freqrider
Does anyone know off hand, what the maximum duration of the green injectors are with the P8 ICM? I'm at 12.8 m/sec now and she still feels a bit lean. I'm wondering how much further I can go? Seems like a lot for an SPO with spaghetti headers/ 50mm cans and a foam filter? I wonder if I'm compensating for clogged up injectors or a tired fuel pump? Newish fuel filter. I may have to check/alter my fuel pressure and clean my injectors?
jakepeewee
I am not sure I understand what you're asking, but if it is the maximum injection duration for a P8 system: 17 ms (in the eprom that corresponds with the number 255).
But it depends on the rpm if those 17 ms are also available.
The available injector duration in ms at a certain rpm is (2 x 60.000) / rpm
So at approx 7000 rpm there's a max of 17,1 ms injector duration available. Up till 9400 rpm there's 12,8 ms available, so if the lean condition is below 9400 rpm there's is some room to lengthen the injector duration.
If that's not enough than you can either switch to higher flow injectors or bump up the pressure to 3.5 or 4 bar (right now probably 3.0 bar). But that will change the fuelling over the entire map.
BTW: Double injectors per cylinder help to inject enough fuel at rpm above 7000 because they both fire at half the injector duration that's in the fuel map (so max. injector time 8.5 ms).
freqrider
Thank you Jake, that is precisely what I meant. I was thinking there was a limit to the injectors themselves. Makes sense now. You don't want the injectors firing after the valves have closed! 😉
My lean condition seems to be at around 6-7000 rpms so I have some room. I've been ironing out the lean spot little by little. It used to feel raw at 5000. Now she's buttery up to about 6,500-7000 where she starts to feel raw again. Then smoothens out at 8000. (Right at the dip in the map) I'm almost there because she ran much smoother at higher elevations this weekend where the air is thinner, so I'm getting close! Thanks for the formula!
nine16
You might want to just have the injectors cleaned and matched.
I had the green ST4S single injectors bored for my project, but that needs more fuel than a strada. No way your bolt on mods should stretch the limits of the stock injectors unless something isn't functioning properly.
