with as in depth and intelligent span of people we have on this site I felt that's why I should put this in the advanced tech because quite honestly when getting to the real grease and grime of it all so to speak its very hard choosing a good fuel and/or fuel additive when running a vehicle to its full potential. Yea bigger injectors larger fuel pump etc get ya going but without the right fuel the pumps underrated the injectors act like my neighbors. I maybe exaggerating but hey its a forum, embelishment is ok a little occasionally. But at least you've walked away with knowledge.

I was just giving you a hard time. There is a lot to fuel, and I learned some things from the aviation fuel debate above. I wanna see that 383 N/A in the mid 10's though !

:goodluck:

[waggl1]

To be quite honest jcnova I agree it could've been in another section but with as in depth and intelligent span of people we have on this site I felt that's why I should put this in the advanced tech because quite honestly when getting to the real grease and grime of it all so to speak its very hard choosing a good fuel and/or fuel additive when running a vehicle to its full potential. Yea bigger injectors larger fuel pump etc get ya going but without the right fuel the pumps underrated the injectors act like my neighbors. I maybe exaggerating but hey its a forum, embelishment is ok a little occasionally. But at least you've walked away with knowledge.

I was just giving you a hard time. There is a lot to fuel, and I learned some things from the aviation fuel debate above. I wanna see that 383 N/A in the mid 10's though !

:goodluck:


I'll do what I can lol.

[popo8]

Anyone ever see that episode of family guy...where peter put jet fuel in his pickup truck...and imagined he was flying it like in Top Gun?


Larry (Popo8) Co-owner
LTXtech.com

[waggl1]

Anyone ever see that episode of family guy...where peter put jet fuel in his pickup truck...and imagined he was flying it like in Top Gun?


Larry (Popo8) Co-owner
LTXtech.com

I watched that last night actually haha.

[popo8]

I watched that last night actually haha.

Its all i could think of...every time i see JET FUEL


Larry (Popo8) Co-owner
LTXtech.com

[CALL911]

Let me rephrase " extensive research"

This is the only thing that makes any logical sense out of your post. I stated it earlier, there are no facts anywhere to support that everything in aviation fuel would be safe to run in your car. However, there are plenty of facts, (and trust me I could post plenty of links to them) showing its NOT safe. But you and your thousands of followers go on believing what you want.

I'm not trying to be a dick either, but I can't in good mind let people believe it is a good idea, or "safe".