Turbo Lag- Scared myself

BlueZ4Arizona · 07-31-2013, 05:41 PM

I drive in sport mode and sport drive most of the time and have no turbo lag.

Hearing that you've investigated and found there to be severe turbo lack is surprising. Are you sure this was not about the e85 - previous generation?

bmwmick · 07-31-2013, 08:52 PM

Quote:

Originally Posted by Roadstergal

In four years, I have never experienced any turbo lag.

+1 in 2 years BUT I would never have purchased an automatic either.

Mick

Frank Costanza · 07-31-2013, 10:45 PM

Anytime you need to make an evasive maneuver always slap the tranny to the left into S Mode.

Eliminates most if not all the lag. In standard D mode, city driving there is considerable turbo lag. I've caught myself out at first and it was very frustrating at times.

bmwmick · 08-01-2013, 02:54 PM

Quote:

Originally Posted by Frank Costanza

In standard D mode, city driving there is considerable turbo lag. I've caught myself out at first and it was very frustrating at times.

That has nothing to do with turbo lag, that is simply your automatic transmission deciding what to do. I have a diesel with considerable turbo lag and this engine has none.

Mick

CedarZ4 · 08-01-2013, 03:10 PM

Quote:

Originally Posted by bmwmick

That has nothing to do with turbo lag, that is simply your automatic transmission deciding what to do. I have a diesel with considerable turbo lag and this engine has none.

Mick

Exactly. There seems to be too much confusion regarding turbo-lag and transmission response. If putting it into "S" mode removes this "lag" then it isn't turbo lag, it's just the transmission shifting sluggishly. As someone else stated already, this is BMWs way of making the ride smoother and less jerky for those who prefer a more comfortable ride. Any delay in gearing or throttle response is a matter of the ECU learning your driving behavior, and not a mechanical issue (turbo-lag). There is a post about how to reset this, or, just drive aggressively for a week or two and the car should adapt as so.

Frank Costanza · 08-01-2013, 08:34 PM

I do a lot of downtown city driving in traffic here.

What frequently happens to me is that if I leave it n D and am slowing down and moving quite slowly the tranny stays in D3 as it always selects the highest possible gear as early as possible. I'll get back on the gas and it stays in 3 but for a moment there is nothing. Then a waft of torque comes on and it pulls away effortlessly. When none of the sports modes are engages it takes a fair bit of pedal travel to provoke a kick down and I'm familiar with the amount of pedal travel before the tranny will kick down in D. What I experience is definitely turbo lag because the tranny is already fully engaged in a gear. It's very brief but I've experienced it more than a few times now.

There are other times when I'm standing still and jump on the accelerator quickly (ie. while making a left) and I get absolutely nothing. Then suddenly a second or so after I've hit the pedal the car jumps. Just have to get used to the fact that DCTs are not as good as torque converter automatics in this regard and don't repeat that mistake.

bmwmick · 08-01-2013, 09:39 PM

NOT~

z4z4z4 · 08-02-2013, 01:23 AM

Frank, your DSC sees your steering angle and when you try to accelerate from the traffic light and make a left turn there are computations going on to effect minimizing wheel slip n maximize safety. No DCT issue. IF you eased onto the throttle the result would be immediate acceleration. If you turnoff the DSC you can do instant donuts with the wheel turned, not the setting for inexperienced drivers who stomp the throttle to beat oncoming traffic.

SgtGigglebox · 08-02-2013, 06:29 AM

My suspicion was the transmission's decision making ability, but couldn't quantify it.

There certainly "seems" to be significant behavior adjusting to current driving habits and if you're not in sport/sport+ and the car's on a cold start, there is probably logic that's kicking in to save MPG.

nicknaz · 08-02-2013, 09:25 AM

Quote:

Originally Posted by SgtGigglebox

There certainly "seems" to be significant behavior adjusting to current driving habits

Easy fix then.....

