Single Turbo RX-7's Questions about all aspects of single turbo setups.

the difference between divided and nondivided

Thread Tools
 
Search this Thread
 
Old Feb 13, 2009 | 04:21 AM
  #1  
ttviper's Avatar
Thread Starter
Junior Member
 
Joined: Nov 2008
Posts: 19
Likes: 0
From: new england
the difference between divided and nondivided

hey guys i have a question. what is the difference between divided and non? can u mismatch the two, like i have a nondivided manifold and a divided turbo, how will they work together? what is the point of having ether divided, specially on a rotary that only has two exhaust ports? Thanks
Reply
Old Feb 13, 2009 | 07:10 AM
  #2  
janrx7's Avatar
dominican boost junkie
 
Joined: May 2008
Posts: 325
Likes: 0
From: Dominican Republic
a divided turbo will spool up faster than an undivided one.
Reply
Old Feb 13, 2009 | 08:02 AM
  #3  
calculon's Avatar
On flats
Tenured Member: 20 Years
iTrader: (29)
 
Joined: Oct 2004
Posts: 1,379
Likes: 0
From: Albuquerque
^ He's correct.

To answer your other question, yes you can "mismatch" the two, though I wouldn't call it mismatching, necessarily. The only effect would be an increase in "lag" and possibly some added back pressure, though I'm not sure how noticeable/quantifiable that would be.
Reply
Old Feb 13, 2009 | 08:12 AM
  #4  
Barry Bordes's Avatar
"Elusive, not deceptive!”
Tenured Member 15 Years
 
Joined: May 2007
Posts: 930
Likes: 13
From: Slidell, LA
State your type and size housing and maybe someone will want to trade their mismatch.
Barry
Reply
Old Feb 13, 2009 | 09:17 AM
  #5  
classicauto's Avatar
Crash Auto?Fix Auto.
Tenured Member 15 Years
iTrader: (3)
 
Joined: May 2003
Posts: 7,831
Likes: 2
From: Hagersville Ontario
FWIW, I ran a divded GT3574 on a greddy log (open valute)

Worked well.....worked better then I thought it would actually. Full boost by 3800RPM......well, that is until I sent some apex seals through it. That slowed down the spool more then the mistmatched mani/turbine housing
Reply
Old Feb 13, 2009 | 01:04 PM
  #6  
ScorpionT's Avatar
Senior Member
iTrader: (3)
 
Joined: Jan 2009
Posts: 432
Likes: 1
From: Arctic Circle
Question has been answered. You should really use a divided manifold/turbo though, spool really is helped. The exhaust pulses are pretty powerful and its easy for them to interfere with each other, the divided setup really helps.
Reply
Old Feb 13, 2009 | 01:29 PM
  #7  
Zero R's Avatar
Just in time to die
Tenured Member 10 Years
iTrader: (1)
 
Joined: Nov 2001
Posts: 4,143
Likes: 2
From: look behind you
You can run a undivided, on a divided manifold with little negative effect. You can even run divided on a non divided manifold though it is not ideal. You should cut back the centre divider in a c-shape and do not knife edge it, just round the edges knife edging it will cause it to crack prematurely. This is if you plan on running the divided housing on a non divided manifold.
Reply
Old Feb 15, 2009 | 11:48 AM
  #8  
rofuz's Avatar
Snail-Turbo *)
Tenured Member 10 Years
 
Joined: Jan 2003
Posts: 123
Likes: 0
From: Sweden
divided manifold = 2 wastegates
undivided = 1 wastegate

Reply
Old Feb 15, 2009 | 12:04 PM
  #9  
Evil Aviator's Avatar
Rotorhead
Tenured Member 15 Years
 
Joined: Feb 2001
Posts: 9,136
Likes: 39
From: Charlottesville, Virginia, USA
Originally Posted by rofuz
divided manifold = 2 wastegates
undivided = 1 wastegate

Apparently, that is only in Sweden. For the remainder of the planet, the divided manifold has a 2-1 feed pipe for one wastegate.
Attached Thumbnails the  difference between divided and nondivided-hks20ss.jpg  
Reply
Old Feb 15, 2009 | 12:48 PM
  #10  
marky.'s Avatar
Full Member
Tenured Member: 15 Years
Liked
 
Joined: Sep 2008
Posts: 151
Likes: 1
From: England
As above really
Reply
Old Feb 15, 2009 | 06:17 PM
  #11  
rxspeed7's Avatar
F-IT
Tenured Member 15 Years
iTrader: (5)
 
Joined: Jun 2006
Posts: 995
Likes: 0
From: ocala,fl
^^ what kind of manifold is that
Reply
Old Feb 15, 2009 | 07:16 PM
  #12  
RacerXtreme7's Avatar
NASA geek
Tenured Member 10 Years
iTrader: (2)
 
Joined: Mar 2002
Posts: 2,215
Likes: 2
From: Virginia
Hks
Reply
Old Feb 16, 2009 | 06:21 AM
  #13  
rofuz's Avatar
Snail-Turbo *)
Tenured Member 10 Years
 
Joined: Jan 2003
Posts: 123
Likes: 0
From: Sweden
is that divided all the way to the wastegate? Great, i didn't think of it!
But if u just join the two u would get negative impact on why u have divided in the first place.
Reply
Old Feb 16, 2009 | 09:45 AM
  #14  
rofuz's Avatar
Snail-Turbo *)
Tenured Member 10 Years
 
Joined: Jan 2003
Posts: 123
Likes: 0
From: Sweden
I could have explained better but this url explains it all:

https://www.rx7club.com/showthread.php?p=8822010
Reply
Old Feb 16, 2009 | 02:36 PM
  #15  
Monkman33's Avatar
Goodfalla Engine Complete
Tenured Member: 20 Years
Liked
Loved
Community Favorite
iTrader: (28)
 
Joined: May 2005
Posts: 3,243
Likes: 42
From: Kennewick, Washington
The wastegate isn't where you are worried about being divided anyways. And the length of the runners should counteract any "pulse" interference anyways. The primary concern is how the pulses hit the turbo.
Reply
Old Feb 16, 2009 | 04:42 PM
  #16  
rofuz's Avatar
Snail-Turbo *)
Tenured Member 10 Years
 
Joined: Jan 2003
Posts: 123
Likes: 0
From: Sweden
Originally Posted by Monkman33
The wastegate isn't where you are worried about being divided anyways. And the length of the runners should counteract any "pulse" interference anyways. The primary concern is how the pulses hit the turbo.
I don't agree. If u really want a "fully divided" manifold there is no shortcut except 2 wg.
The difference it makes? Who really know? But I don't want that to make a difference on my car that is why I choose to go with two wgs.

And just to be clear it is not my intension to be rude or unpolite I just want to share my 0.2$
Reply




All times are GMT -5. The time now is 10:49 AM.