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

[JP]

The following info consists of things ive personally found on my own powerfc and are not neccesarily the same for all others...

First of all, the powerfc runs a locked 10' of ignition timing when in idle mode. idle mode is active when no tps input is detected and or when rpm/vacuum are around idle presets.
Regardless of what timing you specify in the timing map, it runs 10' however as soon as you touch the accellerator, the timing map is used.

There is a setting to use 'ignition assistance for idle control' in which upon idle, ignition is advanced or retarded depending on the stability of your idle rpm. If your idle rpm is inconsistent or fluctuates ignition is advanced or retarded to try and smooth the rpms out.
From what ive seen timing fluctuates a few degree's either way, but not much.

This can be turned on or off depending on the quality of your tune and hence idle rpms. Ive had it off since day dot as all is required is proper fuel mapping around the idle zone in the first place.

Other people turn it off because it confuses them when trying to tune as they see ignition timing jump around when it shouldnt be.

I have heard that if you set target idle rpm to 0 and manually adjust your throttlebody for idle rpm that the 10' lock is removed. Id say this is so those without a ISCV can tune idle ignition properly in conjunction with manually adjusting the idle via throttlebody.

Yep, aware of the idle ignition control etc but haven't played with a MAP sensored JZ PFC, only MAF based PFC's for the vvt 1J, 1zz MR-S and 2zz celica which all seem to do whatever they like regardless of the settings/tune.

[Disturbed1]

heres my dyno graph of my home tune which i ran at same dyno day as todd - he thinks my tune sux htough ahhaha




the green line is the result of an extra .4psi boost which is in untuned territory.

would love to try get rid of the dip at 116 mph but so far havent been successful, not sure if its commig on boost to hard or not....... and would love to try smooth out the 74km to 116 range rather then going up and down.

need more time on it.

[JZA70 R]

hey todd - im guessing your turbos are pumping some hot air- dont have a knock sensor on my car but runnign 16 degrees at max torque and havent popped a motor or heard it ping/knock. experimented with incresing timing at high rpm and didnt make much diff. really need a dyno to see hwo all these little tweaks effect stuff

Yep, the difference between you and me is, my engine is suffocated with the tiny turbos which are spinning so far out of their efficiency range its not funny. They are pumping hot air the engine is choked. This is pushing my setup as far as it can go so timing has to be dialed way back to accomodate all this.

Where as with your setup, its not really even doing any work to make that power. Your turbo is only just waking up and nothing is really working against each other unlike my setup. So you can be quite aggressive while your turbo is working at low efficiency.

IMO thats why you can run more timing than me. Apples and Oranges.

[JZA70 R]

I think you practically tuning blind with the tools you use. You're using no tools to show you the trend/relationship between adjacent cells and thats why your AFR are all over the shop. do you have a 3D representation of your fuel map? i reckon that will tell all if you do...

[Disturbed1]

no idea what tune this is - deff not the current 1 but would be very

[thechuckster]

Disturbed1: get a wideband O2 sensor. Tuning opportunities will increase massively.

Also - 4.5ms seems like a long dwell time?

Also 2 - no sync sensor used? or have the knocked off a tooth or two from the trigger wheel?

[Disturbed1]

1: got a wide band - see page 3 for my logs usign it. hav e troubl egiven the rpm/boost on the lm1 isnt identical to that of the ecu load points (about 100 rpm off and 1 psi)

2: apparently ls1 coils like their dwell

3: i got a 7mgte - no idea what sync sensor does

[JZA70 R]

what do the values in your fuel map/cells represent? and do you use a fuel correction map?

[Disturbed1]

no fuel correction map - and fck knows what thos evalues indicate hahaha

perhaps ms of fuel??

the higher the number the more fuel - about as much as im aware they range from 0-255 hahah

[gwilmarlio]

Todd you have amazed me with how far you have come and how well you understand tuning and the input you give to others like in this thread keep it up

[JZA70 R]

Thanks Gwil

Chris the PFC reads in milliseconds and maximum value on my 440cc injectors is like 18ms @ peak torque and boost and minimum is like 0.4 @ idle... so dunno wtf yours is reading.

I was hoping it was in MS because then i could run your map through my mapping spreadsheet and neaten it up.

See if you can convert it?...

[Yotaholic]

So ive finally had the opportunity to put my car on the dyno to see how my own tune performs and also to see what it looks like compared to other tunes. I knew it wasnt bad because the car had never driven so smooth, or felt as powerful throughout its entire rev range. Plus it did well at the drags (12.4 @ 111) so I had a feeling it was on the right track.





Sorry if this bores the shit outta you guys, I find it extremely interesting and exciting lol. If anyone gains any positive knowledge from my experience then i feel it was worth it.

That was very informative and a good read ! Nice work on your street tune. +rep

I finally had the car tuned on the dyno last week. My own tune produced 353rwhp @15psi. Not a smooth curve like yours and not ideal a/f's ( pig rich). My ongoing problems trying to hold boost and maintain any consistant results all point back to my Profec B ebc. It would hold for a run then fail on the next . Droping back to stock boost then picking it up again . It's no wonder I couldn't get it setup right Slipped in a manual controller and problem solved . How can I test the profec solenoid ?

I learned a lot watching him navigate through the EMU with ease. He answered all my questions and walked me through his tune. I was sctratching the surface of the emu but I honestly don't think I could ever get it to the level he did in just 4hrs. I'm very happy with the results but if I want to get the most out of my setup i'll need a bigger IC . The T3G's have more lag than the ct12's but I can live with that

Maps available upon request

[OnAll-FOUR]

I was playing with the logging on my wolf and out of interest I plotted RPM Vs Load (which is the Map sensor in my setup) so I could get an idea on how to test different parts of the maps.

How accurate are people when doing a street tune? I guess ideally you would cover all load points, but from peoples experience is there a point where it is practical to stop and assume it is okay in between?

What also caught my attention is the area between 4500 and 5000 RPM. There seems to be a reasonably significant dip in the MAP reading and it seems to be quite consistent as it transitions through that RPM band at different loads. Of about 10 different load runs through that region, only 1 didn't follow that trend and I think that was because it wasn't a straight acceleration run.

Any ideas on what is going on there?

[JZA70 R]

do you have a wideband and are you logging AFRs?

were you playing with a boost controller during logging?

[OnAll-FOUR]

No no wideband as yet and that is why I wasn't changing any of the map settings. This is a dyno tune from a local workshop and I'm just trying to lean more about what they have implemented it and how it is all working at the momment. The different loading is part throttle, rather than different boost levels on a boost controller. I was playing with tryingto make it do closd loop boost control on the Wolf v500 but I didn't change the setpoint.

I dont want to play with any fuel or ignition map settings untill I understand what is going on and I can measure my changes appropriatly. I was just more interested to see a pretty consistant dip in the map reading at that rpm range?

This is a log from this morning and you can see that dip clearly again in the last part. However I notice that it is also right where I have adjusted the throttle. Maybe it is conincidence that it I keep doing that at the same point.

JZA70 R - Do you normaly play with the boost controller during logging? Is that how you chase the desired load points?