E90Post
 


 
BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Technical Forums > Tracking, Autocrossing, Dragstrip, Driving Techniques > Need help getting a better 1/4 mile!



Reply
 
Thread Tools Search this Thread
      06-11-2013, 05:13 PM   #1
3DIRTY5NJ
Private
1
Rep
72
Posts

Drives: e90 335i LCI JB4
Join Date: Aug 2012
Location: New Jersey

iTrader: (0)

Garage List
2009 BMW 335i  [0.00]
Need help getting a better 1/4 mile!

Posted this up on n54tech and no one is of any help and they keep talking about auto or dct trannys when I'm 6mt. Any help of info would be great. Thanks.

So this past Wednesday I did a 1/4 mile run for the first time in my 2009 e90 lci 335i 6MT. Mods are jb4 G5 ISO, DCI, DPs, and a 60/40 mix of e85. I did my first run in map 7 and left DTC on. Time was an upsetting 13.440, 60' 2.230 and trapped at 106.09.I was shooting to be in the 12s since these cars stock professionally driven can do 13.5. Car is my first 6 speed and I've never done a 1/4 mile before. I know I shifted late in a few gears which is why I have a slow trap and also my launch was slow. I launched around 3k but my friend told me I should be launching at the highest torque curve which I have no idea what is it since I've never dyno'd. So please let me know what I can do to be in the 12s or even a 13 flat would make me happy. If anyone needs any more info feel free to ask. Thanks guys!
Appreciate 0
      06-11-2013, 05:42 PM   #2
RandomHero
Private First Class
United_States
25
Rep
159
Posts

Drives: 2008 335i e92
Join Date: Apr 2013
Location: Austin,tx

iTrader: (0)

What was the DA at the track for that day? A high density altitude can mean the difference of running a 13.4 or a 12.4

Was your 2.230 60' spinning or did you dead hook? Generally, shaving .1 off your 60' will yield .2 off your et. For instance, if you could get that down to a 1.8 you'd probably be in the mid 12s.

Missing shifts isn't going to hurt you a ton, but it could still help you shave off a tenth or two.


Add all that together and in an optimal situation you're knocking on 11s.

EDIT-I saw DA numbers as high as 2200ft for the tracks in Atco and Great Meadows. That's not terribly high, but when corrected numbers factoring the DA would put you somewhere around the 13.1-13.2 range.

Last edited by RandomHero; 06-11-2013 at 05:49 PM..
Appreciate 0
      06-11-2013, 10:00 PM   #3
3DIRTY5NJ
Private
1
Rep
72
Posts

Drives: e90 335i LCI JB4
Join Date: Aug 2012
Location: New Jersey

iTrader: (0)

Garage List
2009 BMW 335i  [0.00]
Quote:
Originally Posted by mmahany View Post
What was the DA at the track for that day? A high density altitude can mean the difference of running a 13.4 or a 12.4

Was your 2.230 60' spinning or did you dead hook? Generally, shaving .1 off your 60' will yield .2 off your et. For instance, if you could get that down to a 1.8 you'd probably be in the mid 12s.

Missing shifts isn't going to hurt you a ton, but it could still help you shave off a tenth or two.


Add all that together and in an optimal situation you're knocking on 11s.

EDIT-I saw DA numbers as high as 2200ft for the tracks in Atco and Great Meadows. That's not terribly high, but when corrected numbers factoring the DA would put you somewhere around the 13.1-13.2 range.
I mean there was a tire chirp when I went off the line but I think I hooked it since I had DTC on and then shifting to 2nd gear traction light flashed on robbing me of power. I'm not sure about the DA, on the time slip the only thing I see weather related is the absolute barometer being at 29.75? Thanks for the help. Hopefully island drag way opens up soon so I can get more runs and getter more practice and try different things
Appreciate 0
      06-11-2013, 10:07 PM   #4
RandomHero
Private First Class
United_States
25
Rep
159
Posts

Drives: 2008 335i e92
Join Date: Apr 2013
Location: Austin,tx

iTrader: (0)

Turn the DCT completely off. It's a joke in my opinion. Work on your launches. Your friend is right. Your goal is to build as much boost as you can off the line so it launches as hard as possible. Obviously, you have to hook, but your car should easily be capable of 1.8s with a hard launch and a dead hook.

