wrxrick

I went out and drove on both ignition maps. Everyone say's to use the Trubokitty map, and I thiink I will, but I noticed the stock diyautotune ignition map has more advance in the low rpm's and I could tell the car moved better at low rpm's on the diyautoune map, although it does not appear to be as safe as trubokitty's. I have mostly street car on a t25 turbo. It looks like the diyautotune map is too advanced, right?


trubokitty ignition map

diyautotune ignition base map

LeoNA

Yes. The diy is just to get the engine started the first time. It only needs 10-14 degrees at idle.

curly

iTrader: (25)

I personally like to keep my idle advance below 22-25 degrees max, including ignition correction. It's usually hovering around 18 and perfectly happy. A lot of people will tell you it supposed to be 10, they're wrong. That's what the stock cars lock out at when you set timing, but once you pull the TEN/GND jumper, it goes up a bit.

Try to take screen captures, this old man pastes them into Paint, save as a .JPEG, then attaches here, yours are near impossible to read.

But from what I can tell, you copied everything below 100kpa, so you haven't fixed any of the dangerous advance in boost, in the 110 and up rows. As a start, 100kpa should max out around 28 degrees, then each row should go up by 2 psi. So first row is 114, then 128, etc. Drop timing 4 degrees for the 114 row, then 2 every row after that. Should end up with 10-12 degrees by 18psi, which is really safe. You'll probably increase that 2-4 degrees on the dyno and find some power if you every make it to one, and the engine/coils/injectors/etc is happy with it.

StanTheMan

i just upgraded to the MS3pnp
239@ 0.50 duration cams
11.5:1 compression
VVT bottom end
modified BP4W head
COPS conversion
using BP-4W sensors as intended (Removed CAS)
BP-4W conversion on a NA6 Chasis
flat top intake

basic port & polish
36-2 wheel
Rx8 injectors
Totally N/A car

I loaded both Turbo Kitty & DIY auto tune maps

The starting & idle sequence for my engine the DIY auto tune was miles ahead. only needed minor adjustments.
my cams run at 65 kpa with the overlap
I did adjust the timing a little ( reduced) I idle on just over 1000 rpm but idle is sooo beauty full once it hits PID

.I added a few degrees to the base timing on the DIY auto tune
the logged & logged more .

It feels enthusiastic
not tired
revs like ****


I never4 took the Turbo kitty map any further than start up sequence.

Just make sure you're running on the correct timing. as in check your base timing before anything else

wrxrick

thanks for the responses.
I want to advance the idle cells and low throttle so the car doesn't feel so sluggish on the street...

I took a screenshot of my updated ignition map hoping this is safe (and fun) until I get a professional tune. Need to get my fuel cells and accel enrich down, first and get more accustomed to the process

LeoNA

How much is a bit? Why do you believe 18 is better than 12 for idle?

engineered2win

There is tradeoff at idle between ignition advance and air. You only need a given amount of combustion torque to maintain idle speed and any more torque will increase engine speed.

Curly's approach with less air and more IG will give crisper throttle response off idle. You're closer to MBT on the IG vs torque curve to start and with a higher manifold vacuum you will get more transient air for the same throttle blip. I don't find this to be super important, but it should be balanced. It can make a car feel a bit livelier in that it revs a bit quicker and has more perceived throttle response.

I tend to prefer the more air and less IG approach, which is usually the OEM approach. This allows your closed loop idle IG control much more authority to recover in the event of sudden load step changes. The IG can respond quicker than the IAC or DBW to recover a dip in engine speed from a transient input (accessory load or letting out the clutch). This is because you're further to the left on the IG vs torque curve, which is also a steeper slope. So for the same amount of IG increment you are getting more torque increase (10->12deg will have higher impact to combustion torque vs 18->20deg). This approach should reduce engine stalls. The main drawback is how your ECU transitions between your closed loop idle control and your base IG map. It's not always possible to do this seamlessly in the aftermarket.

Moderation is the key, as with anything. It doesn't take long to try a few increments between 10 and 20 deg base idle IG. You can do it in your driveway.

Jesse99James

Wow, thank you for taking the time to explain and type that technical response. My tuner has mostly tuned the hot idle dip out but the adjustments aren't exactly what I'd hoped for. Of course he's only looking at data logs and not seeing and feeling the differences. Once he's done I'll take the knowledge I've gleaned and try variations of earlier revisions and other tweaks that I'm learning to see if I can't get even closer to OEM idle response.

LeoNA

Basically the point I was going to make. Better idle control and lower emissions. The bore diameter is relatively small at 83mm which is the main factor in determining the spark lead and 10-12 deg of advance at idle is fairly high for the era. From my testing 10-14 is ideal and it appears Mazda had come to the same conclusion. 18deg is probably close to the MBT which would limit the idle advance control from raising the idle speed.

Ted75zcar

iTrader: (2)

If only there was a way to run different timing when idle conditions are met...