CobraMarty
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And how long do you think that it will take till it fills like going open loop?
How do you or can you propose a fix for this?
6-7 pounds, but I have to see just how much the kit puts out.
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Sprintex / Boostec Supercharger Install
- Thread starter CobraMarty
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And how long do you think that it will take till it fills like going open loop?
How do you or can you propose a fix for this?
6-7 pounds, but I have to see just how much the kit puts out.
cobra marty, look at my 1st post on this thread, you have to clamp the 02 sensor signal somehow otherwise the ECU will just cut back the fuel to the main 6 injectors until it goes down to 14.7.
I have an AEM AFR gauge on board so i can tell you for sure the jeep stays in closed loop 90 % of the time, it only goes to open loop when you floor it and the RPM is above 3500.
The point is , to enjoy the mid throttle thump of a supercharger with a 4 L engine you have to control the ECU in closed loop, or u'll detonate all the way to open loop.
so , one of the AEM key abilites is to clamp or offset the O2 sensor signal, you will find the pinout diagrams for those connections posed somewhere in this forum.
so here's my modest opinion
: since you have your AEM anyhow, and you are going to wire it in any how, why not wire 6 more wires and connect your AEM to your main 6 injectors and o2 sensor, ? the jeep injectors run at 70% duty cycle at max flow, so there is around 15% room to increase their pulse to 85%, that can be enough for 6 psi.
I have an AEM AFR gauge on board so i can tell you for sure the jeep stays in closed loop 90 % of the time, it only goes to open loop when you floor it and the RPM is above 3500.
The point is , to enjoy the mid throttle thump of a supercharger with a 4 L engine you have to control the ECU in closed loop, or u'll detonate all the way to open loop.
so , one of the AEM key abilites is to clamp or offset the O2 sensor signal, you will find the pinout diagrams for those connections posed somewhere in this forum.
so here's my modest opinion
: since you have your AEM anyhow, and you are going to wire it in any how, why not wire 6 more wires and connect your AEM to your main 6 injectors and o2 sensor, ? the jeep injectors run at 70% duty cycle at max flow, so there is around 15% room to increase their pulse to 85%, that can be enough for 6 psi.
CobraMarty
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That is very useful. I will wire the O2 sensor and clamp it with the AEM. Any suggestions as to what to clamp it at?
One AEM will can not control both the 6 stock injectors and the 7th. I would need 2 FIC's.
I don't think that adding 15% more fuel from the stock injectors will be enough. 6 lbs should add 30-35% more hp to 275hp maybe 300hp with the larger TB and headers and will require 30-35% more fuel.
The 7th injector is located on the plenum area under the TB, before the supercharger. The fuel goes into the s/c and gets 'homogenized' with the air and goes to all the cylinders with the air.
Thanks for your input.
One AEM will can not control both the 6 stock injectors and the 7th. I would need 2 FIC's.
I don't think that adding 15% more fuel from the stock injectors will be enough. 6 lbs should add 30-35% more hp to 275hp maybe 300hp with the larger TB and headers and will require 30-35% more fuel.
The 7th injector is located on the plenum area under the TB, before the supercharger. The fuel goes into the s/c and gets 'homogenized' with the air and goes to all the cylinders with the air.
Thanks for your input.
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CobraMarty
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With regard to the O2 sensor- the wiring pinout diagram shows
O2 sensor 1/1 signal, 1/2 signal, 2/1 signal and 2/2 signal. 4 different wires.
Which is the front cat? And which is the one to clamp?
What is the difference between the 1/1 and the 1/2?
O2 sensor 1/1 signal, 1/2 signal, 2/1 signal and 2/2 signal. 4 different wires.
Which is the front cat? And which is the one to clamp?
What is the difference between the 1/1 and the 1/2?
my xj only had 2 o2 sensors 1/1 and 1/2 . "1/1" is the one before the cat. and its very important to the PCM , this is what you should tap to, the "1/2" monitors the overall performance of the cat for emission reasons, its signal still affects the PCM but is not a "priority signal. so its a choice, some people tap it , others say its not necessary
i believe the 2/1 and the 2/2 are applicable only if you have o2 in your headers " california vesrion.
the interface in the AEM software is quite easy, if you have the AEM manual itself, it will give you everything you need,
the overall objective is that your o2 sensor signal is always " offset " to cancel the effect of the "rich " AFR you run, this way, the jeep PCM feels no changes.
by the way, can you share some details you managed to build a wire harness for the AEM?
i believe the 2/1 and the 2/2 are applicable only if you have o2 in your headers " california vesrion.
the interface in the AEM software is quite easy, if you have the AEM manual itself, it will give you everything you need,
the overall objective is that your o2 sensor signal is always " offset " to cancel the effect of the "rich " AFR you run, this way, the jeep PCM feels no changes.
by the way, can you share some details you managed to build a wire harness for the AEM?
