E90Post
 


GT Haus
 
BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Technical Forums > Tracking, Autocrossing, Dragstrip, Driving Techniques > Tips for driving manual better on track?



Reply
 
Thread Tools Search this Thread
      09-09-2013, 12:42 PM   #1
shapptastic
Enlisted Member
0
Rep
48
Posts

 
Drives: 09 e92 335i
Join Date: Oct 2011
Location: Floral Park, NY

iTrader: (0)

Tips for driving manual better on track?

I just had a DE event at Lime Rock, first time I had ever been there. I have done a few DE event prior to this, but this was the first time I felt like I might break my car because of my lousy driving skills. The first two turns on the track are two right turns. On my way back to the start of the track, there is a long straightaway. This is where I typically redline it in 3rd and shift to 4th. The problem I have is once I get to the point where I need to brake going into the first turn, I drive like I usually do on the road. This means braking with clutch in, slowing it down enough until I can put it in 3rd without needed to blip the throttle. My instructor told me to brake hard, then go clutch in --> 3rd -> clutch out quickly and everytime I did that I got the squeak of the synchros (mostly because I can't heel toe). In order to avoid completely ruining my clutch at my next event, anyone have any suggestions for either other ways to approach the turn(maybe downshift after the apex?) or is this a case of needing to learn and practice heel toe? As it is, I'm driving the track basically like an automatic (in 3rd the whole time). Any suggestions for ways to improve?

Thanks!
Appreciate 0
      09-09-2013, 02:10 PM   #2
DallasBoosted
Captain
DallasBoosted's Avatar
11
Rep
864
Posts

 
Drives: '08 E92 335i
Join Date: Apr 2012
Location: Dallas

iTrader: (3)

Garage List
2008 BMW 335i  [5.00]
You need to learn to heel/toe or just brake early, then take your foot off the brake, blip the downshift then get on the gas in the corner.

Don't just drop the clutch in gear without rev matching, you'll lock up the rear tires.
Appreciate 0
      09-09-2013, 02:11 PM   #3
HP Autosport
BimmerPost Supporting Vendor
United_States
418
Rep
11,446
Posts


 
Drives: F80 M3
Join Date: Mar 2007
Location: Santa Barbara, Brembo, GIAC, Koni, Ohlins, Performance Friction, Quaife, Stoptech, Vorshlag

iTrader: (29)

Quote:
Originally Posted by shapptastic View Post
I just had a DE event at Lime Rock, first time I had ever been there. I have done a few DE event prior to this, but this was the first time I felt like I might break my car because of my lousy driving skills. The first two turns on the track are two right turns. On my way back to the start of the track, there is a long straightaway. This is where I typically redline it in 3rd and shift to 4th. The problem I have is once I get to the point where I need to brake going into the first turn, I drive like I usually do on the road. This means braking with clutch in, slowing it down enough until I can put it in 3rd without needed to blip the throttle. My instructor told me to brake hard, then go clutch in --> 3rd -> clutch out quickly and everytime I did that I got the squeak of the synchros (mostly because I can't heel toe). In order to avoid completely ruining my clutch at my next event, anyone have any suggestions for either other ways to approach the turn(maybe downshift after the apex?) or is this a case of needing to learn and practice heel toe? As it is, I'm driving the track basically like an automatic (in 3rd the whole time). Any suggestions for ways to improve?

Thanks!
My question to you is do you heel toe properly? BMWs are setup in a way that when you 'heel toe' you aren't using your heel at all. The brake pedal sits up pretty high so even under extreme braking, unless you have an impossible foot, you can't rotate to use just your heel.

What you want to practice on the street is rev-match downshifting. To achieve this you want to do the follow: Have about half of your right foot on the brake and half of it hovering over the gas pedal...

1) Brake (which should bring the right side of your right foot very close to the gas pedal)
2) Depress clutch
3) Slip gear into neutral (when gear is in neutral, blip the throttle with the right side of your right foot, all while the left side of your right foot is continually depressing the brake)
HINT: The amount you 'blip' the throttle will depend on braking. The harder you are braking the less you have to blip because your RPMs will be dropping quickly. This is ALL about feeling your gear ratio and practicing.
4) Shift into lower gear
5) Release the clutch

So overall just practice on the streets. I ALWAYS rev-match downshift (unless there is a cop around). It is quite rewarding once you get the hang of it.

