Tuning help for my sr20det

[florian77270]

hi everyone,

i am florian from france, sorry if my english is not perfect.

in my previous topic i find which ROM add to my new used ecu with nistune.

my config:
forged piston cp 8.5:1 / forged rod / TOMEI ARMS SR M8270 ( actual 0.8bars because my last ecu have a stage 1 horsman ) / Big FMIC / 255lh walbro / boost controler / 3" exhaust
my futur config:
bigger injector ev14 approx 1000cc for e85 / turbo to 1.2 bars / z32 MAF / cd009 6 gearbox

But first i just want to make the car run like before with my previous ecu( horsman stage 1) and beggin slowly the tuning.

so i have to :
Check IGN on nistune and compare with strombo light, check CAS, clean maf, check spark plug
-1 burn the 82F0F ROM
- because i do not change my injector and MAF, i do not touch the K constant or TIM in my case because i have an FP1
-Check if my FT is ok at idle and cruise 2000trs 4 gear + ( need to do this if i do not change injector and maf ?)
-Adjust the fuel map in low boost but on all range of RPM (maintain 14.7 in the blue area)(trace afr againt fuel map ?) do i have to correct it by using a % change in blue area ?
-Adjust the fuel map in hight boost in hight load area, check the AFR (11.7 :1 AFR) by lowering the value in % only in the hight area ? how many to begin ?
-Make a knock copy to ajuste knock fuel map
-up the turbo to 0.9-1-1.1-1.2 ( contrôle if its knock and adjust the timing map if necessery
-Adjust timing map until a knock is detected by nistune there is another methode ? i am not sure to understand how to ajuste it correctly ? same as fuel map, by area ?
not shure what the best option to check afr against fuel map and knock agaist timin map by tracer or hightlight ?

because i have a differente turbo who is beager and blow later than the original how i have to react for this ?


tank you for all

[Matt]

Hi Florian

You can start from factory file (82F0F attached)

Your FT should be fine since you have standard injectors. You normally only need to change on boost so you are around 11.5:1 AFRs (over half way over map)

Monitor for detonation (knock) also

There is no knock fuel map with FP1

If increasing boost, usually we aim for peak torque method (more boost pressure, until no more power is made). Around or over peak torque will result in knock

Nissan ECUs will detect knock in certain ranges and reduce timing. However montior for knock with headphones, knock box or similar

If larger turbo, it will suck more airflow and create more power. You might reach the limit of factory MAF/injectors

If load exceeds that in the maps, you can reduce K (lower load reading) and increase TIM to offset fueling

[florian77270]

Hi matt, tank you for your reply.

i think i will stop my tuning to 0.8 bar first to have less thant 300hp because of the stock MAF.

i am not sure to understand your last answer

"If load exceeds that in the maps, you can reduce K (lower load reading) and increase TIM to offset fueling" this case is only if i keep the stock map ? right ?

One other question for the turbo

the stock map 82f0f is build for a t28 turbo so smaller than my new tomei, so i need to have in mind that with egual pressure i have more air in the engine and need in any case to ajust the fuel map , right ?
second thing this new turbo is bigger and have more latency, so it blow later than the stock and make the fuel map and IGN make shifted a bit ? how to make it neatly ?

tank you

[florian77270]

hello i make my first run this weekend, all seem good
Tp in cruise is about -1/+1
But when i controle my crank position, on the car it is 15° and on nistune it show 10°, the only situation that i can have 15° is only when i accelerate a bit, when it return to idle nistune show 15° during 10-15sec and fall to 10°

do you have an idea ?

[Matt]

I think stock MAF will reach about 200rwkw (270rwhp)

Basically you can move load cursor left by lowering K constant

Lowering K constant will also decrease fuel pulsewidth (leaner) so you can increase TIM to adjust

Say you lower K constant 20% (TP tracing moves 20% to left) and AFRs also leaner 20%

So increase TIM by 20% to get AFRs to where they were

With fueling, normally Nissan maps are tuned rich. But when you adjust injector size, then you need to lower fuel by amount of injector (say 370CC injector resize to 740CC then top of fuel map is usually halved)

If standard injectors, you may not need to adjust fuel map much. Turbo size wont really alter fueling, but increased boost available due to increase turbo efficiency may require adjusting timing to reach peak torque without detonation

Yes there will be more latency (turbo lag) so you might have to move ignition further right. I think fueling should still be fine where it is

With timing : Nistune changes between idle timing and timing map. See 'workshop tuning notes' which show the modes of timing changes. So that may explain difference?

[florian77270]

Hi matt tank you for you reply but i am really sorry, i dont understand wy i need to adjust k and tim. i read 3 times all manual, try to view tuning video but dont understand, i think its du to my english level sorry.

Maybe you can rephrase it with example please ?

ajusting TIM will make my fuel map correctly tuned with my new turbo instade of correct it miself case by case ?

tank you

[Matt]

TIM => Adjust fuel amount over entire map
K => Adjust load indexing (also affects fuel amount over entire map)

So we adjust K so we can access all load points in map

Then we adjust TIM to have correct fueling over map (usually adjust for cruise mixtures to be at 14.7:1)

After this adjust fuel map where needed

[florian77270]

tank you matt