E90Post
 


Extreme Power House
 
BMW 3-Series (E90 E92) Forum > BMW E90/E92/E93 3-series General Forums > General E90 Sedan / E91 Wagon / E92 Coupe / E93 Cabrio > 6MT shifting with AC on



Reply
 
Thread Tools Search this Thread
      06-15-2007, 07:15 PM   #1
Wissam
Private First Class
Canada
6
Rep
141
Posts

Drives: 2007 e90 328I
Join Date: Dec 2006
Location: GTA, Canada

iTrader: (3)

6MT shifting with AC on

I normally shift around 2700-3000 rpm, but I noticed when the AC is on it becomes hard to shift smoothly at these rpms and I would have to go north of3500 rpm to help smooth the shifts out. Are you guys noticing the same thing? I know the AC puts extra load on the engine, but it should not be this noticeable on an engine this size.
Appreciate 0
      06-15-2007, 08:08 PM   #2
itsbrokeagain
itsbrokeagain's Avatar
United_States
173
Rep
15,732
Posts

Drives: E28 535, 1996 Dodge Ram Diesel
Join Date: Mar 2007
Location: Valley Stream, NY

iTrader: (7)

Send a message via AIM to itsbrokeagain
i have noticed that as well...below 3000 rpm the engine drops like a rock and I have to quick shift or blip the gas to keep it from lurching.
__________________
AUTOCouture Motoring: Handling reflector installs to turbo upgrades and superchargers, and everything in between
15-01 Pollitt Drive, Fairlawn NJ 201-666-3500

<-Official Vehicle Transport for AUTOCouture
Appreciate 0
      06-15-2007, 09:33 PM   #3
wj4
Major General
United_States
137
Rep
7,719
Posts

Drives: E90 manual 335i
Join Date: Nov 2006
Location: Burbank, CA

iTrader: (8)

Send a message via AIM to wj4
I, too, notice that. But I notice it with other cars as well. I believe when the a/c is on, it's using a lot of juice from the surge compressor that's why.
Appreciate 0
      06-15-2007, 09:57 PM   #4
achien
AC
Canada
32
Rep
2,378
Posts

Drives: E90 Post Members Crazy
Join Date: May 2007
Location: Toronto, Canada

iTrader: (0)

Yes, especially if you "Max" out the A/C. I feel the power lost is more apparent when shifting from 1st to 2nd.
__________________
Your Supreme Leader
Appreciate 0
      06-15-2007, 11:54 PM   #5
Wissam
Private First Class
Canada
6
Rep
141
Posts

Drives: 2007 e90 328I
Join Date: Dec 2006
Location: GTA, Canada

iTrader: (3)

Thanks guys for your feedback...
Appreciate 0
      06-16-2007, 12:11 AM   #6
MPoWeRMAN
First Lieutenant
MPoWeRMAN's Avatar
United_States
10
Rep
388
Posts

Drives: 2007 E91
Join Date: Aug 2006
Location: Rancho Mirage, CA

iTrader: (9)

Send a message via Yahoo to MPoWeRMAN
especially here in the desert where its 120 in the summer, if I need a little more power off the line, I shut off the ac till I reach speed
Appreciate 0
      06-16-2007, 01:53 AM   #7
TRZ06
Captain
TRZ06's Avatar
United_States
43
Rep
753
Posts

Drives: 08' IB E90 M3
Join Date: Apr 2007
Location: Bay Area, CA

iTrader: (0)

You know I never thought I would say this, but with this particular car and this particular auto tranny....

This car is better driving and more user friendly and for the most part faster with the Steptronic. It's almost as if this car was built around that tranny.
__________________
16' M3 Mineral Gray, DCT, Adaptive M sus., 19" wheels
15' Audi S4
13' Audi TTRS (APR stage 1, MSS springs)
09' C6 Z06
08' M3 Interlagos Blue: 6sp, Tech. & Premium Package
Appreciate 0
      06-16-2007, 07:22 AM   #8
bmw0perat0r
Lieutenant
bmw0perat0r's Avatar
United_States
4
Rep
494
Posts

Drives: 2014 328i xDrive Sport Line
Join Date: Apr 2007
Location: MD

iTrader: (0)

Quote:
Originally Posted by TRZ06 View Post
You know I never thought I would say this, but with this particular car and this particular auto tranny....

This car is better driving and more user friendly and for the most part faster with the Steptronic. It's almost as if this car was built around that tranny.
I don't notice the a/c on at all with my steptronic. Shifting is consistantly smooth with or without it on. Engine speeds between shifts do not change. In short - one does not notice any difference in engine power/smoothness.

