hi! from a newbie in canada. rb25det neo, in 240sx

[Matt]

After that, if AFRs are good then it may be coils or plugs. The OEM ones are fairly old so are breaking down. I put splitfires in mine

[polemite]

the plugs don't really have much use on them yet. maybe 10,00kms? probably underestimating. but even if it's 16k, that's not really a lot for plugs, is it?

i did the audi r8 coils last year, so maybe 4000kms.

but i have no idea if these coils need an adjustment to the dwell to optimize them.
i see some specs for the r8 coils here, https://www.50ignite.com/installation-manuals/
but i can't find any details about the oem dwell, so i'm not sure how to translate this data into nistune, as it looks like we make adjustments as a % above oem.
edit- ha! i happened to look under the instructions for the r35 coil kit on that site, and that's where they mention the spec on the oem dwell time.

oem is 1.9~2.1ms, and the r8 is 2.8ms. that would mean an increase of 33% (if assuming 2.1ms as oem). does that seem like a lot? i don't want to suddenly be melting wires or anything.

[Matt]

http://nistune.com/docs/Nistune_Mapping_Guide.pdf
Refer page 55

We see about 2.4-3ms on earlier Nissan ECUs FWIW. Normally we are increasing dwell tables for LS coils (by increasing values in dwell/volts table)

R8 sounds close to factory Nissan dwell time

[polemite]

ok, thanks for that.

i kick myself every time, as i always search this forum, then google, when i'm looking for specs, but i really need to train myself to check the nistune documents on each topic first.

since the last time i made a run, i have adjusted k and tim, as i ran off the load scale when boost touched 15psi.
need to adjust my map again to match the new settings. not much though.

but my factory o2 sensor must be on the way out. takes quite a while before it's warm enough to start reporting anything. it just stays stuck in one spot till the engine hits operating temp. once it does finally start, it swings between 0-.7, and it seems kinda slow. i'd say closed loop afr averages 14.3-14.7, but i get the feeling that it should be reacting quicker, and holding closer to 14.7.

unfortunately, the part appears to be hard to get in canada, and fairly expensive! guess i shouldn't be surprised by now.

[Matt]

It's getting expensive everywhere unfortunately. I almost need an index to all the questions and where to look!

[polemite]

yeah, all your documentation is awesome, but it would certainly be nice if there were an index to reference.

i assume that would be a huge task though, when you consider all the little differences between each board, ecu, and particular setup for each user.

i hope that by documenting everything here, it helps someone else some day. haha.


well, my most recent map change has me second guessing a bit.

i lowered K to 324, which recalculated my TIM to 737. but the trims didn't look great to me, so i adjusted TIM all the way up to 820. seems like a big move, but the trims look real good. the part that has me wondering is the o2 sensor- can i trust that the trims are accurate if the o2 sensor is lazy? i guess i won't know till the new one shows up.


in response to k and tim, i've had to cut more fuel from the map. i've gone from a plateau of 20, down to 16, and it's still rich (10.7)
again, seems like a lot, but maybe that's perfectly normal considering the TIM.

i'm also still noticing that there's an attempt to correct (or a bounce in?) afr's in the boost transition when i first stomp on it.
for the heck of it, i'm attempting to smooth it out with a bit of extra fuel in the map. looks like a steep ski jump though. not sure if this is normal stuff, but it looks a bit funny to me.

afr bump on trans.jpg

(194.64 KiB) Downloaded 519 times

also, here's my latest map and log from this morning. i plan to trim the map some more before my trip home today.

[Matt]

Just had to go through this post (all pages) checking what MAF setup you had. There are a lot of posts in here over 3 years so I need to double check all this, since it changed since post#1

It seems you were running factory, then had R35 MAF

r35 maf and 3.5" pipes to fab an inlet with

Also injectors were DW 440, now 570cc R35 injectors?

Is this what you are using now?

Because currently you have set 3" tube?

2022-07-20 11_03_00-Nistune [WC34 STAGEA S2 (RB25DET) Feature Pack 1 (Version_ 1)].png

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Also 3.5" selections maybe Start with factory load to get things running to start with, and then change to Max Load after

A mismatch will mess everything else up, and values of 17 in your fuel map is too low for 570CC (I would expect this for 1000CC) which is why your TIM is so high at the moment

So back to scratch....
WC34 RB25DET MAF => R35 3.5" MAF (factory) + 570CC =>

2022-07-20 11_03_00-Nistune [WC34 STAGEA S2 (RB25DET) Feature Pack 1 (Version_ 1)].png

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2022-07-20 11_09_25-Resize Injectors.png

(6.2 KiB) Downloaded 514 times

If that kind of starts okay then we can try that with 3.5" MAF at max load

2022-07-20 11_10_50-Resize Injectors.png

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Here we end up with K=598 and TIM=512

Note: If we are not going to use the full load, then say pull K back 20% and add 20% to TIM (K=478, TIM = 614)

In your case at the moment you have about 45% pulled back (K = 324, TIM = 737) with the wrong MAF scale selected

Fuel map should be upto about max value of 370/570 so about 33% less (from 60 max value to 40 max value in fuel maps)

[polemite]

Oh, wow....

i don't have my laptop with me today, but if i messed up and selected 3" instead of 3.5", then that probably explains my hard starting issues as well as the massive amount of trimming i've had to do from the map.

for reference, back on page 6 of this thread, near the bottom, is where i found out last time around, that the 3.5" 444hp selection didn't play well with my setup. the 621hp selection did.

i really shouldn't have started from scratch this year. i should have just built off of last year's tune. would have saved me from a few mistakes/omissions that i've had to relearn.

thanks for taking the time to find that. i'll check when i get home, and start over.

on a side note, i have tried to add a signature to my forum posts, which details all of my current setup details (maf, injectors, turbo, etc) as a quick way to reference what i'm working with, but i can't figure out how to activate the sig. it's all there when i look at my profile, but it's not posting along with my forurm posts.

