The Tuning Talk Thread - Forced Induction EFI & JZ Tuning.

[JZA70 R]

At what boost levels does Ignition Timing become an Issue on the 1jz?

Yeah that doesnt really make any sense matie.

[pato]

hey yotaholic
have u got the ignition cut feature set up ?
i tried it and its freakin stupid.
it cuts it for like a second, and is just increadibly annoying
know any way of speeding it up ?

[renxun]

talking about EMU... perhaps i would like to share my bits here.. i run emu now as i couldnt get some1 to get my car streetable wid the microtech over here in my place..
tuning was done myself wid dynojet wide band commander.

the thing that i observ, is the injector input duty cycle, although i had clamped down to around 4.1v it will still see somewhere near 100%.. the key is dont let the injector input ran up to 100% else the signal will go fluctuating madly.

ignition wise, u will notice the datalogging on timing will be in negative value if you happen to trigger the stock ecu to do the knock prevention. on around 33% knock the stock ecu will not do anything. wait till it hit 60 over percent and it will retard n u lost the top end power instantly. but still at 60% its not audible in the car.. maybe gotta use a headphone to detect. i tune my car up to around 30% knock on the day time. as during the drag i would mix 20% methanol to my 97ron pumped fuel and knock can minimized to around 4% which is good for me... night time knock will be at around 6-11% without the mix.

pato- try go back to the parameter setting, click on vehicle and rpm sensing u select the crank sensor . u are good to go after that. retard as much as u can for the launch control to build more boost. since its just a piggy back wid restricted flexibility , you can expect to see around 0.6 bar of boost during launch control

regarding spark blow out, i faced tis problem during my 1.9bar tuning wid stock gap on a set of denso iridium plugs IK24. once i had reduced to 0.8 problem solved but its just a temporary solution to "mask" the issue. but then it shows that the ignition limit is around the corner on my side. well its just me in tis issue and i belive it varies.

i set my idle at 14.5 afr.. full boost at 11.5-11.8 on low boost 1.7bar.max retard down to 16deg and build up to 21deg at the end. and 10.8-11.3 at around 2.1bar. *couldnt get exact value as my boost gauge max at 2bar* timing retard down to around 13-14 deg and build up back to 18 at the end.

[pato]

the thing that i observ, is the injector input duty cycle, although i had clamped down to around 4.1v it will still see somewhere near 100%.. the key is dont let the injector input ran up to 100% else the signal will go fluctuating madly.

for some reason once i reach a certain point on the occasion, my duty signal goes insane, 100% then 0% then 100% and so on in a space of probably 20rpm. can u explain this ?

ignition wise, u will notice the datalogging on timing will be in negative value if you happen to trigger the stock ecu to do the knock prevention. on around 33% knock the stock ecu will not do anything. wait till it hit 60 over percent and it will retard n u lost the top end power instantly

my knock is around 4-5%, sometimes a little higher, but never over 20%, and yet this negative timing crap happens. one day i started teh car and it instantly went to -ve number, was running fine when i stopped it ? can u elaborate more on this topic, cause i think my car goes into this limp mode crap fairly often

try go back to the parameter setting, click on vehicle and rpm sensing u select the crank sensor . u are good to go after that

why what does this do ????

i set my idle at 14.5 afr.. full boost at 11.5-11.8 on low boost 1.7bar.max retard down to 16deg and build up to 21deg at the end. and 10.8-11.3 at around 2.1bar

so the higher the number the more the advance ? or is it the higher the number the more retard.
i allways just assumed negative was retard. but this is why i havent touched timing yet


thanks heaps for what u have said so far. will make a difference iam sure

[renxun]

[QUOTE=pato]for some reason once i reach a certain point on the occasion, my duty signal goes insane, 100% then 0% then 100% and so on in a space of probably 20rpm. can u explain this ?
thats why i say you cant let it hit 100% it will go mad. and signal will fluctuate. its the EMU rule of the game. dont let it hit 100% easiest way is to see your datalog at what map voltage during your injector hitting 95-97%. clamp your boost cut there.

my knock is around 4-5%, sometimes a little higher, but never over 20%, and yet this negative timing crap happens. one day i started teh car and it instantly went to -ve number, was running fine when i stopped it ? can u elaborate more on this topic, cause i think my car goes into this limp mode crap fairly often
-thats the problem wid piggyback. when you see that happen you can either close the emu program and restart it or restart your car. it should help. the emu system arent tat stable you know.

why what does this do ????
so the higher the number the more the advance ? or is it the higher the number the more retard.

the ignition map in emu is just an adjustment map. its not like standalone where u can key in ur timing figure and exact retard u want. here what u do is datalog your stock ZERO adjustment and adjust frm there. your existing map definitely will retard when boost came in. what u can do is to change the timing curve in reference to the existing 1. complicated? yah definitely and a standalone is much more straight forward n simple in this kind of job
i allways just assumed negative was retard. but this is why i havent touched timing yet


thanks heaps for what u have said so far. will make a difference iam sure

[Yotaholic]

hey yotaholic
have u got the ignition cut feature set up ?
i tried it and its freakin stupid.
it cuts it for like a second, and is just increadibly annoying
know any way of speeding it up ?

No I set it at 8K over 50% and haven't messed with it since . Still no knock readings to report ... i;m starting to wonder hmmm

I've been having a few issues as well .. I'm hoping it's just my battery and not the voltage regulator or alt. The battery doesn't seem to be holding a charge. The engine will stall at idle if the lights , fans and tunes are on . Turn it all off and it idles smooth as butter . 12. 3v on the battery when off ( not great) .. 12-14 when running so it sounds like the battery or regulator to me . I'm replacing it tomorrow and i'll test the alt at the same time just to be sure.