In my old e36 m3 ...oh yeah, you felt it kick in even while at highway speeds...car would slow for a second when you turned it on, needless to say I rarely used the a/c.
Appreciate 0
      06-16-2007, 12:53 PM   #9
CaptChaos
Captain
CaptChaos's Avatar
Canada
11
Rep
753
Posts

Drives: E92 335
Join Date: Oct 2006
Location: Richmond, BC, Canada

iTrader: (0)

Garage List
2007 E92 335  [0.00]
Yes, I can tell when the AC is turned on. The revs must drop faster during shifts so this requires more attention to be smooth.
Appreciate 0
      06-16-2007, 12:57 PM   #10
epiphone3
Lieutenant Colonel
30
Rep
1,672
Posts

Drives: 2013 BMW X3 35i
Join Date: Oct 2005
Location: Calgary

iTrader: (0)

I notice the same thing... I try to keep the AC off as much as possible.
Appreciate 0
      06-16-2007, 04:32 PM   #11
danimal
Captain
danimal's Avatar
United_States
20
Rep
757
Posts

Drives: '14 228i
Join Date: Jan 2007
Location: San Diego, CA

iTrader: (0)

Garage List
Quote:
Originally Posted by epiphone3 View Post
I notice the same thing... I try to keep the AC off as much as possible.
+1

They need to make a/c run off the electrical system, not the engine.

-Dan
__________________
2014 228i
alpine white | sport line | 6-speed manual | lighting package | driver assistance package
interior - black Sensatec | aluminum & red trim


Appreciate 0
      06-16-2007, 04:51 PM   #12
fdc
Second Lieutenant
United_States
7
Rep
212
Posts

Drives: E90 325xi
Join Date: Sep 2005
Location: Chicago

iTrader: (0)

Quote:
Originally Posted by danimal View Post
+1

They need to make a/c run off the electrical system, not the engine.

-Dan
it is much worse ...
in this case the a/c will take the power from the generator that of couse
will take the same power off the engine (becaming harder to spin as you
request more current). Not only, since the generator has a 80%
efficency you will loose ... after this your 'electric' A/c will require a compressor (another electric motor ...).

Attaching the compressor directly to the engine is actually the most
efficent option

fdc
__________________
325xi, leather.

Departure: Bremerhaven Sept 28, 2005
Vessel: Franconia K-line (http://www.kline.com/PCC-RoRo/schedu...ticshuttle.asp)
Arrived at the Port of Charleston at 04:40 on Oct. 10, 2005
Arrived At VPC: 10/11/05
Left the VPC: 10/14/05 3:40pm
Arrived at the Dealer: 10/15/05 3:00pm
Delivery: 10/18/05 10:00 am
Appreciate 0
      06-16-2007, 04:54 PM   #13
Chesmu
Brigadier General
Chesmu's Avatar
United_States
41
Rep
3,013
Posts

Drives: 2013 X6
Join Date: Dec 2005
Location: Phoenix,AZ

iTrader: (2)

Garage List
2006 330i  [0.00]
2006 330i  [0.00]
Send a message via AIM to Chesmu
never noticed this....
i guess i usually shift higher than 3500 rpm....
__________________
"Teach the ignorant. Ignore the stupid."
Appreciate 0
      06-16-2007, 05:12 PM   #14
Walked U
Brigadier General
72
Rep
3,117
Posts

Drives: RR sport s/c, E82, E89 3.5is
Join Date: Nov 2006
Location: USA

iTrader: (5)

I got the cdv delete. Now it shifts like a hot knife through butter. Even with the AC on
__________________
Previous - E90 335i, E82
Current - E89 / Range Rover sport Super charged.
Appreciate 0
      06-16-2007, 07:12 PM   #15
danimal
Captain
danimal's Avatar
United_States
20
Rep
757
Posts

Drives: '14 228i
Join Date: Jan 2007
Location: San Diego, CA

iTrader: (0)

Garage List
Quote:
Originally Posted by fdc View Post
it is much worse ...
in this case the a/c will take the power from the generator that of couse
will take the same power off the engine (becaming harder to spin as you
request more current). Not only, since the generator has a 80%
efficency you will loose ... after this your 'electric' A/c will require a compressor (another electric motor ...).

Attaching the compressor directly to the engine is actually the most
efficent option

fdc
I'm not an electrical engineer, so I can't really debate you on the details, but I know the a/c on hybrids tends to be electric (since the engine is frequently turned off) and electric power steering is popping up on all types of vehicles, so it's definitely possible. Electric a/c may require a higher voltage electrical system or a larger battery, but those things are likely to appear anyway with the increasing use of electronics in vehicles.

