Race Engine Forum UK

Some interesting observations.

As a matter of fact I want to say this:
As many of you know - you can only get more power from a fuel per-se (that is to say without other mods) if it has a higher calorific value. Such racing fuels do of course exist, I have test feedback with quite expensive fuel from the USA which netted around 6bhp at full power tested back-to-back on a full spec XE Vauxhall.
What is used in F1 I have no idea but I would be amazed if it is not of such type.

A fuel with higher RON rating has a higher knock limit which permits higher CR, higher boost - so higher power is possible. But putting higher octane grade (of the same calorific value (which I think 97 and 95 RON are) will never release more power per-se unless perhaps the engine was detonating or the knock sensor was working overtime to prevent such a thing and the higher octane fuel stopped these tendencies and permitted optimum ignition timing to be used.

It is of course true that, depending on the primary cause (because there are several) detonation/knock can be stopped by ignition retard. This naturally leads to power loss compared with what would be achieved by the engine if the right RON rating fuel was used.

GC

An update on what I posted on this thread regarding AvGas.

A trip to my local airfield this weekend has given me a slight supply problem. Aparantly the CAA (Civil Aviation Authority) has recently put a hold on selling this fuel to non-aircraft. This is as a result of people buying it for motorsport use and giving false aircraft registration marks. So my local airfield will now only dispense directly into aircraft. They know many people use it for 2 stroke engine racing and they were always happy to sell it to me in the past with me giving them my name and address on the invoice (ie no false aircraft reg). Their limit was 20 litres at a time into MOD spec jerry cans. But now this is no longer acceptable. I was told that this should now be the ruling across the UK, but the airfield also told me that some other airfields may actually sell it to me.

So for anyone using AvGas 100LL, check your local supply.