Let me know if you have any further questions.

-Mike
Appreciate 0
      09-09-2013, 11:34 PM   #4
paddy335
Major
10
Rep
1,014
Posts

 
Drives: 335i Touring; X5 40d
Join Date: Jun 2011
Location: New Zealand

iTrader: (0)

What the previous guys said. There is no need to be rough on the clutch. The bulk of your braking should be done before you downshift.

Nice description of 335i-specific heel-toeing by HP Autosport. Maybe we should rename it 'ball of foot rolling'. Doesn't have much of a ring to it though. I always rev match whether on street or track, even when there ARE cops around

Racing shoes/boots aid heel-toeing, they are built up on the outside of the foot.

Off topic I know, but I'd also ask why you want to go to redline in third.....your way out of your optimal hp/trq point by redline in the 335i. It's just putting unnecessary strain on the engine for less gain than an upshift a bit earlier.
Appreciate 0
      09-10-2013, 07:52 AM   #5
3002 tii
Major General
3002 tii's Avatar
United_States
145
Rep
8,617
Posts

 
Drives: flat out
Join Date: Apr 2008
Location: NNJ

iTrader: (50)

Garage List
LRP is a really FAST track with not many hard braking zones. It's a true momentum track. Turns 1/2 are going to be your classic double apex and you should really trailbrake into that first turn. The only area I need to heel toe is the left hander from 4th to 3rd. But as others said, learn to heel toe on the street and I totally agree with Harold... BMW's pedal placement makes a little difficult to H/T. Consider looking at pedal extensions for the gas so you can hit both pedals at the same time. I also agree with Harold in that before you even get on the topic of H/T, are you properly revmatching on the street? That's the first step when doing H/T...
__________________

Recaro | Volk | AST | Vorshlag | Quaife | Stoptech | Active Autowerke | BMW Performance

Click here for my track videos
Appreciate 0
      09-11-2013, 12:20 AM   #6
aleckzandr
Major
aleckzandr's Avatar
United_States
13
Rep
1,380
Posts

 
Drives: '09 n54 e92xi, 6mt, kw v3
Join Date: Sep 2009
Location: Colorado, USA

iTrader: (0)

Garage List
2009 335xi  [4.22]
Mike (that's not Harold!) is spot on. Do eeeet everyday going to work, getting milk, etc. Don't try on doing it quickly at first, that comes later, instead work on being smooth, and then really smooth, and smoother still! Warning, you'll be about as smooth as a 15 year old driving for the first time in driver's Ed. Do it long and well enough and you'll notice the difference a full tank of gas makes over even a 1/2 a tank with the difference in brake pressure required. (Extra credit: add double clutching, though it's not needed in our cars but still fun to do. I have it so engrained it's hard for me to single clutch.)
__________________
KWs - Vorshlags - APEX EC-7s - "My garage" has suspension install pictures.
_____________________

Last edited by aleckzandr; 09-11-2013 at 12:26 AM.
Appreciate 0
      09-11-2013, 11:41 AM   #7
will.c
Lieutenant
will.c's Avatar
United_States
17
Rep
588
Posts

 
Drives: E46M
Join Date: Mar 2011
Location: Central Jersey

iTrader: (5)

Yep, you gotta learn it. It's pretty essential in tracking a manual car. Otherwise you'll be slow, inconsistent, and more importantly, more prone to wear & tear and damage.

Another thing I noticed when I tracked my 335 was that I didn't get much faster by redlining. So I always short shifted around 5.5-6k, and it still pulled well b/c of low end torque. (AND it kept the temps lower, which is a delicate aspect of these motors.) As such, I didn't really feel the need to downshift in many of the turns. I mean, of course it depends on the track/corner, but saving half a sec on upshifting vs keeping in higher gear might be worth an experiment on corner-by-corner basis for these cars.
Appreciate 0
      09-11-2013, 06:45 PM   #8
CJ421
Brigadier General
CJ421's Avatar
United_States
60
Rep
3,263
Posts

 
Drives: 2011 E92 335i
Join Date: Feb 2011
Location: PA

iTrader: (1)

Garage List
2011 BMW 335i  [4.66]
Easier on track

Quote:
Originally Posted by will.c View Post
Another thing I noticed when I tracked my 335 was that I didn't get much faster by redlining. So I always short shifted around 5.5-6k, and it still pulled well b/c of low end torque. (AND it kept the temps lower, which is a delicate aspect of these motors.) As such, I didn't really feel the need to downshift in many of the turns. I mean, of course it depends on the track/corner, but saving half a sec on upshifting vs keeping in higher gear might be worth an experiment on corner-by-corner basis for these cars.
Agreed, I shift at 5-6k on track. The 335 runs out of steam 6k+.