-Dan
__________________
2014 228i
alpine white | sport line | 6-speed manual | lighting package | driver assistance package
interior - black Sensatec | aluminum & red trim


Appreciate 0
      06-16-2007, 10:12 PM   #16
achien
AC
Canada
32
Rep
2,378
Posts

Drives: E90 Post Members Crazy
Join Date: May 2007
Location: Toronto, Canada

iTrader: (0)

Quote:
Originally Posted by bmw0perat0r View Post
I don't notice the a/c on at all with my steptronic. Shifting is consistantly smooth with or without it on. Engine speeds between shifts do not change. In short - one does not notice any difference in engine power/smoothness.

In my old e36 m3 ...oh yeah, you felt it kick in even while at highway speeds...car would slow for a second when you turned it on, needless to say I rarely used the a/c.
Quote:
Originally Posted by TRZ06 View Post
You know I never thought I would say this, but with this particular car and this particular auto tranny....

This car is better driving and more user friendly and for the most part faster with the Steptronic. It's almost as if this car was built around that tranny.
This is the same for AT, you guys don't notice the powerloss because you are already being "shielded" from the torque-converter.

AT usually gives up 10% to 15% of the engine power compared to MT as a result of powerloss in the torque-converter.
__________________
Your Supreme Leader
Appreciate 0
      06-16-2007, 11:57 PM   #17
s4iscool
Major
United_States
12
Rep
1,128
Posts

Drives: 06 330i
Join Date: Dec 2006
Location: Neccos

iTrader: (2)

i posted this same topic a couple months ago, check it out
Appreciate 0
      06-17-2007, 12:15 AM   #18
ward
Major General
73
Rep
6,162
Posts

Drives: F
Join Date: May 2005
Location: T

iTrader: (0)

Quote:
Originally Posted by danimal View Post
I'm not an electrical engineer, so I can't really debate you on the details, but I know the a/c on hybrids tends to be electric (since the engine is frequently turned off) and electric power steering is popping up on all types of vehicles, so it's definitely possible. Electric a/c may require a higher voltage electrical system or a larger battery, but those things are likely to appear anyway with the increasing use of electronics in vehicles.

-Dan
FDC's right

with AC the way it is now, you have a certain amount of engine power that is required to turn the AC compressor

if you had an electric AC compressor, you'd need electricity, which is made by the alternator, which is spun by the motor. So if you needed electric AC the alternator would draw more energy from the motor

turning mechanical energy into electrical energy is not a %100 efficent process, so if you had an electrical AC compressor your engine would have to work harder than if you had a standard mechanical AC compressor
Appreciate 0
      06-17-2007, 01:27 AM   #19
jonerik26
Lieutenant Colonel
jonerik26's Avatar
Philippines
20
Rep
1,869
Posts

Drives: black 335i e90 PRE-LCI
Join Date: Apr 2006
Location: somewhere

iTrader: (21)

Garage List
2007 335i  [4.00]
1998 Acura Integra  [4.25]
2006 325i  [4.00]
i just tried to avoid the ac just because i know its going to change the car's performance
__________________
Appreciate 0
      06-17-2007, 01:31 AM   #20
GraphiteBrawler
Elton John Impersonator
GraphiteBrawler's Avatar
United_States
15
Rep
329
Posts

Drives: 2016 LCI M3
Join Date: Jun 2007
Location: Boston, MA

iTrader: (0)

Wow, having Step, I've never experienced this, but it sounds like a pain in the ass, any way to fix it for you 6mt guys?
Appreciate 0
      06-17-2007, 01:54 AM   #21
IndianPoweredE90
Loner in 909
IndianPoweredE90's Avatar
United_States
2
Rep
154
Posts

Drives: 335i Sedan 6MT Blk/Blk
Join Date: Jan 2007
Location: REDLANDS, CA

iTrader: (1)

Send a message via AIM to IndianPoweredE90
i noticed this with my ac on as well. but i figured since the ac was on it was normal. and sine everyone else is posting about it i guess it is.. i cant shift was smooth..
__________________
-=2007 335i Sedan=-
-=6spd MT=-
-=Jet Black=-
Appreciate 0
      06-17-2007, 02:36 AM   #22
karliejai
Da Kid
karliejai's Avatar
Hong Kong
57
Rep
4,576
Posts

Drives: JetBlack e90 335i
Join Date: Mar 2007
Location: Livingston, NJ

iTrader: (4)

Send a message via AIM to karliejai
drive with window down =P
__________________


MODS: OEM Front Splitter | ACS Roof Spoiler | OEM Trunk Spoiler | Matt Black Front Grill | Black Shadowline Window Trim | Painted Front Lower Rod | Blacklines | JDM Yellow Fogs | Custom Silver CF Headlights with LUX 4.0 | Eisenhaus Sports Exhaust
Appreciate 0
Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -4. The time now is 11:11 AM.




e90post
e90post
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST