I am planning to get the APEXi N1 series exhaust system for my 1986 mazda rx-7 gxl and i was wondering should i go with the dual set up or the single exhaust set up...i currently have dual exhaust but i'm wondering would more backpressure from one exhaust give me more horsepower....thanx again

 

single.

 

No, more backpressure is a bad thing.

Regarding the dual vs. single debate..i'm thinking that if you get a sufficient enough diameter a single setup can be as good as a dual.
Unfortunately your car is an n/a...so a single apexi N1 is gonna be LOUD AS HELL. The duals are already intolerable from what i hear.

 

The single will provide more flow, and weigh less. It will also be infinitely louder. The N1 is a loud exhaust to begin with, and this will most likely be an uncomfortably loud setup. But people do run it. Depends on your tolerance for pain I suppose.

Steve

 

On the topic of exhaust, what should i do with that pipe that goes to the main cat(o2 pipe i believe) if I want to run a straightpipe?

 

Go for the dual n1's. Your ears will still hate you but not as much as with the single.

 

N'1 duals all the way!! They are insanely loud. Hope u dont go on many trips because its hard to tolerate more then about an hour of it. But besides that, they sound great. Its also fun to drive through a parking lot setting off car alarms

 

Go with the single...I am not sure does the N1 come out the driver side or passenger side...I had a 87 rx-7 with driverside single looked good. I also beleive that the single has less restricted flow.

Ty

 

It bolts up to the engine, you want to remove it at that point and get a block off plate from some people like k2rd.com or something like that to seal the passage.

Steve

 

If N1's are too loud to tolerate what exhaust system do you guys suggest that i put on my RX-7?

 

I think single exhaust on a car that had and has indentations in the back bumper for the duel exhaust should keep duel exhaust. I ran a duel N1 catback for a few months with a main cat and pre-cats and I wished it were louder. I took off both pre-cats and main cat and replaced them with a RB downpipe and custom stright pipe, that made it really loud. Good thing I bought silencers with the catback now with the silencers in it is as loud as before cat removal. Oh yea Molotovman, that pipe you thought was the O2 senser is where the air pimp hooks up to the main cat to help it burn excess fuel, the O2 senser is in the header.

 

Block it off.
As for duals or singles, there are lots of different opinions on whats better. Things to know for sure: Single is, lighter, but louder, and cheaper. Duals are not as loud, a bit heavier, and cost quit a bit more. Performance wise, I don't believe there will be a noticable difference, they both flow very well.

 

That depends, how much money do you have to spend?

Steve

 

If money were not the problem then what systems would i want to look into for the rx-7?

 

Racing Beat. Hands down. It's a little heavier than the others, but sounds the best and is the most streetable. After that comes the HKS duals. Or you can fabricate your own using borla cannisters and it'll sound nice too. Be cheaper as well.

900 posts! w00t!

Steve

 

I have apex single with stock cat and downpipe and it isnt loud at all. As for when I get the cats n a 3" Dp im sure that will be another story

 

turbo's keep the noise down. NA's will usually be louder if not higher pitched.

 

just go with whatever looks good for you...i got duals, aint got no problem, could've gone w/single but i like to show that duals match w/FCs

 

I have a single N1 on my car. Right now I have stock ports, I have a racing beat down pipe, and pre-silencer to the cat back. And my N/A isn't loud at all, not nearly as loud as I thought it was. Infact my YZF600 engine makes the RX seem quiet.

 

i have a strait pipe with resinator going back to duel 3 1/2 tiped apexi n1 muffler (just a small n1). I love the noise, i cant get enough of it, people run off the road, they hold children close, they dont know to react, most hate it, ricers cant believe it... Im taking my resinator out, getting a header and replacing the small n1's with 5'' tiped ones... i hope it alot louder

 

Racing Beat Hands down, without a doubt the best.
I love it on my turbo 2. I have the Full Racing Beat Exhaust System, and I love it for the Turbo 2 its Lovely.
The other one I love is the Greedy PE "Power Extreme" or the old school model which is the SP Series which is no longer available. I would do the following set up if I went went Greedy. The Greedy Power Extreme with the Racing Beat Pre Silencer, with the Racing Beat Downpipe. The only thing I dont like is if im not mistaken the Greedy is not SS. The Racing Beat is, and wont rust.