Thanks! I just signed up for a user account. Waiting for it to be approved by the admin. Lots to learn... here I go again. I thought the NSX was done for this year!
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Opinions on the AEM FIC/U and the CTSC
- Thread starter HotRod
- Start date
Thanks! I just signed up for a user account. Waiting for it to be approved by the admin. Lots to learn... here I go again. I thought the NSX was done for this year!
1. The FIC does not deal with altitude at all, the OEM ECU will and it has a baro built onto the main board of the ECU. The ECU will use this sensor like any other sensor to act as a fuel or ignition trim. So after the ECU looks at the fuel table and picks the amount of fuel to inject based on RPM and MAP voltage it will apply the fuel trims to that calculation. Some fuel trims add fuel others remove fuel, some fuel trims work only in closed loop other mays be global and act on the calculated fuel all the time. I am not sure of the ins and outs of all the trims and how the ECU is using them. SR5Guy is close to mapping them out and maybe we will all know soon.
The OEM ECU always uses the OEM MAP sensor, the problem is the OEM ECU will go into limp mode if it see's a MAP voltage that represents boost so the F/IC looks at the OEM MAP sensor voltage and will intercept that voltage going to the OEM ECU once you go into boost. Once intercepted the MAP voltage that the OEM ECU will see is whatever you program into the F/IC to send back out to the OEM ECU. So now that we have kept the OEM ECU from going into limp mode we need to know how much boost the engine is seeing and adjust the fuel and timing to be correct. The F/IC does this by using its own MAP sensor that is built into the F/IC. Actually the F/IC is always using its own MAP sensor to decide how to modify the fuel and ignition so the transition to boost is seamless to the F/IC.
2. The AEM and Snow and many other Meth system use a progressive controller to ramp up the amount of Meth being used based on an internal MAP sensor built into the controller. Most of these controllers let you pick the start point for spraying say 1-2psi and the point were the pump is at 100% say maybe 10psi. In this example the pump will be at about 10% at 1psi of boost and ramp to 100% at 10psi. By moving these points around you can get to just about any pump percentage from 10% duty cycle to 100% duty cycle.
3. In your example the IAT are still at 160-180 degrees you will want the ECU to pull timing and add fuel while these conditions exist, the only way to prevent the OEM ECU from pulling timing and adding fuel is to control the intake air temps. What really needs to happen with Meth and the CTSC is to design a plate that would go between the blower and the intake to spray the Meth directly at the blower discharge port. There may not be enough time for everything to mix correctly given the short path from the blower to the intake valve. So the next logical plan would be to do a muti-port system with a spray nozzle in each intake runner. Both of these methods are much harder to do than just sticking a nozzle in the intake tube before the blower so that is what most people do.
4. The wideband input on the F/IC is there to aid the tuner during the tuning process, the F/IC will log all the connected sensors and it is a big help to have all the data in the same place at the same time while tuning. The F/IC can look at the OEM narrow band O2's and you can program the F/IC to modify the O2 voltages going to the ECU and change the closed loop AFR point, since narrow band O2's tell the ECU were 14.7:1 AFR is if you modify the voltage going to the OEM ECU you can trick the ECU into any AFR while in closed loop by making it think it is at 14.7:1 when it is really at some other AFR. While this can be done it is not ussually done with the NSX. If the closed loop AFR does not need to be modified the OEM Narrow Band O2's should NOT be wired into the F/IC.
Hope this helps,
Dave
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Yes, very helpful Dave! Thank you.
Nothing left to do now but roll up my sleeves and get dirty with the F/IC.
Nothing left to do now but roll up my sleeves and get dirty with the F/IC.
My next project is Im going to set my meth injection up direct port. This way i can use all the benefits of it. Thanks DDozier great info on the Fic
I've given this some thought. I think if one was to go direct port then you'd need direct port IAT sensors too (or at least I would). The runner distance is so short in that packaging the whole thing would be a challenge. Definitely interested to see what you come up with.
If one was to go this far tho.. the aftercooler options becomes more appealing. That way the one IAT sensor is still useful and cooling dispersion is a bit more uniform. Then again, it'll raise the height, you got hoses all over the place, and got another heat exchanger to worry about... not to mentioned COST Decisions!
