Hi, I am looking at buying an exhaust for my 1990 with VVT swap. I already got a 94-97 racing beat header and I narrowed my options to:
Racing beat resonated mid pipe + test pipe + muffler ~$625 shipped
or Borla spec Miata exhaust (deletes cat) + optional muffler for the street
Miata 1994-1998 Header/Manifold-Back Exhaust part # 12668
Miata 1989-1997 Cat-Back & Rear Section Exhaust part # 60537
$650 shipped

Then there is the enthuza Na racer but I am afraid its too loud for me.

The car is mainly going to be a track car with occasional street use.
I am leaning towards the racing beat combo but wanted to know if anyone uses the Borla and how loud it is.
Thanks

 

The double-muffler Borla is supposed to pass sound at Laguna, so it's fairly quiet.

 

Do you know if it's true that the first 2 or 3 inches are only 2" in diameter.

 

I've been running the full borla setup with a stock 94-97 header. It's a pretty nice race exhaust. Sounds good and is really light with the single muffler and turn down, and is super quiet with both mufflers. Multiple people have told me they couldn't hear my car on track when I was running both mufflers. There's still a decent amount of noise inside the car with both mufflers, but my car has zero interior, so...

I just walked out to the garage and measured. There's an 8 inch section of 50-51mm OD pipe between the flange and the first muffler. Everything behind the first muffler is roughly 57mm OD. The RB header is 59-60mm OD at the flange. With the RB header, I would probably buy the full RB exhaust over the borla. Partially because the pipe sizes should match, and partially because I hate the way the borla 2nd muffler looks- exiting at the center of the car instead of in the cutout in the stock bumper.

 

Thanks jpreston. That's exactly the information I was looking for. Rb it is!

 

Brianan, my dad's car has the Enthuza NA racer, I really like the sound and it's not too loud either.

 

I've had issues with my Enthuza (mostly stemming from it being built for the wrong style axle), but it's been mostly reliable. It's cheap, makes power, and getting it patched up when the hangers broke off has only cost me $20 twice.

 

Are you using poly hangers?

 

If you are going to go with a header back system, we have used the MBS spec miata exhaust on our enduro car and love it. It's pretty quiet and is only $269.

Spec Miata Race Exhaust - Mandrel Bending Solutions

 

New stock hangers.

I guess I wasn't clear, the hangers on the exhaust side broke off (causing a late exhaust leak + more exhaust movement).

 

I followed. It's common to have metal hangers snap off the piping with the stiffer poly hangers. Sucks yours snapped off.

 

Do you have a picture of it installed? This sounds good!

 

I cannot speak for that exact exhaust, but MBS is an excellent company to work with. I get the majority of my pipes from them and have never had an issue. I might pick up that exhaust when I finish my VVT Na build.

 

I wish MBS would build 2.5" or even 3" versions of their exhaust.

 

We have the Borla XR1 on one of our cars. It's very quiet but sized for a 130whp Spec Miata. We prefer the full Racing Beat resonated exhaust which we have run 300whp through at 10psi with a Rotrex. Virtually every other car here has the same RB resonated exhaust. Resonated as opposed to straight through midpipe, keeps it quiet. Bombproof, makes power.

 

I have the MBS on my car and it fit like a glove onto my RB header and stock hangers. So far so good. Unfortunately, at my first track day on Laguna Seca (bone-stock 200k miles 1.6, MSPNP2, no AFM), it bounced off the sound meter at 93db on a clear day.

Adding a resonator from Summit right after the header outlet brought it down to 91db on a very cloudy and soggy day a few weeks later. Of course it was 90db max both those days and eventually I got black-flagged enough to get sent home early. Ahh Laguna Seca sound gods. At least SCCA weekends there are still 103db max so I had no problem at the races.

Not only does the resonator cut down on the decibels a tad, it just makes the Miata burble a lot more pleasing to the ears. There have been about 6 million posts about the same thing so here's another.

 

You can always throw a Supertrapp Muffler cap on your current exhaust

 

The only thing I wanted to know is if the borla spec miata exhaust was quiet and if it had a bottleneck at the beginning. Could not find any posts about that.
I'll be buying the racing beat setup

 

Robert, I also like to see a pic of the installed spec exhaust.

 

I just put a MBS exhaust on my car. It seems really well made for the money and the fit was perfect other than the flange gasket they sent with the kit. I ended up using the oem donut gasket.

I got the exhaust simply for the price. For a dedicated track car (ie Spec Miata) it would be great, but I drive my car pretty much everyday, so I had to quiet it down some. Welded in a big resonator and now all is good.

The full Borla system is pretty expensive. If I had that much money in the exhaust budget I would just buy the full Racing Beat system. I had one on my car before the MBS system and it sounded better than any Miata I have heard... before bent the tail pipe and cracked the mid-pipe...