Notices
996 Forum 1999-2005
Sponsored by:

Downshifting...

Thread Tools
 
Search this Thread
 
Old 12-03-2004, 01:24 AM
  #1  
RevUrGT3
Racer
Thread Starter
 
RevUrGT3's Avatar
 
Join Date: Oct 2004
Location: San Antonio, TX
Posts: 438
Likes: 0
Received 0 Likes on 0 Posts
Question Downshifting...

Howdy,

I was reviewing some Porsche racing and "track day" videos I have collected and I was noticing that some the drivers, while downshifting before a tight corner that requires slowing down considerably, do this:

- Beging breaking, heel-toe to rev-match, downshift to 5th
- heel-toe to rev-match, downshift to 4th
- heel-toe to rev-match, downshift to 3rd.

Can't you break as hard as possible and wait until the speed is correct then heel-toe to 3rd?

@ PDE school, the instructor almost slapped on the face me when I asked if you can slow down the car by downshifting and said "ONLY brakes where intented to slow down the car...". That makes sense and I swore to never use the transmision to slown down the car.

So... what is this 5th-4th-3rd thingy? I am clearly missing something.

Flood the dryness of my ignorance with the river of your knowledge please!
Old 12-03-2004, 01:38 AM
  #2  
jj99c2
Rennlist Member
 
jj99c2's Avatar
 
Join Date: Mar 2004
Location: Seattle, WA
Posts: 263
Received 17 Likes on 9 Posts
Default

I have always been taught to go straight to the gear you need exiting the corner (ie 5th directly to 3rd) on a modern car with synchros. Its definitely easier on the track this way as you only have to make one gear change. Just reember to give the throttle a healthy blip on the double gear downshifts.
Old 12-03-2004, 01:55 AM
  #3  
Moogle
Race Car
 
Moogle's Avatar
 
Join Date: Jul 2002
Posts: 4,451
Likes: 0
Received 1 Like on 1 Post
Default

we do it for the SOUND

oh so sweet

anyway, in a modern car, it is unneccessary, brake as hard as you can and shift into whatever gear you use when you exit the turn
Old 12-03-2004, 03:18 AM
  #4  
Apx2Apx
Track Day
 
Apx2Apx's Avatar
 
Join Date: Nov 2003
Location: Rowland Heights, Ca
Posts: 17
Likes: 0
Received 0 Likes on 0 Posts
Default

The 5-4-3 gear change is preferred way to downshift by most drivers because it's easier to find each gear as your downshifting and less of a chance of dreaded 5th to 1st gear downshift...

I find that going through the gears allows me to get in to a rythm and setup for each turn without worrying about everything all at one time... Many of the race instructors from the schools i've attend always stress breaking down the transition into several small steps rather then one big step.

When i'm coming into a hot turn with cars next too me the last thing I want to think about is if i'm engaging the proper gear and overrevving to match a two gear downshift...

Lastly, by doing so the gear box lastes much longer inbetween rebuilds... I have a teammate that skip shifts and goes through 2x more gearboxs then myself... He is now sequence shifting.. to preserve long enduros lasting 3+ hours...

Like what others have stated it sounds and feel awesome !!!

My .02
Old 12-03-2004, 07:52 AM
  #5  
jasoncuk
Instructor
 
jasoncuk's Avatar
 
Join Date: May 2004
Location: Europe
Posts: 121
Likes: 0
Received 0 Likes on 0 Posts
Default

It can be a religious discussion in racing circles. Generally they prefer you not to miss gears (UK racing schools anyway) as if you are threshold braking, the speed of decelleration may mean a very late gear change is called for to avoid overrevving and a rushed change can cause you to either miss a gear or find 1 instead of 3 for example.

In a racing car I usually don't skip gears to keep rythym and timing - although if you double clutch and match revs you won't wear the synchros any more than with a normal change. you try driving really aggressively on a track without matching revs through heel toe and you will burn through the synchro (and be slower). On the street I frequently miss gears - as it is easier and often smoother.
Old 12-03-2004, 08:04 AM
  #6  
fast1
Race Car
 
fast1's Avatar
 
Join Date: Oct 2004
Posts: 3,899
Received 221 Likes on 146 Posts
Default

I agree with your instructor that the brakes and not the transmission should be used to slow down a car. I agree becuase it helps me to hold down my car maintenance expenses.

I can easily change brakes and if need be rotors. Clutches are a pain, but the average back yard mechanic can also do that. Now if I have transmission problems, I have to take that work to a Porsche certified mechanic, and that means a very large repair bill.

So since I'm cheap, I skip gears when downshifting.
Old 12-03-2004, 10:56 AM
  #7  
Sanjeevan
Three Wheelin'
 
Sanjeevan's Avatar
 
Join Date: Feb 2003
Location: dayton,ohio
Posts: 1,687
Likes: 0
Received 0 Likes on 0 Posts
Default

Ivan, what you are describing is NOT braking with the gears, in the same way that you are not braking with it...when you skip gears. Those race car drivers, during the course of one "braking-complex", rev match throughout the spectrum of RPM, ...you and I wait for the speed to drop to either 2nd or 3rd and then downshift.
Old 12-03-2004, 04:23 PM
  #8  
RevUrGT3
Racer
Thread Starter
 
RevUrGT3's Avatar
 
Join Date: Oct 2004
Location: San Antonio, TX
Posts: 438
Likes: 0
Received 0 Likes on 0 Posts
Default

Interesting comments... it is always good to hear what everbody has to say...



Quick Reply: Downshifting...



All times are GMT -3. The time now is 02:29 AM.