Tranny Selection Info
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Melting Slicks
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From: Fidalgo Island Wa
Tranny Selection Info
TRANSMISSION SELECTION INFO...
TURBO-350
- The T-350 is by far the most common automatic transmission available for the Chevy V-8 engine, and is available with a lock-up converter, called a T-350C. There were 3 different lengths of tailhousings available, the 6", 9", and 12" long versions. The 3 different length tailhousings all require a different length driveshafts, but they all share a common rear mount location, allowing the same transmission crossmember to be used with all T-350's. While a reliable transmission and well supported by the aftermarket, the lack of an overdrive gear means increased engine rpm, over that of the stock rotary, when used for this conversion. If you want to use the T-350, you can, and many people do. Fortunately, if you want to change to an overdrive transmission at a later date, the 200-4R has the same overall length and output spline as the T-350 (providing your T-350 has the most common 6" long tailhousing), so when you step up to overdrive, a new driveshaft is not necessary.
NOTE : If you decide at a later date that you would like to use a different transmission in your V-8 powered RX-7, we will exchange your existing trans crossmember (provided that it's in good condition) for the one you need, at no extra charge, except for shipping !!!
200-4R
- The 200-4R is the recommended choice if an automatic transmission is desired. It was used from '81 to '87 in everything from RWD Cadillacs to GNX Buicks. Weighing in at a lite 157 lbs, it features a "universal" bellhousing bolt pattern that fits Chevrolets as well as BOP (Buick, Olds, Pontiac, Cadillac). The main case is a one-piece design, with no detachable tailhousing. Rated for a maximum vehicle gross weight of 6000lbs, overall torque capacity is only 20 ft/lbs less than that of the 700R4. Closer and more desireable gear spacing is another advantage over the 700R4. First gear has a ratio of 2.741 (vs. 3.059 for the 700R4), while the overdrive ratio, at .674, is nearly identical to that of the stock RX-7. This means that cruise rpm will be the same with the V-8 as it was with the rotary engine. A kickdown cable from a T-350 will fit and can be used to make the adaption to a carbureted engine easier, but proper adjustment is important. The 200-4R uses 3 control wires. (2) are for the internal converter lockup solenoid, while the 3rd is a feedback wire that indicates when the transmission is in overdrive. The transmission can be used without hooking up the converter lockup, but a built-in over temp switch will automatically lock it up if the trans fluid temp exceeds 260F. A simple relay and vacuum switch can be used to restore automatic converter lockup when used with an un-computerized, carbureted engine. The modified 200-4R has about the same capacity as a modified 700-R4, 600 ft/lbs and 700 hp. The output spline and overall length are the same as the short shaft T-350, so the same output yoke and driveshaft will fit either transmission.
700-R4
- The 700-R4 is now called the 4L60, and computer controlled 700-R4s are now called 4L60-E (the "E" stands for electronic). The 700R-4 can and has been used for RX-7 conversions, but expect to do some minor modifications to the trans. tunnel. The 700R-4 is quite a bit heavier than the 2004-R and has more parasitic losses. An engine computer is not required for proper operation of the pre-'92 transmissions, but minor re-wiring is required for operation of the lock-up converter. The 4L60-E REQUIRES the proper ECM/engine combination to function correctly. Output shaft spline is the same as the T-350 and 200-4R, but the overall length is longer. The 700-R4 from a 60 degree V-6 will NOT fit a 90 degree V-6 or any V-8, as the bellhousing bolt pattern is different. The Corvette 700-R4 does not have provision for a conventional transmission mount.
Borg/Warner T-5
- The Borg Warner T-5 5 spd manual transmission, at only 87lbs including the bellhousing, is the preferred choice for a light-weight RX-7 conversion. It was used in the '83 to '92 Camaro/Firebird. '88 and up boxes feature organic synchros, and are called "World Class". The V-6 unit has a 1"-14 spline input shaft (requires a special clutch disc if used with a V-8), while the more desirable V-8 gearbox uses an input shaft with 1-1/8"x26 spline. Overdrive is close to the same as the stock RX-7 at either .63, which came behind throttle body injected engines, or the .73 ratio that was used with Tuned Port engines. The shifter is in the correct spot for the 1st gen cars, and very close for the 2nd generation. Use an older bellhousing with a "straight-up" transmission bolt pattern, rather than the 17 degree angled pattern bellhousing used on the '83 & up Camaro's. Any Nova, Chevelle, or pre- '83 Camaro or Corvette bellhousing will work. This puts the shifter in the middle of the console, rather than off to the left. Our T-5 cross-member has a special angle that permits this application. Aftermarket hydraulic throwout bearings are available for use in these non-hydraulic bellhousings, or a hydraulic clutch slave cylinder can be fitted. Driveline length is the same as the T-350 and uses the same driveline yoke.
Borg/Warner T-56
- Weighing in at 125 lbs dry, the T-56 is the 6 spd transmission used behind '93 to '97 LT-1 powered Camaro/Firebirds. The '93 box used a 2.97 or 3.36 1st gear, combined with a .62 ratio for 6th. For use with a V-8 powered RX-7, the '94-'97 box is better suited with a 2.66 1st gear and .50 ratio for 6th gear. The T-56 uses the same driveline yoke as the T-400, and is the same length overall as the T-5. Shifter location is a little over 1" farther back than the Camaro T-5, and to the left of center. The special T-56 clutch and bellhousing are required, as is a special flywheel when used with a pre-1986 crankshaft. There is no provision for a mechanical speedo cable output. The T-56 slave cyl. comes with a 1" bore, and should be used with a 7/8" clutch master cyl to get the proper feel (use a 1" clutch master cyl. for a quicker, but stiffer, clutch pedal).
