Notices
RX-8 Discussion General discussion about the RX-8 that doesn't fit in one of the specialty forums.
Sponsored by:
Sponsored by: CARiD

Rev matching

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old 08-09-2004 | 08:33 PM
  #1  
jgoldstein2000's Avatar
Thread Starter
Registered User
 
Joined: Jul 2004
Posts: 203
Likes: 0
Rev matching

None of my upshifts are smooth but my downshifts are worse... everyone talks about rev matching but how do i know what rpm i want for each downshift?

also...

Should i "blip" in the new gear (with the clutch in of course)?

Do i then gently give it gas while i release the clutch?

I am still sucking at shifting and my pride is taking a beating
Old 08-09-2004 | 08:55 PM
  #2  
takahashi's Avatar
New Member
 
Joined: Mar 2003
Posts: 9,944
Likes: 2
From: Melbourne, Australia
No heel toe in a new clutch but good heel toeing is nice when driving hard. You are not subject the car into such a high rev to require heel toeing right? hehe
Old 08-09-2004 | 09:47 PM
  #3  
jgoldstein2000's Avatar
Thread Starter
Registered User
 
Joined: Jul 2004
Posts: 203
Likes: 0
Originally Posted by takahashi
No heel toe in a new clutch but good heel toeing is nice when driving hard. You are not subject the car into such a high rev to require heel toeing right? hehe
taka... no idea what you just wrote
Old 08-09-2004 | 10:53 PM
  #4  
takahashi's Avatar
New Member
 
Joined: Mar 2003
Posts: 9,944
Likes: 2
From: Melbourne, Australia
Heel-toe is a technique when you down shift.

You downshift from say 3rd to 2nd, you want to avoid compression lock up, that is when the engine suddenly engage in high rev and lock up. Like locking up the rear wheel.

So you press down the clutch and start down shifting, and at the same time, press the gas to match the rev of a lower gear, THEN you release the clutch.

It is very useful in wet tracks.
Old 08-09-2004 | 11:59 PM
  #5  
RotorMotor04's Avatar
RX-8 "SE3P"
 
Joined: Apr 2004
Posts: 269
Likes: 0
From: Florida Gulf Coast University
Originally Posted by takahashi
You downshift from say 3rd to 2nd, you want to avoid compression lock up, that is when the engine suddenly engage in high rev and lock up. Like locking up the rear wheel.

a.k.a "back scratch"
Old 08-10-2004 | 12:34 AM
  #6  
5Gen_Prelude's Avatar
Registered User
 
Joined: Aug 2003
Posts: 133
Likes: 0
That isn't heel-toeing. What you described is rev-matching.

For starters, heel-toeing is only necessary when you want to slow down and do a rev-match downshift all at the same time (ie, heading into a corner). Why? You need to use all three pedals at the same time. Using your right foot, you use the heel to add gas (with the clutch in or in neutral - I'll get to that in a minute), and the toe to brake. Thus the term heel-toe.

The advanced form of this is double clutching. It's exactly the same thing, except you put the clutch in, shift into neutral, clutch out, revmatch, clutch in, downshift, clutch out. The advantage to this is you save your syncros, and very necessary in a car without syncros. It's job is to match the layshaft with the engine speed.
Old 08-10-2004 | 12:43 AM
  #7  
gansan's Avatar
Registered User
 
Joined: Jul 2004
Posts: 38
Likes: 0
Here's what heel and toe looks like from the pedal standpoint in my Integra:

http://homepage.mac.com/gkawano/heel%20and%20toe.mov

The first shift is single clutch, the second is double clutch. Sorry I don't have the shifter movement shown, but it happens as usual while the clutch is down.
Old 08-10-2004 | 06:54 AM
  #8  
takahashi's Avatar
New Member
 
Joined: Mar 2003
Posts: 9,944
Likes: 2
From: Melbourne, Australia
Originally Posted by 5Gen_Prelude
For starters, heel-toeing is only necessary when you want to slow down and do a rev-match downshift all at the same time (ie, heading into a corner). Why? You need to use all three pedals at the same time. Using your right foot, you use the heel to add gas (with the clutch in or in neutral - I'll get to that in a minute), and the toe to brake. Thus the term heel-toe.
I have read it ten times. I have trouble thinking it is different from what my Porsche Carrera Cup professional racer taught me - "heel-toe". The heel toe is from the old days when the brake and gas is far away that you need to use heel and your toe. Now it is more like toe-side of foot.

I do what exactly gansan posted - the first one. I want to ask gansan... that if I am lazy to double clutch, I can leave the clutch pressed, right?
Gernerally, when to heel toe and when to double clutch??

Thanks
Old 08-10-2004 | 12:00 PM
  #9  
gansan's Avatar
Registered User
 
Joined: Jul 2004
Posts: 38
Likes: 0
Originally Posted by takahashi
I have read it ten times. I have trouble thinking it is different from what my Porsche Carrera Cup professional racer taught me - "heel-toe". The heel toe is from the old days when the brake and gas is far away that you need to use heel and your toe. Now it is more like toe-side of foot.

I do what exactly gansan posted - the first one. I want to ask gansan... that if I am lazy to double clutch, I can leave the clutch pressed, right?
Gernerally, when to heel toe and when to double clutch??

Thanks
To answer your question, in modern cars with synchronized transmissions, you don't ever HAVE to double clutch. Instead, it is a good technique that is useful to reduce wear on the syncros, and to be able to drive a damaged transmission where the syncros no longer work correctly. Also, if you ever get to drive a serious race car without syncros, then you must double clutch when downshifting. I do it most of the time when the braking zone is long enough (so that I have enough time), because it is fun, and to save on syncro wear.
Old 08-10-2004 | 12:21 PM
  #10  
Smoker's Avatar
RX-8: Hmmmmmmmmmmmmm.....
 
Joined: Feb 2003
Posts: 799
Likes: 0
From: Toronto, Canada
Taka, they are three totally different techniques:
Rev Matching = Clutch in, rev engine speed to match the gear you are shifting to, clutch out.
Double Clutch = Clutch into neutal then rev engine speed to match the gear you are shifting to, clutch into the next gear.

Heel and toe = Braking while blipping the accelerator with the same foot.

And yes, For racing, the Heel and Toe technique are usually use TO perform the Rev Matching technique.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Shankapotamus3
Series I Trouble Shooting
28
03-14-2021 03:53 PM
WranglerFan
New Member Forum
4
11-05-2017 09:35 AM
garryg
Australia/New Zealand Forum
2
10-01-2015 04:54 PM
Jb4ker96
Series I Trouble Shooting
0
09-27-2015 10:06 PM



You have already rated this thread Rating: Thread Rating: 0 votes,  average.

Quick Reply: Rev matching



All times are GMT -5. The time now is 12:21 PM.