Tuning

[V8toilet]

The tuning is more for adjusting how the engine responds at certain engine loads, power delivery etc.. if more power is made I'll take it. I'm still getting tuned and already have -1sec 0-60 time vs stock tune.

So your CX5 goes 0-60 mph in 7.0 seconds or less purely because of ECM/engine tuning? What was your baseline run and with what device did you use to measure it with? What was the elevation and was it level? Did you test it in both directions and average it out and not just take the best one?

You realize that the European version with 189 ft-lb of torque and 189 HP with a 14-1 compression ratio only makes 4 ft-ib and 5 HP more respectively than your 2.5 Skyactiv with a 13-1 compression ratio and that the European engine needs 93 octane fuel. Most publications specify a 0-60 time in the 7.0-7.5 second time with a lighter Mazda 6 using the more powerful European Skyactiv 2.5 liter gasoline engine.

I hope you're careful Chris because adding more ignition timing on a high compression engine like the Skyactiv 2.5 has got to be pushing the limit of the internal strength of the parts. I'm assuming this but it wouldn't surprise me if Mazda made the internal reciprocating parts of the Skyactiv engine light duty in order to shave/save weight. They're reliable under normal duty but start increasing cylinder pressures beyond what Mazda designed them for and things could start breaking after a few thousand miles. I've seen this happen before with other makes.

 

[Sassimac]

V8toilet...

When it comes to testing, I always use the exact same piece of road, from the same starting point. That way I can line up my data more accurately.

I also use a data logger connected to the OBD port that can record the run. It basically starts timing as soon as the speed is greater than zero, or as soon as the car starts to move. It stops when the speed is 100kmh. This removes any guesswork. I also have a Beltronics Accelerometer.

My baseline is 8 - 8.2 seconds 0 - 100kmh. I'm down to 6.39 seconds best effort.

 

[Chris_Top_Her]

So your CX5 goes 0-60 mph in 7.0 seconds or less purely because of ECM/engine tuning? What was your baseline run and with what device did you use to measure it with? What was the elevation and was it level? Did you test it in both directions and average it out and not just take the best one?

You realize that the European version with 189 ft-lb of torque and 189 HP with a 14-1 compression ratio only makes 4 ft-ib and 5 HP more respectively than your 2.5 Skyactiv with a 13-1 compression ratio and that the European engine needs 93 octane fuel. Most publications specify a 0-60 time in the 7.0-7.5 second time with a lighter Mazda 6 using the more powerful European Skyactiv 2.5 liter gasoline engine.

I hope you're careful Chris because adding more ignition timing on a high compression engine like the Skyactiv 2.5 has got to be pushing the limit of the internal strength of the parts. I'm assuming this but it wouldn't surprise me if Mazda made the internal reciprocating parts of the Skyactiv engine light duty in order to shave/save weight. They're reliable under normal duty but start increasing cylinder pressures beyond what Mazda designed them for and things could start breaking after a few thousand miles. I've seen this happen before with other makes.

Yes I and my tuner are careful about what the motor is doing. I use the same place for my tests, the same spot (actually 2 spots on the same stretch different directions) and the conditions have been pretty steady at the times I was doing them. I'm not saying I have a 7 sec 0-60, I'm saying with the timing device I use, from the same spot (which is not 100% level in either direction), in similar conditions consistently yielded upwards of 1 second reduction in one direction, and .5-1 on the other. This was done flashing on the spot (I can do it in the car form my laptop) on at least 3 different occasions. I always check my logs for engine knock, misfires etc, temps and afr's and it's all clean. My tuner would notice right away if something was getting out of limit way better than me. My motor is not being tuned to the edge. There are over 40 PIDS that are adjusted and monitored, it's not about changing one pid (like ignition timing) and leaving the rest. I use 0-60 as a test because it's easy to quantify compared to paying $100 for an AWD dyno to find out how much hp/tq was gained and where. I can tell the difference on my DD's in specific situations. And, with 3000+ mi a month I get plenty of driving to figure these things out.

 

[MikeM.]

MikeM...

With respect, I have to disagree with you.

It is very possible to "tune" the car to reach 260kmh. Whether or not it physically can, I have no idea.

No, it's not. The car has not reached 260 mph when it's on a dyno. It's standing still.

You are very correct in mentioning the actual real world possibility the car would simply never be able to propel itself to that velocity.