O-Gauge Steamer
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Here is the thing about the O2 sensor offset funcion in the F/IC. It has been tried, by several folk here on the board, without any level of success which is why I abandoned the E85 project. Do a search and you will find the threads. The Stroker Guys have been attempting to get it to work and not even AEM can explain why it doesn't except for the normal "Well it is a Chrysler product" disclaimer. Out PCMs are not very user friendly.
Enrichment under acceleration. As the F/IC reads the injector pulse sent by the PCM and operates the extra injector per the table. What this means is, if the PCM is calling for a longer duration pulse width, the AEM will use that width as part of the calculation. My suggestion, to those interested. is to download the dcumentation and read it.
Under WOT, the PCM goes open loop. I have mine adjusted to hold mostly mid 13 AFRs in these conditions. IMO, into the 12s is a tad fat. That being said, I have a couple of points that drop down to an AFR of 12.9.
Installation and wiring of the F/IC. I installed my F/IC right above the brake booster (made a sheet metal bracket for it to sit on) and cut into the harness at the inner fender line approximately 1' away from the firewall as it made it easy to sit and solder the wiring... It is just cut into the factory harness and wire in the new. I used cable covers to match the factory wiring. If one is not completely comfortable with doing the wiring, do not attempt it, find help.
There isn't a pre-made harness anymore. Only two were ever made and I built them both. One was put into the Boostec XJ and the other went to South America. Plus, the two in question were for the Perfect Power SMT8-L controller, not the AEM F/IC. Even my initial installation (SMT8-L) had me cutting into the factory harness and I was still associated with Boostec at that time.
It was as a reward for pointing out the wiring solution to Sprintex that I obtained my kit. Sprintex, gobally, was having issues with folks screwing up the wiring and then attempting to blame Sprintex for thier failure. I solved a problem for them. As a Process Engineer, it is what I do. Or did, anyway, for a living. Plus, I do provide feedback to Sprintex on the performance of the system. Legally, Sprintex holds title on thier parts in my Heep. I do not own it.
AEM had to discontinue the 96-04 ECM Extension Harness from thier catalog due to the manufacturer of the PCM side connector (the single large one) discontinuing production due to lack of orders. The Extension Harness has been out of production for over a year.
CobraMarty, you will see 7lbs and you may see 8lbs of boost as you are near/at sea level. I get 6lbs here where the air is a tad thinner... Providing, of course, that the engine is in good nick to begin with.
Just an FYI on fusing Aluminium. Aluminium was being welded together long before MIG/TIG welders had been invented by using a brazing process. Take the aluminium up to 720F with an Oxy/Acetelene Torch and apply the rod to it. Permanent bonds are achieved.
Enrichment under acceleration. As the F/IC reads the injector pulse sent by the PCM and operates the extra injector per the table. What this means is, if the PCM is calling for a longer duration pulse width, the AEM will use that width as part of the calculation. My suggestion, to those interested. is to download the dcumentation and read it.
Under WOT, the PCM goes open loop. I have mine adjusted to hold mostly mid 13 AFRs in these conditions. IMO, into the 12s is a tad fat. That being said, I have a couple of points that drop down to an AFR of 12.9.
Installation and wiring of the F/IC. I installed my F/IC right above the brake booster (made a sheet metal bracket for it to sit on) and cut into the harness at the inner fender line approximately 1' away from the firewall as it made it easy to sit and solder the wiring... It is just cut into the factory harness and wire in the new. I used cable covers to match the factory wiring. If one is not completely comfortable with doing the wiring, do not attempt it, find help.
There isn't a pre-made harness anymore. Only two were ever made and I built them both. One was put into the Boostec XJ and the other went to South America. Plus, the two in question were for the Perfect Power SMT8-L controller, not the AEM F/IC. Even my initial installation (SMT8-L) had me cutting into the factory harness and I was still associated with Boostec at that time.
