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Gavincsy, I think there are 6mt's in their turbodiesel 2.2 line, in Europe. I am not sure what their gearing is, though. I think they are non-Skyactiv-MT transaxles. The latter are light duty.
 

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Well you would have to agree that they took a good long while to develop their kit.
Again, not knowing what they are doing and relying on their name to generate interest and free money to play with their own cars, while maybe finding someone who knew a little bit about turbos. It wasnt about making the safest kit out there. Meh, i digress.
 

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Cool info. I was wrong, obviously, about the torque converter. It seems, then, it is NOT a torque converter at all, but rather a wet clutch. This is exactly what a person can find in a dual-clutch automated manual transmission, except in the Skyativ-AT, there is only one such clutch, not two. Obviously, then, Skyactiv-AT monitors whether your foot is on the brake, 'cuz if your foot is on the brake the wet clutch is fully disengaged. When your foot comes off the brake, and to induce creep, the wet clutch partially deploys. As Tango and Woodinville Dan say, this multiplate style of clutch is exactly a motorcycle clutch...
This has five implications, to my way of thinking:
i) no torque multiplication at roll-out;
ii) perhaps less heat generation than a TC-based automatic (???);
iii) perhaps more wear of "consumables" - "frictions", "steels" - than with a torque converter based automatic... so possibly less life expectancy between rebuilds;
iv) less "cushioning" at start off and at creeping to a stop than a TC based A/T; and
v) more generation of "swarf" (abrasive wear particles)... which can wear out valve bodies sooner, along with other A/T internals. This last observation suggests to me that bypass tight media filtration would have merit with Skyactiv-AT transmissions.

Cool. Thx for the info!
Is this dude for real?!?!?

I think he mistook this for the VW forum.

Mazda dies NOT manufacture or use any type of automated manual or dual CLUTCH transmissions in any of their cars. They are either a manyal transmission, the type with 3 pedals of an automatic with a lockup TORQUE CONVERTER.
 

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Well you would have to agree that they took a good long while to develop their kit... I think that there are limits to what the 6MT can take, and they ran up against that limit, breaking transaxles... It would take a pretty savvy engineer to know, by calculation, what the actual limits of the transaxle are... Seems to me that empirical testing is the only way to know, and then to limit the tune to values of HP and torque that are empirically shown to not break transaxles. I suspect that is what they did.

It all points to a cautious approach. For me, I would follow what Woodinville Dan did, i.e. the VT supercharger. I would go moderate, by way of HP and torque. Dan's already done all of the hard work (Kudos, Dan!).
Mazda stated that they didn't offer the 2.5T (especially on the Mazda 3) because the 6MT internals couldn't handle the torque of the motor. Cant believe there are people who think they know more that the engineers that built the cars.
 

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That's because the 6ATs are built for the diesels with 400 + torques, I don't believe there is MT in the high output version of diesels

Maybe it makes that but drivability, usability, smoothness I question somewhat

And Mazda 6 chassis just cannot cope with a heavy engine, drive the diesels and you'll see how much the handling deteriorated from the gasoline ones just from being so head heavy. Understeer is perpetual.
uhhh, are you trying to say that adding a about 70lbs to the engine would deteriorate handling? Even though my car is still 300lbs lighter than a Mazda6 with the 2.5T (3280 vs. 3580)
Not been my experience at all, in my current configuration it corners like a race car, no under-steer and will actually kick out the rear if I flick it, while being reasonably comfortable (coil-overs, custom bump stops, stiffer RSB, etc.).

The big let down of the 2.5T is how it runs out of breathe, it's a great SUV motor or commuting motor, but for anyone that enjoys driving and pushing their engine, the power falls off as you rev past 5000rpm, that's just a deal breaker for me.
Upcoming* the newer version of the 2.5T in the CX50, and others to come, is using a different turbo setup with a twin-scroll and not constricting the exhaust to achieve the ultra low boost (which means it should have much better top end power) so there's hope for the future.
 
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Mazda stated that they didn't offer the 2.5T (especially on the Mazda 3) because the 6MT internals couldn't handle the torque of the motor. Cant believe there are people who think they know more that the engineers that built the cars.
Engineers are controlled by bean counters. They arent gonna claim its rally worthy even if it is, cause people will rally with it and abuse it and expect a free replacement. Duh.
 

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Is this dude for real?!?!?

I think he mistook this for the VW forum.

Mazda dies NOT manufacture or use any type of automated manual or dual CLUTCH transmissions in any of their cars. They are either a manyal transmission, the type with 3 pedals of an automatic with a lockup TORQUE CONVERTER.
Before you ask if I'm "for real" could you please actually READ the post and the subsequent ones? Where did I suggest that Mazda offered dual clutch automated manual transaxles? COOL YOUR JETS...
 