Yep, that is why 99% have the nozzle in the tube aproach, it works and it is easy.
I have to think about it again but if you have the CTSC with the removable top blower mounting plate it could be machined to have three small nozzles pointing up at the blower output and I think you would have a consistant mix in the intake. I will have to look through a bunch of old pics of my old CTSC setup and think this through. A big concern with the nozzles being in the intake would be dealing with a clogged nozzle and having to remove the blower assembly to get at those nozzles.
I do not have time to develope the part but a good machine shop should be able to come up with something that will work.
Dave
Dave, believe it or not, my biggest concern with this setup is my fear of having a nozzle come loose and it fall down into the plenum. Yikes! Not sure how likely this event is though but given the butterflies coming loose on the VViS...
I don't know what nozzles you are using but most of them are NPT thread which cannot fall inside since they are tapered, on another note I did direct port long ago and found it scary because if one nozzle became plugged it would spell the end for that cylinder.
If your atomization is good then you should have no real distribution issues.
My reason to go direct port would be to gain the benifit of being able to spay the meth evenly into all 6 cylinders and make some power on with it. I'm not sure how much more cooling i would gain but i dont think i would. The cooling comes from the water and if i switched my set up i would change the mix to 50/50. I have a guy that can fab an aftercooler up for my comptech but im looking at close to 3k for that and its not worth it to me at this point
btw.. one last question (i hope) with the F/IC. Does it have the ability to switch maps based on some input like the EMS does? Say for example if my meth system sends out a signal that fluid level is low. Can the F/IC receive that and can it switch to a pre-programmed "safer" map?
Taking this one step further, it'd be nice to have a "street" & "race" tune with just minor differences in either say when you have a bypass exhaust valve or running higher boost via a boost controller you'd want to run the "race" tune.
Taking this one step further, it'd be nice to have a "street" & "race" tune with just minor differences in either say when you have a bypass exhaust valve or running higher boost via a boost controller you'd want to run the "race" tune.
In terms of the F/IC with OBD1.. I understand it's a bit more difficult to tune but evidently it is possible. Is this because the OBDII allows for the use of a scan gauge in which it's much easier to monitor what the factory ECU is doing via various of built-in sensors? Perhaps on OBD1 cars because it's not easy to discern when the ECU is in Open Loop vs. Closed Loop? (By the way, if you're an OBDII guy you don't know how lucky you are to simply be able to plug in a scan gauge!)
I also foresee issues with adjusting Short Term Fuel Trims and calibrating the "wizard" for the TPS.
I plan to incorporate the new RDX injectors at an initial 56psi rail pressure. That roughly translate to a 500cc of flow which I calculated needed a -48% initial startup correction compared to the stock 240cc. However, the manual doesn't quite say how to account for this. I'm assuming this is accounted for in the fuel trim maps themselves. Need to dig into it more..
I also read that you can plug in the F/IC to your laptop and configure/read from it w/o having it hooked up to 12V. If that's correct... That's fantastic!! Someone like me can get comfortable with the interface and the software while doing some initial configs way before actually plugging it into the car.
Also, is there any documentation somewhere on the boomslang harness and which wires it bypasses/taps? For example does it assume you want the O2s bypassed? I wasn't able to find a wiring diagram but it's not a big issue to simply trace the wires.
Just trying to air out my questions if in case someone else was thinking of taking the plunge into this.
I also foresee issues with adjusting Short Term Fuel Trims and calibrating the "wizard" for the TPS.
I plan to incorporate the new RDX injectors at an initial 56psi rail pressure. That roughly translate to a 500cc of flow which I calculated needed a -48% initial startup correction compared to the stock 240cc. However, the manual doesn't quite say how to account for this. I'm assuming this is accounted for in the fuel trim maps themselves. Need to dig into it more..
I also read that you can plug in the F/IC to your laptop and configure/read from it w/o having it hooked up to 12V. If that's correct... That's fantastic!! Someone like me can get comfortable with the interface and the software while doing some initial configs way before actually plugging it into the car.
Also, is there any documentation somewhere on the boomslang harness and which wires it bypasses/taps? For example does it assume you want the O2s bypassed? I wasn't able to find a wiring diagram but it's not a big issue to simply trace the wires.
