VE, spark and EGT, I think I got it...

Hey,

I started notice that my EGT while cruising is alarmingly high.

I could get up to 950C/1750F+, at first I thought the EGT is off (it does have a bad ground and the needle jumps around sometimes)

One drive when I was cruising @ 100kph/60mph~ I saw the EGT is very high, for every little gas pedal moment the EGT would raise even more...

It was dark, I pulled over and opened the hood, the exhaust manifold and the turbo turbine were glowing red like I never saw it !

Investigation begins...

Many reading days later, conclusions:

- Higher BTDC degree = Less EGT = Less power
- AFR lower or higher then 14.7 = Less EGT

My ignition map when EGT was too high:

The marked area is my cruise cells.

I added spark to the cruise area like so:

The EGT dropped by as much as 300C/570F~ !!
Of course the power in the area dropped too.

I'm ultra happy with my little win :)

Now I need to find the right balance between EGT and powa.

***UPDATE***

Beside the ignition map update I did something else that I didn't thought is responsible for the big change in EGT - I was wrong...

As I wrote:
- AFR lower or higher then 14.7 = Less EGT, max EGT @ 14.7

I changed my afr map - that is incorporated into ve table, so every change I make in the afr table should bring the afr to the value present.

High EGT AFR Table:

Keep in mind that my wideband could be off a little... still checking.

Low EGT AFR Table:

As  I wrote:
(real) 14.7 will get the highest EGT, lower or higher AFR should get lower EGT, so...

15.4 got me very high EGT, 14.7 gave very cool EGT, I think my wideband is a little off.
Could be my 15.4 is closer to real 14.7 and my 14.7 is lower then real 14.7.

I need to find a way to check that.

Anyway the AFR change made the big difference in EGT.

Change it and you will see the difference in no time.

:)

*****In the new post about mileage EGT and AFR I sort things out - please check it out.*****

Sequential Injection, installation and setup #2

TunerStudio seq inj setup:

Settings to change:
Squirts Per Engine Cycle: 1
Injector Staging: Simultaneous

Sequential Injection: Sequential/Semi-sequential
Timing Trigger: End-of pulse
Fixed Timing or Table: Fixed Timing
Fixed injection Timing 1(deg): -350
Cranking Injection Timing 1(deg): 360
Injector Drivers: Additional drivers

k?
k!

When I was running batch, I used to hear that the injection timing is not right, but I couldn't do anything about it, now I can !

"Fixed injection Timing 1(deg)" will let you choose the deg you want the injector to shoot, you want it to shoot when the intake valve is closed.

You can play around with numbers, -350=370 if it makes it easier for you.
A full explanation can be found here:
http://www.jbperf.com/sequential/index.html

And here:
http://www.extraefi.co.uk/Seq_MS2.html

Make sure you use the numbers I gave or from DIYAUTOTUNE (which are the same).

Another thing, "Fixed Timing or Table", fixed timing of ~-350 will work, but a table with changing injection deg will work better (less fuel will be used)

This is the table I came up with:

This table works ok, if you want it perfect you need to tune it on a dyno.

Another advanced option, is "VE trim tables", when you enable this you can trim each injector in order to reach the same AFR/EGT on all cylinders...

I think you need 4 widebands/EGT for that.

After I finished installing and tuning seq inj, I've found out:

1. I need less fuel in general on fuel map - lower VE.
2. I don't need AE for now... (!) on the little tune trip I made I disabled AE and noticed car runs great ! (I will keep an eye on this)
3. Smoother idle - more accurate.
4. Better throttle response all around.

Thank you for reading !
Drop a comment !
Be safe !

Next:
Barometric correction for 14$

Sequential Injection, installation and setup #1

Hey,

I just finished installing and setting up my seq inj kit.

Let me show you what is it about.

I'm talking about DIYPNP, other MS ECUs already feature seq inj or they can be upgraded in a similar way - check specific instruction for you specific ECU.

The kit:
Kit

Installation instruction:
Instructions

You need to solder the kit male header to the location pointed in the pic:

After Installation:

I run my MS without seq inj for sometime (if  I knew about it the first place I would have installed it from day one...)

Anyway, the default inj installation is batch (running two injectors at the same time), so two injectors were connected to one driver, as follow:

(from 96-97 instructions)

 You can see that INJ1 shoot 4U and 4W and INJ2 shoot 4V and 4X.

The seq inj kit will give us 2 extra INJ drivers (4 total) INJ3,INJ4.

