Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Go Back   Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum > General > Tech Talk

Tech Talk Technical Discussion About The Nissan 240SX and Nissan Z Cars


Reply
 
Thread Tools Display Modes
Old 09-01-2001, 06:03 PM   #1
Guest
 
Posts: n/a
whats double clutching i asked my friends and they couldnt explain it to me
  Reply With Quote
Sponsored Links
Old 09-04-2001, 06:27 PM   #2
konkman
Zilvia Junkie
 
Join Date: Aug 2001
Posts: 534
Trader Rating: (0)
konkman is an unknown quantity at this point
Feedback Score: 0 reviews
Double clutching only applies to up shifting.

When shifting normally you are shifting from 3rd to 2nd with the clutch engaged then slowly removing the clutch to match rpms until you are fully in gear.

Double clutching is where you rev your engine up to the correct rpm level for that gear example 3000rpm's 3rd is 60km/h.  

How you do it:  1.hit the clutch and move the shifter into neutral.  
2. Hit the gas
3. Quickly move the shifter up one gear
4. Before  the rev's drop let the clutch out quickly.
This should allow you to upshift without the need to use the clutch to ease your car into gear.  This will save your clutch (once you learn to do it correcty).
konkman is offline   Reply With Quote
Old 09-04-2001, 06:40 PM   #3
my240likenoother
Zilvia FREAK!
 
Join Date: Aug 2001
Posts: 1,261
Trader Rating: (0)
my240likenoother is an unknown quantity at this point
Feedback Score: 0 reviews
Send a message via Yahoo to my240likenoother
not useing the clutch is power shifing
my240likenoother is offline   Reply With Quote
Old 09-04-2001, 06:47 PM   #4
konkman
Zilvia Junkie
 
Join Date: Aug 2001
Posts: 534
Trader Rating: (0)
konkman is an unknown quantity at this point
Feedback Score: 0 reviews
To powershift, how high do your rev's need to be.  Wrecking my tranny is a fear.
konkman is offline   Reply With Quote
Old 09-04-2001, 07:01 PM   #5
LanceS13
AutoX Junkie
 
Join Date: Jun 2001
Location: MS
Age: 42
Posts: 2,044
Trader Rating: (0)
LanceS13 is making a name for him/her selfLanceS13 is making a name for him/her self
Feedback Score: 0 reviews
double clutching is a waste of time and energy on a tranny with synchros.
If you're planning on driving a real race car or a semi, you might want to worry about...otherwise, don't.
LanceS13 is offline   Reply With Quote
Old 09-04-2001, 07:02 PM   #6
my240likenoother
Zilvia FREAK!
 
Join Date: Aug 2001
Posts: 1,261
Trader Rating: (0)
my240likenoother is an unknown quantity at this point
Feedback Score: 0 reviews
Send a message via Yahoo to my240likenoother
dont know never did it to scared
i heard storys about people that power shift
my240likenoother is offline   Reply With Quote
Old 09-04-2001, 07:05 PM   #7
LanceS13
AutoX Junkie
 
Join Date: Jun 2001
Location: MS
Age: 42
Posts: 2,044
Trader Rating: (0)
LanceS13 is making a name for him/her selfLanceS13 is making a name for him/her self
Feedback Score: 0 reviews
And konkman, you don't have to rev match an upshift b/c the rpm's need to be lower in the next gear up.  If the rpm's have dropped significantly below what they need to be, you're taking a long time to shift or you have a really light flywheel.
LanceS13 is offline   Reply With Quote
Old 09-04-2001, 09:02 PM   #8
Jeff240sx
I hate you too...
 