It's not a possibility it couldn't go 260 kph with a software tune, it's a fact. 260 kph is 161 mph.

 

[piotrek91]

You guys might be interested in this post/thread from mazda6 forums:
http://forum.mazda6club.com/2-5l-i-4/314193-2-5g-power-potential-14.html#post4301345

2015 CX-5 AWD 2.5L tuned for 93 octane
Stock HP/TQ : 139/155
Tuned HP/TQ: 165/176

There certainly is some room for tuning to make a difference on these motors. It's unknown what the impact on engine durability is, but getting an extra 20lb/ft of torque across the board for a couple hundred dollars is nothing to sneeze at.

 

[piotrek91]

it's a fact. 260 mph is 161 mph.

(iagree)

 

[MikeM.]

You guys might be interested in this post/thread from mazda6 forums:
http://forum.mazda6club.com/2-5l-i-4/314193-2-5g-power-potential-14.html#post4301345

2015 CX-5 AWD 2.5L tuned for 93 octane
Stock HP/TQ : 139/155
Tuned HP/TQ: 165/176

There certainly is some room for tuning to make a difference on these motors. It's unknown what the impact on engine durability is, but getting an extra 20lb/ft of torque across the board for a couple hundred dollars is nothing to sneeze at.

Well, I wasn't born yesterday so I don't accept those numbers as being an accurate representation.

It's the oldest game in the book.

Too easy to fudge the results to suit the agenda of whoever measured it.

If you could get those numbers (and I agree it's possible), the effect on longevity would be disastrous.

 

[Chris_Top_Her]

You guys might be interested in this post/thread from mazda6 forums:
http://forum.mazda6club.com/2-5l-i-4/314193-2-5g-power-potential-14.html#post4301345

2015 CX-5 AWD 2.5L tuned for 93 octane
Stock HP/TQ : 139/155
Tuned HP/TQ: 165/176

There certainly is some room for tuning to make a difference on these motors. It's unknown what the impact on engine durability is, but getting an extra 20lb/ft of torque across the board for a couple hundred dollars is nothing to sneeze at.

OV charges $50, for the tune. I was the first 2.5L sky (anything) to give him an ECU dump. He is now doing 6 tunes after unlocking some need tables.

 

[MikeM.]

He is now doing 6 tunes after unlocking some need tables.

I'll bite.

What is a "need table"?

 

[Chris_Top_Her]

I'll bite.

What is a "need table"?

I meant needed*, the 6 ecu is slightly different.

 

[thedaddyb]

Improving the driving dynamics, drive by wire throttle response, and overall power/torque delivery through a tune . . . sure.

Seeing that big of an increase in power in a NA motor with no other modifications . . . too good to be true. Wait for the "my motor blew up" threads to soon follow.

 

[V8toilet]

piotrek91, those numbers translate into roughly 218 HP and 210 TQ at the flywheel, which is pretty impressive for a naturally aspirated 4-cylinder engine that doesn't rev much past 6300 RPM. what kind of dynamometer did they use to get those numbers and how did they control the baseline/post conditions for a reliable result? I read that they increased timing advance from 6-degrees to 15-degrees at 6000 RPM. the tuner is claiming that the motor is considerably de-tuned. If this is the case would that be because it was the best compromise for fuel economy, emissions, and reliability? It seems that he is tuning a manual transmission equipped Skyactiv, which for emissions purposes would have a considerably different tune than an automatic transmission equipped model.

Chris_Top_Her and Sassimac, keep up the good work and please keep us posted with the results.

Thanks

 

[piotrek91]

piotrek91, those numbers translate into roughly 218 HP and 210 TQ at the flywheel, which is pretty impressive for a naturally aspirated 4-cylinder engine that doesn't rev much past 6300 RPM. what kind of dynamometer did they use to get those numbers and how did they control the baseline/post conditions for a reliable result? I read that they increased timing advance from 6-degrees to 15-degrees at 6000 RPM. the tuner is claiming that the motor is considerably de-tuned. If this is the case would that be because it was the best compromise for fuel economy, emissions, and reliability? It seems that he is tuning a manual transmission equipped Skyactiv, which for emissions purposes would have a considerably different tune than an automatic transmission equipped model.

Chris_Top_Her and Sassimac, keep up the good work and please keep us posted with the results.

