Hi Guys,

I live in Australia and have a heavily modded Cooper S. I have been reading about this Vaccum Gain System. Can someone please explain to me what it's purpose is please and how it helps.

My Mods are as follows:-

Powerchip ECU upgrade
JCW injectors
Plasma Booster
Screamin Demon 40,000 V Coil Pack
Nology Hotwires
Beru Spark Plugs
Detroit Tuned Bypass Valve
Alta Cold Air Intake
15% Supercharger Pulley Reduction
Big Bore Throttle Body
Schrick Camshaft
Alta 3% Crank Pulley
Alta 5% Alta-Nator Pulley
Alta Intercooler with Air Diverter
Alta Oil Catch Can
The Cylinder head has been ported and polished for high flow
Ultrick exhaust Header with Modified Cat
JCW exhaust from Cat Back
Light weight Flywheel
Limited Slip Diff
Uprated Clutch kit
Wilwood Big Brake Kit
KW Coilovers variant 2
17" Gold Rimms
Carzone Bodykit
Union Jack Wing Mirror and Rear View Mirror Covers
Flame Head light covers
Carbon Fibre Intake Scoop with Lip To divert more air in

Just ordered a Unichip. Will have to get it custom tuned for our climate though and also we run 98-100 Octane.

I have noticed the car sort of hunts like the revs will go up and down when idling. Feels like it is going to die but then it will come good again!! When I drive and come to a stop, put my foot on the clutch the revs will drop to about 500 RPM and then bounce back up to normal Idle speed of about 750-800 RPM. It doesn't like it either when I turn the A/C on either!! Is this something to do with the changed Vaccum of my car?

 

I think what you are describing has nothing to do with a VGS, which has to do with air intake. The idle of the car has more to do primarily with the tuning software and perhaps to some degree the cam. Maybe a software tune more specific for the set of mods you have will help more than anything.

 

Thanks cosmic. I am hoping that the custom tune on the Unichip will solve this problem!! One can hope I guess. If it doesn't, it's back to the drawing board!!