Nistune Forums

I am hoping to play with my acceleration enrichment settings. Reving from idle it sometimes stumbles from being lean, but it likes to go very rich when you go full throttle while cruising before getting back to a reasonable target.

I noticed in the latest version of the mapping guide that there are new "Wall Flow Tables" described on page 34. It says that this is for the rb20det, but I cant find the table in any of the HCR32 .bin files I open.

I just updated Nistune to 1.4.3 and installed FP ROM Pack 2.21.
Am I doing something wrong so I am not seeing the tables, or are these tables not actually available for the rb20det?

You may have to adjust the user mode (File > Config > Misc) to expert to see those tables

However normally you should not need to mess with those. Ensure that normal idle and cruise mixtures are correct, and on boost that they also look right before tacking acceleration issues

Perhaps post some logs showing the issue and the maps you have

There are acceleration and wall flow (additional fuel for cylinder walls) in the HCR32 ECU

Sorry for the delayed response, I promise I didn't forget about this thread. To address your points in order:

1. Thanks, now I can see those tables!!!
2. Ive been on Nistune for a few years now. Steady state idle, cruise, and boost mixtures look great. In general the car drives fine so I dont NEED to adjust these. However there are some changes that I think are throwing off the stock tuning, like larger EV14 injectors (I believe better atomization and spray pattern), and low temp thermostat (normal driving is at 72C without AC on). I am also running ethanol now and want to optimize for that as much as I can.
3. I attached a log file of some night time street driving. Look for long sections with tps maxed out at 4. Most of these are at relatively low rpm & high gear so I can keep it in one spot on the map to illustrate the problem. In a couple spots it looks like the issue is from an overshoot in the MAF readings, but not always (btw this is an r35 MAF in a 3" tube). The steady state full throttle values were actually quite lean since I had never properly tuned this area in steady state. These are better now.

My main question is what does each of the enrichment map do? I have some experience adjusting accel enrichment on rx7s with Megasquirt, but these table names are less intuitive to me. My guesses are as follows:

Wall flow accel temp factor
This appears to be a pulsewidth that everything else is based on. It obviously varies with temp.

Wall flow accel TPS delta factor
Scale is 30 to 480, and values get higher with larger scale. Is this a change in TPS voltage that triggers the enrichment?

Wall flow accel TPS factor
Scale is 0 to 4800, I assume thats 0-4.8 volts on the tps. Values are larger at the low end, its this changing the enrichment based on where the TPS started when enrichment was triggered?

Wall flow accel time factor
The scale looks like RPM, but values get higher at high rpm. I dont understand what this is.

Wall flow accel rate factor
Scale is 0-188. Values start low, curve up, then flatten out. Is this related to the speed of TPS change?


Any tips or tricks you can offer would be great. I mostly want to know "which knobs to turn" so I can start dialing this in.

http://nistune.com/docs/Nistune_Mapping_Guide.pdf
Refer to page 34 of this for the tables. They are all multiplied together

Wall flow accel temp factor
This appears to be a pulsewidth that everything else is based on. It obviously varies with temp.

Correct. It is the base table used for calculations

Wall flow accel TPS delta factor
Scale is 30 to 480, and values get higher with larger scale. Is this a change in TPS voltage that triggers the enrichment?

Yes it is the TPS adjustment change by time (movement)

Wall flow accel TPS factor
Scale is 0 to 4800, I assume thats 0-4.8 volts on the tps. Values are larger at the low end, its this changing the enrichment based on where the TPS started when enrichment was triggered?

Yes that is the mv value of the TPS. The higher the value the higher the factor used for injection (more throttle)

Wall flow accel time factor
The scale looks like RPM, but values get higher at high rpm. I dont understand what this is.

Wall flow accel rate factor
Scale is 0-188. Values start low, curve up, then flatten out. Is this related to the speed of TPS change?

We are really working with hardly any documentation here, but we just know that the TPS rate over time is used with these tables. For experimentation we can watch the injection time response at different pedal positions and change rates

Sorry for the delay on my response also, have been away on vacation and playing catchup.

I didn't really see anything apart from idling in that log file.

With the overshoot, you can use TTPmax to adjust for TP overshoot as a result of MAF voltage if required

With the adjustments to the wall flow tables, not something I've adjusted much myself