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OP, the 6AT transmission is a conventional one with a lockup torque converter; no dual-clutch arrangement there. Regardless, that is not germane to the whole discussion. Incidentally, the torque converter is quite small, and the control methodology encourages early- (and often) clutch lockup.
 

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Discussion Starter · #22 · (Edited)
OP, the 6AT transmission is a conventional one with a lockup torque converter; no dual-clutch arrangement there. Regardless, that is not germane to the whole discussion. Incidentally, the torque converter is quite small, and the control methodology encourages early- (and often) clutch lockup.
Are you sure? Here is where I got my information, maybe its the newer models?
Did I misunderstand and they are just claiming that their TC design is better than DCT?

Edit: Yes, yes I didn't read enough originally haha, its a tricky page at first. Some good marketing
 

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@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 :)
 

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Throwing in my 2 cents - I'd put the supercharger kit above a turbo kit. Money's the same, Dan's already proven it, plus turbo lag and surge-y behavior is no fun.
 

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Are you sure? Here is where I got my information, maybe its the newer models?
Did I misunderstand and they are just claiming that their TC design is better than DCT?

Edit: Yes, yes I didn't read enough originally haha, its a tricky page at first. Some good marketing
The major difference with Skyactiv-Drive and a conventional automatic is that the torque converters are different. The conventional converter uses a large, single hydraulically operated clutch that will lock the torque converter to the flex plate, preventing slippage.


Skyactiv-Drive uses a multiplate clutch arrangement, similar to that of a motorcycle clutch, to lock the torque converter to the flex plate.

 

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Ummmm, if this is something you really want, why not just buy a factory turbo?
Or a different car with more power?
These gas prices have got the uneducated coming up with some really stupid ideas just to save some money. A guy on Reddit wanted to convert his 3 to flex fuel, i had to school him on how much it would cost just to switch it over. Not sure if i got through to him or not.
 

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I
The major difference with Skyactiv-Drive and a conventional automatic is that the torque converters are different. The conventional converter uses a large, single hydraulically operated clutch that will lock the torque converter to the flex plate, preventing slippage.


Skyactiv-Drive uses a multiplate clutch arrangement, similar to that of a motorcycle clutch, to lock the torque converter to the flex plate.

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!
 

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It seems, then, it is NOT a torque converter at all, but rather a wet clutch.
Unfortunately, no. There is still a conventional fluid coupling like conventional torque converters. The lockup portion of the converter in the SA-D is what is most different. The turbine, impeller, and stator are smaller in the SA-D than in conventional torque converters, but the lockup clutch arrangement is larger and is of a motorcycle-multiplate style. Watch the video below and listen to what YoutTuber Jason Fenske is saying as he explains how the SA-D is different.

 

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Unfortunately, no. There is still a conventional fluid coupling like conventional torque converters. The lockup portion of the converter in the SA-D is what is most different. The turbine, impeller, and stator are smaller in the SA-D than in conventional torque converters, but the lockup clutch arrangement is larger and is of a motorcycle-multiplate style. Watch the video below and listen to what YoutTuber Jason Fenske is saying as he explains how the SA-D is different.

I realized this, looking at the FSM... where they mention torque converter. Also, per memory, 'way back, Mazda said small TC...

Thx.
 

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Has anyone ever done a Skyactiv G 2.5L Naturally Aspirated to Turbo Conversion? I've seen so many people make videos about the ridiculously expensive supercharger from VT Racing but haven't seen anyone use a turbo from something like the 2018 Turbo model and retrofit it to a different car. From what I've seen the engine head and everything is identical except for the turbo/intake/other turbo related parts and coolers. It's making me doubt myself if it's even possible. Am I just not good at reading and finding someone else who did it, and any experts here to assist if I was the first to try, especially with the ECU/Electonic part of things? This engine is built really well and I believe it definitely deserves a turbo to show what it can actually do.
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.
 

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I don't know if it's worth the hassle, yes the car handles well but it's a big sedan at the end of it, the 2.5s are not overbuilt engines for modding or tuning. I think you're better off just looking for the 2.5T together with the upgraded interior to boot
This is the wrong group to try and say that to, i mean, cause, youre already proven wrong.
 

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I don't know if it's worth the hassle, yes the car handles well but it's a big sedan at the end of it, the 2.5s are not overbuilt engines for modding or tuning. I think you're better off just looking for the 2.5T together with the upgraded interior to boot
I would have just upgraded to a 6 with the 2.5T but it's way too slow and not fun to rev!
At this point I am significantly faster than a 2.5T while getting better gas mileage and for less cost than upgrading to another car.

These engines are more over built than most engines, what we are learning (now that there are dozens of people running multiple boost setups on the Skyactiv-G engine) is that it can take far more boost than anyone ever anticipated, the transmission will be a limit before the engine is (consensus is stock 2.5 is probably good to ~320wHP)
 

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Well, particularly the automatics are up to the task. CorkSport, with their turbo's apparently kept losing 6MT's with their turbo development...
 

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CorkSport, with their turbo's apparently kept losing 6MT's with their turbo development...
Again, cause they dont know what the hell they are doing :)
 

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Well, particularly the automatics are up to the task. CorkSport, with their turbo's apparently kept losing 6MT's with their turbo development...
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
I would have just upgraded to a 6 with the 2.5T but it's way too slow and not fun to rev!
At this point I am significantly faster than a 2.5T while getting better gas mileage and for less cost than upgrading to another car.

These engines are more over built than most engines, what we are learning (now that there are dozens of people running multiple boost setups on the Skyactiv-G engine) is that it can take far more boost than anyone ever anticipated, the transmission will be a limit before the engine is (consensus is stock 2.5 is probably good to ~320wHP)
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.
 

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Again, cause they dont know what the hell they are doing :)
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!).
 
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