BMW M3 Forum (E90 E92)

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


Go Back   M3Post - BMW M3 Forum > E90/E92 M3 Technical Topics > Engine, Transmission, Exhaust, Drivetrain, ECU Software Modifications
 
GT Haus
Post Reply
 
Thread Tools Search this Thread
      05-11-2009, 11:22 PM   #1
KiokenM3
Lieutenant Colonel
 
KiokenM3's Avatar
 
Drives: LIFTED JEEP JK!
Join Date: Dec 2008
Location: LA

Posts: 1,507
iTrader: (4)

how would a 4.10 FD affect 1/4 mile times?

i have a e92 m3 and im just wondering how a 4.10 FD would affect 1/4 performance. dinan says its like a 6% increase but would it hurt or improve 1/4 mile times?
KiokenM3 is offline  
0
Reply With Quote
      05-12-2009, 06:17 AM   #2
J08M3
Major General
 
J08M3's Avatar
 
Drives: 2011 M3 COUPE
Join Date: May 2008
Location: NEW YORK

Posts: 6,012
iTrader: (8)

I think it would help as long as you can get through the 1/4 mile without an extra shift. I'm going for this mod soon. It's not a drastic change but it should be a nice one. What I like about it is that it is a 6% increase in torque over the entire RPM band with no questions. Not like some of the engine mods that only improve at high RPM and are still questionable due to their testing strategies.
__________________
J08M3 is offline   United_States
0
Reply With Quote
      05-12-2009, 06:27 AM   #3
MrHarris
yodog
 
MrHarris's Avatar
 
Drives: '86 Corolla
Join Date: Jun 2007
Location: Diamond Bar, Ca

Posts: 5,037
iTrader: (5)

Garage List
2009 BMW  [5.00]
Send a message via AIM to MrHarris
I'm thinking it would improve times if it's a DCT. How much does a new FD cost?
__________________

2009 E92 M3 | Alpine White | Black Extended | Advan RS | Turner Test Pipes | Dinan Axle-Back | OETuning | Eibach Springs | UUC SSK | VRS Front Lip | VRS Type I Diffuser | Matte Black | RPi Scoops | MS Filter | Yokohama AD08 | F1 Pinnacle
Special Thanks: Gintani | OETuning | eAs
MrHarris is offline   United_States
0
Reply With Quote
      05-12-2009, 06:49 AM   #4
J08M3
Major General
 
J08M3's Avatar
 
Drives: 2011 M3 COUPE
Join Date: May 2008
Location: NEW YORK

Posts: 6,012
iTrader: (8)

it would be too low for DCT
__________________
J08M3 is offline   United_States
0
Reply With Quote
      05-12-2009, 09:33 AM   #5
KiokenM3
Lieutenant Colonel
 
KiokenM3's Avatar
 
Drives: LIFTED JEEP JK!
Join Date: Dec 2008
Location: LA

Posts: 1,507
iTrader: (4)

any idea what gear i should be in at the end of a 1/4? i think i might be at the top of 3rd. if i end in 4th gear, then the 4.10 should help.
KiokenM3 is offline  
0
Reply With Quote
      05-12-2009, 09:54 AM   #6
Ilia@IND
BimmerPost Supporting Vendor

 
Ilia@IND's Avatar
 
Drives: F10 M5
Join Date: Oct 2006
Location: Chicago

Posts: 2,162
iTrader: (3)

At least as far as MPH go, a E92 M3 with a 4.10 and OEM 18" wheels and tires will just hit 100mph at the top of 3rd, and be pushing 135ish at the top of 4th.

A shorter final drive will always help with overall acceleration, and the nice thing about the 4.10 is that you still run out of gear at about 180mph- more than most M3 owners will ever need.
__________________
Ilia@IND is offline  
0
Reply With Quote
      05-12-2009, 10:03 AM   #7
FStop7
I like cars
 
FStop7's Avatar
 
Drives: M6
Join Date: Oct 2008
Location: Newbury Park, CA

Posts: 5,059
iTrader: (3)

I think the 4.10 gears would be a good mod. The M3 GT4 is running them from the factory, btw.

As far as 1/4 mile gains, who knows. Probably a modest gain since it's not a big jump. The toughest part would be maintaining traction in 1st gear since that can already be a challenge with the stock gears.

Last edited by FStop7; 05-13-2009 at 09:48 AM.
FStop7 is offline   Vatican City State
0
Reply With Quote
      05-12-2009, 10:57 AM   #8
J08M3
Major General
 
J08M3's Avatar
 
Drives: 2011 M3 COUPE
Join Date: May 2008
Location: NEW YORK

Posts: 6,012
iTrader: (8)

Wouldn't traction be better with lower gears? Since the wheels will be spinning slightly slower when making the same power?
__________________
J08M3 is offline   United_States
0
Reply With Quote
      05-12-2009, 11:05 AM   #9
Ilia@IND
BimmerPost Supporting Vendor

 
Ilia@IND's Avatar
 
Drives: F10 M5
Join Date: Oct 2006
Location: Chicago

Posts: 2,162
iTrader: (3)

A shorter final drive like a 4.10 would make getting traction more difficult, as power at the ground would be improved. Technically a taller ratio like a 3.43 would improve traction, but only by hurting overall acceleration.

