2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

88 NA, wanna replace mufflers with str8 pipes for now, back press. be ok?

Thread Tools
 
Search this Thread
 
Old Oct 23, 2001 | 05:21 PM
  #1  
ItsNiceToBurnRice's Avatar
Thread Starter
Senior Member
Tenured Member 05 Years
 
Joined: Oct 2001
Posts: 487
Likes: 0
From: Tampa, FL
88 NA, wanna replace mufflers with str8 pipes for now, back press. be ok?

I know I have a Bonez high flow cat, I just wanna cut my mufflers off and weld some straight pipes on for the time being, I dont have 800 bucks to put a whole system on now, plus Im tryin to work out some kinks in the motor. So I just wanna hear some exhaust screamin', will my back pressure be ok so that my ports open? Cause if they wont, then its obviously not worth it. Thanks everyone!
Reply
Old Oct 23, 2001 | 05:51 PM
  #2  
tesla042's Avatar
Senior Member
Tenured Member 10 Years
 
Joined: Feb 2001
Posts: 611
Likes: 0
From: louisville, KY
...You could always tie them open if you want high end..

-Tesla
Reply
Old Oct 24, 2001 | 02:53 AM
  #3  
FC3AZ's Avatar
Senior Member
Tenured Member 05 Years
 
Joined: Oct 2001
Posts: 464
Likes: 0
From: Peoria, AZ
I like this idea, I might do it myself to get a new sound, and save me MAJOR cash. So, how bout it? Back pressure ok? or no? Thanks....
Reply
Old Oct 24, 2001 | 07:37 AM
  #4  
t_mak@mail.plymouth.edu's Avatar
Senior Member
Tenured Member 10 Years
 
Joined: Jun 2001
Posts: 307
Likes: 0
From: Norwich CT
Your car will be slower with no mufflers
Reply
Old Oct 24, 2001 | 07:41 AM
  #5  
RX-7 GT's Avatar
HyperREV.com
Tenured Member 10 Years
 
Joined: Mar 2001
Posts: 1,162
Likes: 0
From: Oregon
Originally posted by t_mak@mail.plymouth.edu
Your car will be slower with no mufflers
how?
Reply
Old Oct 24, 2001 | 07:46 AM
  #6  
t_mak@mail.plymouth.edu's Avatar
Senior Member
Tenured Member 10 Years
 
Joined: Jun 2001
Posts: 307
Likes: 0
From: Norwich CT
no back pressure
Reply
Old Oct 24, 2001 | 08:27 AM
  #7  
The Ace's Avatar
Greek Power
Tenured Member: 20 Years
 
Joined: Aug 2001
Posts: 2,375
Likes: 0
From: Greece
Talking

Just go here http://www.rotaryengineillustrated.com and all will be explained. NA engines need the backpressure for low end power, while turbos dont need ANY backpressure at all
Reply
Old Oct 24, 2001 | 02:05 PM
  #8  
FC3AZ's Avatar
Senior Member
Tenured Member 05 Years
 
Joined: Oct 2001
Posts: 464
Likes: 0
From: Peoria, AZ
Well, I do have the complete stock exhaust system( from the header back). The previous owner replaced the 2 or 3 stock cats with one new cat. That still wont provide enough back pressure?
Reply
Old Oct 24, 2001 | 04:17 PM
  #9  
FC3AZ's Avatar
Senior Member
Tenured Member 05 Years
 
Joined: Oct 2001
Posts: 464
Likes: 0
From: Peoria, AZ
come on now, TTT
Reply
Old Oct 24, 2001 | 05:39 PM
  #10  
hypntyz7's Avatar
Banned. I got OWNED!!!
Tenured Member 10 Years
 
Joined: Jul 2001
Posts: 3,052
Likes: 1
From: usa
The rotary engine does not need or want backpressure to make the most power. However, the intake system was designed upon backpressure. IF you take away the backpressure you have to change your intake(by wiring open the 6 ports) to match. IF you want your intake to remain stock(6 ports) than your exhaust has to remain stock. A NA rotary would be at its strongest with the 6 ports wired open and a totally open exhaust.
Reply
Old Oct 24, 2001 | 06:05 PM
  #11  
Ryde _Or_Die's Avatar
...
Tenured Member 10 Years
 
Joined: Aug 2001
Posts: 7,539
Likes: 0
From: Tampa, FL
I think the very best performance would be by having no back pressure...but having use of your 6 ports. Open them with your air pump. I will find out how well this works.
Reply
Old Oct 25, 2001 | 01:24 AM
  #12  
FC3AZ's Avatar
Senior Member
Tenured Member 05 Years
 
Joined: Oct 2001
Posts: 464
Likes: 0
From: Peoria, AZ
Ok, this is what I am askin..........How do high flow muffler designs keep the 6 ports open, if you say with no back pressure they should stay closed? Correct me if I am wrong......High flow mufflers are the same as no mufflers??? I am a tad confused....please help!!!!!!!!
Reply
Old Oct 25, 2001 | 03:04 AM
  #13  
The Ace's Avatar
Greek Power
Tenured Member: 20 Years
 
Joined: Aug 2001
Posts: 2,375
Likes: 0
From: Greece
Talking

In a NA, you need a minimum amount of backpressure to open the 5th and 6th intake port (dont know exactly how much, heard something about 2psi ??). Because your stock exhaust provides much more than that, you can replace with a catback, that can still provide that little bit of backpressure, but not any more! Just the absolute minimum needed for the 6ports. So you still have the funcionality of the 6ports, and you have the highest flowing exhaust possible


PS: Thats why custom exhausts are a possible danger. The designer/maker must calculate this minimum amount of backpressure, and take it into account...
Reply
Old Oct 25, 2001 | 01:51 PM
  #14  
FC3AZ's Avatar
Senior Member
Tenured Member 05 Years
 
Joined: Oct 2001
Posts: 464
Likes: 0
From: Peoria, AZ
Ok, so let me get all this in perspective.......sorry for annoying some of you.

Stock header, 1 cat, no muffs = no 6 ports

Stock header, stock cats, no muffs = no 6 ports

Stock header, 1 cat, aftermarket muffs = yes 6 ports

Stock header, stock cats, aftermarket muffs = yes 6 ports

??????????? Am I 100% correct????????
Reply
Old Oct 25, 2001 | 02:08 PM
  #15  
Ryde _Or_Die's Avatar
...
Tenured Member 10 Years
 
Joined: Aug 2001
Posts: 7,539
Likes: 0
From: Tampa, FL
Do we even have a stock header? Thought it was just a stock downpipe.
Reply
Old Oct 25, 2001 | 02:25 PM
  #16  
FC3AZ's Avatar
Senior Member
Tenured Member 05 Years
 
Joined: Oct 2001
Posts: 464
Likes: 0
From: Peoria, AZ
Sorry, got the term wrong...... downpipe/header/manifold/piece o' chit, whatever that thing is under the heat shield.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Th0m4s
Build Threads
25
Feb 26, 2019 02:04 AM
bb6guy
Old School and Other Rotary
10
Oct 1, 2018 08:07 AM
sYnth.
Build Threads
0
Aug 19, 2015 06:27 PM
bb6guy
3rd Generation Specific (1993-2002)
3
Aug 12, 2015 03:29 PM
86rxNa
2nd Generation Specific (1986-1992)
2
Aug 11, 2015 11:51 AM




All times are GMT -5. The time now is 09:50 PM.