I introduced myself here:http://mazdarotaryclub.com/forum/index.php?topic=83041.0
I purchased my RX-7 on 19 April and it's almost all original except for an Apexi twin intake, Fujitsubo exhaust, Blitz ZZ-R coilovers, Defi water temperature gauge, Billion VFC fan controller, a Momo steering wheel and that stupid headlight vent which I will replace at some point. It's done about 82,000 miles but mechanically it is in excellent condition. The exterior is actually pretty good barring rust on the bottom of the driver's side door (Carl at Hayward Rotary said it looks minor), rust under the rear hatch on the passenger side (looks very minor) and the fact that the car desperately needs a thorough cleaning with heavy duty soap and a clay bar followed by paint correction. The interior is in pretty good shape and should look better once I have tackled it with a heavy duty plastic cleaner followed by a few plastic rejuvination products and both front seats should ideally be reupholstered.
The RX-7 is going to replace my RX-8 as a weekend only vehicle that does about +/- 6,000 miles per year and sees the track about 10 times per year. My plan is to keep the car on the stock 99-spec twins and try to make somewhere between 300-350 bhp. Today (7 May), I took the car to Hayward Rotary for a full check-over of the engine, drivetrain, suspension, etc. and came away very pleased.
The car was compression tested with a genuine Mazda rotary tester and the starter motor was cranking at 265 RPM. Before the results for the front rotor were calculated as the car was cranking his team said it sounded very healthy. The corrected results at 250 rpm are (in bar):
Front rotor: 7.7, 7.6, 7.6
Rear rotor: 8.0, 8.0, 8.0
Carl and his team inspected the entire engine from top to bottom (except they didn't individually check each solenoid), checked the coolant and brake fluid levels, vacuum hoses, all pipe work, engine mounts, front and rear suspension and diff bushings, rotors, calipers, etc. and also took it for a test drive to ensure the car ran alright, boosted correctly, the transmission shifted properly, etc.
We had a chance to look under the car very closely once it was up in the air and we were able to confirm how clean the chassis and suspension is and I was also able to confirm that the down pipe and catalytic converter were stock units. The visual inspection picked up the following:
- Brake Fluid reservoir cap is broken and needs to be replaced;
- Rear turbo has the slightest oil leak. It is not dripping at all but is just a touch damp at the bottom front of it. I was advised to not worry about it for now and run it until the turbos go south sometime in the future;
- Rear passenger-side brake disc has over heated and is scored so both rear discs will need to be replaced;
- Passenger-side top pillowball bushing needs to be replaced;
- Drivers-side lower pillowball bushing needs to be replaced;
- Main differential bushing has burst and is leaking oil and needs to be replaced;
- Catalytic converter is slightly dented but works fine;
- Fujitsubo cat-back exhaust reduces within the muffler to about 2.5 inches rather than remaining a full 3 inches; and
- Blitz coilovers suspension should be replaced if I want to use this car on the track.
We then took the car out for a drive (Carl was driving) and confirmed that the turbos were spooling correctly in any gear and at any time he depressed the throttle. He also said the idle was fantastic, the transmission shifted very well and that the car was very stable. He noted that one of my wheels needs to be rebalanced as there is quite a bit of vibration in the steering wheel (I have noticed this too but thought it might be the way the Momo wheel was attached) and he didn't like the coilovers.
Overall, Carl and his team were extremely impressed with the car's condition and he said that considering how well it runs and the condition of the rest of the mechanicals, if it were his car he would keep the mods light and just focus on the suspension, brakes and tires. His ideology is if it isn't broken then there is no sense in replacing it or fixing it unless you are looking to make significantly more power.
He recommended a 3 inch silenced decat, a proper 3" cat-back and a Power FC with a tune. With this he said I could expect about 300 bhp at 12-13 psi (0.83-0.9 bar). Contrary to what I have researched online, he does not recommend changing the AST if it is in good shape as he thinks most aftermarket units don't seal as well and in his experience very few RX-7s he has worked on have had the ASTs crack and start leaking. Also, at this power level he said that the stock intercooler is more than sufficient for track days as is the S8 radiator with the additional airflow from the 99 spec bumper. He also had some sympathy for rewiring the fuel pump but he didn't specifically say anything about needing to change the ignition coils.
He said if I wanted to try for up to 350 bhp on the twins then I should look into 1680CC secondary injectors, HKS down pipe and an intercooler (front mount or v mount) as a minimum but that the turbos would not last long at 1.0 bar or higher of boost when tracking the car often.
On the suspension side of things he really likes the Tein Street Flex coilovers as a good compromise for street/track use which also aren't too expensive (Ohlin's if you have the budget), uprated anti-roll bars (either Racing Beat or Cusco), stock RS brakes (but admits a good big brake kit is night and day), braded brake lines, and uprated brake pads (he prefers Hawk HP+ but advises that they will not be nice to discs and will damage wheels with all of the brake dust). For tires which will be used on the street and track he says the Federal 595 RSR tires are really good for the price, if you want to spend a bit more the Yokohama AD08s are amazing, and if you want to spend even more then he says you can't do better than the Pirelli Trofeo R's.
Overall, the visit was well worth it as I found out for certain that the car is in great mechanical condition. The next thing I have scheduled is an appointment with Super 7 Autos next week to repair the rust issues on the driver's door and the rear hatch as well as respray the following:Driver's door - Repair rust and respray.Rear hatch - repair rust and respray underside of the hatch.Front bumper and lower diffuser - Respray.Headlight covers - Remove and replace headlight air vent and respray both headlight covers.Brake vents - Respray.Front Passenger Side Wing - Fix flat spot and respray.Door Mirrors - Respray both.Body kit - Remove and respray as it desperately needs to be touched up.Sills - Clean up when body kit is removed and if necessary respray.
Depending on the price of things I may just look into respraying the entire car but I would rather use the money saved on:
- Reupholstering the seats;
- Replacing all of the speakers;
- Installing the Toad Cat 1 alarm I have brand new in a box;
- Installing sound deadening in various locations;
- Fixing as many interior rattles as possible;
- Buying a few new OEM interior items to make the interior nicer;
- Replacing all window trim, the front cowl, exterior door mirror triangles, side markers, windshield wipers, etc.;
- Take the car for preventative rust treatment to top up the waxoyl and inject cavity wax everywhere;
- Fix the mechanical issues that were identified above, buy new brake pads, different coilovers, stickier rubber in the right size (235/45R17 Front, 255/40R17 Rear), decat and Power FC tune;
- Have the car aligned and geo'd;
- Take the car to Offset Detailing for a paint correction detail/valet of the entire exterior, engine bay, interior, wheels, etc.; and
- Finally, go to Snetterton or Oulton Park before the end of July!