Turbo and NA - Let's love them both

[sm1ke]

As far as I know, there is no kickdown "switch". The entire thing is drive by wire with "kickdown" determined by load and pedal position. There is a detent at some point but it is neither on the floor nor is it a kickdown. It's for driver feedback only.

Yep, press the accelerator to the "floor", then push it a bit harder and there's the detent. On drive-by-wire cars you can do this with the engine off to see what the detent feels like, without having to waste gas or get onto a main road where it's safe to accelerate to WOT. As you said, the detent does nothing but let the driver know that the pedal isn't going to go any further.

 

[Lazy2.5]

Yep, press the accelerator to the "floor", then push it a bit harder and there's the detent. On drive-by-wire cars you can do this with the engine off to see what the detent feels like, without having to waste gas or get onto a main road where it's safe to accelerate to WOT. As you said, the detent does nothing but let the driver know that the pedal isn't going to go any further.

In my experience, the transmission will downshift into the lowest allowable gear and upshift at redline. Is it simply because the pedal is all the way down, or does it send some sort of signal to the transmission as well?

Because, although the throttle position is obviously open wider with the detent switch pressed, the electronic throttle body doesn't actually open any wider with the detent switch clicked or otherwise.

And, if you click it, and then release, it will still shift at redline. So i'm pretty sure clicking it does do something.

 

[sm1ke]

In my experience, the transmission will downshift into the lowest allowable gear and upshift at redline. Is it simply because the pedal is all the way down, or does it send some sort of signal to the transmission as well?

Because, although the throttle position is obviously open wider with the detent switch pressed, the electronic throttle body doesn't actually open any wider with the detent switch clicked or otherwise.

And, if you click it, and then release, it will still shift at redline. So i'm pretty sure clicking it does do something.

I've tried it with my CX-9. In my experience, pushing the pedal to the floor and pushing the pedal "through" the floor achieves the same result. The kickdown detent (and the throttle position past that point) are just for driver feedback, as far as I can tell.

 

[Mazdahawk72]

Although 0-60 seems to be the accepted benchmark, in my opinion, 40-70 or even 50-80 are far more important. My 2021 NA CX-5 is quite adequate in those scenarios. I came to my CX-5 from SAABs. They were not great 0-60 either, but they were the most comfortable cars to pass other vehicles on 2-lane country roads. The caveat however is that they were turbocharged. SAAB however used small turbos that spooled up quick and delivered an extremely flat torque curve from about 1500 rpm on. They were not high revvers, but much more usable power and torque in real world situations. And 3rd gear pulls up on ramps were amazing. I feel like Mazda looks at things in a similar fashion. The 2.5T would be very SAABish. My 2.5 NA seems to have reasonably flat torque curve well. For me, it isn’t quite as fast as my 2007 SAAB 9-3, but I find it to be quite fun to drive. Just my 2-3 cents.

 

[7eregrine]

As you said, the detent does nothing but let the driver know that the pedal isn't going to go any further.

That is KICKDOWN. From the 2022 CX5 Manual. So unless somethings changed...since 2022, Y'all have kickdown.

 

[sm1ke]

That is KICKDOWN. From the 2022 CX5 Manual. So unless somethings changed...since 2022, Y'all have kickdown.

No one is arguing that we have kickdown or not. We're talking about the switch/detent, which does nothing but provide feedback that the pedal will not go any further.

As far as I know, there is no kickdown "switch". The entire thing is drive by wire with "kickdown" determined by load and pedal position.

 

[7eregrine]

As you said, the detent does nothing but let the driver know that the pedal isn't going to go any further.

That sounds to me like you are saying there is no kickdown.
Happy to be wrong...we can move on. lol

 

[DoubleCH]

No one is arguing that we have kickdown or not. We're talking about the switch/detent, which does nothing but provide feedback that the pedal will not go any further.

According to this... Youtube when you're in manual mode (gearshift to the left) and hit gas pedal just before the "kickdown" switch, it will keep you in gear (even if it hovers just below rev-limiter, good for auto-crossing when you do NOT want it to upshift). But, if you click the switch it will upshift.

 

[N7turbo]

According to this... Youtube when you're in manual mode (gearshift to the left) and hit gas pedal just before the "kickdown" switch, it will keep you in gear (even if it hovers just below rev-limiter, good for auto-crossing when you do NOT want it to upshift). But, if you click the switch it will upshift.

Will have to test this when no one's with me.

 

[sm1ke]

Will have to test this when no one's with me.

I tested it yesterday with my 2018 CX-9, it does work. In manual mode, Sport mode off, cruising along in 4th, I pressed the pedal all the way, right up to the detent. RPM steadily climbed as expected, car stayed in 4th. I pressed through the detent at about 4300 RPM and the RPMs spiked. I forgot to check if the transmission downshifted, but the RPMs spiked right away and kind of took me by surprise because I wasn't expecting anything lol.

This post by @Lazy2.5 from November provides some useful info:

Messing around with this switch while hooked up to Mazda edit, I noticed that you get more throttle opening, as the pedal is obviously closer to the floor, but during actual WOT testing, the ECU won't actually allow the additional throttle position. Let's say the ECU determined that 86% throttle position at WOT is the most it can give you without impeding on drivetrain safety, there's not a thing you can do to get that figure any higher. Not that you would want to! I've never seen the throttle open up any higher than 86% while tuning.

