Vantage V8 Projects


1. Remote operation of the exhaust valves

AKA "the fuse 22 mod".

If your running a standard exhaust on your Vantage, it has two bypass valves fitted in the rear silencer assembly, which AM calls the "Variable Flow Silencer Assembly". AM say it is to enhance top end performance, in practice it just stifles the growl a bit, but we don't want that do we..........

At idle the valves are open, as the revs increase past 1500 rpm the valves close until about 4K when they fully open again. The system is vacuum operated, and could be simply disconnected by just removing the pipes and blanking them off, however this method does not allow the valves to be easily re-enabled. Some people just pull fuse 22 (or fuse 15) on later models and leave it out, again the only problem is that they can't easily be switched back on. It's advisable to do so every now and then, or it has been known for the valves to seize.

Before we look at the different options, note that you undertake any modifications to your car at your own risk, if you are not confident with electrical wiring you should seek professional help.

There are few different ways of remotely switching the valves, one easy way is to simply fit a normal latching switch in place of fuse 22, and run the wiring to a suitable location in the cabin. An inline fuse must be incorporated into the wiring to ensure safe operation.
An even easier way is to use a wireless switch, the big advantage here is that the mod can be easily reversed should you wish. There are two different ways of wiring up the Logisys unit, depending on whether you want the default at start-up to be as std or off.

NC = normally closed relay contacts.
NO = normally open relay contacts.

Note, the Logisys unit only comes with one set of NO relays, so option 2 below will require an additional relay. The Maplin unit has both NC and NO options built in, so can be wired in whichever way you prefer. You will need to tap a switched 12v supply and make connections to the vacant fuse slot in the boot fuse box. An easy and again reversible way of doing this is to use an "add-a-circuit" readily available from ebay. For connections to the Vantage boot fuse box you will need the "full size" type.

  1. Logisys RM02 wireless remote default off = wild, press ON to enable valves or OFF to disable, will reset back to off when IGN is turned off.
  2. Logisys RM02 wireless remote default on = std, press OFF to disable valves or ON to enable, will reset to std when IGN is turned off.
  3. Maplin L26BK. 

Option 1.                                    Option 2.                                    Option 3.

In all cases you will need to slightly trim a male spade connector to fit into the add-a-circuit, this is not shown in the images above. Trim the connector to fit using a small file. Also, note the orientation of the add-a-circuit, the top most terminal as orientated in the images above needs to go in the fuse slot so that the fuse is pointing towards the front of the car. For the Maplin L26BK an additional connection is required to the add-a-circuit.
Finally a small slot needs to be cut in the fuse box lid to allow clearance for the cables. Re-fit the lid and tuck the wireless unit behind the carpet side panel in the boot. The remote is neatly stored in the strap in the drivers door pocket...that's it.

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