CX-9 Skyactiv 2.5L turbo engine

[Unobtanium]

I had a 2000 LS1 Camaro. Chevy saved money by using that weak 7.5 Monza rear end. They protected rearend from manual transmission by putting a small diameter clutch, and high gears in transmission. If you got on it to hard, the clutch would slip instead of spinning the tires, ouch. The trannys gears were way to high requiring 4:10 gears in rear end, but the 7.5 was to small to reliability use 4:10 gears. If you tried to replace the rear end you lost ABS. They strangled engine so it wouldn't match Corvette with same engine. Adding cat back and air lid got a good bit of hp back.

I had a 2001 WS.6, and the clutch was certainly not doing any slipping when I got on it hard. If yours was...it were broked! The rear-end was a factory 3.42, at the "biggest", and a 2.73 for some of the autos. The engine was also not "strangled", and I ran with plenty of C5 corvettes. Every dyno I have seen places them within 10whp, with the F-body usually having more due to less parasitic losses to the driveline. Since some people here don't trust dyno's though, the track backed it up on Saturday night often enough. As did the street.

They DID, however, restrict the hydraulic fluid flow through the clutch hydraulics in an effort to dampen shock on the system on more violent shifts.

 

[Unobtanium]

25 HP? Do you mean 25-35 HP? (rofl2)

Did you ever consider that Mazda didn't want to compete too vigorously with the competition or that Mazda allocated all their inexperienced engineers to developing Skyactiv? (rofl2)

Dude. If Mazda left anything on the table it was so that the LeMans version of the CX5 homologation effort wouldn't be the exact same as the one you buy at the Mazda dealer. You know, like they used to do with restrictor plates to "run in class" back in the day. They put an electronic "restrictor plate" in the CX5 so that the NHTSA would approve it for sales. Otherwise, no-go. Hardcore unbridled racing machines have no place on our streets! Mazda caved, and installed the "restrictor".

 

[Unobtanium]

Well if you did some research you'd realize that is not the case. Mazda has very specific placement of the intake valves to keep them hot (over 400*). They are "deep" into the cylinder head and port. This helps prevent the carbon build up mostly. Along with some cam timing in low load. Low load. Too bad it's already been shown on bone stock vehicles the build up still happens.


Chris_Top_her has had our tune on his CX5 since it practically left the lot, and it's not only doing just fine it's about to be turbocharged...

What is "low load"? Idling in traffic? Freeway at 70 on flat land?

 

[Unobtanium]

Yeah I definitely agree with you. I think it's the case for all car manufactures. Whether it's for safety reasons for the engine to maintain longevity, fuel efficiency, optimal engine output for the variety of environments the car may run in(-20 degrees F all the way up to the low 100s). But being that the skyactive engine is relatively new, who really knows. Just have to trust Mazda's set numbers. That's why there is no way I would go throwing a tune on my CX-5. IMO there is no point with the risks associated for slight gain. The tune isn't going to turn it into some fast car, therefore imo it is not worth the risks associated. Not like other sports cars where the engines are built for performance. I threw a tune on my mustang with ease of mine because I knew that engine is built to be pushed hard.

I dunno about that...what year mustang?

I honestly think the CX-5's motor is a brick s*** house. Physically speaking, it should be PLENTY able to handle anything you can throw at it naturally aspirated, aside from copious amounts of detonation.

 

[jhu8]

I dunno about that...what year mustang?

I honestly think the CX-5's motor is a brick s*** house. Physically speaking, it should be PLENTY able to handle anything you can throw at it naturally aspirated, aside from copious amounts of detonation.

08 GT..Yeah I'm sure the CX5 would be able to handle it, especially the 16s with the forged internals. What I'm saying is clearly a V8 block meant to take 300hp is more willing and accepting to take abuse than a 4banger in a small suv.

 

[Unobtanium]

08 GT..Yeah I'm sure the CX5 would be able to handle it, especially the 16s with the forged internals. What I'm saying is clearly a V8 block meant to take 300hp is more willing and accepting to take abuse than a 4banger in a small suv.

I don't think the block has ever been the problem. The last blocks I heard of having issues were 5.0L Mustang blocks from the 90's. A main girdle past 450hp was a good idea. The super rigid aluminum blocks in today's motors are not an issue at any power level you can achieve N/A (nor were those 302's, really...).

The weak spot in the '08 GT was the heads, regarding flow rates. Here is the flow-bench data:

It's only flowing 10cfm over stock on the exhaust port compared to a 1999 Mustang GT. Intake side is better of course, with the 2 valves. Similar to a 1997 Cobra.

Here is a stock 1.6L (older) Miata headflow dataset


Stock 1.6, stock intake manifold, stock exhaust. Measured at 28" average.

