A question of timing?

Discussion of tuning specific to MAZDASPEED3/MAZDASPEED Axela/Mazda 3 MPS vehicles
skiptownmcat
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Re: A question of timing?

Post by skiptownmcat »

Yeah, I suppose. I'm just nearly at the same base values at 2+ load in the base table as the ones in the max table. I'll raise the max values again and see how it goes.
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skiptownmcat
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Re: A question of timing?

Post by skiptownmcat »

Here's a question,
Say the base value is higher than the max value, the timing decreases, would that be logged as KR as the ignition timing is retarding?
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Steve @ VersaTune
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Re: A question of timing?

Post by Steve @ VersaTune »

No. KR is knock induced timing reduction. Totally based on the knock sensor.
skiptownmcat
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Re: A question of timing?

Post by skiptownmcat »

Another question, o great oracle.
I notice that in the new high load tune, the open loop normal and overload tables are set the same. Is this advisable if you're running higher loads and more advanced timing like I am? I did it today but kept getting 2.0Kr @~4500rpm only in 4th and 5th. I'm asking for 2.2 loads but always seem to hit over those (2.25 or so), so am I right in thinking it would then be using the overload table? I've gone back now but not had chance to run the tune in yet to see if its gone.
Also, in all the tunes you have changed the 2000rpm cell to .91 lambda, what is the logic behind that?
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Steve @ VersaTune
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Re: A question of timing?

Post by Steve @ VersaTune »

I don't think that the overload function is activated. I think it's like the boost tuning. It's a software option that Mazda does not use. I just duplicate those tables to be safe.

The AFR bump at 2000 is to increase EGTs a bit to help spool.
skiptownmcat
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Re: A question of timing?

Post by skiptownmcat »

Steve @ VersaTune wrote:I don't think that the overload function is activated. I think it's like the boost tuning. It's a software option that Mazda does not use. I just duplicate those tables to be safe.

The AFR bump at 2000 is to increase EGTs a bit to help spool.
I wonder why I'm suddenly getting 2 KR all of a sudden, I copied the vvt table as well could that affect it by increasing cylinder pressure? Ambient temps are still the same.
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Steve @ VersaTune
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Re: A question of timing?

Post by Steve @ VersaTune »

Does the KR go away with your old tune?
skiptownmcat
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Re: A question of timing?

Post by skiptownmcat »

I'll have a check tomorrow, need an excuse to go for a drive now!!
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skiptownmcat
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Re: A question of timing?

Post by skiptownmcat »

Changed the vvt table back and the KR is gone, I think I'll get everything else done first and then mess around with the vvt lastly.
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mituc
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Re: A question of timing?

Post by mituc »

I strongly suggest anyone to start logging the engine coolant temperature before doing anything to the car, especially timing tuning.
Last year in november I wanted to see if when it gets colder my car would like a bit more timing and I could barely add 0.35 degrees over what I had (the average increase was 0.125-0.25 degrees). Increasing with more than that would result in light knock at high RPM (KR 0.35-0.7-1.05). It was kind of paradoxical but the car liked boost more, so I gave it more boost.

At some point I noticed that the actual advance timing values were quite a lot behind the commanded values, and that was happening in 0-3C weather (32-38F) at boosted air temperatures of 18-25C (64-78F). At that point I started to monitor the engine coolant temperature because it was the only thing that could pull timing and yes, during WOT pulls it was increasing from 92-94C (197-200F) to 96-98C (205-208F).

Back then I started looking into additional cooling setups: larger radiators, WMI, and so on. After all the snow was gone, late in February this year, while the ambient temps were sill a tad below freezing (-2 - 0C) I noticed that the radiator fan was spinning like crazy 1-2 and even 5 minutes the car stopped, and that was happening in slow town traffic. Next day - big surprise, at -2C ambient the ECT was 112-114C. Once I was going into boost the ECT was going down to 108C, probably because the head was getting flooded with oil and because the air flow to the cabin heater (which is drawing heat from a cooling circuit in the head) was increasing.

Long story short, I think I tuned my big turbo setup with a semi-failed thermostat. No damage to the engine was done though. I changed the thermostat about 3 weeks ago and now I get up to 2.5 degrees of timing more around red line (around 11.5-12 degrees at and above 6500rpm at 265-270kPa MAP and 345-355g/s of air).

So if in normal weather (say, up to 25C/77F) the ECTs are above 90C/194F at highway cruising speeds (above 80Kmph/50mph) you need to look into changing your thermostat. It's normal for the ECT to go up to 100C/212F in stop&go traffic, even 104-105F if the summer is hot in your area (over 35C/95F), but otherwise when you do WOT pulls and the weather is normal you should NOT see ECTs above 88-90C.
2008 Cosmic Blue Mazda 3MPS
Built engine + WMI + GTX3071 gen2, ~509BHP @34PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 330-ish BHP
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