Tech question

[pete376403]

[QUOTE=dangerous
Inj is almost instent were carbs have mechanical parts which take time to open which means a lag between 'action and responce'[/QUOTE]
Hmmm.. the mechanical part in a carb is usually the butterfly, which most injection setups also have. the slide in a CV card WILL respond almost instantly to vacuum, but is damped to prevent this happening (recall the oil reservoir in the top of a Stromberg or SU carb)

[menace]

A carb can prodcce more power that an inj however they are not as economical or set up as well.

Ok are you sure about they produce more power? I dont see how this can be true... Maybiee you mean the power delivery or somthing similar. I dont think carbs or injectors have much to do with peak power, that would be more compresion rating related...

I would think that carbs or injectors are only a way to get the fuel suplied TO the chamber, so they dont have much to do with it...


BTW i do understand the the mechanical differences between the two. But chears for saying them anyway...

[Jackrat]

I'm personaly all for anything that makes life easy for the home tuner.
Electronic Ignition "great" Fuel injection "not so great"
Fuel injection is pretty cool but it's taken me years to understand carb's so I don't have to go to shops for a basic tune.
Us thick buggers need things to stay basic
Like I can set the timing on a manuel points system with an out of tune AM radio but I don't know the first thing about fuel injection maping an such.
Hell I even got a hammer under my bike seat.

[jrandom]

I'm personaly all for anything that makes life easy for the home tuner.
Electronic Ignition "great" Fuel injection "not so great"

awww I dunno. Fuel injection *would* be great if the chip emulators and control software were easy to come by. The present generation of petrolheads are all pretty au fait with 'puters it seems, surely running a program up on a laptop and plugging an emulator into a DIP slot wouldn't be too hard. Once that's up and running it should just be a matter of clicking on buttons and going for rides around the block. I know quite a few guys that do just that with their cars, much tider than swapping jets around.

[menace]

awww I dunno. Fuel injection *would* be great if the chip emulators and control software were easy to come by. The present generation of petrolheads are all pretty au fait with 'puters it seems, surely running a program up on a laptop and plugging an emulator into a DIP slot wouldn't be too hard. Once that's up and running it should just be a matter of clicking on buttons and going for rides around the block. I know quite a few guys that do just that with their cars, much tider than swapping jets around.

Thats exactly what i mean... Although i would leave it to the pros to do my tuning but just save a few maps and 'tis all good.

[Jackrat]

awww I dunno. Fuel injection *would* be great if the chip emulators and control software were easy to come by. The present generation of petrolheads are all pretty au fait with 'puters it seems, surely running a program up on a laptop and plugging an emulator into a DIP slot wouldn't be too hard. Once that's up and running it should just be a matter of clicking on buttons and going for rides around the block. I know quite a few guys that do just that with their cars, much tider than swapping jets around.

LOL,Yep I just ain't the current generation.Mate I don't even know what a au fait is, let alone an emulator or a DIP slot.

[Motu]

LOL,Yep I just ain't the current generation.Mate I don't even know what a au fait is, let alone an emulator or a DIP slot.

A DIP slot is where you put the DIP STICK - jeez,you really are ignorant Jack,anyone would know that.

[bungbung]

an au fait is one of those fancy auckland coffees.

[menace]

LOL,Yep I just ain't the current generation.Mate I don't even know what a au fait is, let alone an emulator or a DIP slot.

I think "au fait" i think means that we ar computer literate... Which is probably the case as we are all here on the internet...

And emulator is prty much the interfase you would use to acess the ECU so you can play around with the ingnition ratios ect... DIP slot is just a way to physicaly conect to the ECU


Happy with the computer lesson?

[Posh Tourer :P]

funnily enough, au fait translates pretty well to OK if you use it in context. It is in an old boring language (French) so i would have thought you would have known in Jackrat j/k

[dangerous]

Thats exactly what i mean... Although i would leave it to the pros to do my tuning but just save a few maps and 'tis all good.

Thats just it....... you never have to tune a thing with inj. The only time that the system needs tampering with is when someone wants to make more hp or with the Iti stuff a replacment chip for better running and thats only ever done once, and most Iti stuff is well sorted now at the factory. Its that simple.
I have done over 40000km on my 97 Moto Guzzi 1100i sport and I never touched a bloody thing were as the carb sports would need a tickel up every 5-10000 km to keep em runing sweet eg: winter would need different tuning to summer but with inj the ECU (puter) does it all by its self.... just great realy

[pete376403]

I got my GS1100 in 1990. (and it was pretty old already). I have never messed with the carbs, apart from pull the float bowls once to see if there was any crap in there. Even after I replaced the foam air filter with a K&N, nothing would convince me there is anything to be gained by altering jetting.
Sometimes on a cold morning I'll wind the idle speed up a bit.
Nothing at all wrong with carbs if people leave the damn things alone.

[dangerous]

Thats true Pete, I guess that I'm compairing Itialian carbs (big bulky vintage Deloto's) which can be a real pain in the ass when combined with a high compression V2 to keep tuned.
Mind you there early inj wasent much better

ps: note that I have gone back to a jappa with carbs

[pete376403]

Jawa speedway motors used to come standard with a big Del'Orto, and the thing with those was to have two big frame mounted float bowls. It used to be a standard scene in the pits, people altering the fuel level by moving the bowls up and down, trying to get the things running right. All my troubles ended when I put on a 40mm Mikuni - the f*ckin thing would even idle. Starting was a breeze - put the choke on, and with the bike on the stand, give the back wheel a flick. The Mikuni and the Mitsubishi magneto where probably the best parts of that bike.

[Skunk]

I think the reason EFI has taken longer to get to bikes is because the bikes are more sensitive to incorrect fuelling because of their power to weight ratio. The early computers could not sample all the data required and map it to a fuel amount fast enough to produce smooth power.

I may be wrong but I believe that good systems sample the thottle postion, thottle movement, air density/velocity and map that to the ignition timing and fuel.

Someone correct me...