Intake Exhaust
.050 37 35
.100 67.8 63.7
.20 128 118.5
.25 146 137
.30 160 147
.35 166 152
.40 169 154
.45 172 156

Still working on finding CX-5 data.

 

[Lbear]

I own one of the early 2013 2.0L CX-5's (built in 2012). Every North American CX-5 had the 4-2-1 Skyactiv exhaust header. Was there some early release version (perhaps sold in Asia) without the Skyactiv header? Not that I've ever heard about.

The 2012 Mazda 3 had a 12:1 CR and old style exhaust manifold because engineers couldn't fit the 4-2-1 header into the old body style since the engine bay wouldn't fit it.

 

[CC58]

I had a 2001 WS.6, and the clutch was certainly not doing any slipping when I got on it hard. If yours was...it were broked! The rear-end was a factory 3.42, at the "biggest", and a 2.73 for some of the autos. The engine was also not "strangled", and I ran with plenty of C5 corvettes. Every dyno I have seen places them within 10whp, with the F-body usually having more due to less parasitic losses to the driveline. Since some people here don't trust dyno's though, the track backed it up on Saturday night often enough. As did the street.

They DID, however, restrict the hydraulic fluid flow through the clutch hydraulics in an effort to dampen shock on the system on more violent shifts.

If you every tried to aggressively launch with four people in the car, it would smoke the clutch. With just the driver, it wasn't a problem. The lid and catback were well known cures for hp bottle necks. I could outrun automatic corvettes.

The stock suspension rolled like a boat in a storm. First thing I did was replace entire front end; SS springs, Bilstein struts, bigger sway bar. After that it rode like it was on rails. Leaving original soft springs in back helped it to launch better.

 

[CC58]

All CX-5's have the Skyactiv 4-2-1 header. In fact, the CX-5 was the first Mazda with the complete suite of Skyactiv technologies (chassis, engine (including header), transmission).

I remember the skyactiv 2.0 engine came out before the skyactiv bodies.
They couldn't fit the 4-2-1 exhaust, so they had to drop the compression.

 

[MikeM.]

I honestly think the CX-5's motor is a brick s*** house. Physically speaking, it should be PLENTY able to handle anything you can throw at it naturally aspirated, aside from copious amounts of detonation.

A properly running stock CX-5 with fuel that meets spec does not have copious (or ANY) amounts of detonation! It's only when you load aftermarket tunes, have bad fuel or some other issue with your engine that this starts happening. This misconception stems from an erroneous interpretation of a PID/data item by certain tuners called "knockr" which is an ignition retard command to prevent detonation under certain well defined conditions. The fact that the engine goes into the "knockr" zone on a regular basis does not indicate detonation occurred! "knockr" (standing for knock retard) exists to PREVENT knock from occurring, not because it already happened. This is in direct contrast to error codes P0327 and P0328. If your CX-5 has detected knock, these error codes will be loaded into memory and available with any OBD II compliant code reader. Your check engine light will also illuminate and a fail-safe mode that reduces engine output will be loaded.

Filling your tank with 85 octane might cause knocking and the check engine light to come on. It will not cause the engine to go into "knockr" protective mode any more often because your engine does not know what kind of fuel you have in terms of octane. It is well known that aftermarket tunes can cause knocking and the engine can throw error codes and go into failsafe mode which reduces performance. If this ever happens on a stock engine there is a good chance you have a sensor that has drifted out of range, bad fuel or a more serious issue.

 

[MikeM.]

I remember the skyactiv 2.0 engine came out before the skyactiv bodies.
They couldn't fit the 4-2-1 exhaust, so they had to drop the compression.

Exactly! The Mazda 3 came out first with the Skyactiv engine with reduced compression and no Skyactiv header (wouldn't fit). All CX-5's have the Skyactiv header.

The amount of misinformation spread by people who don't have a clue what they are talking about is disconcerting.

 

[piotrek91]

The fact that the engine goes into the "knockr" zone on a regular basis does not indicate detonation occurred! "knockr" (standing for knock retard) exists to PREVENT knock from occurring, not because it already happened. This is in direct contrast to error codes P0327 and P0328. If your CX-5 has detected knock, these error codes will be loaded into memory and available with any OBD II compliant code reader. Your check engine light will also illuminate and a fail-safe mode that reduces engine output will be loaded.

No.
Lets look up the codes.
P0327:

P0328:

The amount of misinformation spread by people who don't have a clue what they are talking about is disconcerting.

it is indeed.
I know you can't accept the fact that many CX-5 owners notice a small improvement in torque and engine smoothness when running 91 octane, but please stop making stuff up to explain your incorrect theory.

