LS Engine swaps and High Performance Applications
4L60E/65E vs 4L70E
The Gen III GM small block made it's debut in the 1997 Corvette as the LS1. Today there are numerous LS engine designations including the ZR1 LS9 6.2L, producing 638 hp by the way of a Roots-style supercharger and with a 50,000 mile warranty! The LS engines are without a doubt the most popular high performance engines with Hotrodders and High Performance Enthusiasts world wide.
The Gen III engines are usually fuel injected controlled by an ECM. These ECMs can and usually control transmission operation. Depending on the software, the ECM may or may not require an input speed signal from the transmission. In 2006 GM began using an input speed signal in the 4L60E/65E/70E transmissions. Both the 4L65E (M32) and the 4L70E (M70) transmissions had higher torque ratings than the 4L60E (M30) transmission. This was due to a 3-4 clutch change, 5 pinion planetaries and an improved turbine shaft in the 4L65E/70E units. In the 2006 and newer transmissions the turbine shaft has a reluctor machined into the shaft to signal an input speed sensor mounted in the pump. There is a standard duty reluctor type shaft and a heavy duty reluctor type shaft. The heavy duty version uses a superior steel and is treated by electric induction. These shafts are 57% harder than the standard shafts and can withstand greater torque loads. In the high performance world we want the best!
The problem with the factory built 4L65E/70E transmissions is they are only rated to handle a maximum of 400 ftlbs of engine torque. So in factory configuration this limits it's use to the Gen I, Gen II and Gen III engines. The Gen III is actually pushing the limits of the factory built M32 and M70 units. With the Gen I and Gen II engines an adapter kit is necessary for proper installation of the M32 or M70 transmission. We sell this adapter kit at Trutech Transmissions.
To purchase a M32 or M70 transmission with an input speed sensor is expensive. A supermatic M70 is over $3000.00 without a converter. Even then you have a marginal transmission. At Trutech Transmission we specialize in high performance modifications of General Motors transmissions. We have come up with a cost effective solution to your high performance transmission needs. We have modified a brand new ACDelco pump assembly that will fit into any two piece case up to 2003 and will accept the late model heavy duty reluctor turbine shaft input drum. This is a drop in replacement and we have it available in our store. This will allow you to custom build a late model LS engine compatible transmission. With our 4L70E conversion, our master builder kit which has better frictions, a stronger sun shell, GM 5 pinion rear planetary and numerous other upgades you can build a transmission that is capable of easily handling the Gen IV engines. Over 550 hp we do recommend the addition of the input drum reinforcement kit, GM input 5 pinion planetary and the sonnax 2nd and 4th servos. Our 4L70E conversion kits come with or without the input speed sensor depending on your application. Our non ISS pumps can be easily changed to add the ISS later if your needs change. All these parts are available in our store and you can contact us by email or phone if you have questions.
The cost of building a super strong transmission that will stand up to the strongest factory LS engines and far out perform the factory 4L70E is approximately 60% of the cost of the new M70 supermatic. The transmission you build can be custom calibrated for shift performance to suit your personal liking. A high performance transmission does not have to "bang" shift to hold up to high horsepower applications.
If you do not have plans to build your own transmission, at Trutech transmissions we can build custom high performance transmission for your specific application. The price of these units vary depending on modifications. Our high performance transmissions will easily handle 700 hp and shift firm without being uncomfortable. Our units out perform by far the factory units for a slightly higher price. You can use our units in everything from a daily stock driver to a high horsepower vehicle that only is run on the strip.
If you have a 1998 or newer vehicle with a factory calibrated ECM you will need a converter with a carbon fiber clutch. This is because the factory uses a pulse width modulated TCC apply for driver comfort. This PWM apply creates a lot of heat which will burn up a converter with a standard friction clutch. Our units come with the 1600-1800 stall converter with the carbon high heat clutch. For an additional fee we will include the M70 General Motors high performance supermatic converter with approximately 2500 stall speed. Either of these converters will handle 500hp with a naturally aspirated engine. The 4L65E/70E type transmissions use the 300mm converter. If you have a nitrous or supercharged engine we recommend sourcing out an anti-ballooning performance converter. If you plan to use an aftermarket performance converter without the carbon fiber clutch we can modify the valve body to disable the EC3 operation. We do not recommend exceeding 2500 stall speed in a vehicle you plan to drive regularly on the street.
Click on the logo at the top of the page for additional information. Thank you for choosing Trutech Performance Transmission.