It was as a reward for pointing out the wiring solution to Sprintex that I obtained my kit. Sprintex, gobally, was having issues with folks screwing up the wiring and then attempting to blame Sprintex for thier failure. I solved a problem for them. As a Process Engineer, it is what I do. Or did, anyway, for a living. Plus, I do provide feedback to Sprintex on the performance of the system. Legally, Sprintex holds title on thier parts in my Heep. I do not own it.
AEM had to discontinue the 96-04 ECM Extension Harness from thier catalog due to the manufacturer of the PCM side connector (the single large one) discontinuing production due to lack of orders. The Extension Harness has been out of production for over a year.
CobraMarty, you will see 7lbs and you may see 8lbs of boost as you are near/at sea level. I get 6lbs here where the air is a tad thinner... Providing, of course, that the engine is in good nick to begin with.
Just an FYI on fusing Aluminium. Aluminium was being welded together long before MIG/TIG welders had been invented by using a brazing process. Take the aluminium up to 720F with an Oxy/Acetelene Torch and apply the rod to it. Permanent bonds are achieved.
CobraMarty
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I only have the 2 O2 sensors. I was just looking at the pinout and saw the 2/1 and 2/2. So I can connect the AEM to the 1/1 and clamp it. 1 wire and 2 splices that's easy enough.
For those who asked, here's the pic of the patch harness that I made. I went to the junkyard and got an XJ ECU and vehicle-side plugs (with about a foot of wire), ripped apart the ecu for the plug, and did a TON of point-to-point soldering.
Let's just say that it wasn't the most entertaining way I've spent 2 hours of my life... :doh:
P.S. HI YAN!!!!!!! :wave::clap:
Let's just say that it wasn't the most entertaining way I've spent 2 hours of my life... :doh:
P.S. HI YAN!!!!!!! :wave::clap:
Talyn
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Where did you mount the AEM?
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- Rainy side of Washington
I hope you heatshrink insulated all those splices... else they are going to corrode something awful, and probably get shorted by water if you drive it in the rain. Not fun.
CobraMarty
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AEM in the cab, under the dash. Wired into the harness right near the firewall. Not using the jumper harness.
CobraMarty
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Just thinking while having dinner--
So I mapped out the wires near the firewall to cut into for the AEM, I am going to intercept the O2 sensor 1/1 and all the others.
So I had a thought. So basically in 2 crank revolutions the aem will pulse the 7th injector once. And then a lot of crank rotation before the next firing of the injector. I see why you were concerned about only sensing inj #1. So why not tie in 2-6 injectors all tied together with a diode inline to prevent back flow of electrons and tie them all together and into inj #1 input. Then the inj #1 output to the 7th injector. So when each injector fires, the aem will fire the 7th injector. Sure the pulse width will have to be decreased by a factor of how many injectors are tied together.
So instead of having pulses of fuel/air mix - air - air - air - air - air..., there would be if tied 3 injectors together #1+#3+#5 then fuel/air mix - air -fuel/air - air -fuel/air - air...
Just thinking. 5000rpm = 83.33 revs/sec = 12ms/1rev, 2 revs for 1 cycle, so 1 cycle(Intake-compression-power-exhaust) takes 24ms, 80% max DC leaves .19ms injector has latent opening ?1.5-2ms and 1 ms closing, leaves 16ms total time between 1 cylinder firing. If 6 signals then 2ms+1ms(open and close) x 6 times is 18ms leaving not enough time to open and close the 7th injector 6 times in the 2 revs of the engine.
There is probably a mistake here but there is not enough time to open and close the 7th injector 6 times. That is why only connect it to 1 injector. So the firing the 7th injector only once is OK.
If I an only using the aem to control the 7th inj and the timing and clamp the O2 sensor will the 1910 work and not need the 1913?
O-Gauge said somewhere before that sprintex when they used the other controller that the fuel worked fine but it was the timing that was a problem.
Anyway, gotta got do some wiring.
So I mapped out the wires near the firewall to cut into for the AEM, I am going to intercept the O2 sensor 1/1 and all the others.
