From: ah335@cleveland.Freenet.Edu (Richard Banks)
Newsgroups: rec.autos.sport
Subject: [A.H.Henry@gdr.bath.ac.uk: Re: Honda RA168E (a.k.a. that '88 Honda engine) and fuel preheating]
Date: 2 Oct 92 14:47:42 GMT
Reply-To: ah335@cleveland.Freenet.Edu (Richard Banks)



    ================= Begin forwarded message =================

    From: A.H.Henry@gdr.bath.ac.uk (unknown)
    To: ah335@cleveland.freenet.edu
    Subject: Re: Honda RA168E (a.k.a. that '88 Honda engine) and fuel preheating
    Date: Fri, 02 Oct

    
    Newsgroups: rec.autos.sport
    In-Reply-To: <1afnhsINNl43@usenet.INS.CWRU.Edu>
    Organization: School of Biological Sciences, University of Bath, UK
    
    In article <1afnhsINNl43@usenet.INS.CWRU.Edu> you write:
    >
    >I was reading an article on the RA168E and RA167E and it states that the
    >fuel was ran through an engine coolant heat exchanger to raise the
    >temperature of the fuel to within 15 degrees of that of the coolant
    >because racing fuel does not typically contain low boiling-point
    >ingredients.  The fuel was 84% toluene.  I still don't understand their
    >reason for preheating it.  What is the average temperature of fuel and
    >what is the average temperature of F1 engine coolant in an operating
    >engine?  By the way, I would think to they do the exact opposite, cool
    >it, to make it more dense?
    >Any comments?
    >
    >R.Banks
    
    For maximum fuel economy, you don't want to have to spend
    a whole load of energy heating up the fuel before it ignites.
    
    I posted this article a couple of months ago.
    
    From: bspahh@gdr.bath.ac.uk (Andrew Henry)
    Date: Sat, 27 Jun 1992 18:09:12 GMT
    
    In article <1992Jun26.105838.17142@gdr.bath.ac.uk> I wrote:
    
    >Toluene was a major constituent of F1 fuels in the later years of the
    >turbo cars.  When they had a strict limit on the volume of fuel it
    >was an advantage to have a dense fuel.  
    
    The following information is from an article in the December 1989
    issue of the now defunct Performance Tuning.
    
    In 1988 Honda used a mixture of 84% Toluene and 16% n-Heptane, which
    gave a Research Octane Number (RON) of 101.8  (RON 102 is the maximum 
    allowed).  They used a mixture of with a fuel to air ratio of 13.7:1.  
    
    This mixture had a relatively low boiling point of 100 Centigrade.
    Increasing the temperature of the fuel/air mixture from 40 to 70
    Centigrade gave a 2% improvement in fuel economy with a slight loss in
    power.  Increasing the temperature from 40 to 90 Centigrade gave a
    power loss of about 1%.
    
    In 1937 the Grand Prix Mercedes and Auto Unions spent about 1/3rd
    of their racing time on full throttle, 1/3rd on trailing throttle,
    and 1/3rd braking.  For the 1988 San Marino GP, Alain Prost was
    on full throttle for 64% of the race, braking for 20%, with the
    rest being on part throttle.  Hence most of Honda's efforts were
    in improving fuel efficiency on full throttle. 
    
    The RA167E engine was used by Williams and Lotus in 1987, running
    on 195 litres of fuel with 4 bar boost pressure.  The RA168E was
    used by McLaren in the 1988 season with 2.5 bar max boost pressure
    on 150 litres of fuel.
    
    The figures for the RA168E are shown in a 'maximum power' configuration
    (peak power = 685 bhp @ 12500 rpm) when the fuel efficiency was "not
    satisfactory." The more economical setup has a peak power of 620 bhp @
    12500 rpm)
    
    These figures were read from a graph in the magazine and are probably
    accurate to 2 significant figures.  The numbers in imperial units were
    converted from metric and will be the least accurate.
    
           | RA167E              | RA168E (max power) | RA168E (max economy)
    _______|_____________________|____________________|_______________________
    Engine | Power    Torque     | Power    Torque    | Power    Economy
    Speed  | (bhp)    (lb ft)    | (bhp)    (lb ft)   | (bhp)    (lb / (hp*hour))
    (rpm)  |                     |                    |
           |                     |                    |
    6000   |  -       235        |  -       165       | 195      0.52
           |                     |                    |
    7000   | 532      394        | 366      276       | 328      0.48
           |                     |                    |
    8000   | 644      419        | 455      293       | 444      0.47
           |                     |                    |
    9000   | 803      461        | 509      293       | 477      0.46
           |                     |                    |
    10000  | 937      482        | 601      313       | 556      0.49
           |                     |                    |
    11000  | 964      448        | 632      293       | 601      0.45
           |                     |                    |
    12000  | 1010     428        | 678      297       | 609      0.44
           |                     |                    |
    13000  | 983      386        | 674      263       | 601       -
    
    
    
    
           | RA167E              | RA168E (max power) | RA168E (max economy)
    _______|_____________________|____________________|_______________________
    Engine | Power    Torque     | Power    Torque    | Power    Economy
    Speed  | (kW)     (Nm)       | (kW)     (Nm)      | (kW)     (g / (kW*hour))
    (rpm)  |                     |                    |
           |                     |                    |
    6000   |  -       319        |  -       244       | 144      320
           |                     |                    |
    7000   | 393      535        | 270      375       | 242      298
           |                     |                    |
    8000   | 476      569        | 336      398       | 328      288
           |                     |                    |
    9000   | 593      626        | 376      398       | 352      287
           |                     |                    |
    10000  | 692      655        | 444      426       | 411      301
           |                     |                    |
    11000  | 712      609        | 467      398       | 444      278
           |                     |                    |
    12000  | 746      581        | 501      403       | 450      272
           |                     |                    |
    13000  | 726      524        | 498      358       | 444       -
    
    
    			Andrew  Henry
    Sempre  Gilles					bspahh@gdr.bath.ac.uk
    
    
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