Thanks

I'm only making arguments here for the sake of argument. I'm not willing to put my money and engine where my mouth is, but I think that some of you guys are dismissing the skyactiv tuning potential too quickly.
As you said, Mazda struck a good balance between performance, emissions, fuel economy and reliability.
When tuning the engine for maximum performance the other parameters are going to suffer, but odds are that someone tuning their car will never have to experience the fact that the engine is, say, 5X more likely to suffer catastrophic failure. Such an increase is unacceptable for a manufacturer who has to warranty their product, but who cares if the odds of failure go up form 1/10000 to 5/10000 for an individual?



Those numbers, if true, are very very impressive.
That figure would come out to 84lbft per liter of displacement.

Wikipedia has the BMW M3 listed as the highest specific torque per liter of NA displacement. The E46 BMW M3 CSL makes 273lbft out of its 3.25L NA motor, so also 84lbft per liter of displacement.

The skyactiv engine has direct injection, 13:1 compression and 4-2-1 headers. The M3 is just a relatively simple, port injected engine.
It makes sense to me that it should, in theory be possible for the SKY to match the torque/liter output of the M3.

Looking at this graph, there is lots of torque to be gained by increasing the anti-knock properties of the fuel and tuning the ECU to take advantage of it.

 

[4DZC]

Well, like a Bugatti, our new lil 2015 CX-5 Touring is now sporting 4 turbos!!!! Making almost 900whp, we're pretty happy...lol ok, all jokes aside...I found this thread while looking into mods for the CX-5. This is my 1st direct injection vehicle so I admit, I am def still learning. If the parameters are as stated above and not recommended or fruitful to extract a lil better performance then I think im fine with lowering it, larger wheels, and other visual/audio upgrades. In for more info.

 

[V8toilet]

I think that some of you guys are dismissing the skyactiv tuning potential too quickly.

Piotrek, I am skeptical but I was also skeptical once for an I-force Toyota V8 engine I had that gained 20 ft lbs of RWTQ by simply bolting on a freer breathing JBA exhaust manifold with a Spintech muffler and that was verified in controlled conditions on the same dynojet dynamometer so I knew it was reliable. It also shaved a full second off my 0-60 time verified with a G-tech that was used in similar conditions for the most reliable results.

I assumed that Mazda engineers squeezed as much as possible out of this Skyactiv motor and that still may be true if you consider fuel economy and emissions as part of that equation. Whenever I see claims of real numbers though I like to ask questions to find out just how factual they may or may not be or at least help better judge the validity of it. I know the Skyactiv motor has potential on paper but I haven't seen it proven yet and I'm not about to mess with my daily driver at this time in my life. I hope someday someone else will unlock its secrets.

Years ago I used to do some crazy stuff like the time I took a Camaro engine, rebuilt it into a torquey rev happy monster and stuck it into a 1988 Fiero Formula with a 5-speed manual. Or the time I helped a friend build a small block 350 with a monster camshaft and stuck that engine into a 1979 Chevy Malibu with a 4-speed stick and gutted interior.

As you said, Mazda struck a good balance between performance, emissions, fuel economy and reliability.
When tuning the engine for maximum performance the other parameters are going to suffer, but odds are that someone tuning their car will never have to experience the fact that the engine is, say, 5X more likely to suffer catastrophic failure. Such an increase is unacceptable for a manufacturer who has to warranty their product, but who cares if the odds of failure go up form 1/10000 to 5/10000 for an individual?

Like me you're making assumptions and like me could be way off on that. Only time will tell.

Looking at this graph, there is lots of torque to be gained by increasing the anti-knock properties of the fuel and tuning the ECU to take advantage of it.

It wouldn't surprise me if Mazda took advantage of this potential with higher octane fuel in their upcoming Skyactiv Miata, but then again why is the European version with a 14-1 compression ratio and 93 ocntane fuel barely more powerful than the American version with a 13-1 compression ratio and 87 octane fuel?

 

[Beefy]

It wouldn't surprise me if Mazda took advantage of this potential with higher octane fuel in their upcoming Skyactiv Miata, but then again why is the European version with a 14-1 compression ratio and 93 ocntane fuel barely more powerful than the American version with a 13-1 compression ratio and 87 octane fuel?

Emissions? Efficiency?

 

[piotrek91]

It wouldn't surprise me if Mazda took advantage of this potential with higher octane fuel in their upcoming Skyactiv Miata, but then again why is the European version with a 14-1 compression ratio and 93 ocntane fuel barely more powerful than the American version with a 13-1 compression ratio and 87 octane fuel?