I personally don't follow the logic of getting taller gears to improve traction. Turbo guys do this in the US all the time. What good is having a high horsepower car if you're going to diminish acceleration by running a numerically lower gear ratio?
__________________
Ilia@IND is offline  
0
Reply With Quote
      05-12-2009, 11:10 AM   #10
J08M3
Major General
 
J08M3's Avatar
 
Drives: 2011 M3 COUPE
Join Date: May 2008
Location: NEW YORK

Posts: 6,012
iTrader: (8)

The problem I find with a higher gear is once you lose traction and start spinning the wheels and the faster they are spinning the less chance you have at regaining traction. So the lower gear will actually slow the acceleration of the wheel down, yet increase torque at the same time.
__________________
J08M3 is offline   United_States
0
Reply With Quote
      05-12-2009, 11:18 AM   #11
JMD0977
Captain
 
JMD0977's Avatar
 
Drives: 2010 GT3 and ....
Join Date: Apr 2008
Location: I-95

Posts: 994
iTrader: (6)

Quote:
Originally Posted by J08M3 View Post
The problem I find with a higher gear is once you lose traction and start spinning the wheels and the faster they are spinning the less chance you have at regaining traction.
A 3plate diff with variable ramps (30/90) will help in this. I have it because it was installed by DiffOnline when they did my 3.62, should work great with the 4.10 MT. It really is almost night and day difference between the stock diff. Although, I do drive without traction control most of the time.
JMD0977 is offline  
0
Reply With Quote
      05-12-2009, 11:25 AM   #12
Dave07997S
Colonel
 
Drives: 2013 BMW M3 ZCP Coupe
Join Date: May 2009
Location: Playa del Rey, CA

Posts: 2,450
iTrader: (1)

If you can get the car to hook up 4.10's could be worth .25 sec in the 1/4mile with 1-2mph gain in trap speed.

Dave
__________________
2013 M3 Coupe-MR/BLK ZCP, ACM test pipes, BPM Stg2 dev. tune and Megan catback, AFE Stg2. with C/F elbow
Previous rides: 2011 M3 Coupe-MR/Blk
2007 Porsche 997C2S Speed Yellow/Blk sport seats
2004 BMW M3 Imola/Blk
Dave07997S is offline  
0
Reply With Quote
      05-12-2009, 11:27 AM   #13
Dave07997S
Colonel
 
Drives: 2013 BMW M3 ZCP Coupe
Join Date: May 2009
Location: Playa del Rey, CA

Posts: 2,450
iTrader: (1)

Quote:
Originally Posted by Ilia@IND View Post
A shorter final drive like a 4.10 would make getting traction more difficult, as power at the ground would be improved. Technically a taller ratio like a 3.43 would improve traction, but only by hurting overall acceleration.

I personally don't follow the logic of getting taller gears to improve traction. Turbo guys do this in the US all the time. What good is having a high horsepower car if you're going to diminish acceleration by running a numerically lower gear ratio?
Turbo cars make so much more torque they can pull the taller gear (lower numerical) and if you blow off the tires and get back on the throttle you could also be dealing with turbo lag. So sometimes it's better to trade off a little on torque multiplication to getting the car to stick. Also, the 997TT is quicker than the manual car for alot of the same reasons.

Dave
__________________
2013 M3 Coupe-MR/BLK ZCP, ACM test pipes, BPM Stg2 dev. tune and Megan catback, AFE Stg2. with C/F elbow
Previous rides: 2011 M3 Coupe-MR/Blk
2007 Porsche 997C2S Speed Yellow/Blk sport seats
2004 BMW M3 Imola/Blk
Dave07997S is offline  
0
Reply With Quote
      05-12-2009, 01:15 PM   #14
KiokenM3
Lieutenant Colonel
 
KiokenM3's Avatar
 
Drives: LIFTED JEEP JK!
Join Date: Dec 2008
Location: LA

Posts: 1,507
iTrader: (4)

Quote:
Originally Posted by Dave07997S View Post
If you can get the car to hook up 4.10's could be worth .25 sec in the 1/4mile with 1-2mph gain in trap speed.

Dave

actually i have a set of DR that im running on some stock 18's. so hooking up shouldnt be a problem, i just didnt wanna add another shift in the 1/4, because that would hurt my times. so since i should be in 4th at the end of the 1/4, the 4.10 should only improve my times since im not adding another shift. 4.10 it is. im gonna do it
KiokenM3 is offline  
0
Reply With Quote
      05-12-2009, 09:14 PM   #15
niterider
Proove It!
 
