Cant wait to see some numbers man. Great job!

 

So any new updates it's been a little while and I can't wait to see a final project done

 

Qucik Question Are U Able To Put an Slk Hood ON A Crossfire?

 

Well guys, no new updates as I haven't been able to spend any time on it what so ever. I'm kicking myself because it would have been 100% if I had a straight window of time to tweak versus stopping and starting with months between. I often end up finding myself in redo mode because I was onto something, in the middle of a test, but didn't make myself a good note of what it was or where I was at in the process. Right now she makes good boost and it is really only a matter of tuning her up. Although I shouldn't over simplify that task. I'm pretty sure I licked the 4,500 rpm stumble with the AEM, if not I can just take her down and have eurocharged or other finish her on out if it really comes down to it, but that is so NOT where I want to go with my project.

 

Try to just sit on it and come back to it when you are ready. All that work, would be a shame not to get to enjoy it for a while. Thanks for sharing all your details with us, this is a killer thread. Good luck Web 3.0!!

 

Yea, just take your time with the project, Do what you need to do then finish her up when the time is right! Good Luck with everything!

 

I was actually just discussing this build with a friend of mine, and what a phenomenal job you've done. We both admire the innovation that has gone into this. We both agreed that if tuning was the only issue at hand, perhaps it would be less stress and less hair-pulling to simply hand it over to a full-time tuner? They can't take the fab work and the pioneering away from you, but they might be able to provide some assistance in the fuel/tuning area (Perhaps Motorwerks in Houston?). It's kinda like I'm a great landscaper, but a horrible plumber LOL.

Best of luck with school! We're all rooting for you, and again we appreciate the path you're blazing for the N/A guys.

Cheers,

--John

 

Well guys, I've sat on it for a few weeks and am in a better place. I guess I was just feeling very overwhelmed with everything going on, not to mention a move. It is very hard to think about working on your car when your garage is stacked to the ceiling with boxes!

Oh well. Something I've learned is that with the added air flow, I get a random tps error. I plan on running that through the analog b input of the AEM so I can modify the signal and see how that works. However, first things first and that is getting her inspected. She passed last year, but during the process I disabled the egr. I'm going to set that straight, reposition the IC pump as it is in the lower driver's side bumper and it doesn't like the occasional curb block bump. Once those two things are behind me, I need to find a steel idler pulley. I increased the belt tension for the sake of grip and that pulley didn't do too well in the Texas heat with the added stress. I've since lessened the tension but not without causing my idler pulley to complain a little when cold.

Then finally I'll get back to tuning her up. This time, just in case I have an unexpected break, I will keep a log so that I know exactly where and under what circumstances I left off. I guess I finally have so much going on in my life combined with age that I can't remember EVERYTHING the way I used to think I did

 

Well guys, I'm in a much better place! I took some time off a week or so ago from other things with my inspection due today and addressed the following:

- fixed a small leak at the oil filter cap
- replaced the idler pulley (old had damaged bearing)
- replaced the serpentine belt
- uninstalled the rotrex and cut some material off the mount for belt clearance and reinstalled
- installed a new egr valve
- cleaned maf
- designed a solution for proper crankcase ventilation (re-hosed with check valves)
- tuned out a nagging CEL
- re-mounted my IC pump in new location and re-routed hoses (had ripped off in lower front bumper after it got caught on a parking block)
- confirmed, tested, and refit my tensioner solution for the main belt (this time kept it on a low setting)

Wow! Well, a fresh new start with every single little tweak I've wanted to do, done. Then I took her down for an inspection and she passed with flying colors! Perfect, and I mean perfect drivability, idle, everything. Now, I want to continue an experiment with the AEM injector response setting and see where that takes me.

Right now I have low end and cruise at less than 2% LTFT! That is pretty damn cool to anyone in the know.

Now that the foundation is is perfect, I'm actually a little skiddish about turning up the heat!!!!! Oh well, Not really, I'm on a mission, and slowly but surely I'll get there. I need to revisit the high end miss that I had early on and make sure it is gone 100% after all the changes. If it isn't and the AEM proves to be too unruly, I may just go the srt6 ecu route or other. Regardless, success is just around the corner!!

