RotorJoe

I have looked around and it is my understanding that if you have a ported engine (stage 2 street port) and a true dual exhaust set up (like the one from MazdaTrix), you will lose power. Is that correct. I am looking into other exhaust options. Right now I have a RB Header with RB PreSilencer and the CS Single Side Cat Back. This set up is nice but a little loud for me. Good power and good exhaust note, just loud at full throttle. Is the true dual set up good for ported applications or not, and how loud is that caompared to a set up like I have now?
Thanks Guys!

1987RX7guy

iTrader: (3)

hey bro it is me again. For a ported motor a single outlet exhaust will yield the most power over all. The duals will yield a lot of power but not as much as a single. If you want a quieter note then go with the duals. They are not too loud but I have not heard them at WOT from the outside of my FC but it gets loud at about 5k rpms which I usually never go up that high unless I am in a hurry or racing. I would think that it would be quieter than your current set up becaust there are two pre-scilencers and two mufflers hence twice the sound reduction. The RB mufflers are nice. They have a low rumble until like 3k rpms and then it starts getting loud but not crazy until like 5k.

RacerXtreme7

iTrader: (2)

My experience......

I had a large street port 13b six port (also a 48mm Dellorto side draft carb and many many mods) in my 86 sport. I ran a single or collected exhaust set up first (RB collected header, 1 presilencer, RB "Y" pipe, and RB Turbo power pulse mufflers), it ran GREAT... made good power noticably in upper RPM's (4500 and up to 8k). This system was LOUD!!! I then went and fabricated a true dual exhaust using all RB pipes, flanges, presilencers etc. basically duplicating Mazda Trix exhaust system. Now using my Butt dyno, the car made WHOLE lots more power every were in the entire power band with the top end very simular to the single or collected exhaust. The car felt as though it was WAY more powerfull in its entire rev range from then any stock port. Even with its large street port it was more powerful in the lower rev range (2k) with stock having more torque 2k down. This is just my observations.. I have no dyno proof, but I recommend the duals for all porting configurations n/a. I went to the duals looking for more low end and found it and didnt feel as though i lost any top end, I also wanted to quiet down the exhaust.. no good. Theres just is NO WAY to quiet down a ported n/a rotary without significantly loosing power and torque. The duals on my car was World War II Jeep open header sounding... nice high rpm note, cool noises with both pass and driver windows open (can hear pulse left and right 180 out in phase), but LOUD. I hear the same exhaust on a stock port and its semi livable.

~Mike....

SureShot

I had a single silencer for a while, then went to full dual.

The single seemed to give more top end peak, but the duals gave more mid band torque.

My sig has a sound bite.

RotorJoe

Hey Thanks guys this is very helpful. True Duals is an expensive set up and I want to make sure that is what I want. Sounds like you may/may not lose top end power and the gain to the low end is well worth the price. I also wanted to make sure that you don't lose power with a dual set up with a street ported motor. Sounds like you don't. Thanks again. Feel free to keep the replies coming, more info the better.