HerrK · 08-02-2013, 08:38 PM

These behavioral issues appear be specific to the AT side of the family. My theroy is they are related to the XX gene of the vehicle and support the "chick car" designation. There certainly is an abundance of whinning in this thread.

Never experienced anything like this with the MT side of the family.

tranquility · 08-03-2013, 01:40 AM

Let's not turn this into another 'AT' vs MT argument again, even though it's doubtful that it's related to the DCT, which is NOT an AT btw - never is, never was...

Again, my car (DCT) no longer has this prb (only had it during the first few weeks of ownership) and I think it's just a matter of the computer getting used to the driver's driving pattern to get rid of this lag. The DCT shifts way faster than any humanoid using MT, so I find it weird that there's a lag (albeit temporary, for me, anyway) w/ DCT whereas it is supposedly non-existent in the MT.

jparnes1 · 08-03-2013, 06:43 AM

Quote:

Originally Posted by tranquility

Let's not turn this into another 'AT' vs MT argument again, even though it's doubtful that it's related to the DCT, which is NOT an AT btw - never is, never was...

Again, my car (DCT) no longer has this prb (only had it during the first few weeks of ownership) and I think it's just a matter of the computer getting used to the driver's driving pattern to get rid of this lag. The DCT shifts way faster than any humanoid using MT, so I find it weird that there's a lag (albeit temporary, for me, anyway) w/ DCT whereas it is supposedly non-existent in the MT.

The OP has had his car for quite some time. I would think the computer would have learned his driving habits by now. I think think it's quite clear this is transmission-related. Drive the DCT in automatic (yes, it's an automatic - it shifts for you) and you get this "lag", drive it in manual mode, no "lag". This is true for my 5 series, my wife's Volvo, and any car with an automatic I've driven: 1. Give it a lot of gas, 2. Why isn't my car moving? 3. Head bangs the headrest. Throttle response is always lacking with an AT, in my experience.

Constant.S · 08-03-2013, 06:56 AM

Get a true limited slip differential (such as Quaife or Wavetrack) and voila! That hesitation/lag is gone. In my car that was caused by the e-LSD

tranquility · 08-03-2013, 11:39 AM

Quote:

Originally Posted by jparnes1

The OP has had his car for quite some time. I would think the computer would have learned his driving habits by now. I think think it's quite clear this is transmission-related. Drive the DCT in automatic (yes, it's an automatic - it shifts for you) and you get this "lag", drive it in manual mode, no "lag". This is true for my 5 series, my wife's Volvo, and any car with an automatic I've driven: 1. Give it a lot of gas, 2. Why isn't my car moving? 3. Head bangs the headrest. Throttle response is always lacking with an AT, in my experience.

Well, then perhaps he should get it reset or have a different driving style so that the computer can get attuned since I no longer encounter that prb.

DCT is not an AT because it doesn't have a torque converter, doesn't matter that it can shift for you, that's just semantics; it's not just AT and MT, there are many types of trannys out there these days, get it right. So, sure, perhaps MT fanboys can say that throttle response may lack in some ATs, but this isn't necessarily true for DCTs.

HerrK · 08-03-2013, 01:14 PM

Quote:

Originally Posted by tranquility

Well, then perhaps he should get it reset or have a different driving style so that the computer can get attuned since I no longer encounter that prb.

DCT is not an AT because it doesn't have a torque converter, doesn't matter that it can shift for you, that's just semantics; it's not just AT and MT, there are many types of trannys out there these days, get it right. So, sure, perhaps MT fanboys can say that throttle response may lack in some ATs, but this isn't necessarily true for DCTs.

Professor Tranquility please provide a source of your definition of an AT

Here are three of my references.

Collins English Dictionary

automatic transmission (noun - Engineering / Automotive Engineering) - a transmission system in a motor vehicle, usually incorporating a fluid clutch, in which the gears change automatically.

