splcrazy

just want to know if you can add octane booster to 2stroke fuel mix for the baja ??? i use 98 octane fuel mixed with 2stroke , will adding octane booster make it go even better or damage it ?

cobaltltblue

i read a article in a car magazine where they took 5 "octane boosters" and tested Chemically how they worked and IF they worked. NOS was the only one that did what it claimed. as for an R/C motor? unless you have a custom motor it will not help a bit. all higher Octane does is fight Predetination on high compression engines. it does not "Make more Power" just use regular 91 octane and be done with it.

MBX5T Maniac

My Feedback: (-1)

the higher the octane, the less volatile it is, meaning that it's not as powerful. That is the reason you need to go up a grade with fuel if your car is knocking. The octane rating of gasoline tells you how much the fuel can be compressed before it spontaneously ignites. When gas ignites by compression rather than because of the spark from the spark plug, it causes knocking in the engine. Knocking can damage an engine, so it is not something you want to have happening. Lower-octane gas (like "regular" 87-octane gasoline) can handle the least amount of compression before igniting.

The compression ratio of your engine determines the octane rating of the gas you must use in the car. One way to increase the horsepower of an engine of a given displacement is to increase its compression ratio. So a "high-performance engine" has a higher compression ratio and requires higher-octane fuel. The advantage of a high compression ratio is that it gives your engine a higher horsepower rating for a given engine weight -- that is what makes the engine "high performance." The disadvantage is that the gasoline for your engine costs more.

In other words, you would need to increase the compression ratio to increase power, and as a result, you need higher octane fuel.
Just using higher octane fuel won't increase performance.
If a person thinks that higher octane means more performance, that's an easy way to tell they have no clue as to what they are talking about.
So to answer your question, no octane booster won't do anything for you

PAPE

You will actually have gains in power from lower octane.

webdr

All true, I dont see why there is such a popular misconception that high octane gas is a power booster...

MBX5T Maniac

My Feedback: (-1)

People just think bigger is better. I guess it's better, since you can easily pick out the idiots this way, no?

cobaltltblue

hey guys i already said all that..

kennyrccars

Higher octane fuel will make your engine run cooler.

Baja5BLST

Simply put, do not use a higher octane fuel unless your engine knocks, which is really shouldn't. Normal gas is fine. No need to get any special fuel, or octane booster. By using octane booster, you are more likely to lose performance more than anything.

PAPE

you will have gains in power if you run higher compresion and advance ign timing......

To run correctly after those 2 mods you have to run a higher oct, and if you go overboard Alcohol.

in our engines you can alter ign timming by moving the flywheel, but there is a key that puts it in place and you cant move it

Baja5BLST

Pape is right, you must run higher octane fuel if you increase the compression ratio.
But just running higher octane fuel by itself, there are no gains.

MrMikeG

Higher octane raises your exhaust temps as more unburnt fuel exits the exhaust due to slower burn.

PAPE

I dont know about this how would you go arround that Ign andvance???

MrMikeG

This bottom end from QD let's you advance the ignition by moving the coil. Sorry, that is for a boat motor but you get the idea. [8D]

PAPE

on my zenoah I cut small slit into the flywheel where the flywheel key goes and I advance timing on my engine like that I have it about 5 degrees adv from factory but all I run is coleman fuel havent tried the timing advance with pump or race gas

Earth Surfer

I agree with most of what is said---for most engines. But it seems like these small RC engines break some rules. Why do I say that? The stock GP290 cylinder is at leat 18:1 for the compression ratio, and I am sure there are at least 1000 kids running them on peds on pump gas with no holed pistons or detonation problems. Also more compression, with higher octane fuel and advanced ignition = less top RPM.

ttoks

two stroke engines can run much higher compression ratios then 4 stroke because there are no hot spots like the valves in a two stroke, thus the temp of the cylinder itself is lower allowing for a higher compression ratio.

MrMikeG

Doug is right, most times you are slowing your motor down, the only motor I know of that benefits higher octane is the QD's.

ttoks

any engine will benefit from high octane fuel by just milling a few hundredths of a millimeter off the cylinder head to increase the compression.

PAPE

I used to have a poulan 46 (chainsaw motor 46cc) on my goped a few years back I would run 89oct this goped was really fast and the most intresting thing was the stock motor, once I was in high revs I could cut the ignition and it would never shut of I could keep going and going unless I dropped my rpms to low. mabye there I needed higher oct.

as for the timing and compresion WHY do you lose rpms my rasing compresion andadvancing timming, I know I have read this before but I dont understand WHY. Dont you make power power meaning moving the power band higher by advancing timming? and the compresion?

MrMikeG

After a certain point too much compression is like too much drag.

ttoks

you move the power band later by advancing the ignition timing (moving it before top dead center) because it takes a certain amount of time for the fuel to completely burn and reach it's maximum pressure, but as the engine revvs higher it has less time to do this so you advance the timing so that once the piston gets to top dead center at high revvs the pressure is at it's maximum pressure giving the most power.

more compression never creates to much drag, the combustion pressure will always go up in conjunction to the compression ratio by a factor of around 3, so if the compression ratio of the engine is 10:1 the combustion ratio will be aprox 30:1, but if the compression ratio is 20:1 the combustion ratio will be aprox 60:1 ect, so if you double the compression ratio, you get almost twice as much power despite the extra power needed to compress the air/fuel charge.

MrMikeG

increased compression decreases the over run.

crrcboatz

My Feedback: (34)

Some of you guys need to get yourself a good laser temp gun. Check the run temps with the 98-110 octane you are running. Next day tank up with some 89 and run it the same amount of time and then check temp in the same area (on the cylinder near the exhaust port or better yet just above it) you will find the high octane makes these engines run quite a bit hotter! Been there done that. As for compression/hp, higher compression will decrease rpms and broaden the power band BUT at a price, and that is speed. Speed comes in these small engines from rpms. Been there done that too.

Curt

TheFgMan01

^^ Can you tell the difference between running the 89 vs the 93??