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Martin F
22nd September 2003, 08:12 AM
What are the advantages of having an external fuel pump rather than an in tank one ? The only thing i can think of is the easier serviceability.

The obvious advantages of an in-tank pump seem to be heat dissipation, noise suppression.
roy
22nd September 2003, 10:58 AM
i've been given to understand that only the really big power cars/dragster types would require an external pump ? something to do with fuel pressure/delivery at high boost/rpm whereas for a relatively lowish hp figure (around the 400-500 range) it maybe surplus to requirements ?
Chris Wilson
22nd September 2003, 01:12 PM
Quote[/b] (Martin F @ Sep. 22 2003,09:12)]What are the advantages of having an external fuel pump rather than an in tank one ? The only thing i can think of is the easier serviceability.

The obvious advantages of an in-tank pump seem to be heat dissipation, noise suppression.
Got it one Martin, those are the pros and cons.
Martin F
22nd September 2003, 01:47 PM
Cheers.

Must stop answering my own questions, the men with the white coats will call !!
alex h
22nd September 2003, 07:32 PM
To be pedantic - is it not true that cold fuel help the car (I assume its a cooling the intake thing) - I know the Moto GP bikes have their fuel chilled to -30degC before a race. So taking the "heater" (or pump) out of the tank is benefitial if you are serious and can put up with the extra noise.
Chris Wilson
22nd September 2003, 10:50 PM
Quote[/b] (alex h @ Sep. 22 2003,20:32)]To be pedantic - is it not true that cold fuel help the car (I assume its a cooling the intake thing) - I know the Moto GP bikes have their fuel chilled to -30degC before a race. So taking the "heater" (or pump) out of the tank is benefitial if you are serious and can put up with the extra noise.
I think you will find they chill it to get more in a given tank volume, it won't have a marked efect on preformance if it's chilled, by the time it is in atomised form, IMO. in the F1 turbo era they chilled the fuel to get as much in the tanks as possible, then heated it in the lines to reduce the viscosity for the FI to work properly!
alex h
23rd September 2003, 05:34 PM
Well - tell the Moto GP commentators then!! Bl00dy useless technical section in their show http://www.mkivsupra.co.uk/iB_html/non-cgi/emoticons/smile.gif