EASY rotary question for knowlegable rotary people
#1
whitetrash
Thread Starter
iTrader: (2)
Join Date: Feb 2008
Location: San Diego, CA
Posts: 184
Likes: 0
Received 0 Likes
on
0 Posts
EASY rotary question for knowlegable rotary people
Ok, well i have a n/a fc, and i wanted to do an exhaust setup, as i have heard that some of the best power gains can come from an exhaust/header setup. WIth that being said, Apex'i makes one that is 3 inch. Now is that TOO big for a n/a setup, or woul di be ok running that on my car. is there any pro's, con's to running an exhaust without any other mods with a rotary? thanks!
#2
Boost ahoy!
Join Date: Jan 2006
Location: Joplin, MO
Posts: 968
Likes: 0
Received 0 Likes
on
0 Posts
You still require a little bit of back pressure on the NA, but I wouldn't imagine your car would explode with a 3" exhaust, but I don't think the engine will get enough back pressure to open up the 5th/6th ports. I think 2 1/2 is what you're wanting to go for.
But then again, I'd wait for someone else to chime in, as mine is just "what I think", which doesn't count for much sometimes
But then again, I'd wait for someone else to chime in, as mine is just "what I think", which doesn't count for much sometimes
#4
whitetrash
Thread Starter
iTrader: (2)
Join Date: Feb 2008
Location: San Diego, CA
Posts: 184
Likes: 0
Received 0 Likes
on
0 Posts
understandable thanks! i just know that i have heard a wierd story on how someone put a 3 inch exhaust on a TOTALY stock n/a, and somehoe he blew an apex seal or something? but thanks for the input, all else from knowlegable rotary gods on here is appreciated!
Trending Topics
#10
whitetrash
Thread Starter
iTrader: (2)
Join Date: Feb 2008
Location: San Diego, CA
Posts: 184
Likes: 0
Received 0 Likes
on
0 Posts
ok, as im not knowing a whole lot about the exhaust side of a rotary yet(previous owner of 9 hondas) are the stock exhaust manifold and the pre-cats one big piece, is that what ur saying, so getting a header, or a down pipe would eliminate them both? sorry for the dumb question.
#11
Project P --- Pedospeed
iTrader: (29)
Join Date: Apr 2007
Location: Norfolk, VA
Posts: 1,235
Likes: 0
Received 0 Likes
on
0 Posts
if you are worried about the 6pi system actuation, you could always mod it with the air pump or an electric pump. its easy and cheap+ there are several write-ups on both methods. still tho, i agree with everyone else, 2.5 is the sweet spot on an n/a. like george84 said, either a header/midpipe combo or a dp/midpipe combo will be your friend. it all depends on your other mods and how much exhaust noise you can take. for a stock/slightly modded fc the rb dp/presilencer is a god choice: http://www.racingbeat.com/resultset....rtNumber=16206
for a wilder setup or a track car where noise isnt an issure the header with thye same "presilincer" is preferred: http://www.racingbeat.com/resultset....rtNumber=16130
for a wilder setup or a track car where noise isnt an issure the header with thye same "presilincer" is preferred: http://www.racingbeat.com/resultset....rtNumber=16130
#12
Project P --- Pedospeed
iTrader: (29)
Join Date: Apr 2007
Location: Norfolk, VA
Posts: 1,235
Likes: 0
Received 0 Likes
on
0 Posts
the manifold is separate. you can get either the "cat replacement/ presilcer"combo i just posted, or the header with the same presilencer and both setups will bolt right up to the stock y-pipe or an aftermarket bolt-on cat-back
#15
ok, as im not knowing a whole lot about the exhaust side of a rotary yet(previous owner of 9 hondas) are the stock exhaust manifold and the pre-cats one big piece, is that what ur saying, so getting a header, or a down pipe would eliminate them both? sorry for the dumb question.
I came to the conclusion, after asking lots of questions and doing a lot of searching, that no bigger than 2.5", with a header, and presilencer or 1 cat, and a muffler, is best (just as someone had already suggested). I liked my setup for the few years that I had it.
#16
whitetrash
Thread Starter
iTrader: (2)
Join Date: Feb 2008
Location: San Diego, CA
Posts: 184
Likes: 0
Received 0 Likes
on
0 Posts
ok cool....and noise isnt really an issue...and motor wise it is completely stock...anyone care to post up some setups, so i could get an idea of what people are running on near to stock motors?
#17
I am back
Join Date: Sep 2003
Location: Highland, IL near St. Louis
Posts: 829
Likes: 0
Received 0 Likes
on
0 Posts
I have a s5 vert and don't need as much back pressure as you but, I run the stock exhaust manifold, Racing Beat downpipe made for verts (extra cross brace on verts), custom test pipe, Apex'i N1 duels. This setup is pretty loud but sounds really good.
#18
Rotorhead
Join Date: Feb 2001
Location: Charlottesville, Virginia, USA
Posts: 9,136
Likes: 0
Received 39 Likes
on
33 Posts
There was recently a thread on a similar subject:
https://www.rx7club.com/showthread.php
#20
Information Regurgitator
If you want/have to pass emissions you might try the Rotary Performance Header cat combo. it's a Racing beat header and Bonez catthat bolts right in place of the stock manifold and cats. Then just add the catback of your choice. I like the Racing Beat catback myself even though I currently have an old HKS sport system. Not sure if the HKS is sold anymore. Mazdatrix no longer carries it.
http://www.rx7.com/store/rx7/fcexhaust.html
http://www.rx7.com/store/rx7/fcexhaust.html
#23
Back in the game
iTrader: (-1)
Stock cat is probably pretty clogged at this point, might as well get a header and any standard 2.5" cat with an air injection port on it and hook it up to the existing line. Youll have to have an exhaust shop put the flanges on and make the pipe to the stock catback, honestly at that point you're far better off than stock. Stock manifold flows like crap and the cats are a large restriction.
#24
I am back
Join Date: Sep 2003
Location: Highland, IL near St. Louis
Posts: 829
Likes: 0
Received 0 Likes
on
0 Posts
Back pressure on a s4 n/a is necessary if you want the aux. ports to open, unless you have them hooked up to work off of something else.