L99 Delete Whats involved?
 

I know alot of people that are ordering the L99 like the AFM. I am wanting to mod as I please with the automatic. So My question is can you officially delete the AFM by changing the cam and lifters and tune? I want to choose my own cam and mods and not be afm based mods all while having an automatic. I am one that would pay for the gas guzzler tax just to have an automatic ls3 like the corvette. Input please. Thanks

A couple sockets and a box end and pull the whole motor..

In reality; reprogram/reflash the engine computer to remove the cylinder shutdown commands. Cams and Lifters are all VVT related. I'm keeping the VVT but reprogramming the computer to remove the AFM once I pick up my tuner program for my laptop.

I'm starting to think the the Hotrodders of today are going to move from wrenches and hoists to HDDs and Laptops..:/

I beleive it can be turned off with a tune. I do not know about different cam since the lifters and valves are different from the LS3.

Yeah, the whole valve train, seats, etc are different in L99 heads. The core block is the same, but everything else is different.

The perfect fix would be a way to add a manual override button. So that you could use both modes and your own choosing. Probably not possible if it's totally in the flash program.

Being a nerd, this excites me. I am amazed that HPTuners et al is soo much $$$ and there is no sort of open source alternative. Maybe I should get working on that....

This computer is more modernized and has the better CAN protocol. Unless there is some other mechanism. What tells it to go into 4 cyl mode is the question? This engine is already out in SUV's right? Check on there forums if for intel.

You may want to use AFM friendly mods. There is alot that goes into this. This information from Service Information might help.

Cylinder Deactivation (Active Fuel Management) System Description




To provide maximum fuel economy under light load driving conditions, the engine control module (ECM) will command the cylinder deactivation system ON to deactivate engine cylinders 1, 7, 6, and 4, switching to a V4 mode. The engine will operate on 8 cylinders, or V8 mode, during engine starting, engine idling, and medium to heavy throttle applications.

When cylinder deactivation is commanded, the ECM will determine what cylinder is firing and begin deactivation on the next closest deactivated cylinder in firing order sequence. For example, if cylinder number 1 is on its combustion event when cylinder deactivation is commanded ON, the next cylinder in the firing order sequence that can be deactivated is cylinder number 7. If cylinder number 5 is on its combustion event when cylinder deactivation is commanded ON, then the next cylinder in the firing order sequence that can be deactivated is cylinder number 4.

Cylinder deactivation is accomplished by not allowing the intake and exhaust valves to open on the selected cylinders by using special valve lifters. The deactivation lifters contain spring loaded locking pins that connect the internal pin housing of the lifter to the outer housing.

The pin housing contains the lifter plunger and pushrod seat which interfaces with the pushrod. The outer housing contacts the camshaft lobe through a roller. During V8 mode, when all cylinders are active, the locking pins are pushed outward by spring force, locking the pin housing and outer housing together causing the lifter to function as a normal lifter. When cylinder deactivation is commanded ON, the locking pins are pushed inward with engine oil pressure directed from the valve lifter oil manifold (VLOM) assembly solenoids. When the lifter pin housing is unlocked from the outer housing, the pin housing will remain stationary, while the outer housing will move with the profile of the camshaft lobe, which results in the valve remaining closed. One VLOM solenoid controls both the intake and exhaust valves for each deactivating cylinder. There are 2 distinct oil passages going to each cylinder deactivation lifter bore, one for the hydraulic lash-adjusting feature of the lifter, and one for controlling the locking pins used for cylinder deactivation.

Although both intake and exhaust valve lifters are controlled by the same solenoid in the VLOM, the intake and exhaust valves do not become deactivated at the same time. Cylinder deactivation is timed so that the cylinder is on an intake event. During an intake event, the intake cam lobe is pushing the valve lifter upwards to open the intake valve against the force of the valve spring. The force exerted by the valve spring is acting on the side of the lifter locking pins, preventing them from moving until the intake valve has closed. When the intake valve lifter reaches the base circle of the camshaft lobe, the valve spring force is reduced, allowing the locking pins to move, deactivating the intake valve. However, when cylinder deactivation is commanded ON, the exhaust valve for the deactivated cylinder is in the closed position, allowing the locking pins on the valve lifter to move immediately, and deactivate the exhaust valve.

