Heat

I remember reading something about this. For example, tuning 1100cc injectors down 50% will not make them act like 550s.
If I cared enough about it I'd go search on dsmtalk but I'll stick with some 650cc disc/ball style injectors for $250 that PWR VTEC is gonna tell us how to get.

Blasphemous

Ok, I misunderstood what you wrote. I thought you were saying that the AFC could only tune 660's down enough. Why is it that you can only use 660's?

Well, they don't act EXACTLY like 550cc injectors. The 550cc's will be at a higher duty cycle to support a given amount than the 1100cc's will be. So, to supply a given amount of fuel, the 550's will be working harder than the 1100's. The 550's will be smoother when they come on also because not as much fuel's being dumped into the stream at once because 1100's spray more fuel but have a shorter pulse duration.

MeanGreenGSX

Agreed, and i have no idea why 660s are as large as dsms can go with a afc, wouldnt make since 440s ;660 areent 50% larger insize,should be able to run 880's; maybe they do deliver 50% more fuel though. I really dont feel like looking right now for the anwer maybe later

Heat

I'm telling you, the answer is on dsmtalk.com
When I said they won't act like 550s, that's exactly what I meant. I didn't say they won't act exactly like them, I said they won't act like them.
Please refrain from stating the obvious when discussing things with me. It is insulting and a waste of both our times.

Ninety7GSX

I think the main problem is that our cars are tuned rich as fuck from the factory as it is. I pulled 13 percent from mine right now and have not upgraded the injectors yet. Then if you add a set of 750 or larger injectors on there it just won't work out.

Also the injectors don't quite work right under a certain duty cycle. (I would think) There's gotta be a minimun reccomended duty cycle as well as a Maximum. Lets just speak in theory right now numbers are just guidelines. If you are opening a 1000 cc injector for 1 second and spraying the same amount of fuel that a 550 sprays in 3 don't you think the air fuel ratio will be wack? I would think it wouldn't mix right.

Alot of guys I've seen making high horsepower (normally over 500) on a daily driven dsm have been using an 8 injector setup. I'm pretty sure they do this for a reason.

Blasphemous

Most of the high HP rotary guys use a stand alone ECU and roughly 720cc primaries and 1600cc secondaries, two of each. I agree that the 1 sec of a 1000cc and 2 seconds of a 550cc would be a little different. The 1000cc spray wouldn't be as atomized, but it'd still be the same amount of fuel.