With your mods and it being your first time at the track (I assume) your time isn't terrible. I'm sure once you learn how to launch you could easily hit a 12.7-12.8 without doing anything else to the car.

EDIT-All this is general advice of course. I was big into the performance truck scene before getting my E92. If us Silverado guys can get a 4500 pound truck to cut sub 1.8 60s you should be able to also.

BTW, to make you feel better. The first time at the track with my truck I ran a 10.99 in the 1/8th mile (I cut a 2.7 60' time). With the same setup adding only a set of drag radials, I eventually got that down to an 8.1.
Appreciate 0
      06-11-2013, 10:14 PM   #5
3DIRTY5NJ
Private
1
Rep
72
Posts

Drives: e90 335i LCI JB4
Join Date: Aug 2012
Location: New Jersey

iTrader: (0)

Garage List
2009 BMW 335i  [0.00]
Is dyno the only way to find out at what rpm has the most torque? And I keep hearing about hooking the launch, that's means on launched with no spin right? So I should launch around 3000-4500 rpm and find the sweet spot of most power and no spin with the throttle?
Appreciate 0
      06-11-2013, 10:42 PM   #6
RandomHero
Private First Class
United_States
25
Rep
159
Posts

Drives: 2008 335i e92
Join Date: Apr 2013
Location: Austin,tx

iTrader: (0)

Quote:
Originally Posted by 3DIRTY5NJ View Post
Is dyno the only way to find out at what rpm has the most torque? And I keep hearing about hooking the launch, that's means on launched with no spin right? So I should launch around 3000-4500 rpm and find the sweet spot of most power and no spin with the throttle?
Experiment. You may find that launching that high will just cause wheel spin. I've always driven automatics, but my truck had a 3600 stalling torque converter. I could brake stall it up to 3000 rpm, but my best 60' times were when I hammered it from idle.

"hooking" is when you transfer the power to the ground. A dead hook would mean that you had no wheel spin off the line (also referred to as "the hole").
Appreciate 0
      06-20-2013, 01:21 PM   #7
biz77
Captain
165
Rep
608
Posts

Drives: 2021 X3 M40i
Join Date: Aug 2010
Location: Spokane, WA

iTrader: (4)

While practice will help you get better 60' times and ETs, your trap speed is very low for the mods you are running. Your 106 mph trap speeds indicate you are making not much more than stock power. I would work with Terry from BMS. Send him some logs and ask him what he thinks. I would expect your car to run over 110mph even with slow shifting and hot weather. It should be making around 400 whp based on the mods and fuel you listed.
Appreciate 0
      06-21-2013, 04:55 AM   #8
Mavus
Colonel
Mavus's Avatar
2026
Rep
2,669
Posts

Drives: E90 335i, F80 zcp
Join Date: Sep 2011
Location: PA

iTrader: (9)

Quote:
Originally Posted by 3DIRTY5NJ View Post
Posted this up on n54tech and no one is of any help and they keep talking about auto or dct trannys when I'm 6mt. Any help of info would be great. Thanks.

So this past Wednesday I did a 1/4 mile run for the first time in my 2009 e90 lci 335i 6MT. Mods are jb4 G5 ISO, DCI, DPs, and a 60/40 mix of e85. I did my first run in map 7 and left DTC on. Time was an upsetting 13.440, 60' 2.230 and trapped at 106.09.I was shooting to be in the 12s since these cars stock professionally driven can do 13.5. Car is my first 6 speed and I've never done a 1/4 mile before. I know I shifted late in a few gears which is why I have a slow trap and also my launch was slow. I launched around 3k but my friend told me I should be launching at the highest torque curve which I have no idea what is it since I've never dyno'd. So please let me know what I can do to be in the 12s or even a 13 flat would make me happy. If anyone needs any more info feel free to ask. Thanks guys!
I track my car and once I got the LSD it was so much easier to transfer power on the ground. The DTC might be fighting you but you also need to learn when to shift and how to get your car lunched with min wheel spin. I don't know your experience but practice and learn what works on your car. Also, it depends what tires you have and the pressure.
Appreciate 0
Reply

Bookmarks


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



All times are GMT -5. The time now is 07:54 PM.




e90post
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
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