Catless midpipe will get you'd F'd proper in CA.

I'm going to check out the motor mounts and cat over Thanksgiving this year, as well and make sure nothing it rubbing. Maybe disconnecting or insulating the DP -> trans mount is worth trying too.

I do also find it curious that my RB seems of a somewhat different style than perhaps older revisions?

Mine:



Typical:

 

Looks just like mine...again with no drone issue. I also use the DP to transmission mount and would not recommend removing it.
I’m not seeing the ultimate logic even in the consideration of removing a good quality hi-flow cat in an effort to improve sound.
Three or four of us just in this thread have posted no issue with your droning complaint and identical components on the identical car. I’m wondering if it’s just expectations not meeting the reality of a rotary powered car.

 

Hey, I never said I didn't expect drone -- you guys are the ones telling me it shouldn't exist!

 

In my experience with a previous cat-back “droning” was typically experienced at relatively steady cruising speed. It was not an issue on decel or low speed. And that particular cat-back sounded awesome under hard throttle.
So if it’s not an expectations thing, I’m wondering if your definition of “droning” and mine (and possibly others) differs.

 

Ah I guess one more thought.

I don't have a point of reference for the FD specifically since mine hasn't had this issue, but on other cars a noise/whine from the differential or driveshaft could also cause some annoying noises that could be confused with the exhaust.

You've also got all the heat shielding around there that could probably vibrate if its getting loose or otherwise damaged (same for the other metallic underbody trays and the shield over the muffler)

None of us can hear it, so it's all kind of subjective guessing. I do agree with sgtblue that what people typically call "droning" is something that happens at highway speeds at a pretty specific operating RPM.

 

I'm starting to think that I just don't know what drone is.

Nate and I will have to swap to find out if I'm full of **** (hint: probably).

 

Your car sounds great from the outside. The other day on Hwy 1 when you opened it up, it was singing.
I'm thinking maybe RB is using thinner piping these days maybe? Those tips are definitely different, and that would explain why pretty much everyone else with this exhaust doesn't hear the drone. RB better not be cheaping out on us now!!

I've heard good things about the Apexi' Noir and also the Tanabe that was mentioned above.

 

It’s not the RB. Mine looks just like his. And they’ve been making them that way for at least the 5 or 6 years since I bought mine new.

Exhaust “drone” and NVH from the drivetrain are different things.

 

There are a number of different versions of the RB cat-back - some have the polished muffler, some have a painted muffler, variations in tips, etc.

They've been making them FOREVER and there are variations over time. I think a lot of it is the source for a part will dry up and they will go somewhere else or change something to reduce cost, etc.

Dale

 

+1 they used to come (probably) from RSR Japan, these are the black ones, and then the silver ones are made here. i don't know about the FD, but the FC stuff varies a lot, many different designs

 

I had what appears to be the same version of the RB exhaust, purchased new in 2017 and connected to stock cat and JDM catless OEM downpipe (with all the original exhaust mounts). It was louder than stock but any drone was minor by the standards of aftermarket exhausts. It was definitely less drone than the stock exhaust on my Challenger.

 

The stock cat will kill most all performance and sound. Pretty much any exhaust is reasonable sounding with a stock cat. When you open it up with a mid pipe or high flow cat that's where the real sound problem starts.

Dale