426Cuda
SUBLIME!
- Joined
- Dec 15, 2013
- Messages
- 4,181
- Reaction score
- 3,015
- Points
- 113
- Location
- Wagga Wagga
- Members Ride
- VF Redline Sedan - A6 Spitfire MSE...
Hi all,
I have a VF SS series 1 sedan with the L77 engine that in a former life was a NSW highway patrol car (verified by front page in the logbook, as well as minor holes in trim and bodywork and stuff like that).
I'm aware of the upsides and downsides of this, however mine has been trouble free so far. I've heard that in these cars the DOD system that shuts off half of the cylinders at part throttle cruise is disabled or removed, along with other differences like the transmission cooler, the alternator and the brakes (these last three I have verified to be the case).
Firstly, is that likely to be true, and how would I tell? The way the car drives currently, I don't get any tell-tale signs of any shift in engine operation in the conditions where DOD is supposed to work.
Secondly, if it is true, is it done electronically in the ECU or do they use different lifters/a manual spec engine?
For the moment, I'm just curious, but at some point in the future I would like to do intake/exhaust/camshaft changes. DOD not being there would mean I'd need to spend a lot less money.
Yes, the auto L77 has AFM. Personally i've never heard of police variants having this disabled. They may though?
In the VF (unlike the VE) there's no indication in the DIC or elsewhere that AFM has activated. Like you, FORG and others have mentioned, when mine was stock, I couldn't pick it by sound or feel. The only way I could tell, was to watch the instant fuel consumption whilst cruising. I.e, it would drop, then increase significantly with the lightest of throttle application or on an incline. I know this happens even without AFM, but it is different. You can pick it.
Once tuned with exhaust, OTR etc it was easy to pick AFM starting or stopping. A change in exhaust note gives it away every time, and yes, the fuel consumption changes too.
I hope this helps.