Fuel Injection Or Carbs

[dondesoto]

i have been comunicating with a guy in california who races a vehicle at the dry lakes . the engine he uses has a lot of similarities to the rb series 24v . you see hes using a ford taurus sho 3000cc dohc 24 v V6 ( this engine was designed by yamaha ) .

the thing is they have ditched the fuel injection and have gone back to carby for simplicity sake .

results 425hp @ 9600 rpm using a 1000cfm carb , cosworth cams , stronger conrods , heads ported and extractors .

the original output of these engines is very similar to the rb series .

so far their maximum speed has been over 220 mph ( 350 kmh )

[browny]

My understanding is that EFI really shows its advantages in all the stuff that doesn't really matter for a full throttle race car. Things like cold starts, part load drivebility, emissions, responding to ancilliary load etc just don't matter on this sort of vehicle.

EFI isn't magic, it's just a very precise and easily controlled method of metering fuel. All a car such as this needs is something to dump the right amount of fuel into the engine at WOT, which a carb can do fine..

[NA_R33]

My understanding is that EFI really shows its advantages in all the stuff that doesn't really matter for a full throttle race car. Things like cold starts, part load drivebility, emissions, responding to ancilliary load etc just don't matter on this sort of vehicle.

EFI isn't magic, it's just a very precise and easily controlled method of metering fuel. All a car such as this needs is something to dump the right amount of fuel into the engine at WOT, which a carb can do fine..

Very well said dude, i wont add to it cause i dont think i could put it simpler

[dondesoto]

My understanding is that EFI really shows its advantages in all the stuff that doesn't really matter for a full throttle race car. Things like cold starts, part load drivebility, emissions, responding to ancilliary load etc just don't matter on this sort of vehicle.

EFI isn't magic, it's just a very precise and easily controlled method of metering fuel. All a car such as this needs is something to dump the right amount of fuel into the engine at WOT, which a carb can do fine..

yep i agree with you totally . carb setup would be great for top end , but imagine trying to drive a 1000cfm carbed lumpy cam thing around town , would have as much tractability as a wet blanket ( try driving a wet blanket ha ) . but everything has its place . the racer i,m talking about runs wide open throttle for 90 seconds hitting 9600rpm , lotsa air and lotsa fuel .

presently i,m toying with an auxilliary throttle body that opens at over 5000 rpm along with 2 or 3 extra injectors . this would be purely for wide open throttle running and disconnected in normal use .

[Sydneykid]

Several years ago we were given an engine that made 680 bhp on the engine dyno, the task was to convert it to fuel injection from carby. It made 360 bhp average from 4,000 rpm to 7,000 rpm.

After we converted it to fuel injection, it made 685 bhp, 5 bhp gain, big deal, waste of money did I hear you say? But the average power went up to 420 bhp from 4,000 rpm to 7,000 rpm. That's a 17% increase in average power.

The reality is a max power figure at one RPM point is waste of time, what is important is the average power available over the rpm range that is used. That's what determines how fast a car accelerates.

Then there is the how it drives, responds to driver inputs, there was daylight in that comparison as well.

PS; we also did ignition control (via the Motec) at the same time, so the full effect can not be just attributed to better fuel supply control.