The 2.5L skyactiv engine in Europe is still 13:1 compression. The 2.0 is 14:1.
http://www.mazda.pl/assets/poland/cars/cx52015pricelist.pdf

RON95 in Europe is "only" 90AKI. Still a long way to go towards 93AKI gas.
The 2.5L there makes 256Nm, so 189lbft of torque vs 185lbft here.

So, in theory, tuning for 93, assuming a linear benefit of octane on torque puts us at 193lbft without compromising emissions, efficiency or reliability. If you sacrifice emissions and reliability a little, I can see more torque to be gained.
Of course, you're paying for premium gas just to get an extra 8lbft of torque, but many on here have spent thousands to get an extra 30lbft of torque by trading in the 2.0L for a 2.5L.


The beauty of the Skyactiv engines is that even at WOT, the intake valve stays open for part of the compression cycle.
The effective compression ratio is not really 13:1. By closing the intake valve earlier it's possible to get more air into the cylinder for combustion, allowing for more torque, but if too much air is compressed, the temperature goes up too much and you get knock. If you can avoid knock by running rich. You pollute more, but you get more torque.

 

[piotrek91]

I know the Skyactiv motor has potential on paper but I haven't seen it proven yet and I'm not about to mess with my daily driver at this time in my life. I hope someday someone else will unlock its secrets.

Sounds like we are in the same boat here, but the more I read/think about it the more convinced I am that there are relatively safe, reliable performance gains to be had with a tune.

I'm happy with the 155HP/150Lbft, but I wouldn't mind having 170HP/165lbft. But only if it's cheap and doesn't cause my motor to blow up or get clogged with carbon 20k miles later.

 

[thedaddyb]

Those numbers, if true, are very very impressive.
That figure would come out to 84lbft per liter of displacement.

Wikipedia has the BMW M3 listed as the highest specific torque per liter of NA displacement. The E46 BMW M3 CSL makes 273lbft out of its 3.25L NA motor, so also 84lbft per liter of displacement.

The skyactiv engine has direct injection, 13:1 compression and 4-2-1 headers. The M3 is just a relatively simple, port injected engine.
It makes sense to me that it should, in theory be possible for the SKY to match the torque/liter output of the M3.

Looking at this graph, there is lots of torque to be gained by increasing the anti-knock properties of the fuel and tuning the ECU to take advantage of it.

Comparing it to the engine out of the M3, you are missing quite a few variables that allow the engine to preform to those specs. All of the engine internals are designed to be more stout and handle those conditions. Cooling, oiling, timing, the list goes on. IIRC the E46 also revved to around 8k rpm whereas the CX-5 cuts off around 6500.

You can dump as much fuel as you want to prevent knock, but when ringlands start to break, and pistons crack because they are running beyond their engineered specs the picture becomes all too clear.

I have had quite a bit of experience around tuning turbo Subaru engines so I understand the potential of good quality tuning. You would be amazed at how crappy the factory tunes look once they are graphed out. Sure they are designed for reliability and fuel economy, but it also looks like the are hastily put together.

I'm sure a tune could produce a much more lively engine and completely smooth out the power band on the skyactiv engines, but the numbers they are claiming to gain don't sound reasonable in my opinion on stock components.

 

[V8toilet]

I looked harder and the source I used does indeed say the European Skyactiv 2.5 uses a 13-1 compression ratio. That Atkinson like cycle you describe helps reduce engine pumping loses buy holding that intake valve open after BDC during the compression stroke at the expense of some power. Instead of using energy to compress the air during light load conditions the intake is held open longer and the air is not compressed for some of the compression stroke. The 13-1 compression ratio though helps to reduce the power loses. I read that the Computer only uses this mode during light load conditions but I don't have a source handy. It's interesting though that the intake is held open for part of the compression stroke even at WOT.

I can't wait to see if Mazda can actually pull off homogeneous charge compression ignition. Theses are some interesting times for the ancient internal combustion engine that just keeps improving.

My first CX5 was a sport with the 2.0 Skyactiv and it was an efficiency king amount small SUV's. It was even peppy in most conditions with its smooth automatic. I used to like trying to squeeze as much mpg out of it as I could and I got some impressive numbers with it. Using my G-tech I managed 0-60 mph ranging from 8.37 sec to 8.5 seconds. With my current Skyactiv 2.5 I get a very consistent 7.5 seconds 0-60 in the same spot with the same conditions.