A question that's puzzling me here, one for all the chemists out there.

Am I right in saying that if you up the octane of the fuel, you decrease the chances of det, hence people use octane boosters when running higher boost?

If so, how does this work. What exactly is the RON number and how does it stop detonation? does a higher RON fuel have a greater cooling effect on the inlet charge?

I was under the impression that det was caused by too much temp in the compressed air charge from the turbo, but how can upping the octane ratingreduce this temp prior to ignition?

I suppose a detailed answer on what is octane rating would answer this.

Any info appreciated.

Cheers

Rich (a wannabe chemist )

 

A higher octane fuel will actually burn slower, the ignition process is "more" controllable...afaik, and that might be diddly-squat.

/J

 

doesn't always burn slower, just means it will be less likely to explode, and more likely to burn.

I wrote a lengthy post about ron, mon and all his other buddies, I will search it out.

paul

 

http://www.scoobynet.co.uk/bbs/threa...=109409&Page=1

 

WOW! what a thread!

Pavlo YHM m8!

Rich

 

A slightly different, but related question:

What do the Japs do to their fuel to make it 100 ron ? and is there a difference between genuine 100 ron pump fuel and 97 or 98 ron fuel boosted with octane booster ? Should you expect a difference in power output running each fuel ?

The reason I ask is that I have a WRX (240 bhp model) with a panel filter, scoobysport downpipe and HKS Hiper centre and back box. On the rollers at ProSport a couple of weeks ago it made 242bhp. With the select monitor on during the run the timing was checked and wasn't being retarded by the ecu because of the fuel. The car had a fresh batch of optimax in it mixed with 1.5ml per litre of NF Race Formula.

I expected a few more bhp out of it as a result of the mods so I am trying to work out why it is only 2bhp above standard. Could it be to do with the 'energy' value of the fuel being lower than the genuine 100 ron from Japan ?

Thanks in advance

Ken

 

There are a few fuel related links in my posts on this thread. http://www.scoobynet.co.uk/bbs/thread.asp?ThreadID=130443&ForumName=General

Z.

 

Hi Ken,

I have a similar vintage car which made 250 bhp at Well lane, running full decat and K+N at standard boost using Optimax and Millers. A couple of things to note, the car is 240 PS as standard not BHP so drop a couple off there (bout 237 BHP?). Also the car is getting on for 10 years old, i suspect that without the mods you have you would have made about 225-230 bhp which is only 5 and a bit BHP off what Subau claims. I would be happy with that with a car of that age.

Don't worry about it

Tony.

 

Cheers Tony,

I wasn't unhappy with the result, because the car still goes really well. I was just looking for an explanation really as I've seen a few threads on here that have suggested a gain of much more than 5bhp from just changing the exhaust.

I'd still be interested to know what the Japs do to their petrol to make it 100 ron though.

Ken

 

There are lots of things you can put in to petrol to up the octane. The most common components are aromatic hydrocarbons (toluene / zylene), similar to the benzene but less likely to give you cancer. Every 5% extra toluene that you add will increase octane one point. 15% will give you 100 like the Japs.

Z.