De-Wedging a G40 Throttle Body
In this guide I have tried to show pretty much every step involved in de-wedging a G40 throttle body so people with little mechanical knowledge should be able to understand.
Before you start make sure you know what you are letting yourself in for. The throttle body wedges are there to aid low speed throttle control & smooth set-offs. Therefore if your G40 is more of a nice daily driver for you, you may want to reconsider this. If you like to push your car & aren't afraid to put pedal to metal then go for it! This free (if you have the tools already) & easy mod will put the G-smile back on your face.
Tools Required:
The Guide
Firstly remove the boost pipe from the throttle body by unscrewing the jubilee clip. Pull it out of the way as in the picture.
If your car still uses the boost return pipe, remove this in the same way
Now un-clip the throttle cable, shown circled in the next picture & un-clipped in the picture after
Remove the throttle body wiring connector, circled in the next picture
Un-do the 4 throttle body bolts (one in each corner of the base of the throttle body)
Now you can remove the throttle body from the engine. Here it is:
Retrieve the throttle body to inlet manifold gasket. If this looks knackered, re-new it. A leaky gasket will hinder performance
Next, using a flat bladed screw driver prise apart the ball joint that holds the boost return valve linkage, shown disconnected in the picture. The ball joint in the smaller circle, the other showing the top of the linkage. Make sure you don't move the nuts on the linkage as they will be setup to make sure the boost return valve works correctly
Separate the boost return valve & throttle body inlet from the throttle body itself by un-doing the two allen head bolts as shown
There is another gasket between these two. Again, if it is knackered, replace it
In the next picture you can clearly see the wedges screwed to the throttle & by holding the throttle open you can see how much of a restriction there is
Each wedge is held on with 2 small screws. Use a large handled, quite large ended philips screw driver to very carefully un-do the screws. As you un screw them they actually get tighter so go very slowly so as to not round off the heads
Here is a removed wedge
Now, you are left with 4 gaping holes in the throttle body butterfly:
The common way of sealing these up is to use a rivet gun & rivets, like so:
Block each hole up with a rivet & this is the end result:
And from the other side:
I had also cleaned the throttle body out with some carb cleaner & a rag, which is worthwhile when you have it off the car like this
In this last picture you can kind of (it's a bit of a crap picture) see there is now much more space for air to flow through
That's it, job done. Refitting is, as they say, the reverse of removal
Before you start your car when you are finished, take 5 minutes to double check EVERYTHING is reconnected properly