Displacement on demand

[KevinW]

Some Idle questions on DoD injection:

I got talking to a couple of blokes at the thames valley meet about the above.
If anyone has used it on their engines, what did you think, is it hard to set-up, or did you just buy a chip that had the functionality built in?

I'm not planning on using it, just curious - it seems like a great idea.

Kevin

[KevinW]

In case I'm not making sense...

Active Fuel Management - Wikipedia, the free encyclopedia

[Big Thirsty]

Originally Posted by KevinW

Some Idle questions on DoD injection:

I got talking to a couple of blokes at the thames valley meet about the above.
If anyone has used it on their engines, what did you think, is it hard to set-up, or did you just buy a chip that had the functionality built in?

I'm not planning on using it, just curious - it seems like a great idea.

Kevin

Kevin,

This facility is available as a retro fit for the LS2 / LS3 engines, as the standard system has to be converted to give displacement on demand. This involves changing the lifters and modifying the ECU, which can also be suited to a fully electronic auto gearbox system.

[KevinW]

are there any none-GM solutions around?
Actually I know the new Chrysler V10 sports car has something like this, but I suppose I mean something suitable for retrofitting to Rover or Ford engines.

Again, just idle thoughts, but it really does sound like a lot of sense for journeys involving 'traffic', and in the UK, thats a constant bug-bear.

[robert]

It would be interesting to understand what the transition is from 4 to 8, for example is it akin to turbo lag.

[wilf]

When I first saw DoD shown by Chevrolet, a few years back now, they were not just suppressing the injectors, but also the valve actuation, as the pumping losses with the valves operating normally on a "dead" cylinder were huge.

[Big Thirsty]

Originally Posted by wilf

When I first saw DoD shown by Chevrolet, a few years back now, they were not just suppressing the injectors, but also the valve actuation, as the pumping losses with the valves operating normally on a "dead" cylinder were huge.

The LS DoD system will do the following:-

Shuts off the individual coil for the spark
Shuts off the injector for the fuel
Shuts off the lifters, to stop valves opening unnecessarily

To achieve the last point, the valley plate is changed to a hydraulic manifold, which diverts the oil away from the lifters and back down to the engine.

[Big Thirsty]

Originally Posted by robert

It would be interesting to understand what the transition is from 4 to 8, for example is it akin to turbo lag.

The transition between four to eight and back to four again is virtually undetectable and the MPG increase is around 15%. Should you want the ultimate in power delivery / fuel efficiency, we can supply both DoD and Variable Valve timing on certain LS engines.

[wilf]

Originally Posted by Big Thirsty

The LS DoD system will do the following:-

Shuts off the individual coil for the spark
Shuts off the injector for the fuel
Shuts off the lifters, to stop valves opening unnecessarily

To achieve the last point, the valley plate is changed to a hydraulic manifold, which diverts the oil away from the lifters and back down to the engine.

Clever stuff!

So are the lifters hydraulically actuated, or is there a hydraulic" link" that can be interrupted to stop the valve opening?

[Big Thirsty]

Originally Posted by wilf

Clever stuff!

So are the lifters hydraulically actuated, or is there a hydraulic" link" that can be interrupted to stop the valve opening?

It uses hydraulic lifters as we understand them, but there is a hydraulic link which use solenoids to carry the oil away from the lifters.