 

Side note for future reference. The nagging CEL I mentioned was related to the egr. Even after reinstalling, I kept getting the same CEL. It ended up beeing the result of an earlier AEM map where I was clamping the map signal. The ecu performs an egr test where it expects to see a slight drop in the map reading under certain conditions within a specific rpm window. I had the area of the AEM map where this happens clamped too low and when the test was performed, it didn't see a change and boom. Once I realized this, it was a 30 second fix!

Just thought this might be useful to someone in the future.

 

Sounds like you're progressing nicely. Good luck and thanks for the updates.

 

Nice! Are you using the FIC6 or 8?

 

I'm currently using the Fic/6.

 

I will be starting on my crossfire turbo conversion this fall. I have designed three different systems for the new Hemi's, system design is not an issue. I would be highly interested in details on how you set up your F/IC unit and details on the actual settings used. I have used similar technology tuning Hemi's for years, but this will be the first time with the F/IC.Any information would be appreciated.

 

Well, well, well. It seems like every time I take another approach to tuning this beast I hit some kind of a ceiling or notice some odd behavior just as I get close to going all out. I continue to have a stock running crossfire with a great extra kick in the pants but never quite make it to the point where I feel comfortable putting the pedal to the floor and holding it to 6k.

So the latest update is that I scrapped going with a MAF based table and switched to what essentially would end up as a MAF delete by building a custom Map -> Maf voltage table. To do so, I built a base table and left the MAF connected to verify the MAF voltage for each cell. I've been tweaking the holy hell out of it and have it EXTREMELY close. The resulting curves are most definitely not linear and take quite a bit of finesse. The cool thing is that I have dialed in the theoretical injector percentage and can easily tell if a curve is off by the resulting AFR. Too much one way or the other and the same amount of fuel provides drastically different results.

That said, today alone, I made some great progress in getting it to the point where I feel confident I can start pushing her more. That was when I drove down a bumpy road and the car shut down on me for a crankshaft position sensor error. That I blame on the AEM FI/C and its crappy connectors.

I've noticed quite a few minor annoyances with the AEM over time and the weird things it does to the voltages it controls. Having all the extra wiring and depending so heavily on a piggyback just kind of makes me queasy. I started thinking about what would happen if I took it to the track and something similar happened. I could easily end up with a blown motor if not a wrecked car.

So then I decided to give our friend Rudy a call. I had seen that he had a couple of SRT-6 ecus for sale a while back and he did indeed still have them handy. I simply can't think of that many differences between what the ECU needs to see and neither did he. Lantana has been telling me to go with the SRT ECU from the start but I've been fixated on cracking this nut.

That said, I decided to pickup one of Rudy's ECUs and give it a try. I do plan on leaving the AEM in place and continue with my stock ecu tuning as I still want to prove that out to myself. I might also need it there for whatever things I might need to tweak with the other ECU. Regardless, the SRT-6 ecu will get me so much closer that in fact the aem could become more of a scalpel than a butcher knife in adjusting the tune (if it is needed at all).

Considering the stock SRT-6 ecu supports more boost than I plan on running and I have lower intake temps, wouldn't that be cool if I could make great power with oem tuning and safety with something as simple as an ecu swap and fooling a few sensors! I might have to pull a little timing but I am already running stock srt-6 injectors. I'm going to have to lookup and see if our MAP sensors are the same. The one in the N/A tops out at 3.8 volts at atmospheric pressure. It has a little room but not so much that I would think they are the same.

I checked the service manuals and so far this is what I came up with from the powertrain control module section:

Overall, it looks so far like the SRT wants to see the SC clutch and IC pump and the o2s are reversed. I already have the short runner system disabled and just have the solenoid plugged in but not attached. I locked the runners in high rpm mode.

Powertrain Control Module

• C1
  • Pin #1
    • N/A - Not Used
    • SRT - Supercharger Clutch Control
  • Pin #3
    • N/A - Sensor Ground
    • SRT - Throttle Control Motor #1

• C2
  • Pin #9
    • N/A - Not Used
    • SRT - Generator Control

• C3
  • Pin #7 - O2's reversed
    • N/A - O2 2/1
    • SRT - O2 1/1
  • Pin #23
    • N/A - O2 1/1
    • SRT - O2 2/1

 

Glad to hear are going to try the SRT ECU. Rudy has a 55K one waiting for me to pay for. I was mainly interested in it because it has a reminent file in it that will allow me to start my V8 from the key. I wil have to fool it a little because of the s/c clutch, i/c water pump and maybe the bypass valve. You may have to have a SDS system to adapt it to your car.