[Matt]

I've had those disabled. Just enabled them now (only signature text, no links, images etc)

[polemite]

great! i see it's working. i'll try to get all the relevant details in there

i just took a look at the map i downloaded from the ecu before i started all this (the existing map from 2021), and when i bring up the maf change operation, it also says that it detects the r35 444hp 3+ tube. i find that odd, as i know that i set that as the 621hp in 3.5" last year.

is it possible that this is a bug in this year's version of nistune? or something that happened as a result of having to delete and reinstall all my nistune files when i updated? feels like a long shot, but i'm doubting that the bin that was in the ecu just changed itself.

maybe it would detect something different if i was actually plugged in? grasping at straws here. but in any case, i'll be starting over.

[Matt]

The VQ map detection is done from the contents of the fuel map. These are only set when you select the map, and click apply

Potentially you might have saved the file into the ECU (burn) but not to disk. There is no known issues around setting the VQ map, or its detection

[polemite]

ok, i'll try ti figure it out.

"not saving" on the laptop sounds logical, except for the fact that the copy i have of the 2021 map came from downloading it from the ecu. so that's gotta be what's on there. very strange.

[polemite]

started from scratch, from the ov81f base map, and ran through the setup assistance, plus the neo tuning, plus a few of my specifics.

i selected the 444hp r35 maf, in 3.5" tube, and the 570cc injectors. triple checked the maf selection. it held.

it did start up, but still had to crank more than i would expect. idle was good, up till it hit full operating temp (75~80) then it seemed to stumble a bit (target idle rpm is 650)

went for a drive, and trims seemed ok. stopped in a shady spot to review my log. made some map changes, as i was obviously rich during boost.

idle was very rough (86 degrees, 60rpm), and as i decided to drive home, it stalled out, and would not restart. tried several different crank enrich settings, all the way from 0, to 11, to 15, to 50. it actually started to fire at 50, but then it sounded like it was cranking slow. called for help.
dad showed up with jumper cables. still no fire. tried crank enrich at 100!!!! and started to get some firing. backed up to 50 again, at the same time coolant temp was down to 64. finally got it to catch and run. idled good again.
pulled through a few gears to capture a log (and make dad chase me in his corvette), and headed home.

once home i shut it down, and it wouldn't restart again. didn't bother trying again. but i did notice that fuel pressure jumps up over 40psi when the pump primes, then falls back to 26psi. not sure what cranking pressure is supposed to be.

something about temperature is affecting my ability to restart.

log is showing me running off the load scale at like 5600rpm and 9.5psi of boost. still very rich afr at this point, but i get the feeling that i'll still need to adjust K for this. not sure if i should do a manual adjustment, or jump to the 621hp maf. seems unlikely that i'll ever get over 400hp on this setup and fuel, but the 444hp maf setting isn't cutting it.

ps. is it normal that i lose the consult connection while cranking? whenever i make a change before starting, i assume i have to burn it first, as i lose the connection when cranking.

here is the bin and log that got me home. the interesting parts of the log start at 56sec

[polemite]

quick update- after 10pm, ambient air is 15 degrees cooler.
would not start. adjusted crank enrich to 50, and it fired up. suspect that was overkill, but it worked.

checked for leaks, any loose hose clamps on fuel lines, checked base fuel pressure- made about a 1 psi adjustment on regulator.

went for a drive. trims look good, but map was still way too rich. trimmed a bunch, but didn't make much difference. doesn't matter, as i run way off the load scale.

back in the shop, could not do a warm restart. adjusted crank enrich in the 80-90 degree columns to 20, and it fired up.

i will have to start over again, but work with the 621hp maf selection. doubt that will cure the hard starting, but i assume that will be a better load scale. 444hp isn't even close.

[Matt]

For 570CC injectors, I would not go over 8ms so putting 50ms in is literally pouring fuel into the cylinder, and if you are not careful will fuel lock it

If you have trouble starting, firstly zero out the crank table and crank to empty the cylinder. If there is fuel in the cylinders, you can also disable the fuel pump (Active tests option) and crank until there is no fuel too

If you flood it, the plugs will be wet and it doesn't matter how much fuel you put in, you won't get it started until the moisture evaporates

The crank enrich table is obviously coolant temp based, so the numbers depend on that.

If it only works with 20-50 numbers, then maybe there is a problem with crank output of those injectors. Make sure battery is fully charged also

If you run out of load scale, pull back K constant (say 20% and increase). This will also trim back fueling the same as well, and then keep an eye on it