Drives: Gintani Supercharged
Join Date: Dec 2008
Location: City of Angels

Posts: 633
iTrader: (0)

Quote:
Originally Posted by KiokenM3 View Post
actually i have a set of DR that im running on some stock 18's. so hooking up shouldnt be a problem, i just didnt wanna add another shift in the 1/4, because that would hurt my times. so since i should be in 4th at the end of the 1/4, the 4.10 should only improve my times since im not adding another shift. 4.10 it is. im gonna do it
If ur running DR it should only help, I had them on my E46 and it was harder to hook but it made a big difference through the over all powerband. On a 6mt it wont make as big a difference because they are already 3.82s i believe where as E46 M3 was 3.62 but def. make a difference. I got my fastest 1/4 mile times on my E46 M3 with the 4.10s.
niterider is offline  
0
Reply With Quote
      05-12-2009, 11:39 PM   #16
KiokenM3
Lieutenant Colonel
 
KiokenM3's Avatar
 
Drives: LIFTED JEEP JK!
Join Date: Dec 2008
Location: LA

Posts: 1,507
iTrader: (4)

Quote:
Originally Posted by niterider View Post
If ur running DR it should only help, I had them on my E46 and it was harder to hook but it made a big difference through the over all powerband. On a 6mt it wont make as big a difference because they are already 3.82s i believe where as E46 M3 was 3.62 but def. make a difference. I got my fastest 1/4 mile times on my E46 M3 with the 4.10s.
nice
KiokenM3 is offline  
0
Reply With Quote
      05-13-2009, 03:29 AM   #17
mixja
Captain
 
Drives: 2011 E90 DCT Silverstone
Join Date: Jun 2008
Location: Beverly Hils, CA

Posts: 783
iTrader: (1)

3rd Gear with the stock FD maxes out around 107MPH, given the better traps are generally around 110MPH+, I'd say the 4.10 FD won't make any negative impact on a good run and should in theory be slightly faster assuming you can manage the extra torque to the wheels in 1st gear...
mixja is offline   United_States
0
Reply With Quote
      05-13-2009, 06:20 AM   #18
MrHarris
yodog
 
MrHarris's Avatar
 
Drives: '86 Corolla
Join Date: Jun 2007
Location: Diamond Bar, Ca

Posts: 5,037
iTrader: (5)

Garage List
2009 BMW  [5.00]
Send a message via AIM to MrHarris
Quote:
Originally Posted by mixja View Post
3rd Gear with the stock FD maxes out around 107MPH, given the better traps are generally around 110MPH+, I'd say the 4.10 FD won't make any negative impact on a good run and should in theory be slightly faster assuming you can manage the extra torque to the wheels in 1st gear...
Hopefully fatter rear tires can help balance this out
__________________

2009 E92 M3 | Alpine White | Black Extended | Advan RS | Turner Test Pipes | Dinan Axle-Back | OETuning | Eibach Springs | UUC SSK | VRS Front Lip | VRS Type I Diffuser | Matte Black | RPi Scoops | MS Filter | Yokohama AD08 | F1 Pinnacle
Special Thanks: Gintani | OETuning | eAs
MrHarris is offline   United_States
0
Reply With Quote
      05-13-2009, 09:04 AM   #19
KiokenM3
Lieutenant Colonel
 
KiokenM3's Avatar
 
Drives: LIFTED JEEP JK!
Join Date: Dec 2008
Location: LA

Posts: 1,507
iTrader: (4)

Quote:
Originally Posted by MrHarris View Post
Hopefully fatter rear tires can help balance this out

im gonna be running a 265 mickey thompson et street radial.
KiokenM3 is offline  
0
Reply With Quote
      05-13-2009, 09:18 AM   #20
Radiation Joe
Veni Vidi Vici
 
Radiation Joe's Avatar
 
Drives: '11 JB/BBe-6sp-e90
Join Date: Jul 2008
Location: Macungie PA

Posts: 2,749
iTrader: (0)

Garage List
2011 e90 M3-Sold  [4.25]
2003 RS6 - Sold  [0.00]
2009 e90 M3 - Gone  [0.00]
2003 M3 SOLD  [0.00]
old 2002  [5.00]


Totally clueless M3 owners.
Radiation Joe is offline   United_States
0
Reply With Quote
      05-13-2009, 09:46 AM   #21
FStop7
I like cars
 
FStop7's Avatar
 
Drives: M6
Join Date: Oct 2008
Location: Newbury Park, CA

Posts: 5,059
iTrader: (3)

Quote:
Originally Posted by J08M3 View Post
Wouldn't traction be better with lower gears? Since the wheels will be spinning slightly slower when making the same power?
numerically higher = shorter (which is often referred to as 'lower') gear ratio. Shorter ratio, higher torque multiplication.
FStop7 is offline   Vatican City State
0
Reply With Quote
      05-13-2009, 09:49 AM   #22
J08M3
Major General
 
J08M3's Avatar
 
Drives: 2011 M3 COUPE
Join Date: May 2008
Location: NEW YORK

Posts: 6,012
iTrader: (8)

Quote:
Originally Posted by FStop7 View Post
numerically higher = shorter (which is often referred to as 'lower') gear ratio. Shorter ratio, higher torque multiplication.
Yes I know that hence the slower spinning wheels
__________________
J08M3 is offline   United_States
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 05:57 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