M6 MPS cold start high revving

Discussion of tuning specific to MAZDASPEED6/MAZDASPEED Atenza/Mazda 6 MPS vehicles

M6 MPS cold start high revving

by moggies » January 26th, 2019, 10:56 pm

Hi all,

New to this tuning and I have installed the Base 91US/95EU Octane tune to my Mazda 6 MPS to try and get better
drivability, as the installed mapping was incredibly aggressive. No way of knowing if it was standard or not, but the base tune
has calmed it down.

I'm looking to reduce the start up revs if possible, as currently its too fast and noisy. 1750rpm on a cold engine cant be a good idea,
plus it does nothing for keeping the neighbours happy.

I have set the idle speeds on the map software but it still races away on cold start.

Can anyone please help?

Thanks :beertoast
 
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Joined: January 26th, 2019, 10:44 pm

Re: M6 MPS cold start high revving

by mituc » January 28th, 2019, 6:15 pm

When you start it keep your foot on the acceleration pedal just a bit (like 1/4). If you do this it will start at 1250rpm instead of 1750.
2008 Cosmic Blue Mazda 3MPS
Build engine + WMI + GTX3071, ~476WHP @31-32PSI
2008 Icy Blue Mazda CX7
Stock engine, intake and exhaust (YES!!), GTX2867 gen2 + Autotech HPFP, self-tuned to 320-ish BHP
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Re: M6 MPS cold start high revving

by moggies » January 28th, 2019, 8:39 pm

OK thanks, I'll try that. Bit odd as I've lowered the cold start idle on the map?
 
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Re: M6 MPS cold start high revving

by mituc » January 29th, 2019, 7:40 pm

moggies wrote:OK thanks, I'll try that. Bit odd as I've lowered the cold start idle on the map?


During certain situations the engine will use some values in tables I don't think we have access to or are hardcoded in the engine management software, while with these tables we're only changing the calibration/values that works with.
I think this is one of them, the commanded AFR during idle being another one (even if we cna alter the AFRs for that engine speed and load), front radiator fans duty cycle, and so on.
2008 Cosmic Blue Mazda 3MPS
Build engine + WMI + GTX3071, ~476WHP @31-32PSI
2008 Icy Blue Mazda CX7
Stock engine, intake and exhaust (YES!!), GTX2867 gen2 + Autotech HPFP, self-tuned to 320-ish BHP
VersaTuner guru
 
Posts: 881
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: M6 MPS cold start high revving

by moggies » February 10th, 2019, 2:55 am

Ok, this cold start revving is definitely worse with the cold weather, but the rpm appears to lower quicker, if the vehicle is started
without pressing the clutch.

I would also like to lean off the mixture without getting too deep into settings, so is there anything basic I can tweak without effecting anything else?

Thanks
 
Posts: 10
Joined: January 26th, 2019, 10:44 pm

Re: M6 MPS cold start high revving

by mituc » February 11th, 2019, 12:27 pm

moggies wrote:Ok, this cold start revving is definitely worse with the cold weather, but the rpm appears to lower quicker, if the vehicle is started without pressing the clutch.


Press the clutch, especially when cold (and gearbox oil is thick)! The only thing you will do is to put more strain on the starter motor, the cold start ECU logic will not actually change. Newer cars with manual transmissions will not even start if you don't press the clutch, and this is for a good reason.

moggies wrote:I would also like to lean off the mixture without getting too deep into settings, so is there anything basic I can tweak without effecting anything else?


In what situations you want to lean the mixture and by how much? What do you have in mind?
2008 Cosmic Blue Mazda 3MPS
Build engine + WMI + GTX3071, ~476WHP @31-32PSI
2008 Icy Blue Mazda CX7
Stock engine, intake and exhaust (YES!!), GTX2867 gen2 + Autotech HPFP, self-tuned to 320-ish BHP
VersaTuner guru
 
Posts: 881
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: M6 MPS cold start high revving

by moggies » February 15th, 2019, 6:33 am

Just slightly weaken for a bit better economy. The economy map is not that good for general driving so just a tweak on this one.
I'm not interested in thrashing it just a decent drive.
 
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Joined: January 26th, 2019, 10:44 pm

Re: M6 MPS cold start high revving

by mituc » February 20th, 2019, 2:08 pm

If you want leaner AFRs you may need to disconnect the secondary O2 sensor. Then you will be able to command lambda values above 1 without triggering some failsafe in the ECU which will put the lambda back to 1.
If you still have the cats on I suggest you don't go leaner than 1.03.
2008 Cosmic Blue Mazda 3MPS
Build engine + WMI + GTX3071, ~476WHP @31-32PSI
2008 Icy Blue Mazda CX7
Stock engine, intake and exhaust (YES!!), GTX2867 gen2 + Autotech HPFP, self-tuned to 320-ish BHP
VersaTuner guru
 
Posts: 881
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania


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