If you can learn to heel-toe on the street, you can do it on track, where it's easier because the revs are higher.

Remember, perform your shift at the end of the braking zone just before you enter the turn. And if you're going down two gears, just skip the middle one e.g. 5 > 3.
__________________
2011 BMW E92 335i, 6MT, Le Mans blue - Quaife LSD, JRZ RS Pro, JRZ camber plates, Eibach ERS, full M3 susp, custom toe arms, Powergrid end-links, SS brake lines, brake ducting, Michelin PSS, UUC SSK, ETS FMIC, ER CP, Perf. Exhaust, VAC RSIK, Sparcos; work by VAC Motorsports in Philadelphia
Appreciate 0
      09-11-2013, 08:52 PM   #9
DallasBoosted
Captain
DallasBoosted's Avatar
11
Rep
864
Posts

 
Drives: '08 E92 335i
Join Date: Apr 2012
Location: Dallas

iTrader: (3)

Garage List
2008 BMW 335i  [5.00]
Definitely shift at 5500-6000. If you're going to be in 4th long at all, shift lower, 5400-5500.
Appreciate 0
      09-14-2013, 03:20 PM   #10
macmacaman
New Member
United_States
0
Rep
16
Posts

 
Drives: E90 335i, E84 X1
Join Date: Feb 2012
Location: San Francisco

iTrader: (1)

There is a sticky on optimal shift point, but there doesn't seem to be any agreement on methodology. Is there a way to go from torque-rpm curves to take into account gearing to figure out the optimal shift point? It seems like to me that you could go from the torque-rpm curve of a motor, apply the gearing to figure out torque at the wheels, and choose your shift points to optimize wheel torque.

Has anyone done this? Is there something that I am missing or not understanding?
Appreciate 0
      09-15-2013, 11:57 PM   #11
paddy335
Major
10
Rep
1,014
Posts

 
Drives: 335i Touring; X5 40d
Join Date: Jun 2011
Location: New Zealand

iTrader: (0)

It's an incredibly subjective issue I suppose, because there are so many factors involved over and above hp and trq.

Best way is to try and measure different change points by experimenting with lap times. All other things being equal of course.
Appreciate 0
      09-16-2013, 12:08 AM   #12
macmacaman
New Member
United_States
0
Rep
16
Posts

 
Drives: E90 335i, E84 X1
Join Date: Feb 2012
Location: San Francisco

iTrader: (1)

Quote:
Originally Posted by paddy335 View Post
It's an incredibly subjective issue I suppose, because there are so many factors involved over and above hp and trq.

Best way is to try and measure different change points by experimenting with lap times. All other things being equal of course.
It seems to me that it should not be subjective. After all there's only one thing accelerating the car, and that's wheel torque. Or is there something about driving style that I am missing in this? Perhaps timing of the gear shifts and the lost torque while out of gear?
Appreciate 0
      09-16-2013, 12:56 AM   #13
The HACK
Garland Operator 7G
The HACK's Avatar
42
Rep
3,483
Posts

 
Drives: 2006 MZ4C, 2013 Veloster Turbo
Join Date: Oct 2007
Location: Welcome to Jamaica have a nice day

iTrader: (1)

Quote:
Originally Posted by macmacaman View Post
It seems to me that it should not be subjective. After all there's only one thing accelerating the car, and that's wheel torque. Or is there something about driving style that I am missing in this? Perhaps timing of the gear shifts and the lost torque while out of gear?
You're right that it shouldn't be subjective, but you're wrong that it's wheel torque that accelerates the car. It's actually torque X gearing multiplier.

This topic has been debated ad nauseum, with a ton of mis-information out there. The simple answer is, you want as much power delivered to the wheels for as long as possible. And most cars are designed to deliver the majority of their power at or near redline, and even on cars that see significant drop-off in power at or near redline, they're designed to deliver MORE power sooner in the next gear, or at least closer to peak power RPM, for longer, if you shift into the next gear at or close to redline.