 

[Tbot101]

A properly running stock CX-5 with fuel that meets spec does not have copious (or ANY) amounts of detonation! It's only when you load aftermarket tunes, have bad fuel or some other issue with your engine that this starts happening. This misconception stems from an erroneous interpretation of a PID/data item by certain tuners called "knockr" which is an ignition retard command to prevent detonation under certain well defined conditions. The fact that the engine goes into the "knockr" zone on a regular basis does not indicate detonation occurred! "knockr" (standing for knock retard) exists to PREVENT knock from occurring, not because it already happened. This is in direct contrast to error codes P0327 and P0328. If your CX-5 has detected knock, these error codes will be loaded into memory and available with any OBD II compliant code reader. Your check engine light will also illuminate and a fail-safe mode that reduces engine output will be loaded.

Filling your tank with 85 octane might cause knocking and the check engine light to come on. It will not cause the engine to go into "knockr" protective mode any more often because your engine does not know what kind of fuel you have in terms of octane. It is well known that aftermarket tunes can cause knocking and the engine can throw error codes and go into failsafe mode which reduces performance. If this ever happens on a stock engine there is a good chance you have a sensor that has drifted out of range, bad fuel or a more serious issue.

A properly running CX5 does not have ANY detonation? REALLY?

uhh nope, that's not how the KCS or knock retard system works. also you don't get error codes when knock occurs. where they hell did you get that?? LOL check engine light will illuminate and fail safe mode all from knock retard huh??

LOL. Man where the hell do you come up with this bulls***.

let me help you understand with one word:

wrong. wrong. wrong. wrong. wrong

 

[MikeM.]

wrong. wrong. wrong. wrong. wrong

Well, I have to admit, that is some pretty strong evidence that I'm wrong. Maybe if you throw in a couple more "wrong"s, you'll have me convinced 100% !!

 

[Tbot101]

The amount of misinformation spread by people who don't have a clue what they are talking about is disconcerting.

*hands you a mirror*

 

[MikeM.]

No.
Lets look up the codes.
P0327:

P0328:

it is indeed.
I know you can't accept the fact that many CX-5 owners notice a small improvement in torque and engine smoothness when running 91 octane, but please stop making stuff up to explain your incorrect theory.

Those are the error codes for a knock sensor returning values out of range, so I used the wrong DTC error code # there. The engine uses a two stage strategy to prevent detonation:

1) It measures load on the engine by measuring the difference in the air mass vs. the theoretical maximum. Using the MAF sensor takes into account the barometric pressure, dirty air filter, temperature and any other factor that can affect air mass. Because detonation will happen at a lower engine load under hotter conditions, it also adjusts the knockr value based upon intake air temperature. The over-all knockr correction factor is enough to prevent detonation in most conditions assuming a stock engine and suitable fuel.

2) The knock sensor continuously monitors engine vibration. The more vibration the sensor detects, the higher the voltage it returns. Because it outputs a small voltage even before damaging knock happens, it can add a correction factor (if necessary) to the knockr value to insure detonation never happens. But if it doesn't sense impending detonation, the engine management system will not constantly advance the timing above what strategy #1 (above) allows. Thus, in normal operation, the knock sensor never comes into play. The engine is tuned for 87 octane. That is why running 91 octane (or 95 octane for that matter) will result in slightly smoother operation but it will not make any more power (actually, it will make slightly less). If the engine automatically advanced the timing because you had high octane fuel, then the smoothness wouldn't increase (because it would advance the timing to the stage just before knock) however, it would make more power. Both times I've filled an almost completely empty tank with premium, it was slightly detrimental (in terms of power and MPG).

Yesterday I filled my 2013 2.0L CX-5 with 13.9 gallons of 92 Octane Union 76 Premium. Within a mile I noticed the engine had smoother power pulses. As I continued driving I noticed that hills I could previously pull in 6th gear required a downshift to 5th even though I was hitting them at speeds it would normally pull in 6th. I noticed this on several shallow grades I've taken in 6th gear numerous times before. The engine was a little smoother but each power pulse was weaker. I tried maximum acceleration from 0-60. The smoothness I noted at lower rpm's was not as apparent at high rpm's but the car was not quite as peppy. I reset the MPG meter and tried to get the best MPG I could on a 30 mile cruise that should yield above 33 mpg. The best I could muster was mid 32's even though it was a warm day. So both power and MPG took a small but perceptible hit.

92 octane just doesn't have the punch of 87 octane in the 2.0L CX-5. BTW, I'm not making any of this up, I'm reporting my honest observations.

