additional injector(s)?

[peanotation]

i think im gonna give this one a try http://www.034motorsport.com/034SupECU.html with a budget kit from www.tearstone.com. ill let you know how it turns out

why not go the easy and proven route? why not just buy bigger injectors with tuning. you need tuning anyways with a turbo setup.

has anyone tried this on our cars? no. i have done the easy and proven route before, and i didnt like it. yes it works, it works pretty good actually, but its not optimal. piggy backs that alter the airflow signal tend to srew the stock timing and fuel mapps up off boost.

you still havn't convinced me really. if you want optimal, why not get the greddy emanage ultimate? yeah, you have to blow some money but i dont know if what you're talking about would be easier or better.

piggy backs that alter the airflow signal tend to srew the stock timing and fuel mapps up off boost.

duh. thats why you have to tune it. i can't help you with the timing really, but i don't see why the afc would affect the timing at all. get a rising rate FPR at 1:1 for tuning. as the turbo builds boost you'll always have the appropiate amount of gasoline to match it, provided you've tuned everything with the afc or w/e your using.

when i took my car to the dyno the timing was kosher and my a/f ratios were just a little over rich, but i still havn't properly tuned it yet. all i was running at that point was just an afc and bigger injectors, not even my afpr yet.

has anyone tried this on our cars? no.

hundreds of people. literally. most of them are running stable. i'm one of them.

if you do go the route your planning to, please post some pics and a summary. i'd like to see it done and working

[Stewi]

yeah the only time you need secondary injectors is for high HP/high boost applications. example, RX7's are notorious for running secondary injectors. What happens is you have your regular 4 injectors, in vacuum and low boost the 4 injectors give enough fuel, once the car starts boosting higher, the secondary injectors are activated to add more fuel with the extra boost. I know of 2 people with EVO's doing the same thing, they run 2 seperate fuel rails, a walbro 255 pump in the tank, and 2 walbro inline pumps (one to feed each rail), 8, 720cc injectors. 4 of the injectors are on all the time and the other 4 only turn on after 20psi of boost.

Wow I need pics of that 4-720, +1 = 4x900cc +2 = 4x1180cc, and +4 = 4 1440cc injectors, and that is just too much fuel for any boost application I can fathom!!! Why not just run 1660 primaries and then a few 440 secondaries if you need them...that should get you up to about 800whp

Your math just doesnt make any sense. What im saying is, there are 8, 720cc injectors. 4 that are alwauys on and 4 that only come on under high boost, im not saying they come on at 100% cycle. The reason that people dont run 1660's on street cars is because it always runs excessively rich and often fouls spark plugs, although some RX7 guys do use huge injectors. Your only recommended to run injectors at 80% duty cycle. So somone running a 720cc injector is only getting 576cc of fuel out of them, thats the safe way to do it. If you run injectors at 90-100% duty cycle, especially a ball and disc injector and you lock up the injector, your losing that motor. because most likely, at that high of duty cycle your already into high boosting, hot air, spark and no fuel equals big time detonation.

[DOHCstunr]

you can get a lovely idle if you have a fuel management system that can alter pulsewidth and deadtime directly.
larger injectors take longer to open. thats one of the reasons its so hard to get a solid idle w/ big injectors on a stock ecu.

it was easy for me to run 550's cause i had keydiver make me and eprom to configure the 550's to run just like stock. my gasmileage out of boost is still awesome. and my idle is perfect.
now eproms aren't an option for stock ecu's. but reflashes are on flashable ecu's.

there are guys w/ his eproms running 850's with great idles.

just an example of what can be done given the options that are out there.

additional injectors are not the only way to go. injectors are costly anyways. i'd prefer to only have one set... if i could.

[j686m]

<div class='quotetop'>QUOTE(peanotation)</div><div class='quotemain'>
hundreds of people. literally. most of them are running stable. i'm one of them.

if you do go the route your planning to, please post some pics and a summary. i'd like to see it done and working</div>

i was talking about using additional injectors, i havent seen anyone do it on our cars. the safc actually increases timing because the computer sees less air flow and thinks it ok to use a lot of timing, but actually a lot of air is coming in, just less pulsewidth is required for the same amount of fuel on the bigger injectors. you say "duh, thats why you have to tune it" but you cant tune out the timing problem with an safc, you can only make it worse. all im saying is im gonna run mild boost(at first) and put in a set of additional injectors with that fully programable ecu and put a tee in the stock fuel line to feed them. thats all, no need to cut into the factory harness, rig-up fprs or fmus or other stuff like that. most of all i think and it sounds good in theory and want to try it. so ill def post pics and let you know how it all goes