Jump to content
SAU Community

Recommended Posts

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. "

Link to comment
https://www.sau.com.au/forums/topic/35596-food-for-thought-octane/
Share on other sites

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

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.

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.

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.

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

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.

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???

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!!!!!

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?

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?

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

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.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • I'm back from the dyno - again! I went looking for someone who knew LS's and had a roller dyno, to see how it shaped up compared to everything else and confirm the powerband really is peaking where Mr Mamo says it should. TLDR: The dyno result I got this time definitely had the shape of how it feels on the road and finally 'makes sense'. Also we had a bit more time to play with timing on the dyno, it turns out the common practice in LS is to lower the timing around peak torque and restore it to max after. So given a car was on the dyno and mostly dialled in already, it was time for tweaking. Luis at APS is definitely knowledgable when it came to this and had overlays ready to go and was happy to share. If you map out your cylinder airmass you start seeing graphs that look a LOT like the engine's torque curve. The good thing also is if you map out your timing curve when you're avoiding knock... this curve very much looks like the inverse of the airmass curve. The result? Well it's another 10.7kw/14hp kw from where I drove it in at. Pretty much everywhere, too. As to how much this car actually makes in Hub Dyno numbers, American Dyno numbers, or Mainline dyno numbers, I say I don't know and it's gone up ~25kw since I started tinkering lol. It IS interesting how the shorter ratio gears I have aren't scaled right on this dyno - 6840RPM is 199KMH, not 175KMH. I have also seen other printouts here with cars with less mods at much higher "kmh" for their RPM due Commodores having 3.45's or longer (!) rear diff ratios maxing out 4th gear which is the 1:1 gear on the T56. Does this matter? No, not really. The real answer is go to the strip and see what it traps, but: I guess I should have gone last Sunday...
    • 310mm rotors will be avilable from Australia, Japan, and probably a few other places. Nothing for the front can be put on the back.
    • The filter only filters down to a specific size. Add to that, the filter is AFTER the pump. So it means everything starts breaking your pump even if its being filtered out.
    • Just like in being 14mm too small (296mm) makes it not fit, being 14mm too big (324mm) it also won't fit. You want to find the correct rotor.
    • @GTSBoy Ok so that was the shops problem...they showed R33 rotors on R34 page and i did not know 296 do not fit(and are for R33) Yes i bought "kit" with rotors and pads. Pads are ok(i have GTT calipers front and rear). They have some 324mm but no 310mm. So i dont know if they would fit. I have 17inch LMGT4s So another question. Can i fit those in the rear or they are just "too" big for that?
×
×
  • Create New...