From: shaman@cix.compulink.co.uk (Leo Smith)
Newsgroups: rec.autos.sport
Subject: Re: F1 Fuel
Date: 7 Apr 92 20:34:37 GMT
Reply-To: Leo Smith <shaman@cix.compulink.co.uk>
Organization: Gated to News by demon.co.uk

francis@cs.adelaide.edu.au (Francis Vaughan)
writes..

>Yes that is true. Exactly what I meant. The F1 fuels TEST as octane
>102 but when actually burnt in the engine, burn with characteristics
>that allow much higher compression and much meaner timing.

You are going in a direction that I am not _sure_ is right, although
I agree with quite a lot of it..In Motoring News at the end of last
year there was a discussion on fuels...and the impression given
(which *may* have been deliberately misleading) was that they were
developing fuels that had higher energy content.

>It is, I guess a problem that a large number of people think that
>high octane = high power (thermopotential.)

Agreed that they are not the same. High Octane means you can ignite
earlier from a higher pressure without detonating.

>Thermopotential of itself is not what F1 engineers are especially
>worried about. An F1 engine spits a large fraction of the fuel it
>drinks straight out of the exhaust again.

Well I would want to qualify that: Since a large part of the weight
of the car at the start of the race is fuel, there is a definite
incentive towards economy, if one can say that in the same breath as
F1 :-)

Viz Senna's running out of fuel at Silverstone: A drastic attempt to
put the car on a par with the Williams.

> Getting the best burn charateristics, so that you burn as much fuel
> as you can, in the limited time that you have to do this in the
> ignition cycle, without the fuel/air mix detonating is what they
> need. Hence a high effective octane rating is an important
> consideration.

This is undoubtedly one side of the equation but:

        (i) High (realisable) power to weight of fuel means less
        weight in car.

        (ii) Fuel that needs less oxygen per calorie of energy
        released will need less air - obviously oxygen containing
        fuels (e.g. Nitromethane) are banned, but there may be a lot
        of difference between using cyclic compounds (benzenes) which
        have a high ratio of carbon to hydrogen, compared with light
        straight hydrocarbons - eg octane. That way you use the
        available breathing power of the engine to its maximum.
        In this conext the wicked smells are characteristic of
        benzene compunds - irritant and carcinogenic.

        (iii) By careful combustion chamber and injector design, as
        well as attention to the spark plugs themselves, a lot of
        anti-knock can be designed into the engine. This doesn't
        necessarily contradict what you say - indeed it may
        complement it. But my guess is that Elf and Renault have
        engineers sitting side by side somewhere...

>Personally I feel that the sooner they ban these cocktails the
>better. Announce a ban for the next season real soon.

Control Tyres.
Control Fuel

..It'll be rev limiters next.

Half of me agrees with you - they may well be health hazards - but
another half says that that is what F1 is all about - cheating within
the rules!

They will all be using the same fuel next year anyway, as soon as the
principles are (widely) known.

Leo
Newsgroups: rec.autos.sport