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- RDX Aspec Adv.
My concern is that Mazda obviously knew this could/would be do-able, and chose not to. Why? What are you giving up by doing it? My concern, primarily, is carbon build up, or melting a valve, or whatever.
CX-9 Skyactiv 2.5L turbo engine
- Thread starter CC58
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My concern is that Mazda obviously knew this could/would be do-able, and chose not to. Why? What are you giving up by doing it? My concern, primarily, is carbon build up, or melting a valve, or whatever.
You're the only one who called me an "expert", which I'm not and have never claimed to be. I'm just talking really elementary power mechanics here, stuff that most car/engine enthusiasts would have learned back in the '70's. You're the one that called me an "expert". Nice diversion from the subject matter though.
It seems I threaten you somehow or you wouldn't attack the person.
I dunno about that. Here is a dyno from a VQ37 like in my 370Z. It does not have variable intake runners. It is a lot more complex motor than the SkyActiv, though, with a lot more processing going on, IMO
You don't know about what? I didn't say anything controversial. Sometimes I think you just like to argue.
Your dyno chart shows a fall-off in volumetric efficiency becoming really apparent around 6250 rpm's and continuing to redline. That's what a variable intake geometry could improve. But, yeah, extra complexity and expense.
That^. Sure, maybe Mazda didn't optimize the design for the way somebody reading here wants to drive. But there were reasons most of us can't even dream about for some of the design decisions. It's only by crossing lines they didn't cross that we'll find out about these things. And has Unobtanium has often said, the CX-5 is NOT a racing machine - it's an everyday driver. And I suspect Mazda has optimized the design for just that. If you want a faster, more powerful car, best to buy one.
No you don't threaten me, I get a laugh out of your posts.
What I meant was some people like to see actual data rather than just take your word for it. YOu're talking elementary power mechanics here....so how exactly did you devise that the engine is setup for low end power? did you measure the intake ports, the throttle body, the intake manifold ? How EXACTLY did you figure it out or are you ripping off my information too??
By the way what is the flow limiter on the engine? let me help you, pick one:
intake > throttlebody > intake manifold > intake ports > intake valve size > exhaust valve size > exhaust ports > exhaust manifold.
Now what, I am 100% certain you will DODGE this question.
For giggles... Clients 2.5L MZR Sedan with some boost. this is on LOW boost ^_^ we are turning the boost up on the next tune.
https://www.youtube.com/watch?v=WxK4skGeCBk&feature=youtu.be
https://www.youtube.com/watch?v=WxK4skGeCBk&feature=youtu.be
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- RDX Aspec Adv.
OVT increases performance across the entire RPM range. My concern is...why didn't Mazda? 25hp is a LOT to "leave on the table" without a good reason, and these engines are not something that Mazda cobbled together from several platforms and pitched out the door. They were purpose-made, and very thoroughly designed. This is my concern with the OVT tune. I believe them when they say it hits their numbers. My question is...is 91 octane the only "cost"?
That is very easy to answer. Because Mazda designed the tune to run on s*** gas. 87 octane. They did this to make it as cheap as possible for the consumer.
the MX5 ND has the 2.0L, just like the mazda 3. But mazda designed that for 91 octane, guess which engine puts more to the ground
?You get more power out of it simply by "taking off the brakes" that mazda put on the tune so that it would run grocery getter gas
The European CX-5 2L makes 165HP vs 155HP with premium fuel and an increase in compression ratio from 13:1 to 14:1.
I find it hard to believe 25HP gain with same compression ratio and without ill-effects.
Also, both Mazda 3 and MX-5 have the same 155HP (at flywheel) 2L engine. The 3 gets max 150 lbft at 4000 vs 148 at 4600 in the MX-5. Not sure why there is a difference. However, all a tune could possibly do is to increase HP at the flywheel, as transmission losses will not change. Perhaps the MX-5 has less transmission losses?
I too believe that Mazda maximized efficiency of its engine by carefully engineering all components, such that tolerance margins are ever so slim, not what they used to be on older engines. If they could shave it even more to increase efficiency, without impacting reliability, they would have. That is why I think that eating more into these margins will impact reliability in long to medium term.
I find it hard to believe 25HP gain with same compression ratio and without ill-effects.
Also, both Mazda 3 and MX-5 have the same 155HP (at flywheel) 2L engine. The 3 gets max 150 lbft at 4000 vs 148 at 4600 in the MX-5. Not sure why there is a difference. However, all a tune could possibly do is to increase HP at the flywheel, as transmission losses will not change. Perhaps the MX-5 has less transmission losses?
