so what exactly does octane boost do?

cheers guys, dunno if I will knock up a batch in the shed but if anyones keen on a team effort I'll be in.

Octane booster in my car will allow me to advance the timing a few deg and run a few extra psi of boost... if all goes well it may make an extra 10 or 20 kws...

At the risk of stating the obvious, it boosts the octane rating...
Might be by a couple of points even, i.e. from 98 to 99 or even 100. Dunno, how is 'octane rating' determined? Obviously it won't be something you can do in the backyard...

So is this actually the mixture...I don't wanna trust anything straight out of chunkz' mouth!

Also, how much booster do you add per tank?

Ah ha ha lol thats funny as!! But yer MOST off the shelf octane boosts should add atleast 2-3 RON to the original petrol rating ie. 98 PULP should get 100 mabe even 101 RON.

BUT!!! thier is a certain mix that Nitrox do that is for hi-performance imports etc, with high HP figures.. Guess how much a smallish bottle costs...... $50!!! theres gotta be something in that would make the car go from slow to woah!!

Mabe try that stuff out CHEF even if its a once off due to the price.

hi

ok the mixture actaully is expensive just did my sums and its a costly excerise but im sure the octane booster is better quality than what you buy of the shelf

a few things one must work out ???

static compression ratio of your engine
in most case turbo charged cars float aroung 8:1 btw 8.5:1 ratio

once the engine is on high load and turbo pressures the cylinders you have effectively increased the compression ratio of you engine

this will govern what octane rating the fuel should be to run you engine most effiecently and achieve maximium horsepower with out deternation

there are formules ( maybe someone can find this out ) out the that you can estimate the effective compression ratio of your engine under booster which will enable you to use the correct fuel for that application

compression is what governs what fuel type you should be using

example

compression ratio ---------------I----------- fuel octane rating
10.5:1 --------------------------I------------------ 98
11.5:1 ( LPgas ) -----------------I------------------ 104
12.5:1 --------------------------I------------------ 110
14.5:1 --------------------------I------------------ 115


this is a guideline

just thought i would mention this so when i see some people post exstremely high horsepower figures on high boost and mention there running there cars on 98 octane rated fuel mmmmmmmmmmmmmmmm makes me wander

the OCTABE BOOSTER MIX IS AS FOLLOWERS

please note a 30% mixture

750 ml of toluene
190 ml acetone
10 ml transmission fliud

950ml in total to achive a 30% mixture

1600 ml of octane mix to 16 litres of the highest petrol bowser fuel available


hence 1.6 litres of mix to 16 litres of petrol


like i said before do you homework on where you can source the materials from to get the best prices otherwise its a expensive exercise but one worth investigating as the mixture work exstremely well.

remember as toluene is the chemical that does the increase in octane rating you can increase the amount( ratio of toluene in the mix ) to suit your turbo boost levels to match

cya

Good readin' here FPVGTp..

Boost compression ratio calculator:

http://www.rbracing-rsr.com/compression.htm

Or if you're keen on doing the maths:

Final Compression Ratio (FCR) = [ (Boost÷14.7) + 1 ] x CR

-Boost is the maximum boost for the setup
-CR is the current static compression ratio

So for my engine

FCR = [6/14.7) + 1] * 9 = 12.67

*4.9 EF realises that 98 octane @ $1.35/L STILL not good enough* lol

yes fuel governs alot of things

so many people dont relise this

Quality of fuel is very inportant and selections on fuel for a particular application is vital consideration

cya

I guess 98 octane is acceptable (it doesnt detonate at all) but must be running very conservative timing to achieve this...

LOL

piont taken , but try a higher octane fuel and retune

see what happens

yes ur ignition timing maybe ( ? dont know ) retarted extremely far back

but deternation can be still there but not audiable to the human ear

cya



ps : we are talking 100% cylinder fill remember there are restrictions , i know ur going to say we are forcing the air in still have restrictions so we have made a calculated effective compression ratio

ps : maximium horsepower is actived a few degrees ( ignition timing ) before deternation occurs

failed to mention

air/fuel if set on the extremely rich side will add in less chance of deternation as some of the fuel is wasted out the exhaust and used as a cooling the inlet air charge temperatues

if ur running extremely rich mixture settings that is also robbing u of horsepower , but if u have to set the mixtures rich for reasons of preventing deternations well thats another story which tells me ur need a better quality of fuel supply. AND also a intercooler
recterfying the miture setting and igntion timing will yeild greattter throttle responce and hence more power



u stated ur have been conservative with ur final ignition timing on high load (wot) at what ever boost ur running .

but yes u should be running a higher octane fuel for ur application

just a few questions ??

what boost are you run all the time ( WOT )
what inlet air temperatue do u have present on high load (WOT)
what total ignition timing u running on ( WOT)
what air/fuel ratio are you running on ( WOT)

im sorry for asking personal questions about ur car feel free to answer and if u choice not to its ok also

we could talk all day long on th high performance stuff which is greta we all learn something from one another

some people feel information is only for themselves , im happy to share and learn alos if i can help i dont mind.

thats what the forum is all about

cya

No dramas - ive certainly got no secrets. Makes for interesting conversation too...

I dont actually know the specifics of the ignition timing, this was all done by CAPA via a chip on the J3 adaptor (read: NOT an interceptor). The basic idea of CAPA is to provide a safe tune on pump fuel for all conditions (i.e. doesnt ping on hot days etc etc). Speaking with the tuner, there is a few degrees pulled from the factory WOT timing... so probably at around 25 deg BTDC total advance, but that's simply an educated guess...

A/F's are a little on the rich side (12:1 across the board but not perfect as uses an FMU to increase fuel pressure, so goes a little rich just as boost comes in) whereas 12.5:1 would probably be much better for power but im willing to sacrifice a bit of power in the name of having a safe tune that'll give me plenty of km's before something breaking. It's not tuned so rich that it spits fuel out the exhaust (it was originally...).

Peak boost is 7lb at redline but dont usually work her that hard so really the most i see is 6lb (only a little blower on there)...

Inlet temps have not been measured (sacrelidge for someone like yourself i imagine!). No intercooler setup (have a look in my gallery for pics).. There is a basic water injection system which is activated at 3psi. It is probably not needed at low boost with a safe tune but it's all in the name of safety - i.e. i want to make sure there is no detonation...

So yes - a few factors suggest that I could squeeze more power out of her... but at the moment it's nice and safe and still puts a smile on the dial... if i was chasing every last kw i would stop fu**ing around and get an aftermarket ECU for it.... lol

Would be interesting to know what inlet temps your getting with the water cooling. Mine with just the FMIC sit on ambient all the time, or atleast very close to it... I'm thinking of playing with a water/meth injection setup sometime soon.
Anyway, thanks for all the awesome info there guys, I doupt I will cook up a batch right now but its very interesting to see whats in those little bottles... I think I'll just grab some 104+ stuff, Ive used it befor on other turbo cars Ive had

the price of bowser petrol and a bottle of octane booster , when wants to play around my thoughts why bother with that stuff just buy avgas and know u have a better quality fuel

Yeah avgas would be the go... but doesnt it smell? And could they detect it?