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  Reply # 1686735 12-Dec-2016 21:55
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shk292:

 

Fred99:

 

I don't have that wrong, and a huge amount of power is wasted and a lot of heat generated, hence separate heat exchanger for oil-cooling for slushbox autos by way of either separate radiator, heat exchanger for the auto trans fluid built into the main coolant radiator, or compact separate fluid to fluid heat exchanger mounted on the side of modern slushbox autos (looks a bit like an oil filter, but plumbed to engine coolant system).

 

That's why they use lock-up clutches since the '90s - and in the case of recent Mazda SkyActiv, lock-up in all forward gears, as the energy waste from the torque converter is substantial.  Now Mazda have to deal with all the extra crap (wear particles and heat) from the slip on the clutches engaging and disengaging much more as that's happening with every shift in every ratio, so much larger and more expensive torque converter with bigger clutches, trans oil filtration and very very important service intervals.  So far they seem to be okay - and IMO a good alternative for a fuel efficient auto for around town commuting, where I don't like DSG much, and don't trust CVTs based on their shocking history.

 

It's also why DSG and CVT became common - as they're much more efficient than conventional slush-box. (in the case of DSG then even faster acceleration times than manual transmission because the shifts are slicker/better timed than a human can achieve, more economical than manual because computers are smarter than humans at crunching numbers to work out the best time to shift ratio)

 

 

 

 

I stand corrected - and I have just found out that the six-speed auto box in my car has lock-up in all but first, which explains how it behaves

 

It's a shame that CVT isn't more reliable because it should be the perfect system.

 

 

I don't stand corrected (yet). All the info I can find about 97 Nissan Pulsars has them fitted with Jatco RL4F03A 4 speed autos with lockup available when in 4th not in place of 4th.

 

 


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  Reply # 1686757 12-Dec-2016 22:29
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Bung:

 

shk292:

 

Fred99:

 

I don't have that wrong, and a huge amount of power is wasted and a lot of heat generated, hence separate heat exchanger for oil-cooling for slushbox autos by way of either separate radiator, heat exchanger for the auto trans fluid built into the main coolant radiator, or compact separate fluid to fluid heat exchanger mounted on the side of modern slushbox autos (looks a bit like an oil filter, but plumbed to engine coolant system).

 

That's why they use lock-up clutches since the '90s - and in the case of recent Mazda SkyActiv, lock-up in all forward gears, as the energy waste from the torque converter is substantial.  Now Mazda have to deal with all the extra crap (wear particles and heat) from the slip on the clutches engaging and disengaging much more as that's happening with every shift in every ratio, so much larger and more expensive torque converter with bigger clutches, trans oil filtration and very very important service intervals.  So far they seem to be okay - and IMO a good alternative for a fuel efficient auto for around town commuting, where I don't like DSG much, and don't trust CVTs based on their shocking history.

 

It's also why DSG and CVT became common - as they're much more efficient than conventional slush-box. (in the case of DSG then even faster acceleration times than manual transmission because the shifts are slicker/better timed than a human can achieve, more economical than manual because computers are smarter than humans at crunching numbers to work out the best time to shift ratio)

 

 

 

 

I stand corrected - and I have just found out that the six-speed auto box in my car has lock-up in all but first, which explains how it behaves

 

It's a shame that CVT isn't more reliable because it should be the perfect system.

 

 

I don't stand corrected (yet). All the info I can find about 97 Nissan Pulsars has them fitted with Jatco RL4F03A 4 speed autos with lockup available when in 4th not in place of 4th.

 

 

 

 

Actually - it probably is a 4 speed when I think about it.  I never said it (lockup) replaced top gear, whether that's 3rd or 4th, it just bypasses the torque converter, the effective drive ratio increases, and it feels like an extra gear when it actually isn't, and it isn't "overdrive" either.


 
 
 
 


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  Reply # 1686761 12-Dec-2016 22:41
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Fred99:

 

shk292:

 

 

 

It's a shame that CVT isn't more reliable because it should be the perfect system.

 

 

 

 

Yeah - but it's that horrible idea that power should be transferred by friction between components, when to get variable ratio the contact area has to be small, thus there's always got to be some slippage.

 

Nissan have managed to whack their "extroid" CVTs in some higher powered cars (but for performance they still use a DSG in the GTR)

 

 Extroid works like this schematic :

 

 

That's a lot of power being transferred by friction with small contact area.  IMO it's a horrible idea - but it works.

 

Electric (with maximum torque available from 0 rpm up) solves the problem.

 

 

Do you have a schematic on Subaru's Lineartronic?





Swype on iOS is detrimental to accurate typing. Apologies in advance.


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  Reply # 1686763 12-Dec-2016 22:58
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joker97:

 

 

 

Do you have a schematic on Subaru's Lineartronic?

 

 

 

 

A youtube?

 

 

 

 

Looks like a pretty standard variable diameter pulley CVT.

 

These things are simple in concept, but extremely reliant on correct materials and lubrication, hence the importance of strict adherence to service schedules. Look where the chain is friction driven on the edge of the pulley - it's always "scuffing" so will self-destruct quickly if something goes wrong with oil, there's a buildup of wear particles etc.


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  Reply # 1686764 12-Dec-2016 23:01
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Fred99: Actually - it probably is a 4 speed when I think about it.  I never said it (lockup) replaced top gear, whether that's 3rd or 4th, it just bypasses the torque converter, the effective drive ratio increases, and it feels like an extra gear when it actually isn't, and it isn't "overdrive" either.

 

 

The lockup may not be but the Nissan 3rd gear ratio is 1:1 and 4th is .697:1 so 4th really is an overdrive.


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  Reply # 1686766 12-Dec-2016 23:13
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Bung:

 

Fred99: Actually - it probably is a 4 speed when I think about it.  I never said it (lockup) replaced top gear, whether that's 3rd or 4th, it just bypasses the torque converter, the effective drive ratio increases, and it feels like an extra gear when it actually isn't, and it isn't "overdrive" either.

 

 

The lockup may not be but the Nissan 3rd gear ratio is 1:1 and 4th is .697:1 so 4th really is an overdrive.

 

 

 

 

Which gets back to what I said earlier - which is kind of "so what?" as it's an auto transaxle, you never see the gearbox input/output drive ratio before the diff, after the diff the axles are turning at lower rpm than the crank, so there's nothing "overdrive" you can ever see as the entire transaxle comes with an input shaft built-in diff, the only output shafts drive the axles.  It's a matter of definition, but to me true "overdrive" was increasing the ratio with separate overdrive gearing between the gearbox and diff.  Old school - I know.


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  Reply # 1686808 13-Dec-2016 07:08
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Fred99:

 

joker97:

 

 

 

Do you have a schematic on Subaru's Lineartronic?

 

 

 

 

A youtube?

 

 

 

 

 

Looks like a pretty standard variable diameter pulley CVT.

 

These things are simple in concept, but extremely reliant on correct materials and lubrication, hence the importance of strict adherence to service schedules. Look where the chain is friction driven on the edge of the pulley - it's always "scuffing" so will self-destruct quickly if something goes wrong with oil, there's a buildup of wear particles etc.

 

 

Haha the maintenance schedule of the CVT is - "lifetime maintenance free". In fact there the filter cannot be accessed without taking apart the transmission itself! 





Swype on iOS is detrimental to accurate typing. Apologies in advance.




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  Reply # 1686809 13-Dec-2016 07:20
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Nobody answered my question and went off on CVT's, the love has gone. So I went looking myself.

 

A tiptronic is just a way to manually shift a torque based box. It doesnt use clutches etc. It does have safety mechanisms, Ie you put it in 4th but you should be in 2nd it will drop the gear on you by itself.

 

So I took my mates tiptronic out yesterday, and sure enough, the light went from D, to 1 2 3 4. But most often Id get to 4th and it would drop it back to 3rd. they are quite hard to get use to in the sense of timing your gas pedal in 1st and 2nd. 

 

I personally dont have a problem with the old 1,2, D system even if it is 4 speed. Sure sometimes you need to put your foot down to get it into the right gear, but no biggy?


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  Reply # 1686823 13-Dec-2016 08:40
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joker97:

 

Fred99:

 

joker97:

 

 

 

Do you have a schematic on Subaru's Lineartronic?

 

 

 

 

A youtube?

 

 

 

 

 

Looks like a pretty standard variable diameter pulley CVT.

 

These things are simple in concept, but extremely reliant on correct materials and lubrication, hence the importance of strict adherence to service schedules. Look where the chain is friction driven on the edge of the pulley - it's always "scuffing" so will self-destruct quickly if something goes wrong with oil, there's a buildup of wear particles etc.

 

 

Haha the maintenance schedule of the CVT is - "lifetime maintenance free". In fact there the filter cannot be accessed without taking apart the transmission itself! 

 

 

 

 

Be careful with that.  The service schedule says to inspect at certain intervals, and replace fluid if subject to "extreme" driving conditions:

 

Repeated short trips, stop-and-go, extensive idling  
Rough, muddy, dusty, wet, humid, cold, mountainous, salty conditions 
Frequently towing a trailer.

 

Apart from the trailer perhaps, that's all typical NZ driving conditions isn't it?

