pressure switch for injectors
 

I have 4x160lb secondary injectors in paralel, when they kick in I go very rich,

can I use a adjustable pressure switch like they use on water injection pumps,
for 2 of the secondary injectors, cut their curent and power them back up at higher boost, will a switch handle the curent? or hook the switch to a relay to get them going,

also will that hurt the ecu? when they come in they will use the same ms like the other two injectors but @ boost its not that noticable if it richens up for a split second

runing e85 so I need all the injectors

thnx

You'll end up with a spot that is impossible to tune as the remaining two injectors come online.

Why not just stage the secondaries higher?

the best I got is 3250 @ 02vacum, I have 2x1000cc primaries with e85

I have .84ar housing on my turbo that thing spools instantly
and I run in a lean spot 15+afr so my spool is slower then with only 2 secondaries,
and than dip in the 9s when they come on line

my cruise and light throtle is perfect only trasition sucks,

I was looking at the scematic I have one more out put unused, can I that to switch the relay
on and off to kick the other two injectors lets say 10psi,

I think on that boost level it wont be that noticable and maybe will clean up by triming the ms and playing with switch point up and down couple psi

my only concern is if that will effect the ecu , dont whant to damage it by stching the power wire to injectors on and off

I had the staging perfect with an external split second contorler to fire the 2 other injectors,
but took it out fearing that when I hit boost cut or rev limit that thing still shoting fuel and leaning out

Make the secondaries come in later, maybe around 7 psi or higher, Why do you have so much injector? How much will 4 1600cc support on e85?

I just dont have enough injector to run gt4094r @ 7psi with 2x1000cc minus 40% for e85
to have enough fuel up to 3250 I had to cranck up base fuel pressure to 50psi

plus the primaries only shoot on the small ports and the turbo just stops boosting around 4-5 psi and leaned out big time when I had the staging higher,

also I am running the primaries 99% on the staging

this is on 17 to 20 psi spike,
now I am running up to 27psi so I gues I am @ 500whp plus this is mustang dyno reads 8-10% lower

OK, so stage the secondaries earlier and bring up the %Stage.

I need to play with it some more then,

I tried 1350, 1850, 2000rpm and 0, 2, and 5psi is the highest I tried,

I get it close in one gear then next one is way of even steve kan tried couple different settings

the way I have it I can drive stop and go and cruise great and economy is better,

if I need to get on it I drop a gear,

I will get a manifold made in the next few days with 90mm tb and thinking of running 550 cc
on the primarie stock location and move the 1000cc in the big ports so that way I'll have enough fuel to crank the staging higher,

Why not put 2 1600cc for the primaries and bring the fuel pressure back down.....

that will help the staging, the problem is my 1000cc primaries r hi imp. short body injectors,

I can't run hi.imp and lo.imp. in parallel for secondaries,

I don't want to replace the 1000cc with 160lb they r to long and interfere with my secondary
fuel rail, I have the xesive lim with 4x160lb. and dont want to redo everything,

if I only run 4x160lb don't think will be enough for 28psi on my turbo

email Jon at microtech, He will figure this thing out quick and tell you how to fix it or change what your doing...

well I got the transition better then ever I was surprized,
it still dips in to 9s on couple spots for split second but its not noticable,

got the staging @ 1300rpm and 4 psi, it took lots of work, but patience paid off,

I did it on the street this time, doing it on the dyno would clean up some but was worst when back on the street

It helps a lot to use the graphs and not the text matrix table when looking at the secondary stage point. With the matrix table it is easy to create a big fuel ridge between two bins which causes the lump you feel. With the 2D graphs, it is hard to do this because you notice visually right away. Just make sure to adjust all the bins around the two points where it is rich. Pull more fuel out of the bin it is closest to, then compensate by adding a little fuel at the previous bin and the bins above and below. Then make another run and adjust accordingly. It's a rather painstaking process when done correctly.

thnx guys,

will mess with it some more,

the car feels great as soon as I get in load the afr's stay in 12's an turbo spools so fast that the rich poin its not even noticable, i can only c it on the wb guage, not like b4 it would stop spooling for split sec lean out to 15s before secondaries come in,

it transfomed the car, i'm very happy with it, I have .84 exhaust housing so I get over 20psi @ 4k rpm