The Holley Sniper Transmission Controller (STC) is designed for common GM and Ford electronic 4-speed automatic transmissions. Three part numbers cover a complete range of applications—all Sniper EFI systems, Sniper 2 EFI-specific (M8 CAN connection), or a full standalone unit.

The Sniper specific applications connect to your Sniper EFI system via CAN bus and are programmed through the existing Sniper 3.5 in. touch screen. No programming is available with PC computer software; however, the transmission functions can be data-logged and reviewed with Sniper PC software. The Standalone version includes a dedicated 3.5 in. touch screen and is primarily intended for carbureted engine combinations.

GM and Ford 4-speed electronic overdrive transmissions are simple in operation. They have four speeds, with the top gear being an overdrive; and all have a lockup torque converter that eliminates any slippage when the lockup is applied. With a stock torque converter, the lockup should only be applied under light throttle conditions or excessive wear will occur.

Upshifts, downshifts, and torque converter lockup are based on vehicle speed and throttle position (or optionally the MAP sensor) and are adjustable with the 3.5 in. touch screen.

P/N 551-100: Replacement controller unit only
P/N 551-101: Controller unit and power harness only
P/N 551-102: Standalone kit for carbureted applications (includes power harness and hand-held programmer)
P/N 551-103: Controller unit and power harness for use with Sniper 2 EFI systems

Holley Sniper Transmission Controller features:

* Adds electronic transmission control functionality to a Sniper 2
* Controls conventional electronic 4-speed transmission applications. GM 4L60/70/80E and Ford AODE and 4R70W - transmission specific harnesses sold separately:
-- 558-405 – GM 4L60/70/80E
-- 558-455 – 2009+ GM 4L60E
-- 558-470 – 1998+ Ford 4R70W/4R75W
-- 558-471 – 1992-1997 Ford AODE/4R70W
* Tuning is performed through the 3.5 in. touch screen LCD (included with the Standalone version). Future compatibility will include 5 in. display and Bluetooth module
* Tune upshifts, downshifts and WOT shift points
* Full programmability of torque converter lockup
* Full tuning of transmission line pressure (shift firmness)
* Controls and layouts interface mirror Dominator and Terminator X MAX ECUs (except no paddle shift)
* A MAP sensor is needed if using MAP for line pressure, which is usually only done with forced induction applications