Had header single pre saliencers (& Primaflow muffler) on my stock 12A & SP 12A. Had singles system on my other stock 12A. Put duel on the SP 13B I have in my current 81 & there is a big difference in power & throaty raspyness of exhaust note. Go w/ the duel & you can always further upgrade your engine later.
http://members.cardomain.com/snapshot1

sorry to hi jack this thread, but i would like to share my results with the exhaust on my 85 gsl-se.

the old suff was rotting off, so i cut it off after the pre-cat (or what ever the first muffler thing is after the manifold). i did away with all of the cats and what not, then i bent some 2in pipe. i thought i could get away with just a n1 fart-can at the end, but it was waaayyy to loud. so i went and got a dynomax to put in midway and a 40 flowmaster to finish it off at the bumper. it has a verry nice deep tone, and i would recomend it everybody. :)

do rotaries like exhaust scavenging like boingers do? if so, i suspect a nice single pipe would be better.

thats where the long primary system comes into play. lots of people say run dual al the way up till just before the muffler then connect them for scavenging purposes...supposed to be the best.

Running a straight pipe from the headers to the gray thingy on the RB exhaust before the muffler might be too loud for me. Not that I would care, just concerned about the noice level, but then again I shouldn't care.

Only thing I'm concerned about is getting pulled over because of the loudness .. otherwise I would use a straight pipe only if it helped my car's performance.

I wouldn't run dual though. That's just more weight on the car, and with the stock motors, even ported I still wouldn't do it. BTW I would like an RX-7 muffler without the dual tip. Find it unecessary as well.

Thanks for all the opinions guys. I decided to stick witht he duals and just get the leaks fixed. I didnt have enough $ for a single 2.5 all the way back.

Well I post a pic of it when its light again.

As far as performance, I can say it runs alot smother. I think this whole time I had a leak, and it just opened up recently cuz it sounds alot quieter than usual npw that its fixed.

Speed wise, I cant really tell.

Oh heres a old pic. I found.

http://img.photobucket.com/albums/v2.../stuff_008.jpg
http://img.photobucket.com/albums/v2.../stuff_010.jpg

heres a pic of my other cars setup.


This one cost a pretty penny....Just look at it...

http://img.photobucket.com/albums/v2...2/f7bd344d.jpg
http://img.photobucket.com/albums/v2...ITE_SE_051.jpg
http://img.photobucket.com/albums/v2...ITE_SE_067.jpg
http://img.photobucket.com/albums/v2...ITE_SE_052.jpg
http://img.photobucket.com/albums/v2...ITE_SE_073.jpg
http://img.photobucket.com/albums/v2...ITE_SE_069.jpg
http://img.photobucket.com/albums/v2...ITE_SE_068.jpg

DUAL INLET MUFFLER ! !

http://img.photobucket.com/albums/v2...ITE_SE_070.jpg
http://img.photobucket.com/albums/v2...ITE_SE_040.jpg
http://img.photobucket.com/albums/v2...ITE_SE_041.jpg

If you are afraid of loudness, then stay away from 2,5" single exhaust. I currently have RB headers, then 2,5" stainless with two Ferrita (extremly good quality) free flow mufflers. The sound is awesome, but loud!

Oh, talked to a guy that lives of welding custom exhausts, and he told me that a 90 degree bend muffles the same amount of sound as 21 feet of straight pipe! I didnt belive him at first, but he then showed me a RX2 with the same mufflers and about the same amount of pipe that i have. The only difference were a 90 degree bend. The car was so much quieter than mine, so i guess it works!

racing beat is a great setup, i have it minus the muffler (the idiot that used to own this car cut it off for a stupid ass ricer fart can). I've heard the setup on iotus' car, he used to have the N1 style muffler and the racing beat sounds beautiful on the car. Not real loud, but deep and just enough to let people know you mean business yet keep your ears from ringing after driving on the highway. So if you're worried about how loud it is without a cat, dont worry, its pretty mild.

As for the true dual setup, i was really wanting to do this, but after reading rotarygods post (which is great by the way, awesome info) im changing my mind, although i would like to hear how it sounds, i imagine its a pretty unique sound from the rotary.

I don't really consider this system to be a true dual system. There is only 1 outlet on the muffler. It jsut collects internally in the muffler. This makes it a long primary. You wouldn't benefit in the power department from making a shorter primary system.

Wish I live further away from work, say a place that requires some freeway driving. Too many weekend projects and being only 5 minutes away from work are not allowing me to do top end and actually compare the two systems. A good topic and very interesting. :crzyeye:

Come visit on a weekend and have some beer! that way you can fly up the 5. ;)

fly like an eagle?

Ryan,

I have a 2.5" piping that I had in my Prelude. Come take if you want.

Hi Ryan,

The green REPU has rb header, dual 1.75" pipe for a foot, then 40" long 1.75 ID glasspacks side by side, then collects into 2.5" id magnaflow, 90* bend and pacesetter dual resonator tip. Pretty quiet. Dellorto makes a lot more noise than exhaust.

I put a lot of sound deadening foam insulation under the hood and around engine compartment. Dellorto is still louder than exhaust! Since u have a dell u can use that as a reference.

Come over anytime and test listen. U got my #

I say...REMOVE THE PRESILENCERS. its too restrictive...w/o it, you have a chance against CRAD51 :D

his presilencers are just like the glasspacks though... straight through, so it shouldn't hurt much

ok...i want to put the rb sp header on my 12a, and just replace the cats with a straight pipe. i've got a magnaflow muffler with new pipe welded up to 18" away from the cat-pipe(the new pipe starts 18" away from the cats, muffler is still at the bumper). would it be too loud straight piped or should i place a muffler inline where the cats are? and if i should use a muffler, which one?

chould be like me and have dule side pipe exhuast 2.25 to cherry bomb to duale side pipe's 3 inc

it really kinda odd sound fine but ti get alot fo looks and plus it done well i mad eit my self caus eno one i know has vere done it

yes it can unless its old and burnt out. But that take lots of years. So it can hurt performance

thanks for all the responce guys.