tuning help. im really not good at this

[Chris86NA2T]

Im having a real hard time getting my car tuned. It runs and drive great and has plenty of power as you will see in the dyno graph, but I know I have a lot of work to do. The car is off the chart rich under boost and very inconsistent at low speed. let me first give some background on my car. I have a t3 turbine housing stage 3 wheel, to4e 54 trim. Peak power and torque was made at just over 20psi. 450cc DSM injectors and a Z32 AFM. Have a romulator and made all the necessary physical changes to the computer to use the new AFM. K value is 285dec (011Dhex) and null is 91dec (5bhex). The timing and fuel maps are a combination of stock maps as well as the maps from a BIN on Jason’s site. The lean AFRs are what I have changed to get the car to run at around 15.0 on the highway. The bottom line is I can not get the logged AFRs to match the map. I set the values of the fuel map to about 12.5 and tested and each time 285dec seems to work well. When I use that K with real fuel maps nothing matches up. I went so far as to manually type in the scale for the afm as well as calculate my own TP scales through hex. I did everything through hex editor assuming that some quirks in livedit may be my problem. I know im all over the place and rambling but ive really had enough. Im praying for the post that tells me how to get the new nistune because this shit sucks. Is there anyone within driving distance from long island that wants to make some money and do this for me? Dan, I would even take a ride up to you if you if you think you can get this fixed. sorry for the long rant and the big pics, but if i shrink the dyno sheet down with my crap software you cant read it. Anyway, this is more of a complaining session than a question, but if anyone has any comments I would really appreciate it. thanks


Take a look at how the AFRs are completly off the chart, especially during the first run


the car idles at 12-1 but sometimes it brings itself to 18-1 and then comes back to 12.. it does the same thing whether the O2 is plugged in or not.


i thought i heard pinging so i loved the top end timing. thats the least of my problems

[Jason84NA2T]

Those power numbers look ok, but I assume you can get a little more out of it than that.

For tuning the fuel maps, I never pay attention to the AFR displayed in liveedit. It's never accurate to the data in the maps on my setup... only a loose representation at best. Just plus or minus for what you need in the cells that are being used. As long as the k value is reasonably close, you can actually tune the entire fuel map to adjust the fuel curve everywhere except places like cold start enrichment (if you know what I mean).

If you use a map that has all the same data on it, once you have the k value set then trim the void time until the car runs close to or the same afr at higher rpm as it does at lower rpm.

You have no way to know the TP you are hitting on the timing or fuel maps, but you can use a column test to determine where it is. Make sure you're not running too little tp for the last column's setting; IMO it should be at the absolute maximum boost your car should see. Work up and down the last 3-4 columns (which are usually scaled to be in boost) and optimize fuel and timing for each boost setting. Move all the columns around to suit your needs for resolution in boost, but don't take too much from the low end where you might like some better resolution. I use 5 columns for all the loads I call "boost" where manifold pressure is above atmo.

How do you have your fuel pump wired? I'm wondering if the leanness issue is related.

I can tell already... you are going to love NisTune.

[Chris86NA2T]

thanks bro, that makes me feel a little better.. i have a walbro on the stock wiring. do you really think that can be the lean issue at lower rpm? ive got a decent fuel setup otherwise, i thought i would never have think think about fuel again considering what i want to do with the car at this point..

[Chris86NA2T]

oh, speaking of cold start enrichment, it takes FOREVER for my car to get "normal" its off the chart rich for a good 10 minutes of highway driving until it finally settles to 15.0 or so thats quite a few minutes after the engine has reached operating temp... its killing my fuel economy.. i see that the cold start enrichment tables have been identified but there is no explanation as to how they work. i would like to spend some time playing with them at some point.. does anyone have any experience with this?

[Jason84NA2T]

Chris86NA2T wrote: oh, speaking of cold start enrichment, it takes FOREVER for my car to get "normal" its off the chart rich for a good 10 minutes of highway driving until it finally settles to 15.0 or so thats quite a few minutes after the engine has reached operating temp... its killing my fuel economy.. i see that the cold start enrichment tables have been identified but there is no explanation as to how they work. i would like to spend some time playing with them at some point.. does anyone have any experience with this?

Sounds like you might have the K value set too high as well...

For cold start the tables (after start enrich and cold start enrich) are a scale from cold to hot starting at -40 and going to 110 in 10 degree increments. You can adjust them in nistune while looking at your head temperature to trim the cold start appropriately.

[Chris86NA2T]

my god.. when is the new nistune coming out.. it better be soon because i am NEVER going to look at livedit again.

[simply86T]

Chris86NA2T wrote: my god.. when is the new nistune coming out.. it better be soon because i am NEVER going to look at livedit again.

If you already have romulator, you can just get rev B. (if Matt still sells rev B) Most of us are waiting for rev C because it won't require romulator and 88-89 ECU, and I guess it's very likely to cost more than rev B.

[Chris86NA2T]

yea, i was thinking about that. if there is a huge price difference or its going to be a lot longer then ill go for the old one provided they are still available. id like to get the romulator and usb-serial adapter out of there. the amount of wiring behind my dash is incredible.