Road tune
 

Finally starting my road tuning.. :D

While dyno is required for the exact measurement of power, I have been using the MAF voltage as representation of power output with great success in the past back in 350Z days..

I read some posts about stock ECU not allowing to advance timing much, let's see how it goes..

attached file shows the starting point, very rich up top, will start fixing that up and make it 12.5:1 above 6000pm and 13:1 for the rest..

I think I will share my map once I settle with a map later on, so people can use it as a guide or at least give something to compare.

At the moment the car has HKS drop in filter and dual pipe cat back exhaust.

Thanks for sharing. I would like to do something like this myself. What are you using to tune? And what would I need to do the same thing?

I use Uprev Pro Tuner..!

Had it for a very long time and it has been great :D

update..

done the following to the car

HKS panel type air filter
Cat back exhaust (custom dual setup with Fujitsubo muffler)
Stillen oil cooler
Uprev flash (the logging was done using stock map)

Notice the bank 1 is always richer by about 0.5 than bank 2, and base fuel schedule is lower by 0.5 also. the AFM voltage is also dropped, which most probably means I lost power rather than making power.

Not sure if flashing to Uprev causes this issues (although running stock map) or it has got to do with the mods above.

I will try flashing back to stock ecu (before uprev) with the same mods and see how it compares.

The run was also done in the 3rd gear this time rather than in the 2nd gear in the first post, I will have to do another 2nd gear run also to make it more comparable. I shouldve done it using 3rd+ from the first place I was being lazy and did not want to drive far from home :rolleyes:

I am wondering if it has got anything to do with the oil cooler warming up the air on one side, although I would guess that the gush of air from driving at 150kph would make that difference negligible.

so what I gotta do is

1. Remove Uprev temporarily
2. Measure the same parameters in 2nd and 3rd gear
3. Compare the 2nd gear run vs first pic
4. Compare the 3rd gear run vs second pic

Yes i have the same problem with a/f ratio differential .5, and also have a massive oil cooler located on driver side. I was able to fix it by adjusting cylinder trim on 2,4,6 to 104.69 which got me to get rid of that diff, but i believe the problem is not the oil cooler at all, its has to be something electrical from the factory (wires are longer on one of the bank than the other therefore voltage drop, or bad ground. Just guessing here) defect that the factory stock map is tuned for, but not Osiris cuz well they didnt design the car they just trying to make it look like that they know what they r doing. All though i believe that this engine can have its butterfly valves removed and use vvel banks adjustments to let certain amount of air in (cuz vvel can operate on how much u want it to open the cam valve in order to let certain amount of air in to the chamber in order to have a desired a/f ratio) it will be awesome, but Osiris is working on it.

returning the ecu back to stock did not make any change, so it has got to be one of the mods that is causing the issue.. air filter perhaps?

For my car instead of increasing the trim, I decreased it, and now the car sits very close to what is in the target A/F table without touching the compensation table. it is not perfect, but pretty close. the car used to see like 10.5:1 where the table was set to 12:1 for example. I am guessing that Nissan did it this way to leave the head room for low octane fuel for safety? purposefully setting the car to run rich so it wont cause damage.

Are you going to be monitoring knock during your tuning? If I get some time to play with my car I am looking to do the exact same thing as yourself.

I believe u need to adjust ur MAF and then timing, where the table says run 12:1 and ur tooo rich 10:1, u need more air or less fuel. Some members found and ideal 12.5:1-13:1 @WOT but make sure ur idle points are 14.7. The fuel target map i was frustrated that at 2.8k rpm it starts, so i lost power till ~3k rpm, set it to start from 800rpm and then smooth out the a/f ratio to WOT, am not an expert but hope it helps.

PS. Use only same fuel for adjustments never mix or go below 91 oct at 12.5:1 a/f WOT, or ull damage ur engine.

Can you confirm that this is still working for you? I was logging the car for a good 6 hours yesterday and tried the same sort of thing as you, only I removed fuel from 1, 3, 5. It worked for about 5 minutes until the car for whatever reason started addding fuel to bank 1 again. The trim values you speak of only seem to work for a bit before the ECU realizes that bank 1 should be running richer and starts adding fuel.

I lowered 1,3,5 down to 92% and was still seeing a trim of ~115% and a afr of 13.9ish. From those values you can see that the ECU is adding 15% more fuel than my correction table to make it run rich for no reason. The target AFR for both banks is 14.7.

As I said on another thread this is an issue with the 350zs as well and some guys have fixed it by actually unplugging the downstream 02s and turning the codes associated with that off. I have yet to try it as I am down in Montana on a road trip but when I get back Ill unplug mine and take it for a drive and see if

A. The ECU allows closed loop with these unplugged
B. The ECU stops messing with bank 1 and lets it follow bank 2.

been away from the scene for a while..

my HFC is on its way, I will resume with the road tune once its fitted, hopefully make some gains!

ok slowly getting back into it..

after HFC's, the entire A/F went about leaner by about 0.4, maybe this is what contributes to good gain for those cars that do not have the tune, by leaning out the rich stock A/F ratio.

I set mine to 13:1 until 6krpm and 12.5:1 above 6krpm before, after the HFC it became 13.5:1 until 6krpm and 13:1 above 6krpm which is good as it must mean that it can burn fuel more quickly, meaning more power once more fuel is added.

What kind of ignition timing do you guys run after the tune in general? of course it will vary between cars but there must be some generic number with similarly shaped curve. I will tidy up my fuel map again and post it up.

Also, my A/F ratio stays even for both bank A and B after the trim was adjusted? It has been quite some time since it was done and still even on both sides. will keep testing.

update, the attached pic shows the current log, running stock timing with only AFR set to 13:1~12.5:1.

I have not touched the fuel compensation map, only lowered the cylinder trim slightly and it matches up with the target AFR pretty nicely. the base fuel schedule went up slightly, probably why it is running less timing as the map is telling the car to run less timing.

anyone wanna share the ideas of their ignition timing maps?

I read from some post saying that with the new VHR timing compensation unlocked by uprev, the guys could run 32deg or something and gained like 10hp extra, I wonder what kind of curve I should expect.. the car is running 98ron fuel.

I'm going to have to get into this in the spring. I do my own road tuning on my DD, but would like to play with the Z a bit more. Looks like HFC's are the way to go.

Thanks for posting the MAF voltages, looks like even a NA car runs north of 4 Volts under WOT.

As far as timing goes, the best way to do this on a NA car would be on the rollers where you could increase the timing as a whole 1 degree at a time to find the MBT then back it off 1-2 degrees and leave it there. On a NA car I would expect it to be able to reach MBT before knocking, however thats what the headphones are for just to make sure.

The crappy part about this is you really need a dyno to see the exact point when adding more timing stops increasing your power output. Recording the MAF voltages wont work because now your just using the same amount of air but harnessing the "bang" to get a higher average cylinder pressure over your combustion cycle.

Thanks for the posts, nice to see some positive response to my thread.. haha

I agree that dyno is really required for timing adjustment but I thought the MAF would go higher as the power goes up too, although it would be very tiny amount. this method worked well when I was tuning my old 350z's cam timing with aftermarket cams.. but then the fluctuation is too wide to pickup tiny gains.

have you guys had much play with the VHR timing correction unlocked by uprev few months ago? Apparently 370z's got very sensitive and complicated knock control method and I was wondering if it would be safe to increase the entire rev range by 3degree's and let the ecu just self learn from there.. I dont think NA engines can explode that easily? haha