Jeff240sx's Avatar
 
Join Date: Jul 2001
Location: Tampa, FL
Age: 41
Posts: 5,828
Trader Rating: (0)
Jeff240sx has a reputation beyond reputeJeff240sx has a reputation beyond reputeJeff240sx has a reputation beyond reputeJeff240sx has a reputation beyond reputeJeff240sx has a reputation beyond reputeJeff240sx has a reputation beyond reputeJeff240sx has a reputation beyond reputeJeff240sx has a reputation beyond reputeJeff240sx has a reputation beyond reputeJeff240sx has a reputation beyond reputeJeff240sx has a reputation beyond repute
Feedback Score: 0 reviews
He said "upshift" and then gave a hypothetical "3rd to 2nd."
So lets clarify... Konkman, you DID mean downshift, right?
-Jeff
Jeff240sx is offline   Reply With Quote
Old 09-04-2001, 10:31 PM   #9
M3l240sx
 
Join Date: Sep 2001
Posts: 11
Trader Rating: (0)
M3l240sx is an unknown quantity at this point
Feedback Score: 0 reviews
Send a message via ICQ to M3l240sx
Uhh dont listen to konkman...  He doesn't know what he's talking about.  What he refered to is match revving, not double clutching.  Anyone who drives a manual should know how to match rev on downshifts and even upshifts (rare occasion when u let the rpm drop from maybe cruising in neutral)  Konk is not wrong, he just explained the wrong thing.  Double clutching is hard to explain why you should do it(not very neccessary with new cars), but i'll explain how first.  The process is this:
(on an upshift, say from 1st to 2nd)
1.) rev up first gear to u're desired shift point
2.) press in clutch
3.) Gear lever to Neutral
4.) pull out clutch
5.) press in clutch (this is the 2nd clutch movement, hence double clutch)
6.) select 2nd gear
7.) pull out clutch

Quite alot of steps eh? You can actually do it pretty fast.
Why? well today if you drive an 18wheeler, you still do this.  If you drive a remotely new car (i mean like late 70's, to 80's) you don't do this, our don't have to.  to understand why, you gotta understand the main moving parts of a car.  


There's the engine(go figure), the layshaft , transmission, drive shaft.  

Whenever the clutch is OUT, the layshaft, engine, transmission, and car speed (from the driveshaft) will find an equalibrium.  Or you can create the equalibrium with foot work(match revving).  Those that can create that equalibrium drive smoothly, those who dont, jerk the car (because the car will find its own equalibrium)

Now... today we have syncro's that speed up the layshaft to go the speed of the road... so the gears can go in properly without grinding.  But in the past, you had to speed up the layshaft manually (by putting the car in neutral with clutch out inbetween shifts) hence double clutching.  Now what does double clutching do in today's cars?  Well, it helps save some wear and tear of the syncronizers that you already have, but those are made to wear and tear... What other benefits?  When a syncro is busted (from you trying to downshift at too high of an rpm, or just general mishifting during HIGH engine speeds over a period of time) double clutching can save your transmission before you get u're syncro's fixed.  Thats all you really need to know about double clutching =)   you can do downshifts with them as well, but now that you know you dont need it, i'm too lazy to type it up, but if u really want to know i guess you can email me or send me an instant message at "dabomb665"
M3l240sx is offline   Reply With Quote
Old 09-04-2001, 10:43 PM   #10
M3l240sx
 
Join Date: Sep 2001
Posts: 11
Trader Rating: (0)
M3l240sx is an unknown quantity at this point
Feedback Score: 0 reviews
Send a message via ICQ to M3l240sx
As for powershifting, I'm assuming what you guys call powershifting is shifting without the clutch.  How you say? well there's a point in every gear that all the moving parts in the car are moving at the same speed, so it is safe to gear in and out without a clutch during that "point".  You really have to know your car to be able to do these shifts though, EI studying u're gear ratios.  The easier non-einstien way of doing it is studying the speed/rpm of each gear... for example... i owned a type-R and the gears were tuned so well , but anyhow the type-R would go to 40mph in first gear at 8300RPM(redline), and 40mph in second gear was 5900RPM...  SO at 40mph, the match between 1st and second gear is at 5900RPM... at that RPM, you can place the gear lever into second gear at 40mph without grinding.  So you would rev first gear up to 40mph, then pull the gear out, wait a split second for the rpm to drop to 5900, and quickly pull it into second and giving it gas... thats powershifting.  If you have perfect timing you will not grind, u're car will go, and everything will be fine even without the clutch.  HONESTLY though, i still think u can shift just as fast if not faster using the clutch , with practice that is.  I once raced someone like this because the hydraulics for my clutch petal was busted, so i couldn't press the clutch, but i do not recommend this unless you really want to learn to show off.
M3l240sx is offline   Reply With Quote
Old 09-05-2001, 10:19 AM   #11
transient
Premium Member
 
