hemidup

My tune runs really good with the eight 55lb injectors up to 5200 rpm. That's when my tune goes lean. When I add fuel at those rpm's, my MAP voltage is too high and the engine goes lean. I feel that if I went with the auxilary injectors, and brought them on at 5200 rpm, I could correct my a/f's at those rpm's. Remember, I'm still working with "piggy backs" and the POS, PCM.

Sharadon

Hemidup, you should also mention the new 4 bbl intake. It will handle the wet flow much better then the stock intake.

hemifever

I think going with the srt-4 injectors that are 50# are better than the Ford ones you have. In a pulse flow test by srt10kllr, the srt-4 injectors out flowed the Ford units. When I put in the Stage 0 50# injectors I had to remove some map voltage because it was richer than the 55# Ford units. Remember those Ford units are rated 39# at 40psi. They are 55# by spraying the crap out of them. The SRT-4 injectors are already designed to run at your fuel pressure. Then put an FMU on there to activate at 10psi. You'll have enough fuel to take you on up to probably 18psi with a little meth on the side.

Outside of that, using the aux injectors above 5200rpms will help you at the current boost level. But as you move up in boost you're gonna start needing those aux injectors to come on sooner and sooner until you're relying on them again for fuel. Yes, the new intake you're running will be better for fuel distribution but the FMU will ultimately be the safest to ensure each cyl is 100# the same.

I also forgot y'all have been spraying meth through your i/c. I can guarantee you that's why y'all were spraying upwards of 800ml at one point and hardly seeing a change in a/f.

hemidup

Sean, We have the 50# SRT4 injectors installed now. I plan on using the SMT6 (thank you again) to activate the auxillary injectors. I have enough fuel volume and fuel pressure to support a 1000 hp, with my custom setup. The problem is, if I go to the larger injectors to help me up top with my a/f's, I'm worried about my idle and part throttle a/f boost numbers, which I'm pretty happy with now. Even though I spray w/m through my intercooler, by adding more meth, it did lower my high rpm a/f's. There's not much more tuning I can do, until I get a converter.

hemifever

Okay cool, when you wrote 55# injectors up there I figured you still had those Ford units. There might be a little more tuning you can do. I've not verified this with B&G, but I've been told the max parameter for fuel spray at WOT is 20ms. My injectors pulse for 15ms at WOT as does a bone stock truck I checked. If B&G can get 20ms pulse at WOT then your 8 injectors will put a ton more fuel in. Obviously a n/a truck doesn't need that much more fuel but a f/i truck could use it with the right tune to manage it. Could be worth investigating. I've just begun the process to dump my Superchips tuner and get a B&G (despite the 20ms injector spray claim or not) so I'll find out about it at least.