Ignition Timing on DI Engines

Discussion of tuning specific to MAZDASPEED6/MAZDASPEED Atenza/Mazda 6 MPS vehicles
Lolmooses
Posts: 43
Joined: June 16th, 2020, 1:53 pm

Re: Ignition Timing on DI Engines

Post by Lolmooses »

I didn't even think of higher gears on a built block but yeah I see what you're saying. That must be useful when passing someone on the highway instead of having to down shift 2-3 gears and then going for it haha.

I see, so power would be more or less equal then given the same variables and similarly speced turbos. You don't seem to be having that load cap issue I've read about a few times here where they'll shoot for a load higher than 2.2 or so and they have to overshoot to hit it while fighting the AFR's going lean. I haven't run into it myself yet, but we'll see what happens once I get this TMIC on and go for higher loads. I don't know what people have been doing to work around that but it's a bit concerning.
2006 MS6: CS HPFP internals, stage 2 CS intake, CP-E TMIC, CS catback with racepipe, GFB hybrid BOV, CS EBCS
Dolfius
Posts: 64
Joined: May 31st, 2017, 2:54 am

Re: Ignition Timing on DI Engines

Post by Dolfius »

The load cap-lean run issues seem to be a problem on BT cars. Seen it on all 3 variants of MPS. I recently found out about people moving to other platforms because of it and some tuners avoiding tuning on VT because of it.
Screenshot_20200626-184756_Facebook.jpg
Screenshot_20200626-184756_Facebook.jpg (199.09 KiB) Viewed 9340 times
Lolmooses
Posts: 43
Joined: June 16th, 2020, 1:53 pm

Re: Ignition Timing on DI Engines

Post by Lolmooses »

Your thread here and that message from Justin is one of the examples I've seen before. I have a feeling it might happen in my case as well once I upgrade from the K04.
2006 MS6: CS HPFP internals, stage 2 CS intake, CP-E TMIC, CS catback with racepipe, GFB hybrid BOV, CS EBCS
mituc
VersaTuner guru
Posts: 1324
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: Ignition Timing on DI Engines

Post by mituc »

I'm not sure the versatuner limitation mentioned in that screen capture have anything to do with the load cap limit with over time I came to think it has something to do with the tune itself. Actually some people switched from cobb AP to versatuner exactly because versatuner allows tuning past load 2 in some critical tables whch the AP doesn't (or didn't up to a point) allow directly, only by interpolation.
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
Dolfius
Posts: 64
Joined: May 31st, 2017, 2:54 am

Re: Ignition Timing on DI Engines

Post by Dolfius »

mituc wrote: June 28th, 2020, 8:46 am I'm not sure the versatuner limitation mentioned in that screen capture have anything to do with the load cap limit with over time I came to think it has something to do with the tune itself. Actually some people switched from cobb AP to versatuner exactly because versatuner allows tuning past load 2 in some critical tables whch the AP doesn't (or didn't up to a point) allow directly, only by interpolation.
I'm almost certain it does. I've experienced it with my own car before bad luck struck again. And I'm seeing it on a BT 6 and BT Gen2 as well.
Both are pegged at just under 2.5 load (the 6 for example goes highest 2.49 with all targets set to 2.8).
When I used Cobb's formula for calculated load - which is ((g/s*60)/RPM))*(2/3) - the load is over 2.8 in some areas in the lower rev range. That would explain the load being pegged at almost 2.5 as well as the relative lean condition. Said lean condition goes away when the load starts to come down, btw. There's a direct correlation between the two.

I've been saying this since the very beginning when I first started exploring this platform - there are some tables or something that we don't have access to that cause this.
Dolfius
Posts: 64
Joined: May 31st, 2017, 2:54 am

Re: Ignition Timing on DI Engines

Post by Dolfius »

viewtopic.php?t=17

My friend came across this. I'm surprised I missed this topic.
The last entry before mine was in 2010. 10 years later and no update (solution)?
Dolfius
Posts: 64
Joined: May 31st, 2017, 2:54 am

Re: Ignition Timing on DI Engines

Post by Dolfius »

mituc wrote: Actually some people switched from cobb AP to versatuner exactly because versatuner allows tuning past load 2 in some critical tables whch the AP doesn't (or didn't up to a point) allow directly, only by interpolation.
Sorry for the multiple replies but I also suddenly remembered this - the Gen2 load tables only go up to 2. Not 4 like the Gen1 and 6 tables do, if I remember correctly.
mituc
VersaTuner guru
Posts: 1324
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: Ignition Timing on DI Engines

Post by mituc »

Dolfius wrote: June 28th, 2020, 11:48 am viewtopic.php?t=17

My friend came across this. I'm surprised I missed this topic.
The last entry before mine was in 2010. 10 years later and no update (solution)?
I tend to think it's tune related and I think I figured this out while I was tuning my CX7. I need to make more tests though.
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
mituc
VersaTuner guru
Posts: 1324
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: Ignition Timing on DI Engines

Post by mituc »

Dolfius wrote: June 28th, 2020, 11:51 am Sorry for the multiple replies but I also suddenly remembered this - the Gen2 load tables only go up to 2. Not 4 like the Gen1 and 6 tables do, if I remember correctly.
That is indeed correct but you still have the possibility to scale those tables.
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
Dolfius
Posts: 64
Joined: May 31st, 2017, 2:54 am

Re: Ignition Timing on DI Engines

Post by Dolfius »

What loads are you seeing in your 3 MPS @mituc? You're probably running some sort of aux fuelling there but @ 32psi you should see well over 2.5 load in your logs.
Post Reply