So even if someone argues, well, the engine isn't making more power after, say, 5,800 RPM so there's no need to shift at 6,500 RPM? Wrong. There's plenty of good reason to shift at 6,500 RPM. One being the NEXT gear you will start closer to max power engine speed rather than trying to spool up that magical HP for another 800 RPM.

It's the area under the power curve through the gears that gives you the maximum acceleration.

Here's a good brain teaser for you. The 335D produces SIGNIFICANTLY more torque than the 335i. Yet is significantly slower to 60 mph and 1/4 mile. Think about that for a minute.
__________________
Quote:
No way I'd ever take my BMW to the track.
Quote:
Then why do you have $3,000 worth of suspension mods on your car?
Quote:
...
-Overheard at the last B****rfest.
Appreciate 0
      09-16-2013, 01:24 AM   #14
SRanch335i
First Lieutenant
United_States
7
Rep
316
Posts

 
Drives: Silver 2008 335I
Join Date: Jun 2010
Location: Los Angeles County

iTrader: (1)

slip on vans....essential
Appreciate 0
      09-16-2013, 04:07 PM   #15
paddy335
Major
10
Rep
1,014
Posts

 
Drives: 335i Touring; X5 40d
Join Date: Jun 2011
Location: New Zealand

iTrader: (0)

Quote:
Originally Posted by macmacaman View Post
It seems to me that it should not be subjective. After all there's only one thing accelerating the car, and that's wheel torque. Or is there something about driving style that I am missing in this? Perhaps timing of the gear shifts and the lost torque while out of gear?
I am talking about all the other factors that may influence when you change gear: track condition and surface and temperature, tyre condition type and pressure, corner type, road camber, available traction, do you have a LSD or not, what kind of tune you have on your engine, where your peak trq and hp are - the list goes on and on and on....

Even in F1 it is subjective, just listen to drivers disagreeing with engineers about what the best way to drive a track is.
Appreciate 0
      09-17-2013, 10:31 AM   #16
will.c
Lieutenant
will.c's Avatar
United_States
17
Rep
588
Posts

 
Drives: E46M
Join Date: Mar 2011
Location: Central Jersey

iTrader: (5)

Quote:
Originally Posted by paddy335 View Post
I am talking about all the other factors that may influence when you change gear: track condition and surface and temperature, tyre condition type and pressure, corner type, road camber, available traction, do you have a LSD or not, what kind of tune you have on your engine, where your peak trq and hp are - the list goes on and on and on....

Even in F1 it is subjective, just listen to drivers disagreeing with engineers about what the best way to drive a track is.
Agreed.

All the gearing, torque curve, and misc details are more relevant to drag racing or straight line acceleration. I mean, it's definitely good to know the technical stuff and all, but what it really comes down to at a road course is simply what makes quicker lap times.

For just one example out of millions, a driver may choose to short shift into next gear on a particular sweeping "straight" because the higher gear's lower wheel torque helps the driver to maintain stability under full throttle, where as keeping in the lower gear might be more prone to upsetting the vehicle dynamic from minor throttle adjustments. Now if it's Ayrton Senna who can be perfect with the throttle at any given point in that particular sweep, perhaps lower gear is faster for him.

There are sooo many intangible factors, including driving skill, in determining what's faster for that person in that car for that corner on that weather condition, etc. that the driver simply has to try different things and conclude it from lap times & data.

For me, cooling issues, less wear on the engine, and insignificant lap time differences led me to short shift at 5.5-6k. But obviously I'm not so hardcore as to conduct a study on this, so maybe my entire experience is insignificant.
Appreciate 0
      09-17-2013, 01:55 PM   #17
macmacaman
New Member
United_States
0
Rep
16
Posts

 
Drives: E90 335i, E84 X1
Join Date: Feb 2012
Location: San Francisco

iTrader: (1)

I think I may have had a misunderstanding about terminology. When I wrote wheel torque, I thought that meant the torque x gearing = torque applied to the drive wheels (torque transmitted into the tires). From what you wrote, it seems that wheel torque is not torque at the drive wheels, but torque at the FLYWHEEL. Is this correct? Not being an automotive engineer, I think I got a little confused about the terminology.

