injectors too large? what resolution do big squirters have?

[Belly_up]

adding to that, the flow differences in each port may change with velocity and temp, but shouldn't change beyond that. so what you do is measure the differences while tuning (usually done arse about, by measuring either AFR or EGT in the exh runners), adjust each injector accordingly (the flash ecu's can all do this), and then once the car is tuned, it can run on one afm just fine. The problem with multiple afms, is that it's not the cross sectional size that costs money, but almost entirely the electronics and the hotwire. so by running 4 or 6 or 8 afms, you'd increase the cost by 4 or 6 or 8 times.

[Maadmike]

Cool cheers guys, its good to hear i wan't thinking up some flawed design anyway :D

I'm having a poke around the MoTech website now, interesting stuff.

[Matt]

Blah Blah Blah

Secoh - The feature the you should be researching is called "Injector Dead Time Compensation"

This will point you in the right direction

[Matt]

I'm glad someone metioned this - The average injector duty cycle at WOT on a V8 Supercar is 45-50% simply for this reason... Sign for the MOTeC training seminars - they're quite informative and full of little gems such as these.

Does anyone have any ideas on the virtues of using a far larger than necessary injector (running at say 30% duty cycle) to allow you to more accurately time the fuel delivery? I was told by a bloke here that it's quite worthwhile doing this if you have an ECU capable of controlling the injectors. I'm a little sceptical as to the advantage.

Any thoughts?

[psi999]

Something like 12A turbo injectors, a "black" malpassi 1.7:1 rising rate reg will get you the power you want there....... with plenty in the tank if you do decide to push for more power.

Indy blue's are fine with petrol, but geez they are big. Running them at the low pressure you will need will greatly affect the spray pattern (as tinkerbell has already stated).

[Billzilla]

I know you stand the best chance with a Motec as they over-volt the injectors to make them open & close faster than cheapie ECU's do.
So you can run much larger injectors than you would normally be able to.

[psi999]

Just curious Bill, would that affect the service life of the injector?

Makes sence though.

[Billzilla]

Just curious Bill, would that affect the service life of the injector?

Ultimately it would I guess, but for practical purposes I don't think there'd be any real difference.

[Datto-Zed]

I'm glad someone metioned this - The average injector duty cycle at WOT on a V8 Supercar is 45-50% simply for this reason... Sign for the MOTeC training seminars - they're quite informative and full of little gems such as these.

Thanks for the info matt...that was what I was looking for.

[Matt]

I know you stand the best chance with a Motec as they over-volt the injectors to make them open & close faster than cheapie ECU's do.
So you can run much larger injectors than you would normally be able to.

They dont over volt them at all - they switch them on constantly (At their peak rated voltage), then when the injector dead time is up (denoted by peak current flow being reached) , the ECU switches to Pulse Width Modulation (At the same peak voltage) to hold the injector open. Also called Peak and Hold Injector driving.

[BigMuz]

Those indy injectors piss fuel in lke there is no tomorrow- the pattern is not real special to be honest.

As a supplementary injector (like just one of them into a plenum) they are ok- but once you wind the pressure back to try and get some control over mixtures, they will be dribbling fuel all over the joint..

Muz