BMW M3 Forum (E90 E92)

BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read


Go Back   M3Post - BMW M3 Forum > M3 (E90 / E92 / E93) > General M3 Forum (E90 + E92 + E93)
 
BPM Sport
Post Reply
 
Thread Tools Search this Thread
      05-02-2012, 01:11 AM   #1
eNCore
///M 5light
 
eNCore's Avatar
 
Drives: 13 MCB ///M5
Join Date: May 2008
Location: Los Angeles, 626

Posts: 433
iTrader: (1)

Potential Horsepower Decrease?

I am pretty sure most of you are like me, we want to have a 400WHP NA M3 but just can't hit it. M3's stock power can range anywhere from 330WHP - 360WHP on the same dyno! So this got me thinking, is it how we drive and take care of the car? And can we potentially damage/decrease the power of the car with money shifts, bouncing off redline, accidental redline with cold engine, or abused by dealer like me (revved the car to redline with cold engine: http://www.m3post.com/forums/showthread.php?t=673085)? I know the above can potentially shorten the engine's life, but will it decrease its power?
__________________
13 MCB ///M5

11 - 12 MW E92 ///M3 ZCP

08 - 11 E90 335i
eNCore is offline   United_States
0
Reply With Quote
      05-02-2012, 01:25 AM   #2
piloto
Captain
 
Drives: 2011 E90 M3 - AW/FR
Join Date: Jun 2010
Location: Orange County, CA

Posts: 835
iTrader: (0)

If you damage the piston rings or cylinder walls (via a lack of oil, excessive heat, etc.), you will lose some amount of compression in that cylinder(perhaps trivial, perhaps not, depending on the severity), which will cause for a reduction in power. Anything that can bend valves, negatively impact valve guides and seals, can lead to a reduction in compression, and thus in power production.
piloto is offline  
0
Reply With Quote
      05-02-2012, 01:46 AM   #3
eNCore
///M 5light
 
eNCore's Avatar
 
Drives: 13 MCB ///M5
Join Date: May 2008
Location: Los Angeles, 626

Posts: 433
iTrader: (1)

Quote:
Originally Posted by piloto View Post
If you damage the piston rings or cylinder walls (via a lack of oil, excessive heat, etc.), you will lose some amount of compression in that cylinder(perhaps trivial, perhaps not, depending on the severity), which will cause for a reduction in power. Anything that can bend valves, negatively impact valve guides and seals, can lead to a reduction in compression, and thus in power production.
What are the chances of these happening? Will the signs be obvious or not really?
__________________
13 MCB ///M5

11 - 12 MW E92 ///M3 ZCP

08 - 11 E90 335i

Last edited by eNCore; 05-02-2012 at 02:24 AM.
eNCore is offline   United_States
0
Reply With Quote
      05-02-2012, 02:11 AM   #4
piloto
Captain
 
Drives: 2011 E90 M3 - AW/FR
Join Date: Jun 2010
Location: Orange County, CA

Posts: 835
iTrader: (0)

Out of the scenarios you've listed, the money shift is the one that would be most concerning. Bouncing off the limiter is just fine, so long as you have pegged the accelerator down and are just letting bounce of the limiter non-stop (which unless you're crazy, you'd never do). Accidental reving to "redline" on a cold engine is the least concerning, as the M3 adjusts it based on engine temperature.

As to the money shift, you have the potential for all types of damage, depending on the severity. There's the possibility of damage to the main bearings, con-rods, valves, lots of stuff.

If you're concerned about compression loss, just do a compression test, but it'll be a PITA accessing the aft most cylinders on each bank.
piloto is offline  
0
Reply With Quote
      05-02-2012, 05:46 AM   #5
pbonsalb
Lieutenant Colonel
 
Drives: 08 E90 M3, 99 E36 M3 Turbo
Join Date: Feb 2011
Location: Concord, NH

Posts: 1,557
iTrader: (3)

The engine has temperature senders and a reduced redline when it is cold. No need to worry about over-revving a cold engine.