By deactivating the exhaust valve first, this allows the capture of a burnt air/fuel charge, or exhaust gas charge, in the combustion chamber. The capture of exhaust gases in the combustion chamber will contribute to a reduction in oil consumption, noise and vibration levels, and exhaust emissions when operating in V4 mode cylinder deactivation mode.

During the transition from V8 to V4 mode, the fuel injectors will be turned OFF on the deactivated cylinders. To help prevent spark plug fouling, the ignition system secondary voltage or spark is still present across the spark plug electrodes on the deactivated cylinders. If all enabling conditions are met and maintained for cylinder deactivation operation, the ECM calibrations will limit cylinder deactivation to a cycle time of 10 minutes in V4 mode, then return to V8 mode for 1 minute.

Switching between V8 and V4 modes is accomplished in less than 250 milliseconds, making the transitions seamless and transparent to the vehicle operator. The 250 milliseconds includes the time for the ECM to sequence the transitions, the response time for the VLOM solenoids to energize, and the time for the valve lifters to deactivate, all within 2 revolutions of the engine crankshaft.

Valve Lifter Oil Manifold (VLOM) Assembly
The cylinder deactivation system uses an electro-hydraulic actuator device called the valve lifter oil manifold (VLOM) assembly. The VLOM is bolted to the top of the engine valley, below the intake manifold assembly. The VLOM consists of 4 electrically operated normally closed solenoids. Each solenoid controls the application of engine oil pressure to the intake and exhaust valve lifters on the cylinders selected to deactivate. Engine oil pressure is routed to the VLOM assembly from an internal oil passage on the rear of the cylinder block.

All 4 VLOM solenoids are connected in parallel to a fused ignition 1 voltage circuit, supplied by the powertrain relay. The ground or control circuit for each solenoid is connected to a low side driver internal to the engine control module (ECM).

When all enabling conditions are met for cylinder deactivation, the ECM will ground each solenoid control circuit in firing order sequence, allowing current to flow through the solenoid windings. With the coil windings energized, the solenoid valve opens, redirecting engine oil pressure through the VLOM into 8 separate vertical passages in the engine lifter valley. The 8 vertical passages, 2 per cylinder, are connected to the valve lifter bores of the cylinders to be deactivated. When vehicle-operating conditions require a return to V8 mode, the ECM will turn OFF the control circuit for the solenoids, allowing the solenoid valves to close. With the solenoid valves closed, engine oil pressure in the control ports is exhausted through the body of the solenoids into the engine block lifter valley. The housing of the VLOM incorporates several bleeds in the oil passages to purge any air trapped in the VLOM or engine block.

To help control contamination to the hydraulic circuits, a small replaceable oil screen is located in the VLOM oil inlet passage, below the oil pressure sensor. The oil pressure sensor is a 3-wire sensor which provides oil pressure information to the ECM.

During service, use extreme care in keeping the VLOM assembly free of any contamination or foreign material.

Cylinder deactivation may be inhibited for many reasons including the following:

• Engine coolant temperature out of range for cylinder activation

• Engine vacuum out of range

• Brake booster vacuum out of range

• Transmission gear incorrect or shift in progress

• Accelerator pedal out of range or rate of pedal application to fast

• Engine oil pressure and temperature out of range

• Engine speed of range

• Vehicle speed out of range

• Minimum time in V8 mode not met

• Maximum V4 mode time exceeded

• Decel fuel cutoff active

• Reduced engine power active

• Torque management active

• Catalytic converter over temperature protection active

• Piston protection active, knock detected

• Cylinder deactivation solenoid

Yeahh.. Unless you really really REAALLLY know your shit, Itd probably be smart to use AFM enabled mods. Or I foresee a LOT of reliability probs, maintenance time and costs.. :(

All of the above is exactly why I went with the LS3! Thats a whole lotta things to break later on in life.

Ehh. I tend to enjoy the auto. When shit starts takin a leak, which wont be for a while knowing GM engine quality, Ill just put a newer engine in. Maybe even that new diesel people are talkin about.

Hmm, maybe it could be as easy as pulling the Deac Solenoid.. :/

Not Likely.

Yeah..but then Oil would be everywhere.. didn't read that. -_-