How bad is launching 2nd gear?

idrift4wd · 11-13-2011, 12:27 PM

had an argument with a friend last night about launching in second gear.

being that i have a 6AT, 1st gear is kinda useless with these crappy allseasons. and 2nd in my opinion feels like it could be a better launch. From e90post i see alot of people who drag their cars do this.

but my friend said it one of the worst things you can do for your torque converter. all the stress is going to the torque converter and all the heat.

basically.... 2nd gear launch ok?

335BBS · 11-13-2011, 01:48 PM

Quote:

Originally Posted by idrift4wd

had an argument with a friend last night about launching in second gear.

being that i have a 6AT, 1st gear is kinda useless with these crappy allseasons. and 2nd in my opinion feels like it could be a better launch. From e90post i see alot of people who drag their cars do this.

but my friend said it one of the worst things you can do for your torque converter. all the stress is going to the torque converter and all the heat.

basically.... 2nd gear launch ok?

Sure. Why not? Are you standing on both pedals? I'm pretty sure you'd be faster in 1st. Try summer tires too.

cptcrunch · 11-13-2011, 01:54 PM

Shouldn't be a problem, the Diesels launch in second due to the torque. Honestly though, you should just leave it in D and let the car do its thing. If you are losing traction on your all seasons, you are either flooring it with the DSC off or have bald tires.

335BBS · 11-13-2011, 01:55 PM

Quote:

Originally Posted by someguy_99

Why not just i dont know start in first you are doing considerable amount of damage starting in second. Thats like saying i have 6 gears why not just go straight to the 6th and save the others one for later

What language is that?
In AT, if there was damage being done the tranny would shift.

DnA Diesel · 11-13-2011, 02:16 PM

Quote:

Originally Posted by someguy_99

Why not just i dont know start in first you are doing considerable amount of damage starting in second. Thats like saying i have 6 gears why not just go straight to the 6th and save the others one for later

This is ill informed. There is no mechanical basis for such a statement.

A torque converter sits between the engine and the transmission input. It can only ever see a worst case of maximum engine torque and zero rotational speed of the transmission's gear train. It is rated to withstand that maximum torque difference between engine and transmission. Once the vehicle starts moving forward, the TC is no longer in full stall, and the frictional heat rate reduces noticeably.

What WOULD be bad for the driveline would be an extended brake stand, i.e. application of full brake while simultaneously applying full throttle. THAT is what would heat the transmission fluid unnecessarily, and if done for too long a period (several tens of seconds, for example) then the transmission fluid temperature can rise above normal operating limits. Repeated often, this type of treatment will cause the transmission fluid to lose its protective properties and damage to the transmission may result.

Given how sensitive car makers are to litigation, it is unlikely (read they don't) that an auto maker would allow transmission programming that would damage the transmission.

If the diesels can withstand 425 ft-lbs in 2nd (or any gear, for that matter), then there is no reason a 335i AT can't tolerate 300 ft-lbs in 2nd...

Regards
D.

Wires · 11-13-2011, 02:46 PM

Considering driving in "D" ALWAYS launches in 2nd gear, you won't have a problem.

You can search for it, but a lot of guys say you get better ET's in 2nd gear. I'm guessing the PCM does more "granny protection" in 1st. Could also be that the engine ends up hitting the sweet spot in 2nd faster (like a car with a high stall converter), so better launches.

Coolieman1220 · 11-13-2011, 04:40 PM

i rarely ever use first.

ZZZZ · 11-13-2011, 04:49 PM

Quote:

Originally Posted by Wires

Considering driving in "D" ALWAYS launches in 2nd gear, you won't have a problem.

You can search for it, but a lot of guys say you get better ET's in 2nd gear. I'm guessing the PCM does more "granny protection" in 1st. Could also be that the engine ends up hitting the sweet spot in 2nd faster (like a car with a high stall converter), so better launches.

exactly. if you have an AT it starts in second unless you're on an incline. If you have a 8 banger under the hood (5er or 7) then it'll start you in 3rd gear most of the time.

However, keep in mind that the gear ratios and final drive are different on AT vs MT.

11-13-2011, 12:27 PM	#1
idrift4wd Brigadier General 149 Rep 3,552 Posts Drives: Three Hundred and Thirty Five Join Date: Jul 2010 Location: Yonkers NY iTrader: (0) Garage List 2007 BMW [7.00]	How bad is launching 2nd gear? had an argument with a friend last night about launching in second gear. being that i have a 6AT, 1st gear is kinda useless with these crappy allseasons. and 2nd in my opinion feels like it could be a better launch. From e90post i see alot of people who drag their cars do this. but my friend said it one of the worst things you can do for your torque converter. all the stress is going to the torque converter and all the heat. basically.... 2nd gear launch ok?
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11-13-2011, 01:54 PM	#3
cptcrunch Captain Crunch 168 Rep 548 Posts Drives: 2016 340i Join Date: May 2011 Location: Cincinnati iTrader: (0)	Shouldn't be a problem, the Diesels launch in second due to the torque. Honestly though, you should just leave it in D and let the car do its thing. If you are losing traction on your all seasons, you are either flooring it with the DSC off or have bald tires. __________________ On Order (in transit): BMW iX 50, Oxide Grey Retired: BMW Welt Delivery 4/14/16: European Delivery - 2016 340i EBII/Saddle - ZMP \| ZCW \| ZDA \| ZLP \| ZTP \| M Adaptive \| Rear Shades \| MPPSK Before and After Dyno Retired: 2011 335D Space Grey/Black - ZSP \| ZPP \| ZCW \| 6FL \| Sat Radio \| Nav \| $600 Base Audio Upgrade
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11-13-2011, 02:46 PM	#6
Wires Brigadier General 1646 Rep 4,877 Posts Drives: 2016 340i xDrive Join Date: Apr 2008 Location: Calgary iTrader: (0)	Considering driving in "D" ALWAYS launches in 2nd gear, you won't have a problem. You can search for it, but a lot of guys say you get better ET's in 2nd gear. I'm guessing the PCM does more "granny protection" in 1st. Could also be that the engine ends up hitting the sweet spot in 2nd faster (like a car with a high stall converter), so better launches.
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11-13-2011, 04:40 PM	#7
Coolieman1220 Banned 73 Rep 1,770 Posts Drives: 2010 335d Join Date: Jul 2010 Location: New York City iTrader: (0)	i rarely ever use first.
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