Toyo Kogyo Co., Ltd., wishes to extend appreciation for your interest in and efforts with the Mazda RX-7 in automobile competition. This Manual reflects the knowledge gained by Mazda competitors and Toyo Kogyo engineers through much research, development and actual competition, and is to be considered recommended practice. It is intended for use only by those seriously engaged in the construction and maintenance of the RX-7 in competition; the parts, procedures and specifications outlined within the Manual are for racing and competition use only, and specifically have no relation to or application or other purpose for street and highway-driven automobiles. If the information contained in this Manual is applied to a street or highway-driven RX-7, the results may include voided warranties, reduced reliability, and losses in performance, economy and emissions, all or some of which may be illegal in certain areas and which are definitely not approved by Toyo Kogyo Co., Ltd.
With the parts, procedures and specifications in the Manual the competitor can assemble and maintain the engine, drivetrain and chassis components and the various appropriate subsystems involved in a competition Mazda RX-7. The individual competitor should be aware that many of the parts and procedures outlined in this Manual may not be allowed under the rules and regulations of certain competition organizations, and it is the responsibility of the competitor, racer, mechanic or other person associated with racing a Mazda to have a full understanding of the pertinent rules and regulations of his competition governing body. For instance, the reader will notice there is no section in this Manual on the design and construction of a roll cage structure, as these details and requirements vary with different sanctioning organizations.
In competition there is a high degree of experimentation, and the reader is assumed to understand that such experimentation is on an individual basis, is not covered by this Manual, and from the position of Toyo Kogyo Co., Ltd., and its affiliates, is therefore categorized as non-recommended practice. Toyo Kogyo Co., Ltd. is interested in the results of any competition experimentation or experience, but specifically cannot recommend a new procedure until it has undergone a thorough analysis by appropriate company engineering staff.
In any form of automobile competition the individual is also considered to assume responsibility for his or her actions, and to realize and accept that automobile competition is, by its very nature, a hazardous activity with a high degree of risk of damage to equipment and/or personal injury. By the application of this Manual it is assumed the individual will be operating a competition automobile at or near the outer limits of its performance envelope, and the closer to those limits the greater the risk. Neither Toyo Kogyo Co., Ltd., nor any of their affiliates or employees assume any responsibility in any manner for any losses, either to equipment or persons, resulting from the use of any Mazda automobiles in competition or the application of any parts, procedures or specifications outlined in this Manual.
Finally, automobile competition is a constantly changing area of endeavor, subject to new technology, and this Manual is the current best recommended practice but is subject to change, without notice, at any time. Again, thank you for your interest in the Mazda RX-7 in automobile competition, and we extend you good luck and best wishes in your efforts.
Type | 12A Rotary |
Displacement, per rotor | 573 cc |
Displacement, total | 1146 cc |
Compression ratio | 9.4:1 |
Intake porting | Peripheral |
Exhaust porting | Peripheral |
Carburetion | Twin throat, down draft Weber |
Lubrication | Wet sump |
Cooling | Liquid |
Ignition | Transistorized, capacitive discharge (CDI) |
Maximum allowable engine speed | 9,000 RPM |
1. Rotor housing, 4352 10 100 It has the following differences from the stock housing:
The intake and exhaust timing is as follows:
Intake:
Opens 86° BTDC
Closes 75° ABDC
Exhaust:
Opens 73° BBDC
Closes 65° ATDC
2. Side housings, front: 4352 10 200 intermediate: 4352 10 400 rear: 4801 10 300
They differ from the stock housings in these ways:
3. Tension bolts, 4352 10 451A These are the stock bolts with rubber bonded to them which dampens out vibrations at certain frequencies and prolongs bolt life.
4. Stationary gears, front: 4352 10 500 rear: 435210 550 Compared to the stock gears, these have the following differences:
5. Oil pan, 4352 10 700 This is an increased capacity pan to maintain pressure under racing conditions, particularly while cornering.
6. Baffle plate, 4352 10 709 This baffle plate will maintain an adequate oil supply around the oil pump pickup while cornering or braking.
1. Balancer assembly, 4352 11 010 These pieces differ from stock by being balanced to a closer tolerance.
2. Rotor, 4352 11 100
The competition rotor has the fol lowing features:
3. Rotor bearing, standard 1011 11111 oversize: 1058 78 135 The oversize bearing is available to provide the correct oil clearance, and is larger in diameter by 30Mu
4. Apex seal, 4352 11 301 The apex seal is made of carbon and is 3.0 mm thick.
5. Apex seal spring, 4352 11 304 This spring is designed specifically for the 3.0 mm carbon apex seal.
6. Side seal, 4801 11 311 Compared to the stock seal, this side seal is molybdenum treated for increased wear resistance.
7. Corner seal, 1881 78 146 The corner seal has a sprayed molybdenum coating for self lubrication properties.
8. Outer oil seal spring, front: 4352 11 353 rear: 4352 11363 The increased pressure of this spring, different from original, 13 kg/cm2 as compared to 8 kg/cm2 for the standard oil seal spring, prohibits combusion gas blowby. For the inner oil seal, the stock spring is satisfactory.
9. Eccentric shaft, 4352 11 400 The material and configuration of this shaft are identical to stock, but to reduce the likelihood of bearing seizure, the rear half of the rear main journal is machined 20Mu smaller in diameter.
10. Drive pulley, 4352 11 601 This pulley has the following differences from the stock version:
11. Flywheel, 4352 11 755 This flywheel is fabricated from steel but is significantly lighter than stock to reduce rotating inertia.
12. Needle bearing, 0822 78 184 The needle bearing has a higher load capacity to withstand severe clutch engagements.
1. Intake manifold, 4352 13 100
This manifold has the following features:
2. Gaskets, rotor housing to intake manifold: 0862 78 205 intake manifold to carburetor: 0862 78 206
3. Carburetor support, 0862 78 240 This support reduces the transfer of engine vibrations to the carburetor and thereby prevents fuel surging and bubbling.
4. Exhaust header and pipe, header: 4352 78 250 pipe: 4352 78 260 Some of the main features of this exhaust system are:
For courses with very tight or long corners, this float bowl extension will help prevent fuel starvation. The float bowl extension fabrication procedure is as follows:
E. Exhaust System Mounting
This is one of the best ways we have found to utilize the high pressure area at the front of the car for intake air, but its size, location and design are important to maximum performance. the important points of its design are outlined below.
There are two possible locations for the oil cooler as shown in the illustrations below. In both cases, the competition oil cooler hoses can be used, in either the vertical-type or horizontal-type mounting.