 

get that ecu bob! then you wont look like your trying to hotwire that car every time you start it!

 

Web 3.0, have you monitored the voltage for the map sensor versus the voltage for the MAF sensor? I am curious how close they are across the rpm range. The SRT6 map sensor is different, likely a 2.5 or 3 bar sensor, so it will need changed. The unit I use on my turbo Hemi has a MAF simulator function, although I have not used it yet. I have been studying the functions and inputs, and if I were to turbo my NA, then I would likely clamp both the stock map and MAF sensor. I only need them to function in the vacuum range. I can handle fuel addition with the fuel table for WOT, and O2 sensor control in closed loop part throttle boost.

I have not heard anything positive about the f/ic, their methods of table inputs are very strange, primarily they seem to be percentage based. Mine is tuned in degrees of timing, and milliseconds of fuel pulse.

 

If you use the SRT ECU, you don't have to worry about the MAF since there is no MAF input on the SRT ECU.

 

I've been all over every aspect of the AEM to the nth degree for over a year. The plan you layout is textbook AEM but no where near granular enough for the tune I seek.

The problem is that going the maf clamp route you are fighting several things. 1st, the max maf voltage per rpm that the ecu wants to see without crying foul. So you clamp the voltage to 2.2v at 1,200 and add fuel above that via map, but the occasions you reach the same cell with the same air flow at this intersection vary greatly. So you end up with varying afrs and fuel trims, tweaking endlessly trying to find the perfect balance and you still experience variations. Then, if you cap the voltage too low, it screws up the way the ecu confirms the egr is functioning and you get a cel.

The O2 system is also VERY picky and the textbook AEM O2 tap and resistor doesn't work. I've had control of the O2 but get weird cels and/or the trims stop calculating after three minutes. Very weird stuff but not the worst. The good news is that there isn't much need for O2 control with the Rotrex as I am above the maf clamps and in open loop quickly enough. Now, going with a turbo versus my Rotrex that might be another matter. You may very well need to grapple with that monster.

Going maf delete has been the best by far to get the exactness that I want. The map sensor itself is easy, cap at 3.8 volts all the way across at 14.7 psi and .89 at 2.9 and scale up. Perfect map sensor correlation for the NA.

Focus time on matching the internal AEM map to your stock maf readings while clamping at 4.51 volts and all is good. That said, this is by far the most complex method as you really need to have a grasp on simulating maf voltage curves at each load level. I should have a great map by the end of this week while I'm waiting on my other stuff to come in.

The cool thing about this is that when done you can add a temp sensor and delete the maf all together!

Also, the ecu determines load based on a combination of map and maf. If you wanted to get real technical with it you can manipulate both of these curves to make the ecu think you are at less load than you are and effectively increase spark even though the AEM doesn't actually provide for spark increase. You'll have to be careful though at low loads as this can impact your shift patterns with the greatest impact on downshifting with an automatic.

Half my problem now is that I should have just bought a new AEM harness as the one I have has too many quirks. The p0335 IIRC started after simply getting under the dash to double check my vacuum hoses and "touching" the wires! That pisses me off!

I think where I am at now is pretty simple, I've explored the AEM to the extreme and it has been found wanting. I just don't like having to lean SO HARD on a piggyback to make it all work. If I still need it after the ecu swap at least it will be in a minimalistic fashion.

I had started looking for other tuning methods to do this properly and simply can't justify spending the money to buy the tools that eurocharged and others use. If I was going to make a production kit, that would simply be the cost of doing business and I might take the gamble on making it back. That said, my options are full ecu replacement and spend the next year figuring out wiring to make everything else on the car happy just so I can tune it myself, go to eurocharged and let them tune it and be done with it, break some ground by swapping ecu's, map sensor, and fool a couple others and potentially have a pretuned ecu. Hmmm, it might have been cheaper to just go to eurocharged but I so like to tinker

When you get into the thick of it, I'll be glad to share tunes, maps, etc.