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Re: [turbobike] carburation vs fuel injection

John C Williamson (john.williamson5@virgin.net)
Sun, 18 Apr 1999 20:31:48 +0100

flow slightly, as this 'venturi' is the thing that actually draws fuel from
the floatbowl. The flow through carbs is pretty efficient on modern bikes
though so the difference will be quite small.

It is true that fuel injection will allow more accurate fueling in all
conditions, if money / time allows so less flat spots and possible better
throttle responce.

On the other hand my 1100 GSX EF used a cheap stock Mr Turbo kit with a
single draw through carb and this was fine! Idle was a little ragged, but it
kind of adds character! Unlike the short 'banana' drag style exhaust pipe
that tries to turn your left leg to charcoal.

Does anyone know how much extra boost is possible with N2O due to the
cooling effect?


----- Original Message -----
From: Lorcan Parnell <lorcan@globalnet.co.uk>
To: <turbobike@natvideo.com>
Sent: 18 April 1999 19:41
Subject: Re: [turbobike] carburation vs fuel injection


I have to disagree. It is not possible to match the performance of EFI with
carbs. If it was, the F1 teams would use carbs. Indycars would use carbs.
They don't.  EFI will always be ahead and as technology improves more so.
Your point about the variations in flow is simply wrong. Yes, you need 8
injectors, possibly more (my bike has 16). Bikes of the future will all use
EFI. The only reasons to use carburettors is because they are cheap, or
because the rules (like in Pro Stock) don't allow EFI.



-----Original Message-----
From: Christer Johansson <christer.johansson@mbox383.swipnet.se>
To: turbobike@natvideo.com <turbobike@natvideo.com>
Date: 18 April 1999 16:52
Subject: Re: [turbobike] carburation vs fuel injection

I thought of going to EFI ,but I saw no reason to do it.
Efi does have some advantages in that you can map the fuel
and ignition curves more precisly. But itīs possible with carbs
and a adjustable ignition module to.
As long as the engine gets the right A/F ratio there is no advantage
in EFI powerwise. To know what A/F ratio you have,you will
need a lambda cell, also a EGT sensor would be nice.
This goes for both Efi and carb setups.
During the dial in period I will use a lambda cell and EGT sensors in
all 4 exhaust pipes and the collector, on the new system.
Also, blow through carbs could prove more "forgiving" to the design
of the plenum etc than a EFI would be. If you get sligtly more flow
through some carbs the injectors on a EFI system will still spray
the same amount of fuel, on a carb system it will drag the fuel needed.
Also if you run a high hp EFI system you will need 8 injectors on a
4 cylinder engine ,otherwise you could get trouble with idle as the
injectors would be qite big.
Carbs gives better fuel atomizing at low engine speeds.
But a EFI setup looks cooler though....