The money shift is a different issue. If you downshift instead of upshift, you may learn a very expensive lesson. It has happened on some E36M3s. It did not seem to happen when the cars were fairly new, like less than 5 years old. At some point after that, the shift linkage began to wear, the clutch began to wear, the detent bushings in the side of the trans began to wear (and not guide the shifter into gear as well), and the cars were sold to younger and less experienced drivers who wanted to play racer. And the money shifts became more common.
pbonsalb is offline  
0
Reply With Quote
      05-02-2012, 09:36 AM   #6
Nicname
Captain
 
Nicname's Avatar
 
Drives: '12 M3 E92 JB
Join Date: Oct 2011
Location: Bergen County, NJ

Posts: 894
iTrader: (2)

DCT owner. Now what about daily downshifts but not money shifts? Say every time your coming to a light I like to downshift from 3 to 2 then I let the car go to 1st. Or on the highway I'll downshift from 5th to 4th (hitting around 6-7 rpms) to pass and then shifting back up. Is this a huge wear?
__________________


'12 E92 ///M3 DCT loaded l Lux 5000k H8 l Gintani Sport l Gintani HFC x-pipe l Velos Tuning l Amuse Trunk l 20 % tints l Black kidneys/reflectors
Nicname is offline   Brazil
0
Reply With Quote
      05-02-2012, 10:30 AM   #7
DARK_M3
Banned
 
Drives: 08 E90, 89 Grand Wagoneer
Join Date: Mar 2012
Location: So Cal

Posts: 1,294
iTrader: (3)

How does one "accidentally" hit redline with a cold engine?
DARK_M3 is offline  
0
Reply With Quote
      05-02-2012, 10:34 AM   #8
crabman
Captain
 
Drives: M3
Join Date: Dec 2011
Location: WA

Posts: 669
iTrader: (0)

Most of that 20 hp you're talking about is just the individual dyno and all the variabilities involved in making a run. Unless a car is well out of the normal range its probably making pretty close to the same hp as any other car of the same exact type.

I'll give you an example. Back when I got my 3G Dodge diesel it was among the first made with the new engine type. A local diesel shop had a dyno day and 4 of us ran our similarly new trucks with the roughly the same low mileage on that dyno in less than an hour with the shop owner driving the vehicles on the dyno and trying his best to use exactly the same procedure. Because there was a lot of interest in what the trucks would do he ran each one 3 times while on the rollers and averaged the results. All four trucks fell within a 4 hp range. A few months later I rolled by to pick up some parts and at that time he had then run a number of further trucks on the dyno and he told me that they seemed to be falling into the low 220s to low 240s range. Notice how you have a range of about 20 hp on the same dyno but different days? You can pretty much figure that all of them were making close to the same power.
__________________
2012 E92 Space Grey with fox red/black/black, comp, premium, DCT, premium sound, sirius, heated seats.
crabman is offline  
0
Reply With Quote
      05-03-2012, 11:12 AM   #9
TVMA Doc
Captain
 
TVMA Doc's Avatar
 
Drives: 2011 E90 M3, Jerez Black
Join Date: Dec 2011
Location: SF Bay

Posts: 673
iTrader: (0)

Garage List
Quote:
Originally Posted by Nicname View Post
DCT owner. Now what about daily downshifts but not money shifts? Say every time your coming to a light I like to downshift from 3 to 2 then I let the car go to 1st. Or on the highway I'll downshift from 5th to 4th (hitting around 6-7 rpms) to pass and then shifting back up. Is this a huge wear?
The DCT isn't supposed to let you do anything harmful. If you shouldn't make that shift, it should just ignore your request.
TVMA Doc is offline  
0
Reply With Quote
      05-03-2012, 03:56 PM   #10
Meccos
Private
 
Meccos's Avatar
 
Drives: 2011 E90
Join Date: Nov 2011
Location: Anaheim

Posts: 78
iTrader: (0)

what is a money shift?
Meccos is offline  
0
Reply With Quote
      05-03-2012, 04:35 PM   #11
tibra1
Banned
 
Drives: 2011 ZCP M3 - 2007 335i crashd
Join Date: Apr 2009
Location: NYC

Posts: 6,777
iTrader: (4)

Money shifting is like sasquatch..the stories have been told but no one has actually seen it..

