Any help would be much appreciated here guys as i have a few questions..

Basically my stock exhaust is shot, so i am fabricating a new one up from manifold back and have a few questions as im fairly new to RX7s/Rotary engines, so please be gentle with me as im "trying" to learn

I plan to make the exhaust as simple as, but there are so many pipes, like so:

(1)

what the hell is this? what does it do? can i get rid of it?

(2)

What are these 6 holes arrayed around the main exhaust bore? where do they lead too?

(3)

What the hell is this pipe and why does it have its own mini silencer? can i get rid of it?

(4)


After taking the whole system off im left with this pipe (which i believes come from air pump) that connects to this:

the centre box of my exhaust. Am i ok to get shot of this too and what does it do?

Any help would be much appreciated and i am new to all this so i thank you for your patience

Just so you know my plan is to build a new system with ideally a single pipe from that manifold flange back.

Richie

 

I've never seen that triangular flange on an N/a. It resembles the TII turbo flance vaguely but thats about it.

 

Yeah it sure as hell has me all confused

 

Is that a 79-80 1st gen?

 

...looks nothing like what came from my n/a fc

 

its deffo not a 1st gen its a 1988 engish gen2. i think the plan is just **** off all the extra pipes and just have a feed for split air pipe.

 

ok, i can tell you what all that does or you can download the factory service manual (fsm) from this web site or I can send you the fsm over aim "robertpulcen" it is in a pdf format.

you said you want ot make a single pipe to the end, so you will be removing the air pump and some if not all emisions.

this could effect the 5/6th ports acturators........or is that the s5's .....somebody jump in here i am a turbo guy and dont remember all the post arguing about 5/6th ports and back presure

 

also is it a 88 gtu or gxl?

 

This doesn't look like an NA exhaust... The big "box" in your exhaust is the cat. This is definately already a custom exhaust someone slapped on it.

 

S4's need backpressure from the exaust to open the ports. Also, if you just go strait from the manifold back get a ready supply of ear plugs cause that sucker's gonna be LOUD.

 

Yeah, that is not the stock exhaust. The thing that connects to your airpump you need, but you dont need the airpump. That pipe sends the exhaust back to run your aux ports. About the only way to keep them working is to get the RB presilencer/downpipe combo. I personally reccomend getting that and you can custom fab the stuff after that

 

not from n/A (88) anyways.. can tell ya ..I'm still stock and that set-up..mine is different.mine is GX..cat has split air pipe ..O2 sensor on manifold....whole system..manifold..2 pre-cats..to cat..to y-pipe to mufflers..info for ya

 

do whatsideways7 says

 

There are ways of opening up the auxilary ports w/o backpressure. Check the archives. It can be done using the stock air pump or an electric air pump and RPM activated switch. You can always wire the ports open (takes zip ties and 5 minutes) until you can get one of these systems working, at the expense of low end.

Since you're doing a custom system, I doubt you'll have enough backpressure to keep the auxilaries opening.

http://www.idahorotary.com/6portsolution.htm

http://www.fc3s.org/how_tos/electrical/6_ports.html

 

pretty sure it connects to the airpump, for the aux. ports or whatnot.

 

The racing beat presilencer will operate the aux ports regardless of backpressure. I've run with nothing after the presilencer and it still operated them.
If you dont have the money to spend, you can just wire open the aux ports, but I dont reccomend it. You lose lots of low end power and response. As for the other methods of opening them, they just seem like too much of a pita to me.

 

Found out some interesting info about euro spec NAs

As the emissions were not as strict on Euro cars the aux ports were butterflies in the manifold not sleeves and were actuated by inlet vac not exhaust back pressure apparently. So im guessing ditch all air pump?

 

mine was just like that, dont know how it all works but i am pretty sure it is stock
my car is a 1987 na.

 

Do you still have a stock system Eirik? the only thing thats confusing me at the moment is those 6 holes arrayed around the main bore of the manifold... god knows what they do

 

Wow, that english exhaust system is completely different from our American ones. thank you very much for posting pictures I'm going to watch this thread to see if anyone knows what those six holes are for.

Any chance you could snap a picture of your stock exhaust manifold?

 

Well after some more enquiring/researching today i have found out that the manifold on my European NA is actually a thermal reactor (similar to gen1 i believe) as there not as strict on emissions here as they are in the US/Japan etc.. it has an air inlet in which air supplied from air pump is blown around the reactor then flows through those 6 holes into the exhaust co axial system apparently

Im going to build a custom header for the car in a few weeks to take away that nasty thermal reactor you can get away with emissions here kind of if your lucky

I will get you pics of the thermal reactor tomorrow