2017 Mazda MX-5 Miata RF Vs. 2017 Toyota 86

[GoCougs]

Just for fun, here's a thread of Corvette guys sharing stories of destroying their torque converters at the drag strip.
https://www.corvetteforum.com/forums/c3-tech-performance/197978-anyone-ever-blow-out-a-torque-converter.html

I see. You're unfamiliar with hot rodding too.

Those are guys are mucking about with home built hot rods with a lot of power. Simply look at the profile pic of the third poster that claims to have broken lots of torque converters - it's a big block Chevy with at least a 6-71 supercharger.

Just like any drive line component - clutch, axle, u-joint, drive shaft, diff, and torque converter - the component has to be sized properly for the application. Simply peruse TCI's product page and you'll see torque converters for the same transmission range from $300 to $1,000 or more. What you're paying for is power level. Suffice it to say a modern automaker is properly sizing a torque converter for the application.

[MX793]

Just like any drive line component - clutch, axle, u-joint, drive shaft, diff, and torque converter - the component has to be sized properly for the application. Simply peruse TCI's product page and you'll see torque converters for the same transmission range from $300 to $1,000 or more. What you're paying for is power level. Suffice it to say a modern automaker is properly sizing a torque converter for the application.

I see you're changing your tune from this:

You can't overheat a torque converter (it's just metal and a few bearings) and "lots of fluid" shear" is the principal under which it transmits torque.

Obviously, some of those failures in the Vette thread were from too much power in too weak a driveline.  This one, in particular, was interesting:

My first Super Comp car actually caught the fluid inside it on fire. It is not that an unusal occurance

How can the trans fluid catch fire if you can't generate enough heat in the torque converter to overheat anything?

[Soup DeVille]

Isn't brake torquing pretty much a textbook example of an extreme circumstance? And one that the transmission is not designed for in the first place?

[GoCougs]

I see you're changing your tune from this:

Obviously, some of those failures in the Vette thread were from too much power in too weak a driveline.  This one, in particular, was interesting:

How can the trans fluid catch fire if you can't generate enough heat in the torque converter to overheat anything?

Super Comp cars are 800+ hp dragsters (or at least many of them are) that don't use cooling systems of any kind, so they roll the dice on overheating of any component, which is the case with all upper levels of drag racing.

No changes of tunes. Just answering your questions. Do you have any more?

[CaminoRacer]

Isn't brake torquing pretty much a textbook example of an extreme circumstance? And one that the transmission is not designed for in the first place?

A 2-3 second brake torque to launch a car 0-60 isn't extreme. 90 seconds is...

[GoCougs]

Isn't brake torquing pretty much a textbook example of an extreme circumstance? And one that the transmission is not designed for in the first place?

Again, not any more extreme than full throttle driving.

You can't rev an engine past red line. You can't select too low a gear. You can't put a car in reverse when going forward. Beyond the specific details of the event, simply put, if brake torquing was "extreme" for a car it's similarly easy for an automaker to prevent a driver from doing it.

[MX793]

Super Comp cars are 800+ hp dragsters (or at least many of them are) that don't use cooling systems of any kind, so they roll the dice on overheating of any component, which is the case with all upper levels of drag racing.

No changes of tunes. Just answering your questions. Do you have any more?

Cooling doesn't matter for a torque converter, remember?

You can't overheat a torque converter (it's just metal and a few bearings) and "lots of fluid" shear" is the principal under which it transmits torque.

[Soup DeVille]

A 2-3 second brake torque to launch a car 0-60 isn't extreme. 90 seconds is...

If it's not something the car can do in a sustained matter, its extreme.

[Soup DeVille]

Again, not any more extreme than full throttle driving.

You can't rev an engine past red line. You can't select too low a gear. You can't put a car in reverse when going forward. Beyond the specific details of the event, simply put, if brake torquing was "extreme" for a car it's similarly easy for an automaker to prevent a driver from doing it.

Yes, you can to the first two. Absolutely. (Just ask Sporty).

[MX793]

You can't rev an engine past red line. You can't select too low a gear.

LOL.  Tell that to these guys...

http://www.youtube.com/watch?v=aZKZ-c6IUiw

https://www.youtube.com/watch?v=xOnCoqcjDjg

http://www.youtube.com/watch?v=wtaB3oUsVJQ

https://www.youtube.com/watch?v=vvmBRnfAG74

https://www.youtube.com/watch?v=IySQ4kYY5rI

[68_427]

This whole discussion has been about (production car) toqrque converter automatics for the most part, in which Coug's point about not being able to do that is correct in all but some extreme cases.

[GoCougs]

Cooling doesn't matter for a torque converter, remember?

You can't overheat a torque converter - it's just metal. When an AT overheats what fails is the clutches and/or bands, not the torque converter.

[GoCougs]

Yes, you can to the first two. Absolutely. (Just ask Sporty).

LOL.  Tell that to these guys...

