EFI Connection has been working on the coil per cylinder conversion on both the Gen1 and Gen2 (LT1) small block engnes since the Spring of this year.
Milestones:
- April 2008: prototype 24x reluctor is made
- May 2008: gen1 small block engine running on test stand
- July 2008: LT1 engine running coil per cylinder on test stand with LS1 f-body calibration
- September 2008: gen1 small block running on the road with electronic throttle and 4L60E
- November 2008: CNC prototype 24x reluctor is made
Results
The installation in the S10 has been very successful. The major benefit to using the LS1 PCM is that you can control many of the components on newer GM engines; such as electronic throttle, 4L60E/4L80E transmissions, and cruise control. This S10 went to the extreme by installing a 4L60E, Corvette electronic throttle body, and integrated cruise control. The engine made clean dyno pulls and resuted in 311hp/334ft-lb at the rear wheels. There are now over 1,000 miles on this S10 after the conversion!
Critical Conversion Pieces
- 24x crank reluctor
- 24x crank sensor
- Vortec distributor (used only for cam sensor)
- LSx PCM
- 8 LSx Coils
Depending on the engine you're starting with, the conversion goes beyond the parts mentioned above. The significant change between the L31 Vortec engine (96-99 Trucks, 01-02 Express Van) is the 24x crank reluctor and 24x crank sensor. These engines must replace the current crankshaft reluctor and sensor with the 24x pieces.
EFI Connection's Approach
We dismissed the idea of using the LS1 24x crankshaft reluctor due to its size and forseen installation difficulties. The LS1's 24x crank reluctor is large in diameter, balanced for the LS1 crankshaft, and would have to be installed either in front or in the rear of the crankshaft. Regardless of where it would be installed, there would still be problems with getting the reluctor in the proper orientation and crankshaft position sensor mounted in a reliable location. GM had the best solution with the Vortec 4x crank reluctor by installing it behind the sealed timing cover. Orientation is always correct due to the keyway that fits over the crankshaft's key. So we took the same approach and ended up with a 24x reluctor that is CNC cut from a new piece of steel. The Vortec 4x reluctor was not made to clear a double roller timing chain, so we made sure that our reluctor would allow adequate clearance for the installation of a double roller timing chain.
PCM and Calibration
While the popular 12200411 PCM is recommended for its capabilities, you may use any Gen 3 LS type PCM (1997-2006). As a base calibration, the PCM must be loaded with any LS type calibration.
If your engine's throttle is cable driven, you'll use one of many 99-02 truck or 98-02 f-body calibrations. If your engine's throttle is electronic, you'll use one of many 98-05 Corvette or 00-06 truck and enjoy the benefits of integrated cruise control.
If using a 4L60E/4L65E transmission, you'll chose from one of many Camaro/Firebird, Corvette, or truck calibrations. If using a 4L80E transmission, you'll choose from one of many truck calibrations. If using a T56 6 speed manual transmission, you'll get reverse lockout support by using a Camaro/Firebird or Corvette calibration.
This 24x system opens up a whole new world of options to the early small block.
Are You Ready?
We would like to work with a few people who are ready and willing to try out this conversion. It's new...so we're not making any guarantees. What we can do is explain our experience and let you know what to expect with your installation. With over 1,000 miles on the first engine to get this conversion, dyno pulls resulting in smooth graphs, and expected horsepower/torque numbers, I am confident that this system works and will bring all of the benefits of the LS1 fuel management system to the early small block. Please email me at mike@eficonnection.com if you are now ready for this conversion. I will work with you to be sure you have the correct parts for the conversion and provide support along the way. If you are months away from being ready, please keep your eyes on http://www.eficonnection.com as it will soon be updated to provide details for this conversion, parts, and pricing.
What can EFI Connection provide?
We can provide everything except for the PCM calibration and coil brackets.
What does it cost?
Keep your eyes on http://www.eficonnection.com for more details. We will soon update the website to provide information and pricing for this coil per cylinder conversion. If you send email asking about pricing, I will reply asking you to bookmark http://www.eficonnection.com for the latest information. (So please don't email me about pricing.)