Websters College Dictionary

automatic transmission - (noun) - a transmission that automatically changes the gears according to the speed of the car

Wordnet, Princeton University

automatic transmission (Noun) - a transmission that automatically changes the gears according to the speed of the car

Why are you so defensive about driving an AT?

tranquility · 08-03-2013, 01:55 PM

^...because it's technically not an AT, that's it; sure one can have the comp choose the gears but one can choose by oneself as well...is DCT a MT because one can choose gears in the former? Surely not, so there goes that reasoning.

It is something new that is not an AT or MT. It has no torque converter, it's not a slushbox. What is so hard to understand? It is the superior tranny to date.

Class dismissed (Prof Tranquility)

ManiacGT · 08-03-2013, 02:41 PM

Guys lets not argue over this its pointless. The fact is that the car in normal mode is a bit of a softy and sport or paddles are required to get immediate response just as you would with a manual.. Take control!

E89Tardis · 08-03-2013, 04:57 PM

If you drive a DCT the same as you would an Automatic, you will damage it. Like a manual, you are supposed to disengage the clutches by pressing the brake pedal. With an automatic, you can let the transmission hold the car in place and leave your foot off the brake and no harm will come to you.

You should not do this in a DCT. This was discussed in my owners manual and it is important for anyone you let drive your car, to understand the difference. Not an automatic but more like a manual with a brain and no clutch pedal.

Sorry for the off topic but I think It's good info for anyone who has a DCT and doesn't already understand the differences.

ManiacGT · 08-03-2013, 05:18 PM

Quote:

Originally Posted by E89Tardis

If you drive a DCT the same as you would an Automatic, you will damage it. Like a manual, you are supposed to disengage the clutches by pressing the brake pedal. With an automatic, you can let the transmission hold the car in place and leave your foot off the brake and no harm will come to you.

You should not do this in a DCT. This was discussed in my owners manual and it is important for anyone you let drive your car, to understand the difference. Not an automatic but more like a manual with a brain and no clutch pedal.

Sorry for the off topic but I think It's good info for anyone who has a DCT and doesn't already understand the differences.

That's news to me. Why would you not let the car hold on the DCT? It's holding on liquid cooled clutches, it will wear but not damage it. Sure on torque converters there's little to no wear compared but unless you have the car hold you on an incline for extended periods then holding the car for a few seconds when pulling away or coasting in traffic is not an issue IMHO.

E89Tardis · 08-03-2013, 06:38 PM

Page 55-56 in my manual in a section called "7-gear Sport Automatic Transmission with Dual Clutch" under the heading "System limitations" it says to " do not hold the vehicle on inclines by depressing the accelerator lightly and dragging the clutch; otherwise, the transmission may overheat.

May not be a big deal but I just modified my habits a long time ago to comply anyway.

Doesn't say anything about standing at red lights though and it also does not use the acronym DCT anywhere rather they refer to it as 7-gear Sport Automatic Transmission with Dual Clutch, but I still view it as an electronically controlled manual probably because of this limitation that is reminiscent of riding the clutch in a manual.

tranquility · 08-03-2013, 07:15 PM

Quote:

Originally Posted by E89Tardis

Page 55-56 in my manual in a section called "7-gear Sport Automatic Transmission with Dual Clutch" under the heading "System limitations" it says to " do not hold the vehicle on inclines by depressing the accelerator lightly and dragging the clutch; otherwise, the transmission may overheat.

May not be a big deal but I just modified my habits a long time ago to comply anyway.

Doesn't say anything about standing at red lights though and it also does not use the acronym DCT anywhere rather they refer to it as 7-gear Sport Automatic Transmission with Dual Clutch, but I still view it as an electronically controlled manual probably because of this limitation that is reminiscent of riding the clutch in a manual.

Ok, that's a no brainer for *any* tranny as it will wear out parts not to mention gas.

