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Re: [turbobike] carburation vs fuel injection

Bryan Goodwin (bgoodwin@iquest.net)
Mon, 19 Apr 1999 00:51:55 -0500

I realize why he is asking. My theory remains the same. Yes, N2O is an
intercooler, but it is also a tremendous heat generator. In other words, the
cooling effect of the N2O will not outweigh the heat it produces in the
cylinder.

CRAIG S WALKER wrote:

> I believe he is referring to the intake temperature drop.  N2O becomes a gas
> at -127 deg F....quite an intercooler.  This fact alone is what led to
> funnybike racers experimenting with the stuff in the late seventies - early
> eighties.  In those days ,folks like Terry Kizer were running 3 stages of
> nitrous w/30-35 psi of boost.
>
> Speaking of which, I heard Terry Mr. Turbo Kizer has run in the sixes on his
> push button start pro mod/funnybike ZX11.  Has anyone got the low down?
>
> Craig S. Walker
>
> ----- Original Message -----
> From: Bryan Goodwin <bgoodwin@iquest.net>
> To: John C Williamson <john.williamson5@virgin.net>
> Cc: Lorcan Parnell <lorcan@globalnet.co.uk>; <turbobike@natvideo.com>
> Sent: Sunday, April 18, 1999 8:37 AM
> Subject: Re: [turbobike] carburation vs fuel injection
>
> N2O makes a great deal of cylinder pressure and heat. N2O often requires
> timing
> retard and/or good fuel by itself. I do not believe you should add any boost
> because of N2O.
>
> John C Williamson wrote:
>
> > >From a simple 'physics' standpoint a carb always has to restrict the air
> > 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?
> >
> > BURGERMAN
> >
> > ----- 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
> >
> > Christer,
> >
> > 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.
> >
> > Regards
> >
> > Lorcan
> >
> > -----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....
> >
> > Christer