transient's Avatar
 
Join Date: Jun 2001
Location: Los Angeles, California
Age: 40
Posts: 2,947
Trader Rating: (0)
transient has a brilliant futuretransient has a brilliant futuretransient has a brilliant futuretransient has a brilliant futuretransient has a brilliant futuretransient has a brilliant futuretransient has a brilliant futuretransient has a brilliant futuretransient has a brilliant futuretransient has a brilliant futuretransient has a brilliant future
Feedback Score: 0 reviews
Send a message via ICQ to transient Send a message via AIM to transient
How the #### did you start off?!?!
transient is offline   Reply With Quote
Old 09-05-2001, 06:20 PM   #12
M3l240sx
 
Join Date: Sep 2001
Posts: 11
Trader Rating: (0)
M3l240sx is an unknown quantity at this point
Feedback Score: 0 reviews
Send a message via ICQ to M3l240sx
Me?  I wasn't afraid to beat up my beater car so... thats how i learned alot of stuff... and also i was fortunate enough to be surounded by very very good drivers.
M3l240sx is offline   Reply With Quote
Old 09-05-2001, 06:23 PM   #13
LanceS13
AutoX Junkie
 
Join Date: Jun 2001
Location: MS
Age: 42
Posts: 2,044
Trader Rating: (0)
LanceS13 is making a name for him/her selfLanceS13 is making a name for him/her self
Feedback Score: 0 reviews
I think he meant "how did you start from a stand-still w/o the clutch?"
LanceS13 is offline   Reply With Quote
Old 09-05-2001, 06:24 PM   #14
transient
Premium Member
 
transient's Avatar
 
Join Date: Jun 2001
Location: Los Angeles, California
Age: 40
Posts: 2,947
Trader Rating: (0)
transient has a brilliant futuretransient has a brilliant futuretransient has a brilliant futuretransient has a brilliant futuretransient has a brilliant futuretransient has a brilliant futuretransient has a brilliant futuretransient has a brilliant futuretransient has a brilliant futuretransient has a brilliant futuretransient has a brilliant future
Feedback Score: 0 reviews
Send a message via ICQ to transient Send a message via AIM to transient
heh, yeah... maybe I should have rephrased that <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>
It's cool that you had a lot of people around you into racing... i'm basically on my own around here. There are a few people, but no-one that's into imports.
transient is offline   Reply With Quote
Old 09-05-2001, 11:42 PM   #15
M3l240sx
 
Join Date: Sep 2001
Posts: 11
Trader Rating: (0)
M3l240sx is an unknown quantity at this point
Feedback Score: 0 reviews
Send a message via ICQ to M3l240sx
easy... old cars just had to be in neutral to start cars, if it was in gear, the car would lurch foward when started.... New cars have a button behind the clutch to make sure you use it everytime you start the car... just know where that button is and push it with ur'e toes... in the 240 its a little round button. &nbsp;There is no wires involved with the clutch, its purely mechanical... &nbsp;this button is just pushed when u're clutch is pushed to its limit

(Edited by M3l240sx at 11:44 pm on Sep. 5, 2001)
M3l240sx is offline   Reply With Quote
Reply

Bookmarks



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 -6. The time now is 02:32 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
vB.Sponsors
Copyright ? 1998 - 2022, Zilvia.net