Food For thought... Octane

[Dawzey]

this came to me from somebody in the fuel industry(no names or brands)

"What`s the benefit of higher octane?

Higher octane fuel has only one beneficial feature- it allows an engine to run at higher temperatures with more advanced ignition timing under higher levels of compression without detonating/knocking. higher octane fuel does NOT have more potential energy and will not make an engine perform better unless that engine is knocking. on modern engines with knock sensors, higher octane fuel may make the engine run better if the knock sensors are retarding the ignition timing, which hinders performance. high octane fuel does not burn cleaner, it does not clean your engine. it does not increase horsepower or torque(unless your engine is knocking), it does not smell better, it does not increase fuel economy(unless knocking)and it is not better for the environment. "

[2rismo]

Don't some of the fuel co's use additives to the high octane fuel that "clean" the engine?

(Whatever that means!??!?!)

Not neccessarily to do with the RON/MON of the fuel... i.e. the fuel would be 98RON with or without it but they ONLY put the additives in on this premium fuel...

Adrian

[Dawzey]

yeah i was thinkig about that, the reason i posted was because of the money i wasted on octane booster, imean car car shot flames out the back of it but when i dynoed it one day and got less then normal i started looking at fuel maps and boost settings and everything except my fuel.

fuel co`s recomend to use the premium fuel in cars because it cleans out your motor but don`t by it because it will give you more power. who has dynoed there car to see a diff in premium and 95?? it is easy to show a 15KLW gain on the side of a bottle, but there are to many varibles to justify that gain. ,, wheather, temp, where the tests were done, or even which test was done first. these all come into play when you read off a dyno.

[predator]

What sort of octane booster were you using? Some are pretty much useless...

I had one which actually does bump it up a few points (and actually claimed to guarantee that), but it was $20 or so for a little bottle that would do maybe 1/2 -> 1 tank. The others I looked at were very vague "gives increased performance, blah, blah" but no actually RON increase so was suspicious.

You're best off with avgas or toulene or the like though if you're serious.

To be honest, I switch readily between 95RON and 98RON depending on availability and what service station i turn up at, but notice no discernable difference to my cars smoothness or power.

[Dawzey]

i paid $20 for a bigger bottle i think it did 2-3 tanks

maybe the one u used increased the power another way. i would have no idea how but after doing some research on this i can`t see how octane could increase power.

[red900ss]

Increasing the octane rating will, as you top post says, allow the fuel to burn and not detonate. The engine developes more power when burning fuel rather than exploding fuel.

[Dawzey]

yeah so i take it that you have to spend the big cash to get octane booster to burn the fuel....

[51jay]

The best octane booster for our usage is Toluene. There have been several threads on this. Add approx 5% to bring octane rating up just over 100. You qote reasons why it gives more power in your first post, if you reread it carefully. It will ONLY benefit if you tune the motor up to the new octane rating

[RNS11Z]

I used (tolune) 10litres to a full tank. Not sure what that works out too but gave me an extra 70rwhp. With just normal bottle octane booster from Hardcore Racing gained 30+rwhp

[Abo Bob]

Haven't tried it with the line but with my 99 SSS there's no way you could say either that it was lacking power on normal fuel (ie pulled timing) or that it didn't gain it from using high octane stuff.

Don't ask for technical explanations (or a dyno reading) but that's what I think.

[edgasket]

The best octane booster for our usage is Toluene. There have been several threads on this. Add approx 5% to bring octane rating up just over 100. You qote reasons why it gives more power in your first post, if you reread it carefully.     It will ONLY benefit if you tune the motor up to the new octane rating

Can you just add the toulene to your regular fuel? it doesn't do any damage to seals or anything like that???

[Big Twin]

hi guys,

Believe it or not lower octane fuel is more voliatile than the higher octane. So using lower grade increases the chance you will get detonation before tdc and hence loose power, not convinced the octane booster's work but over here we always put 98 ron in when we can!!!!!

[edgasket]

hi guys,

Believe it or not lower octane fuel is more voliatile than the higher octane. So using lower grade increases the chance you will get detonation before tdc and hence loose power, not convinced  the octane booster's work but over here we always put 98 ron in when we can!!!!!

That's the point we're making though? nobody wants knock, we want to be able to advance the timing a bit and run more boost without worrying about putting a hole in the top of a piston... i agree though, that the best thing is to just run the best fuel you can find and then maybe throw some booster into that, rather than running 95 octane and a ball of booster to try compensate.

What about methanol? what's the difference between using toluene and methanol?

[2rismo]

Methanol + Rubber fuel lines/seals = bad.

Adrian

[2rismo]

Oh and methanol engines drink lots lots more of it that PULP motors do.

Usually running AFR's of about 5:1

Adrian

[benm]

I used (tolune) 10litres to a full tank. Not sure what that works out too but gave me an extra 70rwhp. With just normal bottle octane booster from Hardcore Racing gained 30+rwhp

Although your car isn't anywhere near 'stock' right?

[edgasket]

Methanol + Rubber fuel lines/seals = bad.

Adrian

Yeah, i know - but if you were only to use it occasionally like, about 10% mixture? maybe I should just get some Toluene....

[Cubes]

WHen I first bought my 32 I wasnt aware of the difference between premium (95) & ultimate (98). I slapped it on the dyno and made 115rwkw. I was running 95 Premium.

I wasn't able to run any ignition advance to make more power as it was ever so slightly pinging. Slapped the 98 in advanced timing. Made a huge difference.

[Guest INASNT]

There was an octane booster test in last issue of zoom, and the most gain they got was around 6kw@wheels with 3 degrees extra timing.

If u want high octane run on some suncorp 104 which is about $4 a litre or go hardcore and run some C16. If u run C16 u will need to change plugs and o2 sensor frequently coz it burns them out

[chops]

As mentioned by others, higher octane will allow you to tune "harder" and that is where the extra power comes from.

On the question of methanol, DO NOT try to run it on something that hasn't been tuned for it ESPECIALLY a turbo car, as the stoichiometric AIR:FUEL ratio for methanol is approximately 6.5:1 compared to approx 14.7:1 for pump fuel, which is why they run massive injectors and 5:1 AFRs.