This page was designed to express my personal opinions and insight into design and function of the following items for my specific application. I hope you find the information helpfull in determining if the products are suitable for your needs. Price and HorsePower numbers are not the main focus of this page due to the fact that your cost and results may vary. Pictures will be coming soon.
The Apex-i N1 is a single sided exhaust system consiting of two resonators and one stailess steel polished cylindrical muffler. The pipe starts at 60mm and flares to 80mm at which point it connects to the muffler. It is constructed of heavy guage mild steel which is coated in a purple 'Jet Hot' type coating. The entire design is straight through with very few bends for maximum flow. The tip is a massive 115mm. There is also an optional silencer that can be purchased if you feel you need to tone things down a bit.
NOTE- There seems to be quite an interest in just how loud this system is. On an NA- Without the silencer, the tone is very deep and when the car is at low RPMs under load, like climbing a hill, the frequency at which it resonates sounds similar to an 18" subwoofer at 140db hitting 30hz. Any duration at this level quickly grants you with a head ache. On the track it sounds sweet, deep and loud and very aggressive. With the silencer in, the volume is reduced, but more importantly, the pitch is raised to a more tollerable tone. The extreme deep pressure is eliminated by reducing the exhaust output to a mere 2 1/4" hole.
Pros-
One of the main features of the N1 cat back system is there is only one gasket, and that is where it connects to the catalytic converter. I have had four different exhausts on my 7 and have always had a hard time with blowing gaskets. Granted they were mostly the cheap muffler shop type, but none the less, the fewer to worry about the better. I also liked not having to worry about trying to get dual tips to hang evenly. This exhaust has virtually no backpressure and is designed primarily for top end power. I noticed a mild increase in my 3000 to 6000 rpm range and a large increase in my 6000 to 8000 rpm power. The fit of this unit is perfect and installation over a dual exhaust is by far easier.
Cons-
The only negative aspect of this unit is that it hangs quite low on the car and can be prone to scrape the ground over curbs and speed bumps. My car is lowered and the unit sits about 3.5 inches from the ground.
The Bonez high flow cat is a stainless steel enclosure which utilizes stainless steel internally as well, which helps withstand the excessive heat produced by a rotary engine.
Pros-
I recently replaced a test pipe with the Bonez high flo cat and noticed virutally no reduction in preformance. This is an excellent option for those looking to design a high performance exhaust that is capable of passing an EPA sniffer test.
Cons-
The only negative aspect of a high flow cat is the law in your particular area. Most states law reads something to this extent- "It is unlawfull to remove or replace ANY emmission control device on a vehichle UNLESS that particular unit is no longer functioning in the manner it was originally designed to." The UNLESS is the grey area.
The Bonez HiFlo Intake is a conical air filter with an oiled cloth element.
Pros-
This unit allows more air into the system due to it's high flow rate. Installation consists of removing the entire factory air box and attaching the new filter directly to the AFM. The bennefit being that you don't have to remove the 8 or so bolts to get to the filter element. It also is reusable.
Cons-
It draws HOT engine bay air into the system. It is highly recommended you build a cold air box to enclose the filter so it draw cool air in from the outside for maximum bennefit. The performance gains with this mod are minimal at best, but a neccessity to take full advantage of most other mods you plan on doing.
• Bonez Street/Comp Clutch and Pressure Plate
Pros-
I have now had the Bonez steet/comp combo in my car for over a year and it still grabs like mad.
Cons-
When first installing this unit, the clutch engagement is about 1 inch off the floor, so some pedal throw adjustments are reuired. After two months, the engagement is closer to stock.
The MD Racing fuel computer is an ECU upgrade which adjusts timing and fuel curves for optimum performance and throttle response. You must send your ECU in to have the upgrade completed since they desolder an eprom on the circuit board and replace it with a socket connector and insert the new chip with the adjustments made.
Pros-
The MD Racing upgrade does numerous things. What you will notice first is an increased RPM at idle, mine is 1000 RPM. I assume this is a result of the timing advance. Below 5000 rpm the timing is advance over 20 degrees, and after 5000 it returns to near stock levels to avoid detonation. Throttle response is improved greatly and the improved fuel mixture slightly increases mileage and improves horsepower. I would estimate power gains in the 5-10 HP range throughout the band. The top end, 5500+ is much stronger and this is where the product earns it's keep. I would consider this to be an engine management upgrade more over a HP upgrade, and for that purpose I am impressed with the product.
