Suwipin

Hi guys,

I'm practicing my double clutch whenever I downshift these days since some people told me that by doing that the synchros will have a longer life.

However I wonder if (and where) it is necessary to double-clutch when driving on the track?

Oh and what is trail braking? How I can practice trail braking w/o dangering others on the track?

Thank you in advance,
pin (rookie driver)

Robert Henriksen

One, there's plenty of information about this in the archives.

Two, buy a copy of Going Faster! by Carlos Lopez, w. the Skip Barber school. Best read out there.

M758

I just spend a weekend out at the track.

Never Double clutched once.

Did about 4 Heel & Toe downshifts per lap.

Used trail Braking in 70% of the corners.

Trail braking is appling the brakes while turning the wheel. Something I DO NOT advise any novice track driver to do. I drive a 944 and the technique works great to help the car rotate and brake deeper. This probably NOT the right technique for a 911 due to the weight distibution.

Unless you ready to pull back the car from a slide DO NOT TRAIL BRAKE.... BRAKE ONLY IN A STRAIGHT LINE

Trail braking is an advanced technique that highly dependant on variable conditions...

heel & toe hoewever is the process of downshifting while braking. I use the ball of my right foot on the brake. Apply clutch with the left and blip the throttle with side of my right foot in a rolling motion. Then disengage the clutch at the RPM match for engine speed.

TrackJunke

Double clutching is not really necessary to use on modern cars with syncros. But it is good to know how to do and be proficient at. It can be used when skipping gears from say fourth to second, it can make a smoother downshift. And you know that smooth is always best on the track. As for trail braking, that is when you continue your braking after the turn in point. This topic is kind of up in the air, some people say never do it unless you are an expert, some say do it on some corners, and Skip Barber actually teaches the technique to be used on most corners all the time. You may want to have an instructor in the car while you are trying it and they can probably walk you through it, if not done right it can cause some problems with the balance of the car including oversteer and if you are braking too much at the turn in it can cause understeer because you could be using too much of the tires traction to brake and it does not have any left to turn with.

Suwipin

Thank you guys.

I've started heel and toe-ing and it certainly helps me to be smooth.

Based on the advices here, I think I'll ask my instructors to show me how to trail brake (& the benefits) before I try to do it on my own.

hn

I am a little confused. On street driving, I always apply brake during the turn (a little aggressive) only because it's easy and I think it's the only choice for beginners. I am trying to avoid doing that by learning heel ant toe to shift into gear (to 2nd on a right turn)and use engine brake before getting into a turn so I can be on the right gear when exitting. Plese tell me if I am learning the correct technic.

Or maybe the posts above are applied only to driving on the track (at limits)?

On double clutching, I can't avoid it sometimes. It's a (bad) habit (it makes it harder to heel and toe).

TrackJunke

One, if you are in the middle of a turn at the limit of the tires DO NOT hit the brakes or let off throttle. It unweights the rear end causing it to break lose. I am not sure what you were talking about in the first part, just making sure you do not hit the brakes in a turn.
Two, the brakes are for slowing the car down not the engine. The only point of downshifting is to be in the right gear for exiting the turn. That is why you heel &toe. You match the RPM so that the downshift is perfectly smooth and since you are matching the RPM the engine does not do any braking.

SundayDriver

[quote]Originally posted by Suwipin:
<strong>Thank you guys.

I've started heel and toe-ing and it certainly helps me to be smooth.

Based on the advices here, I think I'll ask my instructors to show me how to trail brake (& the benefits) before I try to do it on my own.</strong><hr></blockquote>

You trail brake to move weight. There are two different cases: 1) Move weight on the nose of the car to help the car turn and 2) Move weight off the tail to get it to rotate. While you are really doing the same thing in both cases, your focus is on a different end of the car. Let me give you a couple of examples at Laguna Seca:

T2 - Tight turn where it is hard to get the car around the corner (rotation). Trail brake into 2 (pretty hard) to take weight off the tail, which causes oversteer and the car rotates earlier thus allowing early throttle application.

T3 - The track seems to fall away a bit on entry and the car pushes (understeers). To counteract this, a bit of trail braking puts wieght on the front tires and helps them grip so the car goes where the wheels are pointed.