Its more of a feeble excuse to say "I picked DCT vs MT b/c that way i wont money shift"..ridiculous

OP just drive the car..and dont worry so much...
tibra1 is offline   No_Country
0
Reply With Quote
      05-03-2012, 05:22 PM   #12
hieu1004
Second Lieutenant
 
hieu1004's Avatar
 
Drives: Space Gray e92 M3
Join Date: Feb 2012
Location: Bothell, WA

Posts: 223
iTrader: (0)

Quote:
Originally Posted by Meccos View Post
what is a money shift?
It's an accidental down shift that that results in broken components, a costly mistake that results in a lot of money required for repairs (bent valves, etc.). Example: you upshift from 4th to 5th gear, but hit 3rd accidentally or shift from 3rd to 4th, but accidentally go into 2nd (the more common one), etc.. The rev-limiter isn't going to save you from a mechanical over-rev of this nature.
hieu1004 is offline  
0
Reply With Quote
      05-04-2012, 11:17 AM   #13
M3Denver
Lieutenant
 
M3Denver's Avatar
 
Drives: 2011 BMW M3
Join Date: Mar 2012
Location: Denver CO

Posts: 423
iTrader: (0)

Quote:
Originally Posted by hieu1004 View Post
It's an accidental down shift that that results in broken components, a costly mistake that results in a lot of money required for repairs (bent valves, etc.). Example: you upshift from 4th to 5th gear, but hit 3rd accidentally or shift from 3rd to 4th, but accidentally go into 2nd (the more common one), etc.. The rev-limiter isn't going to save you from a mechanical over-rev of this nature.
ya i dont see this being a problem in the dct
M3Denver is offline  
0
Reply With Quote
      05-04-2012, 11:43 AM   #14
hieu1004
Second Lieutenant
 
hieu1004's Avatar
 
Drives: Space Gray e92 M3
Join Date: Feb 2012
Location: Bothell, WA

Posts: 223
iTrader: (0)

Quote:
Originally Posted by M3Denver View Post
ya i dont see this being a problem in the dct
Correct. It's a concern for manual transmissions.
hieu1004 is offline  
0
Reply With Quote
      05-04-2012, 11:59 AM   #15
KJ
First Lieutenant
 
Drives: 2008 E92 M3 - Alpine White
Join Date: Mar 2008
Location: Toronto

Posts: 374
iTrader: (1)

Quote:
Originally Posted by M3Denver View Post
ya i dont see this being a problem in the dct
My buddy turbocharged his previous car and let his friend race it and he money shifted 3 to 2 instead of 3 to 4. Blew the engine to smithereens.

How he missed the 3-4 shift, I don't know.
KJ is offline   Canada
0
Reply With Quote
      05-04-2012, 12:02 PM   #16
hieu1004
Second Lieutenant
 
hieu1004's Avatar
 
Drives: Space Gray e92 M3
Join Date: Feb 2012
Location: Bothell, WA

Posts: 223
iTrader: (0)

Quote:
Originally Posted by KJ View Post
My buddy turbocharged his previous car and let his friend race it and he money shifted 3 to 2 instead of 3 to 4. Blew the engine to smithereens.

How he missed the 3-4 shift, I don't know.
Some cars have gates that are very close.

I haven't driven one, but I hear the RSX has been pretty notorious from kids money shifting.
hieu1004 is offline  
0
Reply With Quote
      05-04-2012, 12:07 PM   #17
KJ
First Lieutenant
 
Drives: 2008 E92 M3 - Alpine White
Join Date: Mar 2008
Location: Toronto

Posts: 374
iTrader: (1)

Quote:
Originally Posted by hieu1004 View Post
Some cars have gates that are very close.