Those are manual transmission cars being forced into the wrong gear.

Any more questions?

[Soup DeVille]

You can't overheat a torque converter - it's just metal. When an AT overheats what fails is the clutches and/or bands, not the torque converter.

You can't overheat an engine then, it's just metal, right? And jet fuel can't melt steel beams.

Fine Mr. pedantic. The torque converter puts heat into the transmission fluid, and the fluid overheats.

[AutobahnSHO]

You're wrong.  It's impossible for trans fluid in a torque converter to overheat.  In fact, those "transmission cooler" heat exchangers that every AT car comes fitted with are just snake oil.  You can remove them and save some weight with no negative effects.  And the heavy duty transmission coolers they try to upsell you on with truck towing packages are a total money grab.

I NEVER said the torque converter overheated.

I said that my brother mashed the brake, my other brother mashed the gas, and the torque converter broke.   

[AutobahnSHO]

You can't overheat an engine then, it's just metal, right? And jet fuel can't melt steel beams.

Fine Mr. pedantic. The torque converter puts heat into the transmission fluid, and the fluid overheats.

Actually the little googling I've done says the fluid gets really hot which heats the housing and other parts, which expand then collide with each other, breaking the torque converter.

[Soup DeVille]

I NEVER said the torque converter overheated.

I said that my brother mashed the brake, my other brother mashed the gas, and the torque converter broke.   

I do believe that post was sarcastic.

[AutobahnSHO]

I do believe that post was sarcastic.

LOL silly me.

[GoCougs]

You can't overheat an engine then, it's just metal, right? And jet fuel can't melt steel beams.

Fine Mr. pedantic. The torque converter puts heat into the transmission fluid, and the fluid overheats.

Sure you can. When your engine temp gauge says 200F that's okay even though parts of the engine are WAY hotter, say like the head(s), which can reach 1,000F and still be fine. When an engine overheats cyldiner head temps climb way above 1,000F which is the red zone for metal, and things expand and warp and catastrophe of metal components (bearings, rings, usually) happens soon thereafter.

No such analogous process to combustion happens within an AT. AT fluid overheats, but that's only like 250F, and when that happens the bands and/or clutches follow soon after, as they are not metal, not the torque converter, which is metal.

[Soup DeVille]

Well, where does that magical heat come from in the transmission then?

[giant_mtb]

Errr uhhh mmmmmm I know this...fuck fuck fu-FRICTION?!

[Soup DeVille]

Errr uhhh mmmmmm I know this...fuck fuck fu-FRICTION?!

Where?

[giant_mtb]

Where?

In the transmission itself?  I'd assume gears and stuff.  I've no idea really, was just trying to be funny and now people are asking me questions and shit.

[Galaxy]

ALL transmission types - whether AT, DSG, SMG or M/T - generate - torque converters, clutches, bands, gears, pumps, bearings, seals, etc. are ALL are sources of inefficiency.

Any transmission designed today is designed to dissipate heat, ergo, only under extreme circumstances can they overheat.

You are underestimating how efficient modern transmissions are. The ZF 9hp has an efficiency of over 97%. Very little energy gets lost as heat. However if the car is not moving the energy is going somewhere.

[GoCougs]

You are underestimating how efficient modern transmissions are. The ZF 9hp has an efficiency of over 97%. Very little energy gets lost as heat. However if the car is not moving the energy is going somewhere.

Yet another strawman???

[r0tor]

... Pretty sure brake torquing is the worst case thing you can do to a cars torque converter.  A large percentage of whatever power the engine is producing is converted into heat by the converter from massive fluid sheer...

[GoCougs]

So in and among countless YouTube videos of AT launches and burnouts, how many feature "overheating" torque converters?

[Raza]

http://www.youtube.com/watch?v=NSq5Zb5ZNWY&feature=share

For those of you with MotorTrend on demand, the 10 minute mark at this video sums up my thoughts perfectly

https://www.motortrendondemand.com/detail/behind-the-scenes-at-the-track-with-head2head-w-jason-cammisa-jonny-lieberman-randy-pobst-/0_98trlqk5/

Compensation mention in like the third sentence?  A reviewer who kind of looks and sounds like Brian Posehn calling the BRZ, a four seat fixed roof coupe, a sports car twice in a ten second span? 

Can someone sum up their no-credibility conclusion for me, please?  I have to watch some other video where a guy calls a Range Rover Evoque a sports car submarine and then rattles off a bunch of cliches.

[Raza]

The 3i is a dog. As for these cars, it's tough. They are good "in theory" or "right road/environment" cars. If I lived in a rural area with great roads I could do this. But all that jinba ittai shit goes out the window when you are in traffic of densely populated areas IMO. If both of these just had like 20-30% more power they'd be perfect but as is... nah

Don't you live in a rural area right now?  Or did you move back to NYC?

[Raza]

Also, someone mentioned dragon meat?  I'd eat that.