Cons-
The only negative aspect to this mod is the 3-4 days of not being able to drive the car while waiting for the ECU to return.
The RP underdrive pulley is designed to reduce the ratio of revolutions of 'parasitic components' to the eccentric shaft. This particular unit reduces rotation of the alternator and water pump by 15%, thus allowing the power normally required to rotate that extra 15% to be available to the wheels. Also claiming it helps reduce water pump cavitation at high RPMs.
Pros-
With this mod, I noticed the engine revs a little quicker and high end accelleration was slightly better.
Cons-
The main pulley bolt in the eccentric shaft is nearly impossible to break loose with standard methods. This bolt must be removed to replace the pulley. Use a 3/4 impact , or a 1/2 breaker bar leaning up against the fender well and crank the starter just a touch.
• Racing Beat Anti-Sway Bar set
This sway bar set is a perfect fit and is well constructed in tubular design. Comes with pulyurethane bushings and painted bright red.
Pros-
These were one of the best performance improvements made to my car in the suspension category. The car displays nearly neutral tendencies and body roll is reduced nearly 85%.
Cons-
the only negative aspect to this mod is in the installation of the rear bar, it requires the removal of the exhaust to get it into place. I tried everything I could and it would not give me enough space to avoid it.
• Racing Beat Single Outlet Header
The header is chrome, I assume it costs less that jet coat and helps to avoid California paint and chemical restrictions. The P.N. for the unit I installed was 16130 . The unit is heavy duty and the flanges at both the engine side and outlet side are 1/2" thick. The piping is thick walled as well. There is a place for an O2 sensor, but no sensing tube for the 6-ports. The RB Header also comes with the ACV block off plate. The main reason the acv is not needed is that it originally worked in conjuction with the EGR valve, where the header does not accommodate the air inlet tube for this. When you remove the stock manifold you will see the inlet tube built into it. The RB header is supposed to come with a manifold gasket but ask them to double check when ordering.
Pros-
Definitely an improvement in mid to high end power. Low end may have dropped slightly, but the high end improvement makes up for it. If you autocross, this may not be for you. If you run on a road course or like highway power, this is a plus. The power difference can be felt from 3000 RPM and up. I estimate ranges between 10 to 20 HP throughout the band. Overall, I am happy with the gain from the unit. After a weeks worth of driving the chrome is almost all blue from the heat and I am still getting used to the exhaust note, but loving it nonetheless.
Cons-
I managed to cut my hand three times trying to get the factory heat shield that surrounds the stock manifold off. After that, the rest was a breeze. All the nuts seemed to come off without incident. You are required to remove the 6-port actuators to get to the top 2 exhaust manifold studs. This was easy as they are only held on by 2 nuts each. If you have stock exhaust, you will have a difficult time removing the exhaust due to the rusted bolts and it is advised you use a torch and cut them off to remove the exhaust.
• Tokico Illuminas 5-Way Adjustable Struts
The Tokico replacement strut is an excellent choice for a suspension upgrade. It is a direct replacement of the OEM product. Adjustability is at the top of the shock with a dial from 1 to 5. With 1 being the softest setting and 5 being the hardest.
Pros-
If you do any type of racing and travel to different events, adjustable shocks are a must. With an adjustable shock you can dial in the right amount of oversteer or understeer you prefer to suit your driving style or track conditions.
Cons-
The dial used to change the setting requires a small flat head screw driver, a larger dial would be nice for ease of use.
The Wolf A/F Meter is an LED based signal display which uses the signal from the O2 sensor to show rich or lean conditions in your engine.
Pros-
The main bennefit of this unit is to help you understand what your engine is doing fuel wise, and to make it possible for you to tune your fuel curve for optimum performance by showing you where additional fuel is required and where excess fuel can be cut back. This unit has no adjustment features and is solely for diagnosing problems and tuning.
Cons-
This unit is not the easiest to mount in an RX7 due to the interior of our cars. I mounted mine below my radio, but with a stock stereo, this could not be done.