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


Go Back   ZPOST > BMW Z4 Technical Talk > Track / Autocross / Dragstrip / Driving Techniques
  TireRack

SUPPORT ZPOST BY DOING YOUR TIRERACK SHOPPING FROM THIS BANNER, THANKS!
Post Reply
 
Thread Tools Search this Thread
      03-30-2013, 11:39 PM   #1
Kgolf31
Brigadier General
Kgolf31's Avatar
101
Rep
3,840
Posts

Drives: 2007 Z4MC, 2012 128i
Join Date: Sep 2008
Location: Ohio

iTrader: (3)

Even with 4 inches on the ground on Monday, today was a 50+F day for our first autocross. It was a non points event, just a fun day to shake the cobwebs off

Fastest run from today. Car didn't want to put power down, seemed to be upset everywhere on the course, and my inputs were really choppy.

Despite getting owned by a Miata in RTR, finished a respectable 2nd in class and more importantly 12th in PAX even with the trouble I was having....

C&C appreciated.

__________________

Appreciate 0
      03-31-2013, 09:41 AM   #2
a_riddler
Bimmer Noob
a_riddler's Avatar
United_States
7
Rep
541
Posts

Drives: 08 Z4MC;08 MBZ E350 4Matic
Join Date: May 2010
Location: Seattle, WA

iTrader: (5)

nice vid, first runs of the year are always fun runs here as well.

What RPMs are you doing your launch? Seems like you had a lot of wheel spin.
__________________

08 Z4MC /// DKF Exhaust, Stoptech 6/4 BBK, TCK Coilovers, Strong-Strut, Apex EC-7's, APR Splitter/Wing,
AFE Intake, Underdrive pulleys, ZHP Shift Knob, UUC Tranny Mounts, Matte Grill, RPI Scoop, CF Badges
Appreciate 0
      03-31-2013, 11:00 AM   #3
Kgolf31
Brigadier General
Kgolf31's Avatar
101
Rep
3,840
Posts

Drives: 2007 Z4MC, 2012 128i
Join Date: Sep 2008
Location: Ohio

iTrader: (3)

Quote:
Originally Posted by a_riddler
nice vid, first runs of the year are always fun runs here as well.

What RPMs are you doing your launch? Seems like you had a lot of wheel spin.
It was at about 2k...anything under and it would bog, but 2k seemed to work get some heat and the tires would start to skip and get traction.


The tires literally had no heat in them the whole day, it was frustrating. RS3s do not like the cold, so it was an ongoing battle trying to drive on them
__________________

Appreciate 0
      03-31-2013, 01:32 PM   #4
Finnegan
Major General
Finnegan's Avatar
United_States
96
Rep
6,704
Posts

Drives: Sapphire Black/Black Z4Mc
Join Date: Oct 2008
Location: At the track..or wishing I were at the track

iTrader: (18)

The cold weather and RS3s didn't help you work on smoothing out inputs much. Yeah, it's a bit choppy and you know that (winter rust from not practicing), but you're expecting the car to handle differently (as it would with heat in the tires) and when it doesn't, you have to quickly "compensate" which isn't conducive to smooth driving. I'd call it a spring wake up call and work on being smoother (maybe try to "go slower" the first time or two out) the next time out, when hopefully the weather will be more conducive to grip with those tires.
Appreciate 0
      03-31-2013, 02:22 PM   #5
Kgolf31
Brigadier General
Kgolf31's Avatar
101
Rep
3,840
Posts

Drives: 2007 Z4MC, 2012 128i
Join Date: Sep 2008
Location: Ohio

iTrader: (3)

Quote:
Originally Posted by Finnegan View Post
The cold weather and RS3s didn't help you work on smoothing out inputs much. Yeah, it's a bit choppy and you know that (winter rust from not practicing), but you're expecting the car to handle differently (as it would with heat in the tires) and when it doesn't, you have to quickly "compensate" which isn't conducive to smooth driving. I'd call it a spring wake up call and work on being smoother (maybe try to "go slower" the first time or two out) the next time out, when hopefully the weather will be more conducive to grip with those tires.
Yea, this is my actually my first time driving when low temperatures on my car. Other cars it was on Star Specs.

This is a new camera position for me, and with the addition of the mic it really helps determine the on/off of the gas and brakes, as well as tire squeal.

Although it doesn't show the course too well, you can still determine it I believe...

Here is my second fastest time, 0.2 seconds off my FTD. Much more smooth, IMO.

__________________

Appreciate 0
      03-31-2013, 04:21 PM   #6
a_riddler
Bimmer Noob
a_riddler's Avatar
United_States
7
Rep
541
Posts

Drives: 08 Z4MC;08 MBZ E350 4Matic
Join Date: May 2010
Location: Seattle, WA

iTrader: (5)

Agreed, that run was much smoother. Always nice seeing the Z4Ms autox.