TURBO-350
- The T-350 is by far the most common automatic transmission available for the Chevy V-8 engine, and is available with a lock-up converter, called a T-350C. There were 3 different lengths of tailhousings available, the 6", 9", and 12" long versions. The 3 different length tailhousings all require a different length driveshafts, but they all share a common rear mount location, allowing the same transmission crossmember to be used with all T-350's. While a reliable transmission and well supported by the aftermarket, the lack of an overdrive gear means increased engine rpm, over that of the stock rotary, when used for this conversion. If you want to use the T-350, you can, and many people do. Fortunately, if you want to change to an overdrive transmission at a later date, the 200-4R has the same overall length and output spline as the T-350 (providing your T-350 has the most common 6" long tailhousing), so when you step up to overdrive, a new driveshaft is not necessary.
NOTE : If you decide at a later date that you would like to use a different transmission in your V-8 powered RX-7, we will exchange your existing trans crossmember (provided that it's in good condition) for the one you need, at no extra charge, except for shipping !!!
200-4R
- The 200-4R is the recommended choice if an automatic transmission is desired. It was used from '81 to '87 in everything from RWD Cadillacs to GNX Buicks. Weighing in at a lite 157 lbs, it features a "universal" bellhousing bolt pattern that fits Chevrolets as well as BOP (Buick, Olds, Pontiac, Cadillac). The main case is a one-piece design, with no detachable tailhousing. Rated for a maximum vehicle gross weight of 6000lbs, overall torque capacity is only 20 ft/lbs less than that of the 700R4. Closer and more desireable gear spacing is another advantage over the 700R4. First gear has a ratio of 2.741 (vs. 3.059 for the 700R4), while the overdrive ratio, at .674, is nearly identical to that of the stock RX-7. This means that cruise rpm will be the same with the V-8 as it was with the rotary engine. A kickdown cable from a T-350 will fit and can be used to make the adaption to a carbureted engine easier, but proper adjustment is important. The 200-4R uses 3 control wires. (2) are for the internal converter lockup solenoid, while the 3rd is a feedback wire that indicates when the transmission is in overdrive. The transmission can be used without hooking up the converter lockup, but a built-in over temp switch will automatically lock it up if the trans fluid temp exceeds 260F. A simple relay and vacuum switch can be used to restore automatic converter lockup when used with an un-computerized, carbureted engine. The modified 200-4R has about the same capacity as a modified 700-R4, 600 ft/lbs and 700 hp. The output spline and overall length are the same as the short shaft T-350, so the same output yoke and driveshaft will fit either transmission.
700-R4
- The 700-R4 is now called the 4L60, and computer controlled 700-R4s are now called 4L60-E (the "E" stands for electronic). The 700R-4 can and has been used for RX-7 conversions, but expect to do some minor modifications to the trans. tunnel. The 700R-4 is quite a bit heavier than the 2004-R and has more parasitic losses. An engine computer is not required for proper operation of the pre-'92 transmissions, but minor re-wiring is required for operation of the lock-up converter. The 4L60-E REQUIRES the proper ECM/engine combination to function correctly. Output shaft spline is the same as the T-350 and 200-4R, but the overall length is longer. The 700-R4 from a 60 degree V-6 will NOT fit a 90 degree V-6 or any V-8, as the bellhousing bolt pattern is different. The Corvette 700-R4 does not have provision for a conventional transmission mount.
Borg/Warner T-5
- The Borg Warner T-5 5 spd manual transmission, at only 87lbs including the bellhousing, is the preferred choice for a light-weight RX-7 conversion. It was used in the '83 to '92 Camaro/Firebird. '88 and up boxes feature organic synchros, and are called "World Class". The V-6 unit has a 1"-14 spline input shaft (requires a special clutch disc if used with a V-8), while the more desirable V-8 gearbox uses an input shaft with 1-1/8"x26 spline. Overdrive is close to the same as the stock RX-7 at either .63, which came behind throttle body injected engines, or the .73 ratio that was used with Tuned Port engines. The shifter is in the correct spot for the 1st gen cars, and very close for the 2nd generation. Use an older bellhousing with a "straight-up" transmission bolt pattern, rather than the 17 degree angled pattern bellhousing used on the '83 & up Camaro's. Any Nova, Chevelle, or pre- '83 Camaro or Corvette bellhousing will work. This puts the shifter in the middle of the console, rather than off to the left. Our T-5 cross-member has a special angle that permits this application. Aftermarket hydraulic throwout bearings are available for use in these non-hydraulic bellhousings, or a hydraulic clutch slave cylinder can be fitted. Driveline length is the same as the T-350 and uses the same driveline yoke.
Borg/Warner T-56
- Weighing in at 125 lbs dry, the T-56 is the 6 spd transmission used behind '93 to '97 LT-1 powered Camaro/Firebirds. The '93 box used a 2.97 or 3.36 1st gear, combined with a .62 ratio for 6th. For use with a V-8 powered RX-7, the '94-'97 box is better suited with a 2.66 1st gear and .50 ratio for 6th gear. The T-56 uses the same driveline yoke as the T-400, and is the same length overall as the T-5. Shifter location is a little over 1" farther back than the Camaro T-5, and to the left of center. The special T-56 clutch and bellhousing are required, as is a special flywheel when used with a pre-1986 crankshaft. There is no provision for a mechanical speedo cable output. The T-56 slave cyl. comes with a 1" bore, and should be used with a 7/8" clutch master cyl to get the proper feel (use a 1" clutch master cyl. for a quicker, but stiffer, clutch pedal).