I haven't driven one, but I hear the RSX has been pretty notorious from kids money shifting.
OK OK, I'll give his friend a partial pass on this one, it was an RSX! LOL
KJ is offline   Canada
0
Reply With Quote
      05-04-2012, 12:14 PM   #18
1MOREMOD
2014 Track Days - 9|Ridge 1:52:25|Pacific 1:35:72
 
1MOREMOD's Avatar
 
Drives: Race car->
Join Date: Mar 2009
Location: check your mirrors

Posts: 11,969
iTrader: (5)

i thought a money shift was one where you have quick hands and quick feet like your auditioning for the fast and furious and really bang it home. kinda like a money shot its not a bad thing but a well executed shift, or load depending on the term.
__________________

02 Tiag e46 M3|6MT|GC plates|MCS c.o.|GC bars|GC race control arms|GC bushings & bearings|BW eng. & tran. mounts|subframe kit|BW race shifter|BW Jaffster|Euro header|BW race|K&N c.a.i.|Epic race tune|Rouge pulleys|Seibon CF hood|CSL bumper|ST-40|XR-2|SS lines|half cage|Recaro profi|Profi 2 harness|BMWpedals|BW studs|
1MOREMOD is online now   United_States
0
Reply With Quote
      05-04-2012, 12:16 PM   #19
yoelev
First Lieutenant
 
yoelev's Avatar
 
Drives: M3
Join Date: Apr 2012
Location: NYC

Posts: 315
iTrader: (0)

money shift is confirmed to be a NOT good thing.
__________________

2012 E92 M3, Jerezschwarz, Dinan Monoball Kit, Dinan Rear Toe Link, Dinan Front Carbon Fiber Struts, Dinan Stage 1 Suspension, Dinan 3:62 LSD, Dinan Pullies, Dinan Intake, BPM stage 1 and DCT tunes, Passport 9500ci, LI Dual
yoelev is offline  
0
Reply With Quote
      05-04-2012, 12:53 PM   #20
Jamie430
Enlisted Member
 
Drives: honda
Join Date: Feb 2012
Location: mehoa

Posts: 31
iTrader: (0)

The engine has temperature senders and a reduced redline when it is cold. No need to worry about over-revving a cold engine.
Jamie430 is offline  
0
Reply With Quote
      05-06-2012, 11:56 PM   #21
Mike Benvo
BimmerPost Supporting Vendor

 
Mike Benvo's Avatar
 
Drives: 08 E90 M3 / 400whp Turbo 7
Join Date: Apr 2008
Location: SoCal

Posts: 4,599
iTrader: (7)

Garage List
1990 BMW 735i Turbo  [5.00]
2004 BMW M3  [0.00]
2008 BMW M3  [5.00]
Send a message via Skype™ to Mike Benvo
Quote:
Originally Posted by Jamie430 View Post
The engine has temperature senders and a reduced redline when it is cold. No need to worry about over-revving a cold engine.
Not true..

It will let you rev up to about 6K on an cold engine. Way too high. I don't go over 3000 RPM until the oil is atleast 160F. Then gradually raise RPM as temp raises.
__________________

-----| Like us on Facebook | Instagram || Tuning Information | Remote Coding |-----
----Visit us at www.BPMSport.com - Emotion. Driven. | Toll Free: (888) 557-5133----
Mike Benvo is offline   United_States
0
Reply With Quote
      05-07-2012, 05:07 AM   #22
Tony B
Second Lieutenant
 
Drives: 2012 E92 M3, MW, ZCP, 6MT
Join Date: May 2009
Location: UK

Posts: 237
iTrader: (0)

Quote:
Originally Posted by Mike Benvo View Post
Not true..

It will let you rev up to about 6K on an cold engine. Way too high. I don't go over 3000 RPM until the oil is atleast 160F. Then gradually raise RPM as temp raises.
Definitely agree - anyone who relies on the variable red line as a source of useful should think again....this reminds me of the mis-translation from German to English, in the E46 SMG manual...."the shift lights indicate the optimum up-shift revs"......erm no, they dont.

Over-revving when cold (and that means anything less than normal operating temperature) is the quickest way to ruin your engine, either catastrophically (something breaks, or a head gasket pops) or by rapidly increasing wear.
Tony B is offline  
0
Reply With Quote
Post 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 -5. The time now is 09:33 PM.




m3post
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, 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