Good luck this year!
__________________

08 Z4MC /// DKF Exhaust, Stoptech 6/4 BBK, TCK Coilovers, Strong-Strut, Apex EC-7's, APR Splitter/Wing,
AFE Intake, Underdrive pulleys, ZHP Shift Knob, UUC Tranny Mounts, Matte Grill, RPI Scoop, CF Badges
Appreciate 0
      03-31-2013, 04:32 PM   #7
Finnegan
Major General
Finnegan's Avatar
United_States
96
Rep
6,704
Posts

Drives: Sapphire Black/Black Z4Mc
Join Date: Oct 2008
Location: At the track..or wishing I were at the track

iTrader: (18)

Much smoother with hands, on/off braking seems smoother too, as does transition to throttle. Braking, especially coming off smoothly, is huge in terms of increasing absolute grip. (Something I've really focused on with my driving--still learning though, a lot of way to go.) This run is much better--nice work! Good luck this year!
Appreciate 0
      03-31-2013, 06:30 PM   #8
Kgolf31
Brigadier General
Kgolf31's Avatar
101
Rep
3,840
Posts

Drives: 2007 Z4MC, 2012 128i
Join Date: Sep 2008
Location: Ohio

iTrader: (3)

Quote:
Originally Posted by a_riddler View Post
Agreed, that run was much smoother. Always nice seeing the Z4Ms autox.

Good luck this year!
Thank you. I'll be posting videos throughout the year with positive results, hopefully

Quote:
Originally Posted by Finnegan View Post
Much smoother with hands, on/off braking seems smoother too, as does transition to throttle. Braking, especially coming off smoothly, is huge in terms of increasing absolute grip. (Something I've really focused on with my driving--still learning though, a lot of way to go.) This run is much better--nice work! Good luck this year!
Thank you! "Shocking" the car with brakes or throttle isn't ideal, as you'll just disrupt the balance.

Only going into my 4th year for autox, 2nd year with the car set-up as it is currently.
__________________

Appreciate 0
      04-03-2013, 08:56 AM   #9
z3papa
First Lieutenant
United_States
11
Rep
328
Posts

Drives: 11 E92 M3 ZCP, 07 335i, 02 Z3
Join Date: Oct 2009
Location: Bloomington IL

iTrader: (2)

You need to break the habit of shuffle steering. It took a while for me to brake but really keeps turn in inputs smoother. You seem to need more throttle modulation, rather than on/off especially on RS3's in the cooler temps. They really respond to a 2# drop when grip temps are lower. Finally, it looks especially early, you broke, floated and then entered the turn. I'm a huge proponent of braking very late but hard, set the front end, and then immediately roll, even lightly, onto the throttle to transition the weight to the rear. The less time between brake and some throttle the better in our cars with the short wheel base. Overall though, it was pretty good for a first event of the season.
__________________
2011.5 E92 M3 ZCP.
Appreciate 0
      04-03-2013, 11:21 AM   #10
Kgolf31
Brigadier General
Kgolf31's Avatar
101
Rep
3,840
Posts

Drives: 2007 Z4MC, 2012 128i
Join Date: Sep 2008
Location: Ohio

iTrader: (3)

Quote:
Originally Posted by z3papa View Post
You need to break the habit of shuffle steering. It took a while for me to brake but really keeps turn in inputs smoother. You seem to need more throttle modulation, rather than on/off especially on RS3's in the cooler temps. They really respond to a 2# drop when grip temps are lower. Finally, it looks especially early, you broke, floated and then entered the turn. I'm a huge proponent of braking very late but hard, set the front end, and then immediately roll, even lightly, onto the throttle to transition the weight to the rear. The less time between brake and some throttle the better in our cars with the short wheel base. Overall though, it was pretty good for a first event of the season.
Thanks for the comments.

Regarding shuffle steering, should I start doing like hand-over hand on tight corners or what other method? I try not to move my hands when possible (like slaloms, lane changes...etc)

I know my throttle modulation sucks, this is my first time using an external mic so I really got to know how the throttle is....all prior videos it was muffled from wind noise.

Interesting information on the pressure drop. I ran 36# front and 34# rear and at the end of the day I had to go to 37# front to avoid massive rollover past the arrows. This is similar pressure I ran when in the middle of the summer. I'll have to think about that one.

As far as coasting, I've been worse...and have got better. I have too noticed that I do float a bit...the course had a lot of gravel, and of course STR, STX, STU cars that went in the heat prior took tight lines where I needed to open the course up and take more speed, the gravel killed me. Especially after the loop and into the wide left handed sweeper into the slalom the morning I was dealing with massive understeer into oversteer from later braking. I figured I mine as well not do that in the PM runs and try to keep the car more supposed. With heat though in the tires and brakes (as you heard my HP+ pads were still screaming) I can brake later for sure. It's something that I need to work on.

Thanks for the comments. I've seen plenty of your vids and it seems to work for you
__________________

Appreciate 0
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 -4. The time now is 02:00 PM.




zpost
zpost
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