 

[Tbot101]

Those are the error codes for a knock sensor returning values out of range, so I used the wrong DTC error code # there. The engine uses a two stage strategy to prevent detonation:

1) It measures load on the engine by measuring the difference in the air mass vs. the theoretical maximum. Using the MAF sensor takes into account the barometric pressure, dirty air filter, temperature and any other factor that can affect air mass. Because detonation will happen at a lower engine load under hotter conditions, it also adjusts the knockr value based upon intake air temperature. The over-all knockr correction factor is enough to prevent detonation in most conditions assuming a stock engine and suitable fuel.

2) The knock sensor continuously monitors engine vibration. The more vibration the sensor detects, the higher the voltage it returns. Because it outputs a small voltage even before damaging knock happens, it can add a correction factor (if necessary) to the knockr value to insure detonation never happens. But if it doesn't sense impending detonation, the engine management system will not constantly advance the timing above what strategy #1 (above) allows. Thus, in normal operation, the knock sensor never comes into play.

I highlighted everything in color that is absolutely wrong. Sorry dude, but you are totally incorrect. Please reply to my post showing actual data from the car.
Impending detonation......................... Tell us how this works please
Theoretical maximum?? Explain
Compensates knockr from intake temperature huh? REALLY......................... Please tell us how it does that
in normal operation the knock sensor never comes into play?? REALLY ?????? interesting and wrong.

it can add a correction factor to the knockr value (something that does not even exist in the ecu) to ensure detonation does not happen ( wrong ).

Knock sensors are tuned to monitor certain frequencies only. not just any vibrations......... god dude you are so freaking wrong I want to jump off a cliff.



"all over knockr factor" WTF are you even talking about? You are just making s*** up now.

WTF is this "knockr" value you created out of thin air?


Do you actually know how the skyactiv knock control works or are you just copying s*** off of google from a totally separate car, because that is what it looks like, while adding in your own imagination (quite a bit here lol).

Just incase you skip it:

Well, I have to admit, that is some pretty strong evidence that I'm wrong. Maybe if you throw in a couple more "wrong"s, you'll have me convinced 100% !!

Oh I am 100000000000% sure you are as wrong as someone can possibly be.

Please show me the documentation (google) where you deduced the check engine light will come on when the car experiences knock retard? While you're at it why don't you go into a bit more detail about these "knockr" "ZONES" that you are talking about.

how about explain to all of us how the KCS, knock retard system works? How many tiers are there to in and what is it's FIRST line of "defense' for knock retard? How does the engine predict pre-ignition? How about how it dynamically calculates low level knock retard so low the knock sensor cannot "hear" it.

Please explain oh expert. (by the way you're totally wrong lol)

I can show you data-logs of knock retard, and the different ways the ECU checks and adapts. Guess what, the check engine light does not come on.

Check this out, and while you're at it explain to us all what is going on in this log. please

Please explain for us all what you're seeing in this log. What is the negative value? The positive value? Why would there be positive "retard" ?
Why is the knock always happening in the higher RPM?
How much degrees of ignition does it remove for 2* of KR?
Please enlighten us! (watch he wont even respond. or he will come back with some witty response that has nothing to do with this)
How many times did the check engine light come on with this car? this is a skyactiv 2.5L, from your expert knowledge please deduce from this log how many times the check engine light illuminated

The amount of misinformation spread by people who don't have a clue what they are talking about is disconcerting.

*hands you a mirror*

 

[Lbear]

I know you can't accept the fact that many CX-5 owners notice a small improvement in torque and engine smoothness when running 91 octane, but please stop making stuff up to explain your incorrect theory.

Thank you for clarifying this. I firmly believe from what I have read, what you and others posted, that running 91+ octane in the SkyActiv engine will produce a smoother engine and it will make more peak HP/Torque levels. Especially when under load and climbing grades. I run 91 octane in my CX5 and overall the engine runs better. I climb a lot of grades and the engine is under load quite a bit.

With such a high compression ratio 13:1 (the highest of any production vehicle in the US market), there is no way that the engine will not pull timing when running 87 octane and under heavy loads. As summer roles up the odds of the SkyActiv engine detuning itself is high due to the higher outside temps and the vehicle under heavy loads. Detonation is a constant issue with low octane gas and high compression. The engine design and header helps to reduce detonation but there is no way that the SkyActiv engine is running peak HP/Torque when running 87 octane and under heavy loads/climbing grades/towing/hot temperatures.

 

[Lbear]

Please enlighten us! (watch he wont even respond. or he will come back with some witty response that has nothing to do with this)
How many times did the check engine light come on with this car? this is a skyactiv 2.5L, from your expert knowledge please deduce from this log how many times the check engine light illuminated

I bet the check engine light NEVER came on and the computer pulled serious timing numerous times to prevent detonation.

Am I right?

 

[NelsonLewis]

I bet the check engine light NEVER came on and the computer pulled serious timing numerous times to prevent detonation.

Am I right?

Gotta be part of it for sure...