07-31-2013, 05:41 PM	#23
BlueZ4Arizona Private First Class 4 Rep 101 Posts Drives: 2009 Z4 sDrive 35i Join Date: Jul 2009 Location: Chandler, AZ iTrader: (0)	I drive in sport mode and sport drive most of the time and have no turbo lag. Hearing that you've investigated and found there to be severe turbo lack is surprising. Are you sure this was not about the e85 - previous generation?
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07-31-2013, 10:45 PM	#25
Frank Costanza Private First Class 4 Rep 152 Posts Drives: 540i/6, Z4 35i Join Date: Oct 2010 Location: Toronto iTrader: (0)	Anytime you need to make an evasive maneuver always slap the tranny to the left into S Mode. Eliminates most if not all the lag. In standard D mode, city driving there is considerable turbo lag. I've caught myself out at first and it was very frustrating at times. __________________
	Appreciate 0 Quote

08-01-2013, 08:34 PM	#28
Frank Costanza Private First Class 4 Rep 152 Posts Drives: 540i/6, Z4 35i Join Date: Oct 2010 Location: Toronto iTrader: (0)	I do a lot of downtown city driving in traffic here. What frequently happens to me is that if I leave it n D and am slowing down and moving quite slowly the tranny stays in D3 as it always selects the highest possible gear as early as possible. I'll get back on the gas and it stays in 3 but for a moment there is nothing. Then a waft of torque comes on and it pulls away effortlessly. When none of the sports modes are engages it takes a fair bit of pedal travel to provoke a kick down and I'm familiar with the amount of pedal travel before the tranny will kick down in D. What I experience is definitely turbo lag because the tranny is already fully engaged in a gear. It's very brief but I've experienced it more than a few times now. There are other times when I'm standing still and jump on the accelerator quickly (ie. while making a left) and I get absolutely nothing. Then suddenly a second or so after I've hit the pedal the car jumps. Just have to get used to the fact that DCTs are not as good as torque converter automatics in this regard and don't repeat that mistake. __________________
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08-01-2013, 09:39 PM	#29
bmwmick Second Lieutenant 18 Rep 237 Posts Drives: '97 Z3,'11 Z4 35i,'90 C4 Vette Join Date: May 2011 Location: AZ/CA iTrader: (1)	NOT~ __________________ Mick 2011 35i 6-speed, ///M Sport, Deep Sea Blue, Black leather, Carbon trim, Cold Weather package, Premium package, 6CD changer. Delivered 7/15/11. Michelin Pilot SuperSport tires 10/24/12 Tucson,AZ/Santa Paula,CA
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08-02-2013, 01:23 AM	#30
z4z4z4 Lieutenant 45 Rep 547 Posts Drives: 2002 M3 Join Date: Mar 2010 Location: mild mediterranean breezes iTrader: (1)	Frank, your DSC sees your steering angle and when you try to accelerate from the traffic light and make a left turn there are computations going on to effect minimizing wheel slip n maximize safety. No DCT issue. IF you eased onto the throttle the result would be immediate acceleration. If you turnoff the DSC you can do instant donuts with the wheel turned, not the setting for inexperienced drivers who stomp the throttle to beat oncoming traffic.
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08-02-2013, 06:29 AM	#31
SgtGigglebox Lieutenant 100 Rep 494 Posts Drives: '13 Atacama 35is Join Date: Sep 2012 Location: Washington D.C. Area iTrader: (0)	My suspicion was the transmission's decision making ability, but couldn't quantify it. There certainly "seems" to be significant behavior adjusting to current driving habits and if you're not in sport/sport+ and the car's on a cold start, there is probably logic that's kicking in to save MPG.
	Appreciate 0 Quote

