Torque curves for 2.5L Mazda engines
- Thread starter erhayes
- Start date
rockethead26
2019 CX-5 Reserve
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- N. Arizona @ 7000'
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- San Antonio, Texas
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- '15 CX-5 Miata AWD
The bottomline is like the OEM curve on on the 2.5NA, and the top is a good tune.
Not exactly the same car but here is one I could find: http://kandn.com/dynocharts/69-6032_dyno.pdf. Blue line is stock and red line is with K&N cold air intake on a mazda 6 2014.
What are you looking to find with the comparison ?
What are you looking to find with the comparison ?
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- Central Virginia
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- 2019 CX-5 Reserve
I can't wait for my warranty to expire so I can drop $500 to go Zoom-Zoom.
I'm actually surprised the torque curves are the same at low rpm for either fuel.
Based on my experience, high load at low rpm (r.e. turbo) is more prone to detonation than high load high rpm.
If I remember right, torque peak is where you need to be most cautious regarding detonation, so typically timing is reduced the most at peak torque. If that's the case, it seems like the high octane could benefit in low rpm in addition to the high rpm.
Based on my experience, high load at low rpm (r.e. turbo) is more prone to detonation than high load high rpm.
If I remember right, torque peak is where you need to be most cautious regarding detonation, so typically timing is reduced the most at peak torque. If that's the case, it seems like the high octane could benefit in low rpm in addition to the high rpm.
I tought this was the big “breakthrough” with this turbo engine. The fact that it didn’t need higher octane to produce the same high torque at low RPM.
You are right with regards to detonation, but i think there are too many factors in play between different engines to apply a one rule fits all principle to knocking. Knocking is ultimately based on heat, and these engines have a lot of heat management solutions in place to attempt to prevent it (exhaust scavenging, cooled EGR, etc). It is possible that these solutions allow the engine to run at peak torque without having to rely on high octane fuel, but that they aren’t as effective at high RPM. This is all speculation on my behalf of course, but that’s how I see it unless we can get an actual Mazda engineer to dig into the details for us.
good info here if you are interested, although very similar to the youtube video above.https://www.wardsauto.com/engines/mazda-s-innovative-4-cyl-engine-pulls-big-v-6
You are right with regards to detonation, but i think there are too many factors in play between different engines to apply a one rule fits all principle to knocking. Knocking is ultimately based on heat, and these engines have a lot of heat management solutions in place to attempt to prevent it (exhaust scavenging, cooled EGR, etc). It is possible that these solutions allow the engine to run at peak torque without having to rely on high octane fuel, but that they aren’t as effective at high RPM. This is all speculation on my behalf of course, but that’s how I see it unless we can get an actual Mazda engineer to dig into the details for us.
good info here if you are interested, although very similar to the youtube video above.https://www.wardsauto.com/engines/mazda-s-innovative-4-cyl-engine-pulls-big-v-6
Seems reasonable. I'm sure direct injection has something to do with it.
Spraying fuel into the cylinder near TDC of compression stroke?
Compared to port injection where the fuel is sprayed ~during intake stroke and no fuel enters after intake valve closes for compression stroke.
And high rpm could be due to injector pulse width vs. rpm. You have less time to get more fuel into the cylinder, so you have to start injecting fuel earlier during compression stroke.
Again, just blabbering about what I think is happening. I'm lucky that the engine tuning that I do is on my 89 5.0 Mustang, which is relatively simple.
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- CX-5 Signature
We're picking up the wife's '20 CX-5 Signature on Monday and I was quite impressed with the torque this 2.5T has. Since this car takes 87 or 93 (94 up here in Canada), I'm really curious about how the ECU retards or advances timing in these engines. I'm completely new to Mazda and their engines but have some experience tuning Subarus. We have tuning parameters in the ECU such as feedback knock correction, fine learning knock correction, and the ignition advance multiplier (IAM or sometimes called DAM). Does the Mazda ECU use a similar approach?
Looking at that dyno chart above, it appears that the engine is tuned below 4000 rpm to assume 87 octane, where the engine is most likely to spend the majority of its time. It's not until 4200 rpm that the octane differences become noticeable. This makes me wonder if the engine is mostly tuned for 87, even when running 94, and at the higher RPMs the dynamic ignition advance / knock detection does its thing.
That dyno chart does make me wonder about a few things:
- Does 89 or 91 octane give you a little bit more power? What about 94?
- Given the 2020 CX-5 makes 10lb-ft more torque on 93+ vs 87, I have to wonder how conservative the ignition timing is and if, for engine longevity, they've left some untapped potential. The top-end is likely a function of the size of the turbo, heads, etc, so probably not a lot more to get out of it.