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Mazda stated that they didn't offer the 2.5T (especially on the Mazda 3) because the 6MT internals couldn't handle the torque of the motor. Cant believe there are people who think they know more that the engineers that built the cars.
Uh, I have been the individual, all the while, suggesting that the Skyactiv-MT transaxle is light-duty... Mazda likely had multiple reasons for not offering a 6MT with the turbo: drive/tune characteristic of their turbo; demographic and their likely ability to sell many cars (witness NLA Accord 2.0T 6MT); less suitable gearset/ratios in their heavier duty non-Sky 6MT 'box... (applied to their turbodiesels, and likely capable of absorbing the Turbo's torque)...
 

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Mazda does NOT manufacture or use any type of automated manual or dual CLUTCH transmissions in any of their cars. They are either a manual transmission, the type with 3 pedals of an automatic with a lockup TORQUE CONVERTER.
I would respectfully disagree, the Skyactiv-Drive auto transmission, with it's multi-plate clutch housed in the 'under-sized' torque converter, is more closely related to a DCT than a regular TC transmission. In the case of the Skyactivs it only has a single large clutch and uses the torque converter for rev-matching the shifts, they also have an over sized vibration damper.

This difference in behavior is part of the great mpg and the direct feel of the engine locked to the wheels 95% of the time, and it generates very little heat even when racing with a supercharged engine!
 

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Uh, I have been the individual, all the while, suggesting that the Skyactiv-MT transaxle is light-duty... Mazda likely had multiple reasons for not offering a 6MT with the turbo: drive/tune characteristic of their turbo; demographic and their likely ability to sell many cars (witness NLA Accord 2.0T 6MT); less suitable gearset/ratios in their heavier duty non-Sky 6MT 'box... (applied to their turbodiesels, and likely capable of absorbing the Turbo's torque)...
I was agreeing with you... :)
 

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I would respectfully disagree, the Skyactiv-Drive auto transmission, with it's multi-plate clutch housed in the 'under-sized' torque converter, is more closely related to a DCT than a regular TC transmission.
Not even remotely. The SA-D has almost no physical similarity to a DCT and, for all intents and purposes, has all the components, name for name, function for function, of a conventional AT. Let's analyse things: The larger, multiplate lockup clutch, gives a better bight than a single plate arrangement, thus allowing less slippage. That accounts for some of the more direct "like-a-manual" feel. With conventional transmissions, lockup occurs at high road speeds and often only in top gear. But with SA-D, lockup occurs at lower road speeds (from about 7mph) and in all forward gears, adding again to that direct "like-a-manual" feel. This also aids in fuel economy because there is less slippage. The larger dampener is mandatory because all of this directness transmits more vibration throughout the system because the transmission fluid spends less time providing that dampening. Beyond the rather unconventional torque converter and its lockup mechanism, the SA-D still has internals of a conventional automatic, with planetary gears, sun gears, and clutches (but no bands). The truth is that torque converter automatic cars of all types have more in common with a boat (they have metal propellers acting against fluids to provide propulsion, don't they?) than they do with DCTs.
 

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Not even remotely. The SA-D has almost no physical similarity to a DCT and, for all intents and purposes, has all the components, name for name, function for function, of a conventional AT. Let's analyse things: The larger, multiplate lockup clutch, gives a better bight than a single plate arrangement, thus allowing less slippage. That accounts for some of the more direct "like-a-manual" feel. With conventional transmissions, lockup occurs at high road speeds and often only in top gear. But with SA-D, lockup occurs at lower road speeds (from about 7mph) and in all forward gears, adding again to that direct "like-a-manual" feel. This also aids in fuel economy because there is less slippage. The larger dampener is mandatory because all of this directness transmits more vibration throughout the system because the transmission fluid spends less time providing that dampening. Beyond the rather unconventional torque converter and its lockup mechanism, the SA-D still has internals of a conventional automatic, with planetary gears, sun gears, and clutches (but no bands). The truth is that torque converter automatic cars of all types have more in common with a boat (they have metal propellers acting against fluids to provide propulsion, don't they?) than they do with DCTs.
It's interesting in ways I agree with what you are saying about it still structurally being a TC transmission (the anatomy of the transmission still looks mostly like a TC transmission when disassembling)

But you're conclusion is flawed: "torque converter automatic cars of all types have more in common with a boat (they have metal propellers acting against fluids..."
In the case of the SA-D this is not true, except at ultra low speeds, when driving it BEHAVES more like a DCT, even though it is anotomically a TC transmission structure, the vast majority of the time power is NOT transmitted via a propeller in liquid but clutch plates locking the transmission and engine together.
 

