Two months after registering the car the emissions test notice came. I reinstalled the sixth port actuators and reinstalled the OE air box in case they had to do a visual inspection. Went to fix the air pump split air pipe and..... jeepers! This car has a gutted aftermarket cat! No wonder the car didn’t have the split air pipe connected. Lucky for me I have a good friend who graciously loaned me his OE main cat for the emissions test and well lets just say it passed...much to my amazement. The car was now 100% street legal. So now I can really set to work.

                                    CAR INITIAL COSTS and BRAKE COSTS:
                                    1986 Mazda RX-7 Sport                                      $1000.00
                                    OE pax motor mount (new)                                  $39.19
                                    Front brake pads (new)                                        $17.99
                                    Headlight (new)                                                   $ 9.00
                                    Rust repair materials                                            $35.00
                                    Spray paint for body and wing                             $15.00
                                    MD state Inspection                                             $85.78
                                    MD 2 year registration                                         $136.50
                                    MD emissions test fee                                          $14.00
                                    Exhaust gaskets for temp Cat install (new)          $11.41
                                    Spare key                                                             $4.00
                                    Corksport SS brake lines (new)                           $89.00
                                    Corksport SS clutch line (new)                            $18.00
                                    Valvoline DOT4 synthetic brake fluid                 $5.99

With emissions safely taken care of the first thing I wanted to do was ditch the original factory exhaust. It was so rusty in places that to repair flange leaks in the past they had simply welded the flanges together. Add to this a drivers side muffler that was literally hanging off, and the lack of a main cat, the whole system needed to be replaced.

The old rusty exhaust - note angle of drivers side muffler, it was not attached to the rest of the exhaust.
An exhaust "repair" - just weld it!

In all it's splendor - headers, presilencer, no cats, and a single 3" outlet.

Here we go folks....want power you have to use headers. And some of the best headers come from Racing Beat. Not exactly cheap but they are perhaps the best power "bang for the buck" for a normally aspirated rotary. So a road racing/street header and presilencer were purchased and installed.

In the interest of weight savings I wanted a single outlet exhaust. And Corksport was kind enough to oblige with probably one of the most cost effective "cat backs" I’ve ever seen. This is a SS mandrel bent, essentially full 3" pipe, with a polished SS muffler and tip, that comes with gaskets and hardware for only $289.00. ShaZAAAM! Sold. Gone was the entire OE exhaust. In the process of replacing the exhaust and with no cats the air pump was no longer needed so was removed - more weight savings. Similarly with no air pump the air control valve was removed and a blockoff plate (supplied by Racing Beat) installed.

Ah but what about the 6th port actuators you say. Well the RB presilencer comes with a split air pipe connection which supplies just enough back pressure to work the 6th port actuators. Sounds like a winner to me.

With the new exhaust I also installed a new O2 sensor - the existing sensor looked to be the original and was not going to come out of the manifold (I snapped my O2 socket attempting its extraction). Installed, the new exhaust looked fabulous. But there was a problem. Jiminey Christmas this thing was LOUD! Made my one year old daughter cry and run screaming in fright from the garage door when I started it for the first time with the new exhaust. This was NOT going to be "streetable." Thankfully Corksport also offers a muffler insert to quiet things down a bit. I say, a bit. It is quieter now but still requires a very light foot on the street lest you want to chat with the local constabulary.

                                                        EXHAUST WORK:
                                                        Corksport SS Single catback (new)              $289.00
                                                        Exhaust shipping                                           $35.00
                                                        Racing Beat Header (new)                           $187.00
                                                        Racing Beat Presilencer (new)                     $198.00
                                                        Header to block gasket (new)                       $18.00
                                                        Bosch O2 sensor (new)                                 $17.99
                                                        Muffler insert (new)                                      $18.00

This may seem kind of expensive but the car needed an entire new exhaust anyway and the exhaust is still the best place to find more power.  I’d estimate this combination is good for at least another 20-30hp and on a car with 146hp stock this is a pretty decent increase.

Loud and Obnoxious but oh so intoxicating. I dub thee - ATOMIC CHAINSAW!