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Old 02-16-2008, 04:18 AM   #1
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Default Anyone running staged injectors?

I'll have a hell of a time getting a solid a/f idle on 1000cc injectors so I'm considering running staged injectors and adding a set of 750s in the runners and running 250s in the stock injector location. I -could- run the 750s on a boost comp fuel map. Anyone tried this? Opinions?
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Old 02-16-2008, 09:52 AM   #2
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Not on your powerlevel, but i did it on my 180fwhp peugeot, worked lika a charm there.
Can't see that you should get any trouble if you fabricate and tune it properly.
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Old 02-16-2008, 10:04 AM   #3
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bigturbo does something similiar on his EMB setup.
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Old 02-16-2008, 11:08 AM   #4
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Quote:
Originally Posted by lazzer408 View Post
I'll have a hell of a time getting a solid a/f idle on 1000cc injectors so I'm considering running staged injectors and adding a set of 750s in the runners and running 250s in the stock injector location. I -could- run the 750s on a boost comp fuel map. Anyone tried this? Opinions?
Staging works well, provided that the ECU cuts over nicely. As far as the secondaries, keep the 1000's, and just get any size cheap injector you can... stock miata injectors are a perfect choice because everyone dumps them. Once you are pulling the secondaries online the size won't matter.

You should be able to idle the 1000's, have you tried reducing the fuel pressure to compensate? I was able to idle 880's with ease at 60 PSI using a Walbro 255HP.

Mark
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Old 02-16-2008, 12:10 PM   #5
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I can't get a steady a/f with 550s. The pulse width is so low that any change is a large precentage. Idle fuel pressure is ~35psi. I figured another set of 550s would be enough. Going back to stock primaries and 750/1000 secondaries would probably help the idle issue.
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Old 02-16-2008, 01:30 PM   #6
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figure out your 550 idle problem before you play with the 1000s. 550s should idle fine with around a 1.0ms pulse at 1000 rpm. you can run them maybe down to .6 somewhat reliably on stock fuel pressure (40-45 psi).

try datalogging pulsewidth and make sure the PW going to the injectors is actually what you think it is, not just what you put in the tables. it sounds like you're running an AEM and you probably need to lower your microsec/bit value to around 75. Probably lower for the 1000 ccs as well as using the boost fuel correction function to get more fuel at higher rpm/boost. You basically set the boost correction so that 101.3 kpa = 0% and your max kpa is 100% and 0 kpa is -100%

It will allow you to make finer changes in vacuum where you use less fuel.

http://forum.aempower.com/forum/inde...c,11494.0.html

But I haven't actually done it in practice
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Old 02-16-2008, 02:25 PM   #7
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I'm somewhere around 1.23ms near idle. Raw view is 136-165 from the lowest to the highest value in the map. Maybe I'm just too picky. My idle a/f is around 13-14. It's just very sensitive which makes compensation for things like air and water temp even more difficult. I tried boost comp on the whole map and it fucked things all up. lol I spent hours trying to dial that in and I could get close but I was better off with cell-by-cell adjustments and boost comp >0psi. The map itself is fairly linear and with automapping working now I can see it actually adjusting for the VE of the engine. It dips about 3500-4000. My ms/bit is about 68 if I remember correctly. I can't find the setting now. It's been months since I dug around in AEMPro.
What's your opinion of AEMTuner? I can't stand it. It's like trying to use a Mac after owning a PC for 10 years. lol
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Old 02-16-2008, 02:32 PM   #8
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Found it. Advanced fuel trim options. It's at 65. I'm figuring out staged injectors right now.
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Old 02-16-2008, 02:45 PM   #9
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Quote:
Originally Posted by lazzer408 View Post
Found it. Advanced fuel trim options. It's at 65. I'm figuring out staged injectors right now.
Part of the problem is idling on large high imp injectors. They make it more tricky.

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Old 02-16-2008, 06:21 PM   #10
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I was thinking about doing something similar. stock ecu controlling the stock injectors, and a standalone controlling some big injectors and the timing. This way my stock ECU will take care of the idle, AC and all the other stuff. I have an old FMII 8 injector setup so it might work.

