Razor2001

Hi all,

I am thinking about doing a few 1/8 mile runs and I have just purchased some 109 RON OCTANE rating race fuel:

http://www.racegas.com/fuelspecs/default.asp <----- I have the GT PLUS Unleaded one

I have a couple of questions:

Should I run this stuff pure or should I mix it? I have a JDM STI7 with only a decatted zorst and uprated fuel pump. Original Ecu but changed restrictor size so no boost spike etc. Is it a waste to run pure 109 RON OCTANE as the car is designed to run on 100 RON or will the timing and BHP increase more if I run it on pure VS. 50%/50% mix with 98 RON gas ? So basically is there a point where running exessive Octane becomes overkill and a waste because my car is basically stock and once the timing has reached the max threshold I will not see any benefits ? If the previous was true what is probably the most RON octane rating I need to be running for my cars setup to achieve the best results ?

Is the formula to figure out what RON octane you are running is easy as saying, ok I have 5 gallons of 98 + 5 gallons of 109 RON mixed in my tank so I am actually running 103.5 (98 + 109 / 2) ? Is it OK to just add this race fuel to the gas in the tank of my car ? Will it mix together ok etc and not float separately around etc ?

Thank you for the help

Cheers,
Ray

Bob Rawle

Run it as is, still got the uprated ecu .... you should be able to use that with no problem. Worth at least 10 degrees of ignition.

bob

Razor2001

Hi Bob,

Thanks for the reply.

I stuck my old ecu back in (100% stock ecu). I dont want to stick the Mapped one in just for the track run....who knows maybe but I may just run stock. My car shows under 1/4 tank of gas left in, is it ok to add the 5 gallons of race fuel to this or will the gas in my tank just kill the affects of the race gas ?

Cheers,
Ray

Bob Rawle

You need to drain the pump fuel, there are drain points on the fuel tank for this, be aware that most of the benefits from race fuel come from more advanced timing and leaner fueling, unless you can adjust you may not find that much difference, worth a try though even for the extra safety.

bob

Fangoria

iTrader: (1)

Razor

Are you from the UK? as 76 racing fuels dont sell the 109 Ron stuff, just the 105ron/95 mon stuff............... or did you get this from somewhere else...... if you did it would have cost plenty anyway.....

Its really pretty much a waste of money unless you get the car remapped for it..........

Plus to take full advantage you need 100% race fuel - dont bother to dilute it...... otherwise you'd be just as good getting some decent octane booster or mixing circa 5 litres of Methanol (circa 10% of the tank) with your unleaded fuel

Razor2001

Hey,

No I am from Nassau, Bahamas. I think they bring that fuel in from the USA. See the link on previous post. Cost me $65 USD for 5 gallons !!!! Very expensive but not that bad for 109 RON I guess ?

Since my car is not mapped for higher RON fuels I mainly wanted to put the race fuel in to make sure I did not get det while waiting to do a run (I/C heat soak etc). So I assume instead of running this stuff pure I may has well just run 1/4 of the race gas and 3/4 of regular to get my RON above 100 or so ?

Cheers,
Ray

Fangoria

iTrader: (1)

Yeah 109 Ron - lucky you - we cant get that in the UK - in fact we used to be able to get 76 racing fuels competition 100 - but 76 fuels stopped importing and the Sunoco equivalent at 105/95 is not as good

$13 a gallon - Jesus..................... even with the terrible e/r thats £7.22.........(lots of dosh) -Gallon in the Bahamas is the same as USA - i.e. 6.4 Pints - or rather 80% of the UK Equivalent??

I understand now...... last time I was in the Bahamas I dont recall any fuel above 95 Ron....... and with your heat............. cripes

Its not quite as simple to just mix it........ a word of caution as the race fuel is a little thinner than normal fuel..... i.e. if you use race fuel when your mapping you normally have to increase the amount of fuelling you use as the race fuel is not as dense -i.e. less fuel going in - the same applies to Methanol

If you added a quarter of a tank of race to 3/4 normal sure you'd get less knock I guess but not by so much due to running less fuel/air due to the race fuel mix if you see what I mean

Personally if I was in your position I would look for some excellent quality octane Boosters - Nitrous Formula in Aus do these - which I'm sure can be bought in the States but not sure about the punitive taxes that would subsequently be levied into Nassau

Places like Roger Clark Motorsport do this in the UK - or Pentland component parts in Scotland - but you'd be looking at more money to get it across to you - better to go via the States I'd have thought.............. it would certainly be a lot cheaper than Race fuel and should be sufficient to sort out your det issues.........