When rotating the car, you generally trail brake harder and longer - you are actually trying to almost spin the car. For front bite, the effort and duration are less - this is a case where left foot braking works very well.

There is a third case, where you need adjustment in the middle of a long corner. The Keyhole at Mid-Ohio is such a case. About half way through this 180+ deg corner, the track falls away - SEVERLEY. If you maintin the moderate throttle you have been using for the first half of the corner, you will explore the fields on the outside of the track. In this case, you breath the throttle (lift) to shift weight and get the car to rotate.

When driving on the street, try to feel where the weight is and adjust to balance the car. You do not have to be anywhere near the limits to do this - it is great training. It is also best done in a really much car like a Lincoln. The stiffer the suspension, the harder it is to feel the weight.

Suwipin

Hi Mark,

Thank you so much for your description and examples. That really helps me a lot in understanding more about trail braking.

[quote]T3 - The track seems to fall away a bit on entry and the car pushes (understeers). To counteract this, a bit of trail braking puts wieght on the front tires and helps them grip so the car goes where the wheels are pointed.<hr></blockquote>

Mark, when you were instructing me at Laguna Seca a few months ago, you told me that in order to transfer some weight to the front at T3, I should try left foot braking. In this case (T3), does left foot braking is the same as trail braking?

My other question is: from reading your description, it looks like I can achieve the same thing (trail braking = move weight) with throttle steering?

Thanx again Mark

Mike in Chi

Hi hn

"I am trying to avoid doing that by learning heel ant toe to shift into gear (to 2nd on a right turn)and use engine brake before getting into a turn so I can be on the right gear when exitting."

I'm not sure I'm following what you wrote. Hopefully Mark's subsequent (excellent) explanation helped.

You might ask an instructor from your local PCA region to take you out and show you. whether it's on the track or on the street the principles are the same.

Better yet, do the two-day PDE at Road Atlanta. You will have it down pat. Plus you'll have a new addiction.

With practice, these things become almost second nature.

However you shouldn't be using engine compression to slow the car. brakes are much cheaper than engine rebuilds

Mike

SundayDriver

[quote]Originally posted by Suwipin:
<strong>Hi Mark,

Thank you so much for your description and examples. That really helps me a lot in understanding more about trail braking.



Mark, when you were instructing me at Laguna Seca a few months ago, you told me that in order to transfer some weight to the front at T3, I should try left foot braking. In this case (T3), does left foot braking is the same as trail braking?

My other question is: from reading your description, it looks like I can achieve the same thing (trail braking = move weight) with throttle steering?

Thanx again Mark </strong><hr></blockquote>

My comment about T3 is just what you said. It is trailbraking - doing that with the left foot is often helpful - it lets you get back to throttle more quickly. Start just by trail braking and work up to using the left foot. BTW - I will bet that you are already trail braking is some places - you just don't realize it. Almost every student I have had is already doing some.

Breathing the throttle accomplishes the same thing as trail braking - shifing weight. Throttle is a bit more subtle and is far better mid turn.

DJF1

Mark, correct me if I'm wrong but sometimes when you trail brake with the left foot on the brake you can actually use the throttle at the same time to settle the back end. That I think is the major benefit of left foot braking.
I would also advise that learning left foot braking would be safer at slow speeds and not on the limit as our left foot is not as sensitive due to the use of the clutch.

SundayDriver

[quote]Originally posted by DJF1:
<strong>Mark, correct me if I'm wrong but sometimes when you trail brake with the left foot on the brake you can actually use the throttle at the same time to settle the back end. That I think is the major benefit of left foot braking.
I would also advise that learning left foot braking would be safer at slow speeds and not on the limit as our left foot is not as sensitive due to the use of the clutch.</strong><hr></blockquote>

Yes, though for me it is not so much to settle the rear as to keep it planted. T1 at Mid-Ohio - Many take this flat with a bit of left foot brake to help the car turn without taking the weight off the rear as much as lift, brake throttle would do.

Glen

Mark, very nice...
Sincerely,

Suwipin

Thanx again Mark, I really appreciate it