Alcohol added to gas???

[benji]

Ok for one higher octane in a low compression engine hurts performance. Octane is just the rating of how slow a fuel burns, the higher the number slower the burn, also resistance to detenation. Also, the alcohol eas rubber fuel line. Thats why.

It won't hurt performance. Octane doesn't have much to do with speed of burn, it has to do with resistance to ignition. Higher octane rating means it is harder to ignite (however, a stock ignition system won't have trouble igniting it unless you have really high compression or an ignition system in need of repair). It really has NOTHING to do with performance unless your engine is higher compression (ie, H22A in our case, or a built NA F22A), and then, it is only to prevent early ignition (detonation, ping, etc). Advanced ignition timing can cause ping/detonation, so it may be worth your money/time to buy a higher octane, but not knowing how much more advanced you are running is just plain stupid. You can end up melting a valve/piston, but that's your problem.


Regarding the Alcohol, it won't do anything for you. It's mostly psychological. High cylinder temps aren't necessarily bad, and can actually help combust the gas mixture. The best way to not get carbon build up is to not buy the cheapest gas you can find. It won't do anything to compression, someone probably said that to rationalize the loss of power. It does have water in it, it will eat at the rubber.

If you want to run a cleaner through your engine, buy Seafoam, STP, etc, chemicals designed for either octane boosting or engine cleaning.

[CB710AE]

this is like spam mail

sorry but this make me laugh so hard......

[Gotz Cb7]

93 burns better. I get an extra 30-40 to the tank with 91/92/93, than I do with 87. No performance gains whatsoever though. I just run 91/92/93 here and there to clean the system out a tad.

[AccordXRacer]

Why the hell are you guys at the begining of the thread bashing on this guy? Why dont you guys educate instead of posting up something stupid. That is why he posted in the beginners section right? geez.........

[johnl]

Alcohol is less 'energy dense' than petrol (sorry, gasoline...), i.e. per unit of volume and unit of weight it produces less power, necessitating a change in fuel metering (i.e. more fuel per unit of air / oxygen) to avoid running lean and losing power. This means the fuel map needs to be changed when adding alcohol, and even then you won't see any power gains, or any other benefit come to that.

Note that racing cars using alcohol based fuels use about twice as much fuel as those using 'gas', and need to be fuel mapped to suit.

[LewiZ32]

If you are wanting something as a octane booster I would recommend going to a paint shoplike Sherwin-Williams and getting some toluene. That stuff is already in gas in a certain percentage so it is way safer than rubbing alcohol.

[H22Artman]

If you are wanting something as a octane booster I would recommend going to a paint shoplike Sherwin-Williams and getting some toluene. That stuff is already in gas in a certain percentage so it is way safer than rubbing alcohol.

why are we talking about a bunch of different things that MIGHT work ok???

instead, why dont you cheap-ass mofos just go to the auto parts store and buy the shit that is meant for boosting your numbers or cleaning your motor??

i think im gonna go add some gasoline to my beer in hopes of getting me drunker in a more efficient manner......

[ExplodingCake]

Why are you using 93 octane when the car really needs 87?
Did somebody say higher octane is better?

Lemme tell you this , putitng higher octane for a reason that it will give better performance , FALSE.

It won't , even if it does it's all in your head. Seriously. Only performance your're doing by switching to a 93 octane is donating money to the gas station.

Only reason to switch to a higher octane gas is when you have swapped to a higher compression pistons or if your car is have knocks and pings.

Otherwise , it's completely useless.

[91lxf22a1]

Alcohol will make your fuel mixture LEAN and make you engine PING (maybe detonate if too lean), ESPECIALLY since you advanced the timing. Arco gas tends to have higher alcohol levels then Chevron, 76, Shell etc, regardless of the octane. (thats why cars run like shit on arco) I personally wouldn't mess with the alcohol idea. Also i am currently running 91 octane (just to see if it made any difference) I do have a little bit more compression then stock and 2 degrees more timing then stock, so thats why i wanted to see if it made a difference. But honestly i don't notice a difference. So i'm going back to 87 octane to save me a lil $.