I too believe that Mazda maximized efficiency of its engine by carefully engineering all components, such that tolerance margins are ever so slim, not what they used to be on older engines. If they could shave it even more to increase efficiency, without impacting reliability, they would have. That is why I think that eating more into these margins will impact reliability in long to medium term.
I could take pictures of the maps and show you where mazda Detuned certain areas. They actually ramped the VVT back up right at 6000 RPM but cut it off everywhere below except where it makes max torque. The mazda 3 2.0L does not put 150 ft lbs down on any dyno stock. You have to stop looking at the rated numbers and look at REAL WORLD numbers.
Look guys I could care less if you believe me or not, I have been tuning these engines for years, We just had our turbo skyactiv sedan at the track last night.
Believe whatever the hell you want.
Mazda has a 165 version and 120 version in the EU. Exact same engine. You think Mazda detuned one of them to 120 for safety reasons?...... I bet you don't even know what is limited in the tune that stops it from making 165...
Think about this for a moment. These engines have some of the highest compression ratios on the market, lightweight components. 14:1 compression for christ sake you and REALLY DON'T BELIEVE YOU CAN GET MORE POWER?? The Honda K20 makes over 230 WHP with bolt ons and 11:1 compression, without direct injection (which allows for more aggressive yet safe tuning).
14:1 compression ran on 87 octane. Mazda detuned the hell out of these engines. I'm really sorry to say this but you'd have to be pretty damn dumb or clueless to think they are near their potential on 87 OCTANE!!!
By the way, the difference in the tune with the US vs EU market ones aint much.
Now once again, I have tuned these engines for years, so I think I just might have a bit more understanding on these than what you can read on google. And I say that because i'm 99.99% certain none of you have put one on an engine dyno, torn it down and measured the specs, weighed the components, flowed the head, etc.
Unless some of you have? Please share.
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I think many of us are not experts in engine technology. Perhaps you are right, only that I did not read compelling arguments yet.
150HP flywheel, I believe. You have to account for transmission losses (which cannot be tuned through software). The Skyactiv 2L is shared between CX-5, 3 and MX-5.
150HP flywheel, I believe. You have to account for transmission losses (which cannot be tuned through software). The Skyactiv 2L is shared between CX-5, 3 and MX-5.
The MX-5 2.0L has one key hardware difference. and I'm positive nobody here even knows what it is.
I have already concluded there is no compelling argument with this place.
Like I said, question me, don't believe me, I don't care. Show me one other 2.0L skyactiv tuned on the stock ECU anywhere in the world. please. You think something like that is an easy feat? No, it takes in-depth knowledge and understanding of the logic and processes of these ECUs and how these engines work.
C
CX5_Pete
I would like to see this. We are all here to learn and get info.
The k20 makes 230 WHEEL HORSEPOWER with just bolt ons???? I call BS.
I could say the same thing about you.
I think we would all appreciate it if you shared this key difference with us.
K20 will definitely put that down with full bolt ons and tune, sorry for not clarifying.
Why should I share any info or maps? I have been nothing but scrutinized, everything I say questioned scrutinized, been called a liar, theif, snake oil sells man. So while I could share that info, I havent been compelled to do so, especially not by the atittude of folks here.
You guys like to shoot the messenger first then ask what the message is huh
Why should I share any info or maps? I have been nothing but scrutinized, everything I say questioned scrutinized, been called a liar, theif, snake oil sells man. So while I could share that info, I havent been compelled to do so, especially not by the atittude of folks here.
You guys like to shoot the messenger first then ask what the message is huh
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NelsonLewis
Banned
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- 16.5 CX-5 GT AWD w/Tech BRMica
Great post...and YES, The K20 can make that power, and the K24 can make about 15hp more. Bad little mama jamma's...
You're right, these guys just won't get it no matter what you provide. No worries, I too have seen this with my own eyes...keep on keepin' on with the mad science...
Cam's! (And tuning!)
I believe you. Guys who reverse engineer stuff know what they are doing. That is how a lot of new products and ideas are created.
Mazda seriously detuned these engines to run safely on 87 octane. That is no doubt.
I run 91+ octane in my 2.5L CX5 because it seems to run better when climbing grades under load. Maybe it's anecdotal but I believe the engine runs stronger when I use 91+ octane in it. I believe on 87 octane it would pull back timing when climbing grades to prevent detonation.
Thank you.
These engines do benefit some from running 91 even with stock tune. It won't be any massive change in power, but it allows the KCS system to run full time without additional trimming, which allows for more ignition, which allows for smoother torque output, considering stock ignition on the 2.5L w/ 87 octane goes into negative (ignition retard) in low rpm and high load. which really kills power
mazdadude
ZOOOOOOOOOM ZOOOOOOOOOM
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- '16.5 Mazda CX-5 Touring
Yes!
