a 3" exhaust will flow more... i dont know what the back pipe on the rb is. i would measure it....

i will say the back pipe on the ms is 2.5" and loud does not = flow....

the stock exhaust and the borla have 3" back pipes also the turbo xs...

beers

 

I believe it will make little difference for a bolt on system since the pipe is reduced to fit the OEM CAT. You have a chock point that will determine your flow.

 

It was a hard call to let it go.

 

the choke point is in the gasket between the exhaust header and the cat...

look at the photos, this is the stock vs ms / corksport.

beers

 

Yeah, but this is N/A for those of us with a metal or no cat. So, it really does come down to...which cat-back floweth the mostest.

 

Understood I was just pointing out that unless the whole system is of the larger pipe diameter the large piping at the back half will have little effect. If you have the large piping through the whole system and custom fit the RB to it then we are back at needing a dyno test to tell the real story.

 

on that note, do you know the back pipe dia on the rb? i think mazda did a great job on getting the most out of this car from the intake to the exhaust....

so going from the stock dia to anything smaller seems counterproductive to me...

beers

 

The MS is at least as large as stock and the RB is about .5 inch larger but has a OEM size chock point at the connection. You have to remember that even though the CorkScrew and MS dual look alike their construction is different. Take a look at the front of this thread I have a picture of both MS and RB connectors there, they both look larger then the CS.

 

we are talking about the ms dual can correct... do you have a measurement of the back pipe? that is info i dont have...

thx.

beers

 

No, unfortunately I didn't think of getting that at the time.

 

ah,

then we are both right i think... yes the non duel ms exhaust is the same dia as the stock...

i am pretty sure that the ms duel can is the same as the corksport at 2.5 " as the photo shows.

beers

 

Is there a way to eliminate the drone? Just installed my MS last week and I love the sound and haven't noticed the drone.

 

the drone is subjective.. at my mature age, i am not as tolerent. i spend a lot of time on the highway right at the speed that it was bothering me..

if you have it with a stock cat it might not be as bad...

spin9k did a write up of adding padding to the trunk area to help. i did add it and it helped a bit..

beers

 

Sound dampening material on the trunk floor and trunk lid helps cut the sound a lot.

With a midpipe and the Greddy SP2 I don't realize how loud it is until I am driving next to another car. Recently I heard a JIC single outlet exhaust without the silencer installed. That was loud, it sounded like a subwoofer constantly reverberating inside the car.

With the silencer it was a bit louder than my setup and he was running the stock cat with resonator.

The Greddy SP2 with the stock cat is not much louder than stock. A lot of people have said it is a loud exhaust but it is not. Compared to the MS and RB I would say it is in the middle.

 

Very nice it helped me to make my choice between those two....it's gonna be RB
Nice pictures

 

RB for me too! Thanks for the write-up!

 

When I had the MS I was looking at sound absorbing matting myself. Remember to pad the heat shield above the muffler it is very thin and resonates easily.

 

Very interesting reading guys! Thx Raptor75 for the write up!

I just ordered the racing exhaust from Racing Beat... since the RX-8 is my daily driver I hope I can live with it...

 

It's going to be really, really loud for a DD. Nemesis had one on his car for a little bit and took it off because it was much louder than his regular RB unit.

I'm thinking I may be going back to the RB unit again, since I am NA again and I want to get a hi-flow cat. My JIC is quite a bit louder than the RB, and when I had the RP Supercat on it a little while ago (melted/failed when I blew my engine, but I had it on for a little bit after I went back to NA). So I think I will get another supercat, but get a quieter/mellower exhaust.

 

Last night I helped a local member install the RX7store resonated midpipe.

He has the Corksport (what Mazdaspeed copied for the latest exhaust). Wow does it rip. Sounds nice, really nice. He'll have to take it easy around the police (he has a red car on top of that).

 

alnielsen and I had our cars side by side parked a couple months back. We took turns doing some revving to compare the volume of the dual MS and the corksport. The corksport was a little louder. We both have had the exhausts installed for a few months and both felt ours mellowed a bit after having some miles on them.

 

Thanks Ted for helping out putting on the midpipe yesterday. The car sounds really nice and it loud as hell. I hope it will mellow out as it aged. And yes, I was in 4th gear doing 25 mph when I had to drive by the local police station in Rogers. Car pulled harder up top and I almost crash my car going down I94E ramp this morning!

 

I just made a round trip to Daytona for the 24 Hr race. On the way down I was leaving a Georgia gas station. Whoo, what is this. The car had more power, but the original louder sound of the exhaust was back.

 

^ maybe it has something to do with our summer vs winter blend? Or maybe they don't run ethanol in their fuel?

 

Just got my RB dual exhaust installed. Sounds awesome but anyone here know if I risk getting a ticket in SF Bay due to the volume (almost typed noise but it sounds so smoooth)?