Start tuning SR20DET

[kamilp1908]

Any suggestions about my cruising tune?

[PL]

Is it driving OK? If it is then I wouldn't touch it.

PL

[kamilp1908]

Is it driving OK? If it is then I wouldn't touch it.

PL

Thx for Your replay, it runs well so I will leave it as it is.

[PL]

Yeah it's a bit lean in some of those cells but that may just be a measurement anomaly. And momentary lean at low load won't hurt it anyway.

PL

[PL]

Also it'll trim mixtures slightly richer if it thinks things are too lean in the closed loop area.

PL

[kamilp1908]

I have question about idle and low afr.
Here on log You can see that on idle I got very rich afr (~12.7). As You can see timing is fluctuating between 7-15 degs, TP is 11.

idle_low_afr.png

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Idle is correct (idle table below):

target_idle.png

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I assume that problem is TPmin table (table below), because TPmin for 1k revs is 20, but in real conditions TP is 11 for 1k. So ECU use value from TPmin table, what causes overfueling (AFR is getting rich).

min_tp.png

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Do I understand it correctly?
So to get proper AFR (~14.7) on idle I should lower TPmin for this revs?

[PL]

Yes you can adjust TPmin and see if that's holding your inj pulsewidths artificially high. If it's idling nicely though I wouldn't touch it. SR's prefer to idle a bit rich. Once they go to stoich they'll often get a bit unstable. Nicer idle at slightly richer.

Particularly sensitive to this if you have aftermarket cams. If you like a lumpy idle then lean your idle out and it'll accentuate the lumpy idle. Did that to a mate's car - he loved it. Had HKS 264's in it. Sounded great. Childish I know...

PL

[Skyline8075]

With regards to tuning with larger cams like you have is there anything specific you needed to initially do to get AFR's near 14.7 at idle?
Do I still try to keep near stock K's after MAFS and injector sizing or is there something else I should do too with bigger cams?

Just trying to get it to idle without dying so I can start driving and tuning more.

With my larger cams in/ex 258 I'm having problems going lean until it dies. I can hit the throttle and keep it alive but when throttle is closed it wants to lean and die within 10-20 seconds.

[PL]

Can be a bit touchy with bigger cams. Should be OK with 258's though. I usually just increase Latency a bit to richen them up. Either that or you can use your TPmin.

Ideally you'd increase TIM but that will then affect full load mixtures too.

Often increasing TPmin will give most stable idle mixtures.

PL

[Skyline8075]

Is injector latency ok to adjust while vehicle is running?

New to tuning here just don’t want to mess anything up I see there is a message when adjusting injector size that says engine has to be off. Will Nistune always warn if vehicle has to be off for specific modifications?

K, tpmin, tpmax, injector latency, timing maps, etc can all be adjusted, saved, and burned to ecu with engine running?

[Matt]

Everything can be changed with engine running. However the software has warnings for injector size and MAF since those items may stall the car due to the big changes in K/TIM

So yes latency etc can be changed (there is an auto apply tickbox to make immediate changes whilst adjusting)

[kamilp1908]

th regards to tuning with larger cams like you have is there anything specific you needed to initially do to get AFR's near 14.7 at idle?
Do I still try to keep near stock K's after MAFS and injector sizing or is there something else I should do too with bigger cams?

Just trying to get it to idle without dying so I can start driving and tuning more.

With my larger cams in/ex 258 I'm having problems going lean until it dies. I can hit the throttle and keep it alive but when throttle is closed it wants to lean and die within 10-20 seconds.

What spec do You have?
First thingI have done after resizing maf and inj, was to increse latency. Without it my car had problem with stable idle revs. After that I had play with Kconst to get 14.7 on idle. But it was only just the beginning.

[Skyline8075]

Other than K, latency, lowering top right area of timing map, and flatten fuel maps what areas did you have to adjust to get yours running right after cams? What do you mean by just the beginning?

Mine:
Sr20det s14a
Gt2871r
Z32 Mafs
740cc injector
258 tomei cams

[kamilp1908]

What do you mean by just the beginning?

Setting idle is just begenning. Then You have to setup cruising part of maps. And then You can make real power.

Other than K, latency, lowering top right area of timing map, and flatten fuel maps what areas did you have to adjust to get yours running right after cams?

When You are resizing inj/maf Nistune can auto adjust fuel maps (and some other maps). Timing map is different story, You have to adjust this to your boost settings. Different boost, different timing. For ex. for SR20 You have to retard timing in midrange.

[Skyline8075]

Can anyone help me with a idle dying problem. Car idles decently around 800-1000 jumps a lot in that range but I did just put in 258 cams. I can sit in my driveway and push gas pedal and let off car does fine but just a small ride to 2500-3000 rpm put it in netural and car dies instantly. Won't do it in netural without load tho. Why does it keep stalling? I included a copy of the log and my tune. Dont currently have AFM linked to nistune but hopefully this is enough into for someone to point me in a direction?