I understand your point about wanting your next shift to be in the area of the torque/power output curve nearest max power. What is a little confusing to me is that because of the gearing, isn't first gear pretty much always delivering more torque (at the tires) than second gear under all parts of the curve?

Quote:
Originally Posted by The HACK View Post
You're right that it shouldn't be subjective, but you're wrong that it's wheel torque that accelerates the car. It's actually torque X gearing multiplier.

This topic has been debated ad nauseum, with a ton of mis-information out there. The simple answer is, you want as much power delivered to the wheels for as long as possible. And most cars are designed to deliver the majority of their power at or near redline, and even on cars that see significant drop-off in power at or near redline, they're designed to deliver MORE power sooner in the next gear, or at least closer to peak power RPM, for longer, if you shift into the next gear at or close to redline.

So even if someone argues, well, the engine isn't making more power after, say, 5,800 RPM so there's no need to shift at 6,500 RPM? Wrong. There's plenty of good reason to shift at 6,500 RPM. One being the NEXT gear you will start closer to max power engine speed rather than trying to spool up that magical HP for another 800 RPM.

It's the area under the power curve through the gears that gives you the maximum acceleration.

Here's a good brain teaser for you. The 335D produces SIGNIFICANTLY more torque than the 335i. Yet is significantly slower to 60 mph and 1/4 mile. Think about that for a minute.
Appreciate 0
      09-23-2013, 04:00 PM   #18
labedra
First Lieutenant
labedra's Avatar
United_States
4
Rep
304
Posts

 
Drives: 2008 BMW 335i E92 6 MT
Join Date: Jun 2009
Location: Somewhere on Planet Earth for now.

iTrader: (2)

Quote:
Originally Posted by HP Autosport View Post
My question to you is do you heel toe properly? BMWs are setup in a way that when you 'heel toe' you aren't using your heel at all. The brake pedal sits up pretty high so even under extreme braking, unless you have an impossible foot, you can't rotate to use just your heel.

What you want to practice on the street is rev-match downshifting. To achieve this you want to do the follow: Have about half of your right foot on the brake and half of it hovering over the gas pedal...

1) Brake (which should bring the right side of your right foot very close to the gas pedal)
2) Depress clutch
3) Slip gear into neutral (when gear is in neutral, blip the throttle with the right side of your right foot, all while the left side of your right foot is continually depressing the brake)
HINT: The amount you 'blip' the throttle will depend on braking. The harder you are braking the less you have to blip because your RPMs will be dropping quickly. This is ALL about feeling your gear ratio and practicing.
4) Shift into lower gear
5) Release the clutch

So overall just practice on the streets. I ALWAYS rev-match downshift (unless there is a cop around). It is quite rewarding once you get the hang of it.

Let me know if you have any further questions.

-Mike
Pretty much dead on IMO. If you brake very hard you don't even need to blip the throttle at all. Here is what I'm talking about:



Brake late, less foot work ,less steering input = faster lap as long as you get all corner entries/exit correct.
__________________

.../// TURBO! Why in the world would you choose anything else?... ///
Appreciate 0
      09-26-2013, 03:02 PM   #19
HP Autosport
BimmerPost Supporting Vendor
United_States
418
Rep
11,446
Posts


 
Drives: F80 M3
Join Date: Mar 2007
Location: Santa Barbara, Brembo, GIAC, Koni, Ohlins, Performance Friction, Quaife, Stoptech, Vorshlag

iTrader: (29)

Quote:
Originally Posted by labedra View Post
Pretty much dead on IMO. If you brake very hard you don't even need to blip the throttle at all. Here is what I'm talking about:



Brake late, less foot work ,less steering input = faster lap as long as you get all corner entries/exit correct.
Thanks for the agreement. And BTW, that guys driving technique scares me a little bit... He dove every corner when the driver on the outside would like to apex. I wouldn't be a happy camper if he was on the track with me.

-Mike
Appreciate 0
      09-26-2013, 03:47 PM   #20
Meeni
Gateropode
Meeni's Avatar
24
Rep
1,877
Posts

 
Drives: BMW 330i 06
Join Date: Apr 2012
Location: TN

iTrader: (0)

Your instructor is right, follow his advice. Also, do the same on the Road, you should never stay in neutral, ever.
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 -5. The time now is 05:21 PM.




e90post
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