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It's interesting in ways I agree with what you are saying about it still structurally being a TC transmission (the anatomy of the transmission still looks mostly like a TC transmission when disassembling)

But you're conclusion is flawed: "torque converter automatic cars of all types have more in common with a boat (they have metal propellers acting against fluids..."
In the case of the SA-D this is not true, except at ultra low speeds, when driving it BEHAVES more like a DCT, even though it is anotomically a TC transmission structure, the vast majority of the time power is NOT transmitted via a propeller in liquid but clutch plates locking the transmission and engine together.
You're nit-picking here, my friend. By the same token, It doesn't matter for how long the blades are acting against that fluid, the fact is that they do. And the fact is that the SA-D has even less in common with a dual clutch arrangement.
 

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You're nit-picking here, my friend. By the same token, It doesn't matter for how long the blades are acting against that fluid, the fact is that they do. And the fact is that the SA-D has even less in common with a dual clutch arrangement.
That's fair, I guess I don't like lumping these in with other TC transmissions because it's got that direct feel, and yes I'm nit-picking :D
 

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The shocking thing is that many of these advancements are not unique to SA-D. Toyota's Direct Shift-8AT and -10AT both have multiplate lockup clutches, and I recently read that there is a company that specializes in converting several GM, Ford, and Chrysler transmissions from single plate to multiplate. Interesting times.
 

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Discussion Starter · #60 ·
I certainly admire your willingness to try it. That’s an entirely bigger enchilada than I would care to bite into. Why add the turbo? More power? Or a status thing? Or…? You may get deeply into that project and realize that’s more there than you bargained for. Good luck. Whichever way you decide to go on this.
Honestly, I want to see how much more mpg I could get, or at least not lose any. In addition to beating my friend's CIVIC SI :ROFLMAO:.
@Lertu let me share my insights:
  • Auto Transmission: the torque converter contains a multi-plate clutch, so it is a hybrid between normal TC and DCT, where the normal TC style operation is only used for rev-matching during shifting (and at really low speeds)
  • Supercharger is really expensive?! Do some research, most complete boost kits are ~$5k, and most Eaton TVS supercharger kits are ~$6k, whereas the VT-Racing kit (using TVS compressor design) is less than $4k, so it's a really good deal for basically adding 2 cylinders (>50% more airflow).
  • Corksport turbo: with a starting price of $5500 + $1200 exhaust to get the power gains they are talking about, plus cannot DIY install, very difficult, initial customers are paying $2-3k for the install. So by the time you're done with the CS turbo I could have supercharged 2 Mazdas :devilish:
  • DIY custom turbo: this will certainly cost more than the supercharger kit, and given how advanced the ECUs in the Skyactivs are, you're going to have a very hard time getting it to work even if you did mechanically cobble together an engine that theoretically can take a turbo better, I don't know how you'd get it to run well and reliably without some serious ECU expertise.
  • Efficiency after boost: any of these options will cost you more in gas, not less. These will all end up burning more fuel to make more power. There is no chance of saving money on fuel. That being said, even with the supercharger I still get 35mpg, and because of the pumping efficiency of the compressor there are some mild throttle conditions where I get better mpg now than NA, but for the most part more power means more fuel.
*Note: the Corksport kit uses a purposefully over-sized turbo, because they were breaking transmissions... So the Corksport kit has no boost until above 3000rpm...
whereas the supercharger has gentle steadily building boost, and much less heat, with 2-3psi of boost even at 1200rpm, so even though the peak number is undoubtedly less than the turbo kit, the amount of power I have in the rest of the RPM range makes it wicked fast on track or daily driving.



and if you're worried about the supercharger performing... don't :)
Very great comments and I've certainly looked into it a lot, I've completely switched courses from planning a turbo to planning a supercharger, it would be a shame to not use those forged rods to their full potential, as for cost, I'm only worried about parts cost since I consider myself well experienced and equipped to install parts. For the cost of the VT Racing turbo I'd manage to LS Swap my car which in my opinion is too high of a cost for what I'm looking for.

I've also read up a lot more about the engine and tranny, so I'm glad to report I don't think it's a dual clutch anymore XD

Now the latest thing I've been trying to figure out is how I could install something like a Paxton VR-70-86A or a similar supercharger, space is my biggest headache right now due to the engine mount and AC piping interfering around the belt. A supercharger is definitely the way to go but I'm trying to figure out how I could do it with minimal cost and modification. So far if I don't figure out a way to fit in with the stock intake, I might consider replacing the manifold with a custom one I fab that could incorporate the supercharger better. As a side thought, I am also considering running a rod as a pulley extension connected to the belt above the intake which can transmit the rotation to the left and place the supercharger in place of the airbox, but it does seem like a very unstable and stupid idea, who knows.

Heres an example I found on google
Vehicle Car Hood Motor vehicle Automotive design
 
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