Hi guys, I've got a 85 GS and I want to put true dual exhaust on it. If not for the increased flow, for being able to say "yeah, its got dual exhaust". The gas tank rusted out, and I'm gonna put a fuel cell somewheres. My questions are these:

Where should I place the fuel cell ? I was thinking of putting it in the spare tire well, but I'm not sure. I watned to check with everyone here before I start putting things in, though.

What can I do for a true dual exhaust, what kits will fit and is there anything specific I need to look for in a kit to make sure it will fit ?

Thanks for your time guys, I appreciate any help you could lend to me.

 

I would think an easy way would be to take a header and hack off before it converges. That would give you a connection to the exhaust with 2 pipes coming off. Then get custom-bent piping to go back the rest of the way. Not sure how to route it, but probably can be done. Not something I'd do considering how expensive I hear a single exhaust can be, but if that's your goal...that's your goal (:

 

I was trying to acoid something custom built .... Thats lots of $$$$$.

Anyone have suggestions for routing the piping ?

thanx

 

most "true dual exhaust's" are for V configuration engines because they have 2 banks of cylinders on seperate sides of the car. A dual on a rotary would be pointless unless you change where the exhause stroke occurs which would be WAAAAAY custom if you ended up doing that.

If you want dual exhaust for the sake of saying you have dual exhaust, juust get a y pipe off an FC or something

 

i did the tru duel exhaust. it sounds like ****. unless you like the sound of a riced out harley, cuz thats exactly what it sounds like. plus, you lose horsepower becuase the exhaust pulses help to pull the exhaust from one rotor out of the other when connected. dont do it if you want it to be very close, do an x-pipe or h-pipe

 

racing beat's exhaust is pretty awesome by the way. or just make your own. thats what i do. MWAHAHAH 3 INCH DOWNPIPE and ALL THE WAY BACK!!! even goes under the axle for super straightness and its barely lower than the diff!!!!

 

I have a single piple to a single inlet dual canister outlet muffler. Looks like a 3rd gen dual n1. I like it. Works great, get the horses and the looks.

 

Rotary engines don't have the same pulses that piston engines have, and don't have the same benifit as piston engines for connecting the pipes. True duals will actually yield better performance on a rotary engine. It isn't too hard to make either, just get an rb road race header and have some pipes bent for anything behind it.

 

Doesnt RB sell a dual system?

 

It connects before the muffler, so yes and no. It is a "long primary" system.

 

I got the racing beat headers that aren't collected and off of that I just have two pipes going all the way back to right where the rear axles are and from there it just goes into a racing beat muffler that collects into a single outlet. I'm guessing that you can do the same but instead of putting on a RB muffler you can just extend the pipes under the axles into two seperate muffles.

Or are you trying to make them come out of each side like on the FC's?

 

Yeah, rotaries have *stronger* exhaust pulses than boingers. They benefit *MORE* from exhaust scavenging. There's all sorts of big long discussions on this around if you look; I'm lazy.

A properly designed collected system makes more power than an uncollected system. Note that the RB systems aren't "properly designed" exactly; you can get a bit more horsepower by doing math and making your own, but the RB setups are a hell of a lot better than stock.

 

i did that setup actually. I worked in a shop then, bent my own pipes, did the quarter mile a thousand times, decided i hated the sound and ran it duel all the way to the axle. i joined them into one, went over the axle, and stuck a muffler on it (turbo style muffler, kinda restrictive but quiet as hell), and it was way faster.

 

i did that setup actually. I worked in a shop then, bent my own pipes, did the quarter mile a thousand times, decided i hated the sound and ran it duel all the way to the axle. i joined them into one, went over the axle, and stuck a muffler on it (turbo style muffler, kinda restrictive but quiet as hell), and it was way faster.
And yes, the guy above me is right. You get more benefit from joining them than pistons. Remember, a rotary puts out about the same volume of exhaust gasses as a smallblock chevy.

 

There have been several folks who have completed a whole lot of research on the exhaust pulses of rotaries. In the end, they use a collected exhaust because of the advantages gained from the scavenging effect. Why spend a ton of money to create a system that will lose you power?

 

The RB system is WAY TO SMALL!!!! The pipes leading into the muffler are TINY!!!!