[one1er]

Hey guys...

Still not sure what to go for, manual or auto, so here's another question for you knowledgeable guys out there!

I saw this video of a guy doing 50 consecutive launches on a new porsche 911 turbo, saying it could handle it, and other cars couldn't! I read on the 2 series owners manual not to use launch control often because it would prematurely wear down some components, so, the questions are:

1 - How often is considered often?

2 - Does it mean often as in consecutive times, "life expectancy" times, or both?

3 - What components do wear down over this feature, and are they complicated and expensive to replace?

[FoxCrane]

Is that video posted online somewhere? If so, could you link it?

[one1er]

Originally Posted by FoxCrane

Is that video posted online somewhere? If so, could you link it?

here you go

[VeryBadman]

I watched that video and to be honest, that guy acted and sounded like an idiot who got his hand on expensive toy. It doesn't stop you from doing it doesn't mean it's not going to wear the engine and gearbox down. You wouldn't want to do that if it your own car. One thing you have to realize is Porsche 911 Turbo so is about 4 times more expensive than M235i and is designed to withstand track so it's parts are more solid too.

Also, learning from Audi that they have launch control counter and I think other brands have that too. Who knows if they will use that information to against you as excessive and abusive usage.

[one1er]

Originally Posted by VeryBadman

I watched that video and to be honest, that guy acted and sounded like an idiot who got his hand on expensive toy. It doesn't stop you from doing it doesn't mean it's not going to wear the engine and gearbox down. You wouldn't want to do that if it your own car. One thing you have to realize is Porsche 911 Turbo so is about 4 times more expensive than M235i and is designed to withstand track so it's parts are more solid too.

Also, learning from Audi that they have launch control counter and I think other brands have that too. Who knows if they will use that information to against you as excessive and abusive usage.

I get that and completely agree, but the point is not comparing the M235i with the porsche, it's trying to better understand the 8-speed with all it's pros and cons compared to a manual...

I mean, if I have an aggressive style most my driving, the manual will just wear its clutch faster, which's relatively "simple and inexpensive" to replace, nothing else regarding the trans should complaint, but I have no clue how the same aggressiveness would affect the 8-speed in terms of components wear and cost...

[overcoil]

For the manual, clutch friction surfaces and if you shift very fast the synchromesh rings - particularly the 1st to 2nd shift.

For the auto the torque converter almost acts as a shock absorber which is a good thing.

In both if the fluid gets to hot then you have wear issues.

Then driveline wear from transmission mounts to driveshaft to rear diff.

Maximum acceleration from a dead stop is a lot harder on mechanicals for both auto/manual then a rolling start.

[valentinbmw]

I never seen such a useless experiment or test drive, launch, or whatever that guy is a totally deuchbag i wonder if he get paid by launching the car and making stupid faces. What an asshole..,

[adrianv]

Originally Posted by notime

For the auto the torque converter almost acts as a shock absorber which is a good thing.

True, but it is also the first point of failure in an auto when using it this way:

http://en.wikipedia.org/wiki/Torque_..._failure_modes

Brake-torquing a torque converter to launch an auto the way this car implements launch control generates a *LOT* of heat. I would take BMW's 5 minute cooldown recommendation seriously as there is no way of knowing the thermal capacity of the transmission coolers.

To get an idea of how much heat is generated, this car stock is making around 200hp when you are brake-torquing at around 3-3500rpm. Since you aren't moving, 100% of that energy is being generated into heat. 1HP= 2546 BTU/hr, so 200HP = 2546/3600*200 = 141 BTU/second. That is A LOT!

I don't know how much fluid is in this car's torque converter, but for napkin math, assuming 1 gallon of fluid with similar thermal properties of water is close enough. 1 gallon is about 8 lbs, and 1 btu will heat 1 lb of water 1 degree. So:

141/8 = 18degrees PER SECOND!

Just think about that. Say it took 3 seconds holding your car at "launch ready" speed, which really isn't that long. You have just heated your torque converter by almost 60 degrees. You've boiled a gallon of room temperature water in just over 8.

All that being said, transmission fluid can get 4-6 times hotter than water before it boils, so as long as you follow the cooldown instructions, I wouldn't worry about it. It's manuafacturer-approved use, which means that there is headroom in the component's design to support that use if you follow the instructions.

[moldcad]

I fully agree with your comments about complete and utter futility of experiments like the one with the Porsche - however, it's not all the ruining as it might seem; not at least from the temperatures viewpoint. I torque-brake my F10 from time to time (certainly not as often as once per 5 minutes), and for pure curiosity checked the transmission oil temperature rise using Torque Pro (or was it DashCommand - I forgot now). Of course I realize that even if such an application can read and display the right PID doesn't mean the reading is 100% accurate (hysteresis etc.), but the greatest single temperature rise I recorded as a result of torque-braking was a mere 20 C.

Plus of course one must learn how to make it all happen as quick as possible; my launches (i.e. the phase of simultaneous brake and gas application) never exceed 1 second.

[Dr. Indiana Jones]

IMHO this launch control is a marketing gimmick (nominal difference in acceleration), is not good for the car, and s/b avoided. Your decision as to manual vs. teptronic (w shift paddles) s/b purely based on preference not performance, as either will do just fine in the latter category. I myself have had both, and will not likely ever go back to a manual when I can do everything a manual can do but faster and better w the teptronic. That's why all of the high HP exotics pretty much default to teptronic these days.