Just trying to air out my questions if in case someone else was thinking of taking the plunge into this.
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The issue with OBD1 cars is you cannot see the fuel trims to know what to correct in the F/IC. After you have tuned a few OBDII cars the OBDI cars are a little easier to get done. It will take longer and it will take more than one try at it to dial it in. As soon as SR5Guy get the live data link working on the OBDI cars and is ready to sell that product this issue goes away. The TPS and RPM wizzards are not an issue with either OEM ECU.
If you do the RDX injectors with the ECU chip from ProSpeed then the F/IC will not be used to address the different sizes of injectors that will be handled in the reprogramming of the OEM ECU Base fuel table. The F/IC will only be used to add fuel and reduce timing while in boost. If you do not use the ProSpeed ECU reprogram then you will use the F/IC to handle all of teh fuel corrections for the injector change. You can do all the math you wnat to find a starting point but the F/IC will still require fine tuning and without the ability to see the fuel trims in the OEM ECU it is trial and error.
Yes, no connection to the car is needed to work on the F/IC itself.
Info for Boomslang is here: http://www.boomslang.us/aemfic.htm
When you place your order call him and tell him exactly what you want and he will make it for you to your specifications. Wiring diagrams for the F/IC are in the F/IC instructions and then you have to cross refference the wires to the OEM ECU, I use the wire PIN out information in the AEM ECU's instructions to find the correct wires and pin locations for anything else I need.
Dave
- Joined
- 25 February 2012
- Messages
- 2,166
From the FIC manual...
If you're sticking with stock injectors, your maps will have large areas of 0% in them (the parts when you're not in boost) - as in no change to the OEM ECU's injector signals.
However, if you are upsizing your injectors, meaning moving to something that delivers more fuel per microsecond then to idle "like stock" you would want the larger injectors to close earlier than a stock one would in those parts of the map - so you would have negative values in those areas of the map - right?
In fact, if I was going to run larger injectors on an otherwise stock NA motor for laughs, my FIC maps would contain (almost) entirely negative numbers, right?
If you're sticking with stock injectors, your maps will have large areas of 0% in them (the parts when you're not in boost) - as in no change to the OEM ECU's injector signals.
However, if you are upsizing your injectors, meaning moving to something that delivers more fuel per microsecond then to idle "like stock" you would want the larger injectors to close earlier than a stock one would in those parts of the map - so you would have negative values in those areas of the map - right?
In fact, if I was going to run larger injectors on an otherwise stock NA motor for laughs, my FIC maps would contain (almost) entirely negative numbers, right?
The FIC has an initial setting to adjust for injector sizing before you get into the maps.
Yes, with regard to the stock injector part of your statement, just because you extend the injector pulse width by using a positive number in the cell does not mean you will be adding more fuel and in fact you can damage the injector or injector driver. The OEM ECU runs the stock injectors beyond a 90% duty cycle, by placing positive number in the cell you will be adding to the injectors duty cycle. Once an injector gets into the 90% range it is unpredictable and can actually lock in either the open or close state. Honda runs their injectors higher than most other car companies do and most aftermarket injectors are only recommended to run 85% peak duty cycles. So just because you put the number in there does not mean it will work as intended, but your understanding of what the F/IC does with regards to fuel pulse width is correct.
Dave
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Sort of, the F/IC has an Injector Offset Wizard that allows you to enter the old injector size and the new injector size, the wizard does the math for the percentage change in size of the two injectors and fills in the fuel offset table (fuel MAP) for you. It is designed to get you close so you can at least start the car within its ability to trim the fuel, you then use the short and long term fuel trims to fine tune the fuel MAP.
Dave
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- Joined
- 25 February 2012
- Messages
- 2,166
I must have read the FIC manual 10 times now and I don't remember seeing anything about that. Are there instructions available anywhere on how to get to it & use it?
How do I ge ta .fic6 map for the NSX? I can't find it with the software or anything on prime or the Internet
The base map is installed with the software and is all zeros. As in zero adjustment to the fuel map. It's in the program directory as I remember it. You can create a fuel map based on the size of the injectors. Then for the timing table you can just enter 1 set of retard per pound of boost. That will get you running.