Now !

Which INJ to which  pin ? (4U,4W,4V,4X)

I had to contact support for that - I think it should be a part of the instruction...

The instruction does say :

Main board INJ1: Cylinder 1

Main board INJ2: Cylinder 3

Expansion board INJ3: Cylinder 4

Expansion board INJ4: Cylinder 2

But it does not say nowhere (I looked...) which pin represent which cylinder...

And the answer is (for 96-97 Miata):

Output "INJ1" - 4U - Cylinder 1 Injector

Output "INJ2" - 4W - Cylinder 3 Injector

Output "INJ3" - 4X - Cylinder 4 Injector

Output "INJ4" - 4V - Cylinder 2 Injector

96-97 Diagram - Page 9

My DIYPNP:

The black wire on the left is just passing through the hole on the PCB, on its way to 4V.

Sequential Injection Kit

Hey !

Sequential injection means firing each injector separately.
MS default is batch fire, meaning two injector fire at the same time.

Miata (94 and above) run sequential from factory, each injector wire goes all the way to the ECU separately.

So, if your Miata is 94 and above you should start off with sequential injection from the start.
In order to enable sequential injection, you need to add a little module to your MS (DIYPNP only) that will add two additional drivers for the injectors.

The module:

Sequential injection gives you: better efficiency, injection timing, idle smoother, idle smoother with larger injectors, better enrichment, better throttle response.


Do it ! it's good for you !

Coming up - Sequential Injection Kit

Coming up...

Spark Map and Tune

Spark Map and Tune

Basically you want to tune spark on a dyno, and give someone that it is not his first time tuning spark to tune it for you...

How to look on a spark map:

Spark can be dangerous  to your engine, if knock knock on your door your engine could go byebye.
Because of that, if you're a beginner at tuning, I suggest you give the spark tuning to someone experienced - on a dyno.

I understand that my high rpm/kpa cells can use less deg, but this is knock free dyno tested (200whp)

Next:
- TPSdot Uses %WOT
- Getting ready for dyno
- MLV - MegaLogViewer

- TS - TunerStudio dashboards

Closed Loop Idle Target RPMs & PID tune

Hey !

Closed Loop Idle Target RPMs
Closed Loop Idle Target RPMs is where you setup your CLT to RPM curve.

This is my curve, 1600rpm when cold, down to 900rpm when hot.

Every time you start your engine after you set up this curve, pay attention to the rpm, and adjust the curve to your liking.


Closed Loop Idle PID Gains tune

From: MSEXTRA Manual

• Proportional Gain This setting controls the Proportional Gain of the PID algorithm. Setting this higher will result in a larger immediate response to changes in RPM. Setting this too high can result in unwanted oscillation of RPM.
• Integral Gain This setting controls the Integral Gain of the PID algorithm. This is the PID setting used to actually make the RPM meet the target RPM. Setting it too low will cause the RPM to never reach the target. Setting this value too high will result in unwanted oscillation of RPM.
• Derivative Gain This setting controls the Derivative Gain of the PID algorithm. It can be used to help dampen the effects of the Proportional and Integral settings. It is usually not necessary for good control of Idle speed. It is recommended that this is left at 0%.

PID Tune

1. Zero all the gains - Set all the gains to 0%. This is so that the effects of tuning the I-term in the next step are not confused with the effects of any other setting.
2. Tune the Integral (I) gain - The Integral gain is the only term that controls whether the code actually reaches its target. Higher values for Integral gain will result in the code being able to get closer to the commanded target; however, a value that is too high will result in oscillation. The easiest way to determine a good value for the I term is to keep increasing it until oscillation occurs, then slightly lower it. If this value is increased to 200% without reaching a point where oscillation occurs, then the RPM with valve opened setting can be decreased as far as necessary, and the open duty/steps setting and closed duty/steps setting can be made further apart to make the PID loop more sensitive.
3. Tune the Proportional (P) gain - After tuning the I gain so that the RPM reaches the commanded target without oscillation, the P gain can be tuned. The best way to tune this is to set it as high as possible without getting any oscillation. After setting this, try turning on the air conditioning or other accessories that normally lower RPM or increase load. When these accessories are turned on, the RPM should dip a bit then recover (the valve position should increase significantly). Using longer PID ramp to target times can also make it so that when the PID algorithm engages, a higher P gain can be set without causing oscillation.
4. Tune the Derivative (D) gain - For most users, use of the D gain should not be necessary. It substantially dampens the response of the loop.