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

[Yotaholic]

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

15.8 was max boost taken from the EBC . Thanks for any input

[Yotaholic]

Hmm if this is corrct ,,my lag time for the stock injectors is way off . I have it set at .48 ,,, i'm going to try it at .78 and see what effect it has on duty .

http://www.skylinesaustralia.com/forums/post-a143316-

[Z2TT]

Yeah that doesnt really make any sense matie.

Ah, Sorry. I mean on a stock 1jz engine, how far can you raise boost without having to change the ignition timing, at what point would you be required to re-map the ignition timing with the use of a aftermarket ecu or piggyback.

[JZA70 R]

im assuming you have a stock 1jz and are using something like a safc or emanage in conjunction with the factory computer and now want to know at what point do you have to take timing into consideration?....

well i rarely hear of people being forced to add hardware to edit timing due to detonation, some people get a timing piggyback to try and chase more power but yeah i think you will run into the stock turbos inefficiency range before you need to edit timing for knock control.

i never really played around with piggyback fuel and ignition computers, i never liked the idea of them so went straight for the stand alone engine management. obviously if your keeping the car relatively stock then this isnt justifyable.

[JZA70 R]

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.

Before I show you the results I want to show you the last 2 most significant tunes the car has operated on.




Below is a run with the factory 1JZGTE Manual ECU in place, and very limited mods. Not even a boost controller.



You can see the general power curve, and where the wastegates open and start bleeding boost. You can also see where power stops climbing and where it starts tapering off.

The AFR curve is pretty basic and smooth. starts at 13.5 and works its way down almost on a linear scale to sub 11 and then flattens out. I am more impressed by the factory tune then I am with some "professional" tunes these days.













Next is the first (and last) tune performed by a workshop.

I was and still am very happy with this tune, after all the motor is still alive and kicking.

It made GREAT power, felt strong and performed well (13.0 @ 110) at the drags on street tyres.





Looking at the graph you can see power comes on strong and keeps going as the wastegates are held closed by the boost controller. Once again power starts tapering off as usual late in the rpm range and generally the power curve is smooth. Not perfect though.

Looking at the AFR curve, it starts out a bit lean but richens up quick and dives down into safe territory and soon hits a fairly noticable rich spot that you can see costs power...

After that it kinda smooths out again and then turns to shit somewhere after 6000 rpm. Not sure if they even tuned it after 6000rpm, sure as hell doesnt look like it.













Then we have my tune. un-countable hours of trial and error, learning, testing and tuning. All on the road, by myself.



Looking at my own tune, probably the biggest surprise for me was seeing how fat and broad the powerband is. Peak power is held for 70 kph.

Then you can see that power is no longer taking a dive but rather holding on for dear life.

This was due to increasing timing after peak torque and continually increasing timing until rev limit! I cant believe how much a difference it makes when you dont do this. Power will fall off hard!

A lot of people relax timing after peak torque because they fear at those high rpms (6000+) detonation is most sensitive but this is simply not true. I am running 16' of ignition timing at my rev limit which is 7000 rpm and 19 psi! where as at peak torque I can only run a maximum of 11' or knock WILL set in. BP U98

Looking at the AFR curve, it is nice and smooth with no major dips, lean or rich spots. I try and hug 12.0 for any boost pressure over 14.7 regardless of RPM.

The car is making over 200 rwhp at just 90 kph in 4th gear.

The three different power outputs are due to me playing with timing on the fly, on the dyno. The red line is actually the first run performed with the tune in the same state as i raced on. It makes 315rwhp in this guise.

For the 2nd run I increased timing 2' extra over the whole map, and for the 3rd run of 335 rwhp I increased timing another 2' for a total of 4' extra over the entire map. I only did this for fun because I know the dyno doesnt load the motor as much as the road does, gear for gear. I cannot run the car on the street with this extra timing without some form of octance booster.

The first run was ~315 rwhp. the third 335 rwhp which is exactly 250 rwkw.






Below are 3 tunes compared.
1. Power FC Default (dont confuse this with the factory 1JZ ecu tune or the first dyno readout above)
2. Power FC Tune (by a workshop)
3. Power FC Tune (by me)



Timing - default





Timing - workshop





Timing - me






Fuel - default





Fuel - workshop





Fuel - me





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.

[TIMTAMS]

They're awesome results, I really like how smooth you have it with good power figures. Not that I understand it all it was still an informative read.

Cheers graeme.

[YLD-16L]

Good read there mate and definitely interesting.

Your progress is similar to mine JZA70 R, I'm now making more power at 4000rpm than I was at 8000rpm and have nice increase in area under the power curve.

I think it's been a more worthwhile exercise than chasing an increase in peak power in terms of performance in the real world.

It's funny though as only a few people notice these things at dyno days everyone else is just looking at the peak number.

[chris davey]

Hell no, not boring, that is GREAT info. Well done on top quality street tuning!

Would you be able to convert those Power FC numbers to mmHG and psi or kpa please? I would love to slap your timing map into my database to do some comparisons, can send em to you as well

[JZA70 R]

I think you already have Chris, maybe with a slightly older timing map though... you already sent me one too

Thanks for the comments guys. Glad some people find this stuff interesting too

[JP]

a quick question about your idle timing with the pfc, does your idle ignition timing seem to do whatever it wants, separate to what's in the igntion map? A couple of the pfc's I've tuned now do their own thing with idle ignition timing regardless of what settings are used.

[thechuckster]

can I just add that this kind of thread is so, so, so useful - even to folks with different engines.

[JZA70 R]

a quick question about your idle timing with the pfc, does your idle ignition timing seem to do whatever it wants, separate to what's in the igntion map? A couple of the pfc's I've tuned now do their own thing with idle ignition timing regardless of what settings are used.

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.

[RA35GT]

OMG.

That is way kewl JZA70R!!

Nice work on the tuning!!

[Endless]

Very interesting, would love to do some tuning myself.. In the meantime i should get you to re-tune mine Todd haha

[Disturbed1]

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