I'm having a hard time reaching any amount of boost . I've clamped my boost limiter at 4.2v . Between 14-15.5 psi 10.5 a/f i'm hitting what feels like fuel cut. I turned it back to 3.9 ,,same thing .Could this be spark blow out or more side effects from the failed batt or alt. I know I have to pull more fuel up top but I didn't expect the low a/fs would cause the stumble /cut .... I';ve also noticed some surging complete with the bouncing boost guage. Very frustrating few days .... it;'s friday and I need a beer

Thanks for the info on the ig mapping . I'm still at base settings 0 until I get all this figured out.

((((the thing that i observ, is the injector input duty cycle, although i had clamped down to around 4.1v it will still see somewhere near 100%.. the key is dont let the injector input ran up to 100% else the signal will go fluctuating madly.))))))

intersting ,, I wonder if my 650's are hitting 100% when it hits this stumble..

this is where I am at 13-14 psi 1/2 throttle . At wot I show IJ adj 0 and then this weird stumble happens shortly after . I let off the gas and push again only to see the boost surging and cutting when it gets close to 15psi. Grrrrr it ran better stock

RPM 4951
tp 48%
af adj 0
IJ duty 78.0%
IJ adj -15.1
ig adj 0
IJ output duration 9.2 ms
knock 0
IG timing 21.2
a/f 12.3

i'm still in the VERY early stages of tuning and have a lot to learn about the EMU and tuning in general . The safc was a toy compared to this ,, i can't imagine doing a full standalone with or without a dyno at this point.
Any advise you can give is greatly appreciated.

[thechuckster]

you really dont want injectors operating anywhere near 100% duty cycle.

can you log (to laptop) a run that hits the stumble to confirm that it is hitting 100% duty cycle? are you sure it's fuel being cut not spark?

The logs will help determine which device is creating the stumble/miss (e.. factory ecu, interceptor, ignition, etc).

If the factory ECU is dropping spark or injection events, an interceptor is not going to be able to work around that.

[renxun]

actually what he is facing is the injector input duty cycle hitting 100%. it means that the "supposed" signal that the stock ecu pumping out is 100% hence the problem. its not that his "actual" 650 injectors are operating that duty cycle as it will be shown as injector output duty cycle in the emu datalog.

and you are right that in the event of factory ecu dropping spark or injection event, no way an interceptor can do anything againts it. although its there for safety, but tuning a piggyback which had standalone characteristic adds complication for people to learn in the begining stage. due to stock ecu is doing its own job and user have to intercepts it based on the stock map .its not as straightforward as standalone.

[pato]

so are u saying we shoudl clamp it lower, and adjust the maps accordingly to stop it from running lean ?

i have been having shitloads of troubles also.
everytime i start the car it feels like it runs on 3 cylinders.
and eventually comes good.

and cruise ar's are like 12.5, but sometimes at 14.
i dont have a o2 sensor tho so iam thinking that could be to do with it.
either way fustrating as fuck

[thechuckster]

A wideband O2 sensor is essential for tuning ARs - relying on narrow-band data is close to futile.

Get an Innovate or Tech-edge sensor/controller or similar.

[pato]

A wideband O2 sensor is essential for tuning ARs - relying on narrow-band data is close to futile.

Get an Innovate or Tech-edge sensor/controller or similar.

who u talking to ?
i have a wideband
i dont have a stock o2 sensor plugged into my ecu.
only my wideband sensor further down the exhaust

[renxun]

so are u saying we shoudl clamp it lower, and adjust the maps accordingly to stop it from running lean ?

i have been having shitloads of troubles also.
everytime i start the car it feels like it runs on 3 cylinders.
and eventually comes good.

and cruise ar's are like 12.5, but sometimes at 14.
i dont have a o2 sensor tho so iam thinking that could be to do with it.
either way fustrating as fuck

yes... clamp it lower.. i clamped mine at 4.05v and adjust the fuel map to compensate back the higher end... after all u are just having issues wid injector input but NOT injector output.

[thechuckster]

who u talking to ?t

you - you said before "i dont have a o2 sensor tho so iam thinking that could be to do with it. "

[Yotaholic]

you really dont want injectors operating anywhere near 100% duty cycle.

can you log (to laptop) a run that hits the stumble to confirm that it is hitting 100% duty cycle? are you sure it's fuel being cut not spark?

The logs will help determine which device is creating the stumble/miss (e.. factory ecu, interceptor, ignition, etc).

If the factory ECU is dropping spark or injection events, an interceptor is not going to be able to work around that.

Well i'm out out doing some runs today and making some progress. I slipped in a new battery and found out my #2 fan switch is causing the Voltage draw.# 1 is running all the time. I shoudl be running it off the temp sensor and emu . Flick it on and the v's dive and so does the a.f guage to full lean.,,,then stall. Shut it off and all is well. It's cold enough here today that I dont' need it running 16*c . I also have to calibrate my temp sensor . 49-51* running temp.

I snaped a pic for you guys to have a look at .. Duty cycle is very high at 93.6% and the knock sensor spiked to 24 twice . I dont' get it ,,,, i haven't seen a knock signal since I hooked this up and now it's up and down .Granted I did make some changes today ,,,, it's pulling much harder now at 16psi but this knock spike has me worried. I'm going to check the meth line,, i may have crimped it when I installed the new battery.

any suggestions or comments ?

[renxun]

what is your boost? seems your timing a lil bit on the high side