So I had a thought. So basically in 2 crank revolutions the aem will pulse the 7th injector once. And then a lot of crank rotation before the next firing of the injector. I see why you were concerned about only sensing inj #1. So why not tie in 2-6 injectors all tied together with a diode inline to prevent back flow of electrons and tie them all together and into inj #1 input. Then the inj #1 output to the 7th injector. So when each injector fires, the aem will fire the 7th injector. Sure the pulse width will have to be decreased by a factor of how many injectors are tied together.
So instead of having pulses of fuel/air mix - air - air - air - air - air..., there would be if tied 3 injectors together #1+#3+#5 then fuel/air mix - air -fuel/air - air -fuel/air - air...
Just thinking. 5000rpm = 83.33 revs/sec = 12ms/1rev, 2 revs for 1 cycle, so 1 cycle(Intake-compression-power-exhaust) takes 24ms, 80% max DC leaves .19ms injector has latent opening ?1.5-2ms and 1 ms closing, leaves 16ms total time between 1 cylinder firing. If 6 signals then 2ms+1ms(open and close) x 6 times is 18ms leaving not enough time to open and close the 7th injector 6 times in the 2 revs of the engine.
There is probably a mistake here but there is not enough time to open and close the 7th injector 6 times. That is why only connect it to 1 injector. So the firing the 7th injector only once is OK.
If I an only using the aem to control the 7th inj and the timing and clamp the O2 sensor will the 1910 work and not need the 1913?
O-Gauge said somewhere before that sprintex when they used the other controller that the fuel worked fine but it was the timing that was a problem.
Anyway, gotta got do some wiring.
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CobraMarty
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OK?, thanks for your input.
That's why most of us that have/know the AEM F/IC say to just get bigger injectors and screw the 7th injector. It is not cooling the intake charge, but wetting the intake manifold. Do offset the 1/1 o2 sensor(and 2/1 if you have 99+) so that you're not limited to 14.7:1 in closed loop(especially from 2.5K-3.2Krpms). Having an F/IC and only controlling 1 injector is a waste of potential. Don't worry about increasing base timing until you have it nailed as is.
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Ehh. We'll try the 7th injector. If it doesn't work how we want, then we might upgrade to larger injectors. Only time will tell.
As of right now, it's easier to stick with the 7th injector because the supercharger is 100% installed and I don't feel like tearing it apart again. Lol.
Talyn
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How hard is it to get to the stock injectors w/ the sc installed?
You probably won't be able to get the O2 sensor offset to work though.
You probably won't be able to get the O2 sensor offset to work though.
CobraMarty
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Injectors are easy to get to them, just like stock.
What is the problem with the O2 sensor offset? Can't it be used to clamp the output so when in closed loop and then I can add extra fuel, the O2 output will be clamped so it doesn't show a richer mixture.
What is the maximum O2 sensor output voltage seen? What voltage should the O2 sensor be clamped at so that when in closed loop and I add fuel the ecu won't detect this?
What is the problem with the O2 sensor offset? Can't it be used to clamp the output so when in closed loop and then I can add extra fuel, the O2 output will be clamped so it doesn't show a richer mixture.
What is the maximum O2 sensor output voltage seen? What voltage should the O2 sensor be clamped at so that when in closed loop and I add fuel the ecu won't detect this?
Talyn
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It just doesn't work for narrow band sensors. The PCM is looking for a wave pattern or sorts at 14.7:1 or so and adjusts to get that. The AEM can not reduplicate that nor can it offset it in a manner the PCM is looking for. It can't recreate that wave when the AFR is lower or higher. The AEM will intercept the signal and change it, but not in a way that the PCM will like or be useful. To enrich the fuel in closed loop what needs to happen is that the PCM needs to be fed that wave when the AFR is around 12.5:1(or where ever you want it). And rich when less of a value(numerically) and then of course lean when greater. The AEM can change the peaks and troughs of the wave, but that won't allow the PCM to change the AFR.
I've played with trying different things for like 5 hours, but no dice. I have a few other things to try, but i doubt any luck.
I've played with trying different things for like 5 hours, but no dice. I have a few other things to try, but i doubt any luck.
I can't speak for Talyn's issue with the o2 offset, but I was able to do it and get closed loop afrs down in the 13s. Narrow band o2's work from 0-1v, .45v is stoich, >.45v is rich, so use values like +.2 to.4v in the cells to get it richer. Then you will go into your maps and adjust the cells to zero out your new fuel trims based on the afr you chose. You'll want a smooth transition from closed loop to open loop(so no 14.7, then bam, 12.0).
