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Forum nameTurbo/Nitrous Tech
Topic subject8 injector setup and stutter box, why won't mine play together??
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i8&topic_id=52401
52401, 8 injector setup and stutter box, why won't mine play together??
Posted by Kirby, Jul-21-03 01:31 PM
I have the crane ign. and the 8 inj setup. My stutter box worked fine with the old fuel setup, I could build about 9-10 psi. Now it won't go over 0psi while sitting at 4000 RPM's. So the limit works, it's just not building boost. We were thinking it might just be too rich when the extra 4 inj. start to fire. Anyone else run into this issue, or have any other ideas to fix it. So far I plan to raise my cut rate on the EIC so it can get past that rich spot and then build boost. The other idea is to lean that spot out and then re tune the rest of the fuel curve to be correct. Please tell me your thoughts.
52468, RE: 8 injector setup and stutter box, why won't mine play together??
Posted by RyaN95i4, Jul-22-03 03:48 PM
What size injectors are you running now?

wheres your eic set to start spraying the extra 4 injectors at?

I think your right, dumping to much fuel and with little load on the motor, thats keeping you out of boost on the line.

Even the stock injectors will be able to handle a couple pounds of boost on their on, set your cut rate a couple lbs above 0 (make sure you dont creat a dangerously lean spot tho).
52499, RE: 8 injector setup and stutter box, why won't mine play together??
Posted by Kirby, Jul-23-03 08:26 AM
Well my secondarys are 44LB inj. And the richness is the problem, according to the thick cloud of black smoke that came out when I tried it again the other day. The main issue is I don't know how much boost it will build, but I think somewhere around 10PSI. So therefore I would have to have the extra injects comming in. I was going to play with the cutrate a little bit and see what it does. Do you think that if I raise the cutrate it will work? I figured doing that would help me get a little boost at first, but I still think that when they kick in they would make it too rich to build any more boost. Any thoughts on that one?
52500, RE: 8 injector setup and stutter box, why won't mine play together??
Posted by Corbin, Jul-23-03 09:12 AM
Don't worry about the cut rate. You can raise the "cut fuel below" point some. That might let it catch itself enough to spool up. The best option may be to lean out the matrix points below 137 kPa (over the whole RPM scale). 137 kPa is about 5.2 psi boost. Try subtracting 0.03 from each value. That will give you about 3% less fuel at each point. I'm sure you have some room to lean out those values. When you are done, be sure to verify that you have enough fuel for a run at 5 psi (remove the MBC to test that).

Corbin

'95 ESI-T
HRC+FMIC+ETC...



Gimme fuel...Gimme fire...Gimme that which I desire
52515, RE: 8 injector setup and stutter box, why won't mine play together??
Posted by Kirby, Jul-23-03 12:38 PM
My bad Corbin I thought that was the cut rate. So you think I should lean out anything under 137kpa (around 5 lbs of boost), what if it stutters at 10psi though, would that still work? Also can't I just lean up to the 4000 rpm's that the rev limit is set to?
52548, RE: 8 injector setup and stutter box, why won't mine play together??
Posted by Corbin, Jul-24-03 03:10 AM
I'm thinking that once you get the turbo spooled and boosting, that it will work for the higher boost. You could probably just play with the numbers under 4k (I'd just do it all the way to red line to be sure). You'll just have to experiment. Have you tried doing this at part throttle, so the ECU can lean things out as necessary?

Corbin

'95 ESI-T
HRC+FMIC+ETC...



Gimme fuel...Gimme fire...Gimme that which I desire
52549, RE: 8 injector setup and stutter box, why won't mine play together??
Posted by Kirby, Jul-24-03 04:38 AM
No I have not, I will try that and see what it does, then I will go ahead and try to lean it out a little and see if that works.
52592, RE: 8 injector setup and stutter box, why won't mine play together??
Posted by RyaN95i4, Jul-24-03 06:34 PM
also, not sure where you are, but that 137 value will vary dpending on ur location.

for example, im in s. fl and actually slightly below sea level, so mine is set to start the exytra injectors at ~149kpa, which is just 3psi manifold pressure.

to fugure out where you stand, see what the eic registers as manifold pressure with the car off. then you can figure out where to have the injectors come on in terms of kpa vs. boost
52622, RE: 8 injector setup and stutter box, why won't mine play together??
Posted by Corbin, Jul-25-03 07:31 AM
local atmospheric was 118 kPa by the installed sensor. We set it to start fueling at 125 kPa. 137 kPa is just the closest data point in the fueling matrix. He has an external 3 bar sensor, and I think it reads a little high. So the closest data point is probably a little lower than 5.2 psi. I guess you'll just have to keep trying things until you get it right. Thats what it always seems to come down to.

Corbin

'95 ESI-T
HRC+FMIC+ETC...



Gimme fuel...Gimme fire...Gimme that which I desire
52632, RE: 8 injector setup and stutter box, why won't mine play together??
Posted by WheatKing, Jul-25-03 10:30 AM
hehe.. or be an evil bastard...

Drill a hole in the manifold and weld a BIG THICK bung there..

thread in a spark plug.. connect the plug to a good coil.. and a microswitch.. clutch in.. it fires the plug..

basically.. just hope you don't blow your exhaust off.. but i guarantee that it will help spool ;-)

What good is stutter without a bang bang box to go with it?

-- WheatKing