Will the stock ECU have an issue with not have the coil packs hooked up? Just a thought.. You have got me thinking more serious about this now... I want an emissions test friendlt setup, and that might be the ticket.
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Old 02-16-2008, 07:19 PM   #11
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oooh high imp injectors? that might be an issue... probably ok for 550s but i doubt you can get stable low pulsewidths to idle the 1000's. below 1500 rpm anyway.
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Old 02-16-2008, 08:21 PM   #12
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Yes they are high imp 550s now. I would add another set of high 550s. Think that would be a problem?
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Old 02-18-2008, 11:00 PM   #13
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The Haltech provides for staged injectors and offers full control of the merge rate of the secondaries.

Even us non-electron types found it easy.

We did have more success with making the primary bigger than the secondary. Or, at least, not using a shrimp for a primary.
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Old 02-19-2008, 06:51 AM   #14
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Quote:
Originally Posted by Corky Bell View Post
The Haltech provides for staged injectors and offers full control of the merge rate of the secondaries.

Even us non-electron types found it easy.

We did have more success with making the primary bigger than the secondary. Or, at least, not using a shrimp for a primary.
I'm running AEM's EMS. It looks like I have a whole secondary map with resolution equal to the primaries. I haven't figured out how to boost comp them yet. I should let my primaries hit 80% and hold there then the secondaries come on right? I have some 550s now so it would be easiest to pick up another set of these. I wind up with 1100cc (rated) flow. It saves me the expense of an injector driver box. I believe the 1000cc are only sold in low imp.
Corky I need to give you a call someday. I haven't spoke with you in over a year now and I've been making good progress with my car. I need to rattle your brain about a few details.
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Old 02-19-2008, 09:14 AM   #15
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You should send me PMs more often about this stuff. I don't have my laptop now so I can't play around, but I know you also set the percentage of the fuel map going to each injector set, with a max duty cycle on the primaries, etc. As far as boost comp, I do remember AEM saying only use it >0psi. My microsec/bit is in the mid 70's; running 440's and my maps go to 18psi, as if I'd ever go there. Even with that there is a big difference in bits at idle; you have you use the various idle trims which greatly add resolution and control to idle. But with your saturated 1000's, it'd be hard. I've always considered staged injectors and was one of the reasons going to the AEM for me at the time cause I figured I wouldn't have to buy another set of RC's. But the 440s have been fine for me so far.

I haven't tried aem tuner because I really like aem pro and my laptop is pretty old, P2 win98 etc and is finiky with new software. it works, doesn't crash or lockup, so I kinda don't want to screw with it.

EDIT: the part of idle control that is the most PITA for me is compensating for electrical load. My alternator is getting old and I like my 4 H4 headlights, stereo, A/C on high, etc. My battery voltage/injector duty cycle table is much different than the default for the RC440's.
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Old 02-19-2008, 11:59 AM   #16
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Quote:
Originally Posted by mkulak View Post
I was thinking about doing something similar. stock ecu controlling the stock injectors, and a standalone controlling some big injectors and the timing. This way my stock ECU will take care of the idle, AC and all the other stuff. I have an old FMII 8 injector setup so it might work.

Will the stock ECU have an issue with not have the coil packs hooked up? Just a thought.. You have got me thinking more serious about this now... I want an emissions test friendlt setup, and that might be the ticket.
<Hijack> Are you going to run without the MAF? You'll throw a CEL if you do. That's why my Motec failed recently because even though I'm running parallel and the stock ECU is handling CELs, it throws a code because the Maf is gone.

Frank
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Old 02-19-2008, 12:14 PM   #17
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Cant you just plug the maf in and hide it somewhere under the hood, or is the oem ecu smart enough to know there should be a change in voltage as rpms increase?
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Old 02-19-2008, 01:38 PM   #18
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GPO to low pass filter with a map outputting what the MAF wants to see. It's the same function as the emanage airflow output map.
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Old 02-19-2008, 03:43 PM   #19
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Of course you can "emulate" it. Just pointing it out to mkulak so he's not surprised if he wires it up last minute then throws a code. You need to know the values the ECU is expecting.

Frank
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Old 02-19-2008, 04:12 PM   #20
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Quote:
Originally Posted by TurboTim View Post
Cant you just plug the maf in and hide it somewhere under the hood, or is the oem ecu smart enough to know there should be a change in voltage as rpms increase?
it's smart enough to notice it.

Frank: what about a suck-through maf app?
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