Nistune Forums

I have a S14 240sx with a supercharged KA and Nistune ecu...more info on the setup along with recent dyno (241 whp and 241 ft.lbs) can be found here: http://ka-t.org/forums/viewtopic.php?t=45389

I'm considering converting the car from a gasoline setup to E85/ethanol since this supercharger setup inherently doesn't have the capability of being intercooled.

Does Nistune have the capability of switching between 2 different maps (one custom tuned for ethanol and other setup for gasoline) via an external switch? Reason why I'm asking is because I will be daily driving this car and will need a "E85 tune" but might possibly be in areas where all that is available is gasoline. Those that run E85 with sparse availability know what I'm talking about. Sorry if this question has an obvious answer, but I just don't know enough of the Nissan ecu architecture and its capabilities with Nistune directly.

The only other "bandaid" way that I can think of in that scenario would be by adjusting the fuel pressure to compensate for the fuel volume requirement/differences in order to limp home or to another gas station.

I'm not completely against to having one of those small one-purpose laptops in the car in order to make changes on the fly if I need to, but more afraid of someone breaking in the car to steal the computer.

Just checking in on what would be the easiest and most efficient way to go about this...Please chime in if you have experience with this or have any ideas that might help.

Oh yea, just want to add how much I like Nistune so far...I have experience with other systems (AEM EMS, DSM Link, etc) but so far I LOVE how simple and easy to use it is.

Unfortunately we don't have the sapce in the NVRAM chips to allow multi-maps on NIStune boards, so the only option is the "netbook" laptop idea. Not ideal, but it'd get you out of a pinch.

I did a multimap setup for a friend who ran E85 on his S13 SR20DET but I had to use one of our old "EPROM" boards which will take 4 maps in the 1MB flash EPROMs we use. Unfortunately these only work on S13.

Your idea of adjusting fuel pressure would work but I'm not sure how you'd implement it. Fuel pressure is so critical, you wouldn't wanna mess up your main tune by setting the pressure wrong.

PL

well since the "multiple map switching" is out the window, how about setting it up another way using 1 map...

basically I think we can all agree that E85 demands in the range of 25%-30% more fuel volume compared to gasoline to achieve the same afr's as before...so what about possibly having a multiplier table/parameter that's user configurable (depending if they want to use it for E85 and depending on winter vs summer blends, or potential nitrous use, etc) that is triggered from an external switch...I'm not savvy with the way these boards are built and programmed, but just wanted to ask if it's possible to implement or if these stock ECU's have enough I/O's. Jim Wolf programmed an ecu for me once that had an external switch coming out of the ECU case that was used for a "2-step"...since they could do it, I assumed something similar could be done here.

So basically when someone pushes a button or flips a switch, it triggers the ECU to continue using the same fuel map as before, but with an injection multiplier on top of that...I don't have tons of experience with E85 yet so not sure if the extra fuel requirements is pretty consistent all the way through different load cells or not...otherwise, I would say 02 feedback should take care of minor low load/vacuum portions of the map differences.

Now the only thing this idea doesn't compensate for is timing changes when switching fuels since E85 can "take a little more timing" due to different burn rates/detonation resistance...let me know how something like that would fit into the picture.

maybe theres a way to switch maps using the knock sensor input thus switching to main and knock maps?

Fordy wrote:maybe theres a way to switch maps using the knock sensor input thus switching to main and knock maps?

I like the sound of that since it will have separate fuel and timing maps to tune for accordingly.

Matt/Pete....knock sensor is practically useless anyways....can we re-purpose that pin/wire going into the ECU for an external trigger or will that require extra programming with the way the original sensor was interpreted? or am I going to run into problems tuning using the strategy since the overall K value may need to be adjusted in order to get the car to run right?

that part with the extra programming is the bit I dont have time for at the moment. I've got a backlog of work to catch up on after moving but I can add to the enhancement list when I start catching up