This page hosted courtesy of Regan Rotary Racing. December 2009.

Gene Felber Archive: RX-7 Modifications and Specifications


A-SPEC /Garrett GT35R turbo, .70/1.06 AR on the compressor/exhaust.  TiAl 46mm WG and TiAl 50mm BOV.

M2 air box with carbon fiber cover and sides modified to work with the single turbo

ASP/M2 medium intercooler and Greddy elbow

Innovate! LM-1 wide band air/fuel ratio meter with Bosch LSU sensor and heatsink

J&S knock sensor w/dual display

M2 lightweight battery conversion/relocation (to passenger bin area) w/marine battery box 

Hawker Odyssey PC 680 battery

NGK plug wires

NGK BUR9EQP plugs, leading; NGK R6725-105 (10.5) race plugs, trailing

A'PEXi Power FC ECU with Commander

Datalogit for Power FC

Racing Beat 3" dual outlet exhaust with muffled SS center section

Blitz Dual Solenoid Spec-R electronic boost controller

Bosch Motorsports high flow fuel pump (054 254 044), direct wired  with Bosch 30 Amp relay

Greddy WP and Alternator pulleys

SS block-off plates for DT and ACV, EGR, rear turbo oil drain and secondary air

Jaz mini breather catch can for oil overflow and eliminated oil fill PCV valve

Aeroquip StartLite kevlar fuel lines, -8 and -6 with AN hardware

Bosch 1600cc secondary injectors

K2RD secondary fuel rail

SX fuel pressure regulator

SX inline fuel filter


GAB Super R 8-way Adjustable shocks

M2 threaded coilover conversion kit

Eibach 2.5" track springs 550x6" (F) 450x7"(R) -old config

Eibach  2.5" track springs 650x6" (F) 550x6"(R)- experimental config

Eibach  2.5" track springs 650x6" (F) 450x7"(R) - current setup for track/autocross

Unobtainium Motorsports Nylatron differential bushings

Unobtainium Motorsports Nylatron rear suspension bushings for upper A-arm shock mounts

MazdaSpeed front and rear upper A-arm bushings

Unobtainium Motorsports Nylatron front lower suspension bushings

M2 HD sway bar mounts

M2 trailing arms

M2 toe links

GAB strut tower brace

race alignments


M2 expansion tank bypass kit and high pressure radiator cap

M2 50% larger core radiator

Redline water wetter

enlarged radiator inlet

carbon fiber radiator/intake ducts

CWR dual Mocal oil cooler kit and -10 AN hardware/lines


RPS heavy duty pressure plate and 6 puck sprung center hub clutch

RP 8.5lb aluminum flywheel

Neo 75-90HD synthetic transmission fluid

Redline  75W-90 differential fluid

reduced ratio 5th gear (main shaft and countershaft) from MPV/929. Changes stock from .719 to .827





Hawk HP PLUS pads (autocross & street)

Performance Friction 01 (F) & N-Tech comp (R)- SOLO I (Hawk blues front for other track events)

Motul 600 brake fluid for track from Widefoot Racing

M2/AP Racing big brake package with 13" slotted rotors 

custom aluminum brake ducts and high temp 3" hose

stainless steel caliper pistons for AP brakes $$$ from Essex Parts Services

high temp dust seals for AP calipers from Essex Parts Services

Thermax caliper temp strips from Essex Parts Services

N-Tech front brake backing plates/ducts

Mazda 2002 RZ (larger) rear rotors (Mazda Competition Parts)

Mazda 2002 RZ rear calipers (Mazda Competition Parts)


Willans 3" 6-point safety harnesses (from Bethania Garage)

SPA boost/water temp gauge A-pillar

PFS boost gauge with Pettit column mount)

Mazda Miata OEM leather/AL 5-speed shift knob 

Mazda AL door sill plates

CWC Widefoot pedal adapter

lightweight interior felt replacing much plastic - aft of seats, trunk area and tranny tunnel

removal of foot well padding/sound insulation/tar

custom window switches for CF door panels

M2 roll bar -  street/track configuration with harness bar, rear diagonal and main hoop diagonal

Kirkey aluminum road race seat

MOMO 350mm Motecarlo steering wheel (from LTB Motorsports)

custom carbon fiber cruise control mount to the Momo wheel

Mazdaspeed steering wheel adapter (Corksport)

Amperex 10 B:C fire extinguisher with custom aluminum mount

 Exterior & Miscellaneous

1999+ Mazda OEM front spoiler (Mazda Competition Parts)

4'x 4' utility trailer with custom tire rack, trailer hitch

 To be installed:

Nothing at the moment


Mazda 929 master cylinder



169 in.

4293 mm


69.3 in.

1760 mm


46.5 in.

1181 mm


2615 (w/o driver), 2835 (w/driver & racing equip.)

1188 kg, 1288 kg


95.5 in

 2425 mm

track (stock/race)

57.7 (F & R) in

1466 mm

Corner Weights (older weights with driver & 1/2 tank fuel)

LF: 777 lbs.

RF: 677 lbs.

LR: 748 lbs.

RR: 688 lbs.


362 RWHP @ 12 PSI (est.) ~ 409 flywheel HP

415 PS

Weight/HP (w/o driver)

6.4 lbs./HP

2.9 Kg/PS

Goal: 2,500 lbs; 450 HP


Remark: A 1993 base model RX-7 weighs 2840 with 255 HP = 11.13 lb/HP


Updated 10/02/2005