[///M235i]

Help me understand please - I know that Launch Control is a feature in the car I've ordered.... However to be honest I have no clue what it really is, and isn't, or how, or why to use it. Also not sure what the paddles are for... Is that related?

[Killramos]

It's not really related to the paddles. It basically uses the cars computers etc to jump off the line "faster" than you could without being a professional. This feature is why anyone can race a gtr for example.

[hyperzulu]

I'm not reading this thread. Instead, I'll just answer. I have a 335is with launch control on the dual clutch transmission. I've used launch control maybe five times ever and I've had the car since Dec 2011. It's a gimmick and you won't use it, so don't even worry about it.

[///M235i]

Originally Posted by hyperzulu

I'm not reading this thread. Instead, I'll just answer. I have a 335is with launch control on the dual clutch transmission. I've used launch control maybe five times ever and I've had the car since Dec 2011. It's a gimmick and you won't use it, so don't even worry about it.

Your eternal pessimism doesn't change the fact that I want to better understand it, and so do others. This blog is meant to be a Community and perhaps even more so a resource to Enthusiasts. I am always seeing how you and a couple of others constantly discount people's curiosity and yearn to learn. Can someone that actually knows with greater precision what this is, how it operates, and why - please help explain.

[hyperzulu]

Jeez. Way to look a gift horse in the mouth. I have first hand experience with launch control and offered my opinion. You don't like it, that's your problem and I'm sorry for you. I wasn't even responding to you, as I said, I didn't read the whole thread.
You want to know what it is and isn't? It isn't a gummy bear or shag carpeting, nor a teacup yorkie. It allows you to simulate a clutch dump on a manual transmission. Revs to 5k rpm and engages the torque converter as soon as the brake pedal is released. It then limits the amount of power applied to the wheels to minimize wheel spin. Both of these put stress on the transmission. And it's useless on a car like this. I launch better without it.

[pikcachu]

It supposedly releases and engages the clutch really fast several times per second when the wheels start to slip...
It's like an ABS but for the clutch although with an AT there is no really a clutch but a bunch of pieces with the torque converter...

In the same way the ABS releases the brakes when the wheels lock, the lunch control is supposed to release the clutch when the wheels slip and re-engage when they stop slipping...

It's not the same as traction control as TC cuts power, instead launch control does it by releasing the clutch, so RPMs are still up so when it re-engages you have all the power from the engine

hope it helped you understand ....

[one1er]

it seems people boil a little over trans talk...

I know how LC works, how to activate it, what it's for, but I was just wondering on the 3 initial questions...specifically the 8-speed durability/reliability considering an aggressive style!

You see, i'm pretty divided on trans choice, and I'm trying to expose each option shortfalls or Aquiles eels, so I'll make the most "educated decision".

[///M235i]

So, red light turns green, launch control takes you through a faster and screeching start? In plain English, that's what I'm gathering. Dare I say, fast and furious style? Is that correct? I'm actually a techie and understand Technology very well, but what I'm not is someone that knows the greater detail of what's under the hood of a car. I am getting there, so please bear with me! That said, besides launch control, I'm still looking to better understand these paddles. They remind me of cruise control on a Volvo but I know it has nothing to do with that. Shout out and much love to Zulu. Just when he said don't even worry about it when you read that it kind of looks like he's shutting down the conversation when there was still much more to learn. I really don't think he meant to do that. So again much love and thanks, Mr. Hyper Zulu.

[bimmerfile]

Originally Posted by valentinbmw

I never seen such a useless experiment or test drive, launch, or whatever that guy is a totally deuchbag i wonder if he get paid by launching the car and making stupid faces. What an asshole..,

+1

[pikcachu]

Originally Posted by MmmTwo35

So, red light turns green, launch control takes you through a faster and screeching start? In plain English, that's what I'm gathering. Dare I say, fast and furious style? Is that correct? I'm actually a techie and understand Technology very well, but what I'm not is someone that knows the greater detail of what's under the hood of a car. I am getting there, so please bear with me! That said, besides launch control, I'm still looking to better understand these paddles. They remind me of cruise control on a Volvo but I know it has nothing to do with that. Shout out and much love to Zulu. Just when he said don't even worry about it when you read that it kind of looks like he's shutting down the conversation when there was still much more to learn. I really don't think he meant to do that. So again much love and thanks, Mr. Hyper Zulu.

Paddles are for switching gears up and down

[bladeomatic]

Originally Posted by VeryBadman

I watched that video and to be honest, that guy acted and sounded like an idiot who got his hand on expensive toy. I

I agree that the guy is a bit of a dork.

I DON'T agree that the exercise is futile. You read everywhere how modern sport cars go into "limp" mode after several minutes of severe driving. I'm not sure a brand new M3 could do 50 full-tilt 0-60 runs back-to-back like this without showing some adverse effects (overheating, limp mode, etc.). If I'm Porsche, I'm gently patting myself on the back after watching this. Just wish the guy wasn't such a tool. :-)

Fast AND strong.

You can also bet your ass that Bugatti, Lambo or others aren't going to hurry to replicate this test. It's brutal punishment to a car in a short period of time.

I think the point of the piece was to show how over-engineered the Porsche was...even though the test was something that no one would do in practical terms.

To be honest, I don't know how practical it is to put a car on a skid pad either, but these tests provide lateral G measurements that we use to compare against other cars.

[WWM]

I had a C63 which had launch control. I believe the car mags said that while it provided more consistent launches, launching it manually was actually faster. I did both but never timed it, and activating launch control was a timely and convoluted process so I never used it more than a couple of times. Different car, but something to think about.