G60 Throttle Body modification

[outlandish5 0]

We all know when throttle off the inlet butterfly shut, with the G60 the boost return butterfly is open. As you increase the throttle the inlet butterflys open and the boost return close at the same rate, so its only fully closed at full throttle. This makes me think that there is lost boost, so what will happen if I can get the boost return butterfly to close a little before full throttle.

Im not interest in removing the boost return pipe as I've been advised that the oil breather that feeds into helps lubricate the charger.

 

Also what tools are needed to port/polish the internals?

[flusted 0]

I used 40 and 80 grit flap wheels when porting my tb.

Am i right in saying the g60 tb as a wedge of metal screwed to the small butterfly?

[steveo29 0]

if you get a 16v tb the flap hasnt got the wedge on it on it....so swap the flap into your g60 one

[coolrado 0]

Im not interest in removing the boost return pipe as I've been advised that the oil breather that feeds into helps lubricate the charger.

 

the problem is that the hot oily vapour that feeds back into the charger actually washes away the special grease that the internals of the charger are coated with, all you need to do is give the charger a quick spray with the lube once in a while (you can get the spray from g-werks)

before my charger was re-built the internals where very mucky and black it is now very clean inside with a fine layer of the white lube even after several thousand miles.

[flusted 0]

if you get a 16v tb the flap hasnt got the wedge on it on it....so swap the flap into your g60 one

 

Ok,if anyone needs these then i have loads :wink:

[outlandish5 0]

Hmmm I might need to look into that. I'll inspect my TB tomorrow and I may have a 6A TB available to me to take the flap off. I do seem to remember that it looked rather restrictive.

[flusted 0]

the 6a tb also has the wedge

[g60bv 0]

if you adjust the boost return flap. you get boost earlier. but also crap fuel consuption. really bad. for little return.. dont adjust.

[steveo29 0]

i removed the flap wedge and swaped in a kr flap on mine ...seems to affect low speed driving a bit for me, like when creeping along in a car park etc..makes it very on/off

[outlandish5 0]

Inspecting the flap it looked like the wedge was screwed onto the flap and it could be removed. Or is this not the case?

[steveo29 0]

yeah its screwed, then your left with 2 holes

[flusted 0]

then your screwd :lol:

[beavis 0]

There is no gains at all to be had by reducing length of the BRV arm so the BRV butterfly shuts before the main TB is at wide open throttle. The full throttle microswitch should contact as the BRV valve shuts fully. If you adjust the BRV to close earlier the engine is seeing full boost with no full throttle enrichment lading to the engine running lean at this point for a split second.

The throttle pedel will feel like an on/off switch with no progerssion making the car hard to balence on the throttle whist cornering.