GM LT-1 Wiring

GM LT-1 5.7 Engine (1992-1997):
The 1992 and newer Corvette LT-1 engine is rated at 300 HP. In 1993 GM installed the LT-1 in the Camaro, Trans Am/Firebird (275HP) Chevy Caprice and Buick Roadmaster plus some Cadillac models (265 HP). The transmissions available were 4L60, 4L60-E, and manual. You can use the turbo 350 and 400 on 1992 and 1993 engines. The 1992 and 1993 ECM's require four thousand pulse per mile while the 1994 and newer engines require an eighty thousand pulse per mile speed signal.

DIFFERENCES
The LT-1 engine itself has stayed pretty much the same throughout the years it has been produced. In 1992 & 1993 the LT-1 was wired as a speed density (M.A.P.) type system and in 1994-1995 the LT-1 was wired as a mass airflow sensor system. The injectors on the 1992 and 1993 LT-1 engine are activated one side at a time. In 1994 GM went to a sequential fuel injection which activates each injector one at a time. According to GM, these changes did not increase horsepower.

In the 1993 (and with other older ECM's), a prom would be installed in the computer to tell the ECM what size engine it was controlling, rear ratio of the car, tire size, type of transmission, just to name a few things. Starting in 1994 the prom is built into the computer and if purchased new must be programmed with the engine and other information before it can be used. A GM dealer or The Detail Zone can perform this service for you.

While we established that the engine is pretty much the same no matter which vehicle model it was installed in, they are wired differently. For example if you wire it as a 1992-1997 Corvette you will have to use both an ECM and CCM (Central Control Module) in order to receive serial data which is necessary to trouble shoot. Wire it as a Camaro or Firebird and it will still give you great performance at a lot less cost. From our tests it doesn't matter how it is wired, Corvette or Camaro/Firebird, we have tried it both ways and could not see any performance difference.