- Does the car allow you to rev out to ~6000 rpm when in manual shifting mode? I never tried it during the test drive. If no, then once the ECU learns to advance the ignition timing when running 94, is it smart enough to increase the shift point? The default programming seems to shift around ~5200 rpm and those extra 800 rpm might result in a bit better 0-60 times and overall quicker acceleration. Obviously, this vehicle isn't meant to be a rocket, but it seems that 3rd shift to get to 60 hurts the acceleration a bit.
This is all just curiosity though as with this being my wife's daily driver, there are strict rules about touching the programming.
BTW Does anyone know of good tuning resources for these cars? Just curious to read a bit more about these 2.5T engines.
Looking at that dyno chart above, it appears that the engine is tuned below 4000 rpm to assume 87 octane, where the engine is most likely to spend the majority of its time. It's not until 4200 rpm that the octane differences become noticeable. This makes me wonder if the engine is mostly tuned for 87, even when running 94, and at the higher RPMs the dynamic ignition advance / knock detection does its thing.
That dyno chart does make me wonder about a few things:
- Does 89 or 91 octane give you a little bit more power? What about 94?
- Given the 2020 CX-5 makes 10lb-ft more torque on 93+ vs 87, I have to wonder how conservative the ignition timing is and if, for engine longevity, they've left some untapped potential. The top-end is likely a function of the size of the turbo, heads, etc, so probably not a lot more to get out of it.
- Does the car allow you to rev out to ~6000 rpm when in manual shifting mode? I never tried it during the test drive. If no, then once the ECU learns to advance the ignition timing when running 94, is it smart enough to increase the shift point? The default programming seems to shift around ~5200 rpm and those extra 800 rpm might result in a bit better 0-60 times and overall quicker acceleration. Obviously, this vehicle isn't meant to be a rocket, but it seems that 3rd shift to get to 60 hurts the acceleration a bit.
This is all just curiosity though as with this being my wife's daily driver, there are strict rules about touching the programming.
BTW Does anyone know of good tuning resources for these cars? Just curious to read a bit more about these 2.5T engines.
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- '22 X3 M40i
It's been quiet since the start of the pandemic, but DRTuned was looking into it on your side of the boarder, as is Burger Tuning in Southern California. Both are still a ways off from what I understand. I spoke with Burger and they're looking for a 2.5t equipped customer car to do a few full throttle runs and some data logging. Assuming I get a CX-5 turbo, I may buy it in CA and loan it to them for a couple days.
Otherwise there is zero info out there on 2.5t tunes.
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- RDX Aspec Adv.
The only engine tuning you do on a mass airflow 5.0 is tweaking the fpr, lol
Unless you have a chip and tuning software like I do.
Without the chip, you can also bump up the timing and run 92+ octane. That was one of the very common free mods for the old Foxbodies.
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- RDX Aspec Adv.
I've never heard of a dyno tune doing more than about 5-8whp on even heavily modded fox's until you get into turbo/SC.Unless you have a chip and tuning software like I do.
Without the chip, you can also bump up the timing and run 92+ octane. That was one of the very common free mods for the old Foxbodies.
You're definitely right on that. Just bumping the base timing was worth about 5whp. There wasn't much more than that on a stock engine.
Heads/cam/intake can benefit from a dyno tune as well.
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- RDX Aspec Adv.
H/C/I really won't gain much from a tune on that car. They were amazingly adaptable. I ran a huge cam and bumped compression ratio, 24# injectors, etc. and it ran great. No tune. Other than timing and FPR, you just don't tune those cars. Here is an article:
With regular fuel in manual mode the rpm cut off is at 6000rpm on my 2018 cx-9. The manual mode won’t shift for you, you can stay on the cut-off for as long as you want. Don’t know if that 6000 rpm limit is increased with better fuel, but honestly there isn’t much to gain at higher rpm with this engine, all the good stuff is down low in the rev range.
Good gains and I bet there's still additional power available with a tune. Only way to know is to get the tune.
Hell, I drove my 5.0 with HCI and supercharger for years before I got a tune. Ran a best of 12.4 @ 118mph. Never dyoned before the tune. After tuning, put down 437rwhp...but haven't been back to the track so unfortunately I don't have any before/after data. It does get 25+mpg on the highway.
Here's another link with some comments about additional power with a tune on HCI combo.
https://www.stangnet.com/mustang-forums/threads/so-hci-how-importantcis-tune.869847/
"It really all depends on the exact combination but I have found 15 to 40 horsepower tuning a na car. The more radical a combo the more I find I get with a tune"
Anyway, we're getting off topic. I bet the CX5 turbo engine could gain a bit from a tune. Seems like many modern engines are tuned conservatively these days.