08-02-2013, 08:38 PM	#33
HerrK Captain 42 Rep 640 Posts Drives: 21 X5 40i, 77 R100Rs Join Date: Dec 2009 Location: AZ iTrader: (0)	These behavioral issues appear be specific to the AT side of the family. My theroy is they are related to the XX gene of the vehicle and support the "chick car" designation. There certainly is an abundance of whinning in this thread. Never experienced anything like this with the MT side of the family. __________________ HerrK - 2021 X5 40i M Sport l PCD l Atlantis Blue/Ext'd Tartufo Merino l M Sport w/blue Calipers l Matt Popular l HK Sound l 740's l Exec & Drive Pro Pack Sold w/Great Memories - E89 Z4 l ED 2010 l 2011 35i l Crimson/Ext'd Coral Red w/Alum l 6 sp MT l Prem Sound l Sport Pack l 296's
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08-03-2013, 01:40 AM	#34
tranquility sportscars only 3244 Rep 3,195 Posts Drives: 2011 Z4 sDrive 35i Join Date: Aug 2007 Location: Montréal iTrader: (0)	Let's not turn this into another 'AT' vs MT argument again, even though it's doubtful that it's related to the DCT, which is NOT an AT btw - never is, never was... Again, my car (DCT) no longer has this prb (only had it during the first few weeks of ownership) and I think it's just a matter of the computer getting used to the driver's driving pattern to get rid of this lag. The DCT shifts way faster than any humanoid using MT, so I find it weird that there's a lag (albeit temporary, for me, anyway) w/ DCT whereas it is supposedly non-existent in the MT.
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08-03-2013, 06:56 AM	#36
Constant.S Resistance is futile... 54 Rep 640 Posts Drives: BMW Z4 E89(N54) Join Date: Nov 2010 Location: Greece/Canada iTrader: (0)	Get a true limited slip differential (such as Quaife or Wavetrack) and voila! That hesitation/lag is gone. In my car that was caused by the e-LSD __________________ An ounce of performance is worth pounds of promises.
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08-03-2013, 01:55 PM	#39
tranquility sportscars only 3244 Rep 3,195 Posts Drives: 2011 Z4 sDrive 35i Join Date: Aug 2007 Location: Montréal iTrader: (0)	^...because it's technically not an AT, that's it; sure one can have the comp choose the gears but one can choose by oneself as well...is DCT a MT because one can choose gears in the former? Surely not, so there goes that reasoning. It is something new that is not an AT or MT. It has no torque converter, it's not a slushbox. What is so hard to understand? It is the superior tranny to date. Class dismissed (Prof Tranquility)
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08-03-2013, 02:41 PM	#40
ManiacGT Major 85 Rep 1,448 Posts Drives: Z4 sDrive 35i Join Date: Jan 2011 Location: Manchester, UK iTrader: (0)	Guys lets not argue over this its pointless. The fact is that the car in normal mode is a bit of a softy and sport or paddles are required to get immediate response just as you would with a manual.. Take control!
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08-03-2013, 04:57 PM	#41
E89Tardis Private First Class 6 Rep 117 Posts Drives: 2009 Z4 35i Join Date: Sep 2009 Location: New England iTrader: (0)	If you drive a DCT the same as you would an Automatic, you will damage it. Like a manual, you are supposed to disengage the clutches by pressing the brake pedal. With an automatic, you can let the transmission hold the car in place and leave your foot off the brake and no harm will come to you. You should not do this in a DCT. This was discussed in my owners manual and it is important for anyone you let drive your car, to understand the difference. Not an automatic but more like a manual with a brain and no clutch pedal. Sorry for the off topic but I think It's good info for anyone who has a DCT and doesn't already understand the differences.
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08-03-2013, 06:38 PM	#43
E89Tardis Private First Class 6 Rep 117 Posts Drives: 2009 Z4 35i Join Date: Sep 2009 Location: New England iTrader: (0)	Page 55-56 in my manual in a section called "7-gear Sport Automatic Transmission with Dual Clutch" under the heading "System limitations" it says to " do not hold the vehicle on inclines by depressing the accelerator lightly and dragging the clutch; otherwise, the transmission may overheat. May not be a big deal but I just modified my habits a long time ago to comply anyway. Doesn't say anything about standing at red lights though and it also does not use the acronym DCT anywhere rather they refer to it as 7-gear Sport Automatic Transmission with Dual Clutch, but I still view it as an electronically controlled manual probably because of this limitation that is reminiscent of riding the clutch in a manual.
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