So, in short:

WOT with the K/D switch is essentially asking your drivetrain for everything it's got.

pressing the switch will probably speed up the upshifts somewhat, maybe alter torque converter lockup slightly, but nothing noticeable to me in that regard. The downshift speed, aggressiveness, and the redline shift are the main two things i've noticed.

I'm still unsure if the detent itself actually does anything, or if the kickdown is tied to the throttle position achieved when you press through the detent. Guess it doesn't really matter so much. I'll try to see if the detent has an electrical component to it when I reinstall my Sprintbooster this summer.

 

[ScottSt]

IMO the N/A CX5 punches well above its weight for a 3700lb suv with 185hp. Mazda has done a great job tuning-in "responsiveness". And this responsiveness from my POV is super important in terms of feel and fun. This is a combo of the tuning of the engine and the transmission. High HP cars can "feel lazy" if the tuning of engine & trans optimizes for fuel efficiency as an example.

Yes of course the Turbo with an extra 140 lb-ft of torque "down low" where you need it is WAY more responsive in terms of actually building speed. But it's missing that tip-in responsiveness of the N/A cars. It's one of the most responsive Turbo setups I've driven but it's still a Turbo

Both are great. Mazda has done a great job making them responsive and fun. Boy would it be fun if Dave Coleman got turned loose (look him up) to build a Mazdaspeed version.

 

[Lazy2.5]

I tested it yesterday with my 2018 CX-9, it does work. In manual mode, Sport mode off, cruising along in 4th, I pressed the pedal all the way, right up to the detent. RPM steadily climbed as expected, car stayed in 4th. I pressed through the detent at about 4300 RPM and the RPMs spiked. I forgot to check if the transmission downshifted, but the RPMs spiked right away and kind of took me by surprise because I wasn't expecting anything lol.

By spike, do you think it was the torque converter unlocking?

While I haven't see the engine behave any differently with the K/D switch pressed, it certainly does change the transmission behavior. Keeping in mind NA vs Turbo will behave differently.

What's the highest you've seen your 2.5T shift?

I've seen my NA hit 6000rpm, 6200rpm (Soft redline) and 6500rpm (Hard redline) But I don't dare to take the engine past 6000rpm any longer. Even then, i'm paying close attention to the way the engine behaves, and the sound it's making, and won't hesitate to short shift if I deem necessary.

I rarely ever take the rpm's up this high, but I will, since most of my driving is done below 1750rpm. The exhaust sometimes stinks after I hammer it.


I don't ever advise using the K/D switch unless necessary.

BTW, I think you need to press the switch again if you want another redline shift in the next gear.

 

[Lazy2.5]

@sm1ke

Example of it's behaviour:

I go WOT (without the switch) to pass. After downshifting, RPM's are at 3 or 4000rpm. Oncoming traffic appears around the corner. I now click the switch, maintaining WOT. The transmission understands this is an urgent request and drops one more gear. Engine behavior remains the same.

So yes, i think the switch does actually send a signal to the transmission.

 

[Lazy2.5]

IMO the N/A CX5 punches well above its weight for a 3700lb suv with 185hp.

In a 3 or 6 and FWD, the NA suffices.

For the CX-5, esp. when luxury components and AWD are tacked on, the 2.5T would become a more appealing option.

I wouldn't sacrifice NA for (IMO) unnecessary additional curb weight.

 

[ScottSt]

I haven't tried in Sport mode yet, but foot to the mat in Normal in our 2.5T seems to shift no later than 5500rpm. This thing runs out of breath up high so this makes sense as it's probably net faster this way. Need to try Sport mode. Be right back.

 

[sm1ke]

So yes, the switch does actually send a signal to the transmission.

I guess the question that I (and some others) have, is if the detent is actually a switch that sends a signal, or is the kickdown triggered by the throttle position past the detent. I think at this point it doesn't really matter since it works the same regardless - it's just to clarify if it's an actual kickdown "switch".

I don't think I've seen it go past redline. I'll check on my way home today.

 

[Lazy2.5]

I don't think I've seen it go past redline. I'll check on my way home today.

I should clarify that my arguement is leaning towards the signal, vs. change in throttle position, but it doesn't really matter - I agree 100%.

No, the fuel cut off will never allow the engine to go past the hard-redline.

 

[N7turbo]

Someone posted something from Mazda, perhaps from one of the manuals, that specifically said that it's not an actual switch. Maybe they are reading this thread.

 

[DoubleCH]

I tested it yesterday with my 2018 CX-9, it does work. In manual mode, Sport mode off, cruising along in 4th, I pressed the pedal all the way, right up to the detent. RPM steadily climbed as expected, car stayed in 4th. I pressed through the detent at about 4300 RPM and the RPMs spiked. I forgot to check if the transmission downshifted, but the RPMs spiked right away and kind of took me by surprise because I wasn't expecting anything lol.

It's less about downshift than upshift. It's hard to test in 4th because car gets to some crazy speed and you have outside factor like air resistance affecting test results.

Supposedly if you keep in low gear like 1st or 2nd and gas pedal down to just before the switch, engine revs will go up but will not get pass redline or upshift, which means car will no longer accelerate once it reached redline in the current gear. Now if you hit the switch and it'll upshift.

So what's the point holding the gear at redline not upshifting or accelerating? When you're racing (especially autocrossing), you're reaching end of the straight at top of say 2nd gear and you need to brake for the corner. That's when you do NOT want to upshift.

 

[sm1ke]

Tested again yesterday on my way home from work. Car was in 4th, pedal to the detent. Pushed through, and it downshifted into 3rd.