[chillin943]

93 burns better. I get an extra 30-40 to the tank with 91/92/93, than I do with 87. No performance gains whatsoever though. I just run 91/92/93 here and there to clean the system out a tad.

i have to agree, i get more to a tank full of gas too. when i run cheap gas such as 87 with my timing set at mid range, when i call on the a6 i get black smoke commin out of the tailpipe. not ALOT but at night with someone behind me wit the headlights on i can see the smoke. i always run high test, with the dizzy set at mid level. i expermented wit this a while ago.

advanced timing = strong low end and NO top end
retarted timing = sloooooow take off but a decent top end,
both these on high test gas.
high octance has been purified more throughly and burns cleaner, reason its more expensive. power adders such as junk u buy at autozone are pointless in my opinion. never had luck with them. but have heard seafoamin a car helps clean the gunk out of the cly head but never tried personally.
and please don't put watered down rubbing alcohol in ur car.

[cloudasc]

You cannot run e85 in your car the way it sits. To use e85 you need about 30% more fuel to air then you do with gasoline (lengthen the injector pulse, or get bigger injectors). Also alchohol does eat away at the rubber, and our cars are only mean for up to 10% alchohol in the gas, if you want to run more alchohol your going to have to change the fuel system to something compatible. Pouring rubbing alchohol in the gas tank is a trick to passing emissions. Same reason we add 10% alchohol to gasoline, it reduces emissions by 50%.

If you were only run ethenol which has an octane 105-120, you can bump up the compression ratio to almost diesel territories in an all motor build; turbo applications can also benefit from higher octane fuel (someone will have to suppliment information as i have not done extensive research on forced induction)

Alchohol also contains less energy about half that of gasoline.

[EJX_Michael]

Not for sure I set it back about a 1/4 inch or more Advancing it.
I don't know the degrees but I have had it like this for a long time and it runs fine.
My old CB7 I had I always put 93 Octane and it was fine.
Also I added Alcohol to my old CB7 and it seemed to run better.
I think I put all of a big bottle of rubbing alcohol in it too.
I'm looking into putting some E85 fuel in my CB7 some time soon like the next time I need fuel.

Changing the timing at the distrbutor just shifts the powerband around.


87 is no different from 93 except its resistance to explode under heat.

When the air/fuel mixture is compressed, it heats up. If it heats up too much, it will explode before the spark plug ignites.

This is called detonation. Detonation destroys motors.

Most cars, such as the cb7 don't compress 87 octane enough to cause it to detonate.

But, in motors considered "high performance" The fuel will compress more in the cylinders than a normal car. 87 cannot handle the heat, and will detonate. So those motors require 93 to keep the fuel from igniting before the spark plug ignites it.

87 octane is perfectly fine to run in your CB7.

The fuel companies label 93 as "premium" to get the people who don't know this to buy it.

It is fine to put 93 in, but you are wasting $.20 per gallon. If you have the extra money, go for it. But please realize that it is no different to a stock motor.


As said, Alcohol does not produce as much power per liter as gasoline.

Alcohol also destroys parts in the fuel system that are not meant to take it.

Don't put e85 in your CB7. Cars that are meant for e85 have special fuel components and have there computers programed to properly run e85.

[cali-racer]

this is gonna go on forever.

[EJX_Michael]

this is gonna go on forever.

It doesn't help that the first page was mostly useless posts.

[johnl]

In a low compression engine, the only time a higher octane petrol ('gas') fuel will either improve power or increase economy compared to a lower octane fuel is if there is some problem with the lower octane fuel, i.e. it's been cheaply or poorly blended in the first place, or it's been adulterated after leaving the refinery (does happen), or it's stale.

Stale fuel will typically have lost a significant % of it's 'lighter' elements (i.e. the most volatile aromatic chemicals) to evaporation. Fuel that sells less volume will tend to sit for longer in the storage tank, which are vented to atmosphere. The lesson here is to only purchase fuel from outlets that have a high turnover, the fuel will be fresher.

I'd need a lot of convincing that if X fuel gives some improvement in mileage, that it won't also provide at least some power increase. The two go hand in hand, i.e. a more energy dense fuel will produce more power per fuel unit consumed, and require a smaller throttle opening and less fuel consumption...