Nistune Forums

How do you setup the TP values when running a Flex Fuel setup?

On 93 octane fuel I want to run 15 psi of boost
On 50%-60% Ethanol mixture I want to run about 20 psi of boost
On 85% Ethanol E85 (no 93 octane mixed in) I want to run about 25+ psi of boost


How do you go about using the correct TP value for E85 at 25 psi of boost after setting up the base tune running 93 octane fuel and 15 psi of boost?

Since you have to tune on 93 octane fuel first it would be unsafe to find the max TP value at 25+ psi of boost.

Do you set up a different TP value dependent on ethanol percentage?

What I would do firstly is

1. run your 98 tune @ 15 psi to setup a base tune sorting out a basic fuel map and timing map for no ethanol

2. Next I would empty the tank (use the Operations > Active Tests > Fuel pump to drain the tank) and fill with E85.

3. Add extra fueling over the whole fuel fuel map until your AFRs are back to normal (number in this map is just an addition to the normal fuel map raw numbers)

4. Then you would need to see how far TP traces across the map on the maximum boost (25psi) to set your K constant correctly for the tune (using the default factory scales)

5. After this you can drop the boost whilst on E85 to 20psi and then 15psi to take note of how far the TP cursor goes on the tune. Your fueling should not need to change typically between 15-25psi I would think

6. You can then adjust your timing between 15-25 psi on E85 levels. When you do partial tank fills (say putting 98 in afterwards) and drop your boost to 20 psi keep an eye on the timing and also your AFRs are still in the correct range

I'm doing further updates to allow maps to run inverted (so you start your tune on E85 and then use the flex maps to reduce fuel/timing on 98 octane) as well as investigating boost control based on ethanol content for ECU hardware which supports this (R34, S14-S15 ECUs)

Thanks for the info. Makes sense.

I'm still a few weeks from finishing my set up

-1988 300ZX Shiro VG30ET single turbo
-Precision Turbo Billet 6262
-Z32 ECU w/Nistune type 2 board with Flex Fuel setup
-ID 1000cc injectors
-HPX N1 MAF
-etc

previously made 520 whp at 20psi on E85 with a Microtech ECU.




I was in the process of swapping the fuel currently in the tank from E85 to 93 octane in preparation for the ecu install.

How soon with the update with inverted tuning with E85 first?
Seems like it would be better to tune on E85 first then lower the values in the 93 octane map?

How soon with the update with inverted tuning with E85 first?
Seems like it would be better to tune on E85 first then lower the values in the 93 octane map?

Z31 we dont have the feature pack available just yet. I'm working on it at the moment. The invert flex map code has been finished in the based code (used for all Type 1 + 2 models). Just need to sort out the VL turbo code this week

I have a Z31 1988 300ZX but I'm gonna use a Z32 ecu with type 2 board. So the inverted flex fuel map is ready for the Z32 ecu with type 2 board?

Not in a released ENT file yet. As I said, the code has been done, but I would need to compile the code and re-test everything again