 

Auto makers like to have an "out" for warranty claims, not that I've heard bad things about Subaru CVT, but if those are the limitations on "lifetime maintenance-free" , then they're being a bit disingenuous IMO.

 

If they're stating "lifetime" then perhaps they should suggest what that "lifetime" should be.  My guess it won't be the 250,000km or whatever some owners may expect, and the "lifetime" that matters most to the auto makers expires the day the warranty period ends.

 

 

 

 


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  Reply # 1686892 13-Dec-2016 10:05
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Fred99:

 

joker97:

 

Fred99:

 

joker97:

 

 

 

Do you have a schematic on Subaru's Lineartronic?

 

 

 

 

A youtube?

 

 

 

 

 

Looks like a pretty standard variable diameter pulley CVT.

 

These things are simple in concept, but extremely reliant on correct materials and lubrication, hence the importance of strict adherence to service schedules. Look where the chain is friction driven on the edge of the pulley - it's always "scuffing" so will self-destruct quickly if something goes wrong with oil, there's a buildup of wear particles etc.

 

 

Haha the maintenance schedule of the CVT is - "lifetime maintenance free". In fact there the filter cannot be accessed without taking apart the transmission itself! 

 

 

 

 

Be careful with that.  The service schedule says to inspect at certain intervals, and replace fluid if subject to "extreme" driving conditions:

 

Repeated short trips, stop-and-go, extensive idling  
Rough, muddy, dusty, wet, humid, cold, mountainous, salty conditions 
Frequently towing a trailer.

 

Apart from the trailer perhaps, that's all typical NZ driving conditions isn't it?

 

Auto makers like to have an "out" for warranty claims, not that I've heard bad things about Subaru CVT, but if those are the limitations on "lifetime maintenance-free" , then they're being a bit disingenuous IMO.

 

If they're stating "lifetime" then perhaps they should suggest what that "lifetime" should be.  My guess it won't be the 250,000km or whatever some owners may expect, and the "lifetime" that matters most to the auto makers expires the day the warranty period ends.

 

 

Agreed. I get all my info from MRT Performance's youtube videos so I might be a bit off the mark.





Swype on iOS is detrimental to accurate typing. Apologies in advance.


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  Reply # 1686953 13-Dec-2016 10:49
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TeaLeaf:

 

Nobody answered my question and went off on CVT's, the love has gone. So I went looking myself.

 

 

Sorry if this comes across as bolshy, but the reason people haven't responded to some of your more recent questions is that most of these have already been answered previously and in some detail, and asking them again comes across (to me as at least) as if you've not necessarily read these replies thoroughly.

 

For example, posts on this and your other related thread have already explained what "tiptronic" is, and what the differences are between CVT, DSG and torque converter-based autos as well as their main advantages and disadvantages.

 

Seriously, I think you've received a lot of good advice on these threads that can support your decision re a suitable car, but at this point there appears to be an increasing risk of collapsing into paralysis through over-analysis!




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  Reply # 1686956 13-Dec-2016 11:01
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Im a systems and UX analyst, dont judge me. drives the mrs crazy. have to have everything 100% in my head before i can write her spec document with wireframing on what car we should buy before she signs the document ;-p


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  Reply # 1686958 13-Dec-2016 11:04
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TeaLeaf:

 

Im a systems and UX analyst, dont judge me. drives the mrs crazy. have to have everything 100% in my head before i can write her spec document with wireframing on what car we should buy before she signs the document ;-p

 

 

I'm a policy analyst, so anal by nature as well! That said, my general point is perhaps go back and read through the threads carefully as the answers to most of your questions you're asking again are there.




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  Reply # 1686963 13-Dec-2016 11:11
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yes i know, i think im more stating than asking. i just dont trust everything i read once, ie a website might be wrong etc.

 

its all good tiptronics are in almost all cars now. bmw has been using them forever.


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  Reply # 1686967 13-Dec-2016 11:15
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Fred99:

 

TeaLeaf:

 

jonathan18:

 

Have you had a good look at the Jazz? 

 

 

CVT? 2005ish model?

 

 

 

 

Avoid 02-06 Jazz with CVT.

 

Even if they've got FSH, I'd still be very wary.

 

Google is your friend.

 

 

Yep, personally I'd avoid a Jazz or Fit with CVT; the NZ new second series (the one previous to the current series - think it launched in 2008) did not have a CVT but a standard four-speed auto - some, like my wife's came with "F1-inspired' steering wheel mounted shifters (that is indeed how Honda advertised them!). The Fits (the Japanese name for the Jazz) from the same period, however, came with CVT. That's one of the reasons why we purchased an NZ-new model. There don't seem to be as many issues with the CVT box on the second gen Fit (c 2008 - c 2013), but it wasn't a risk I wanted to take.


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