Tag: compressor

Mini Cooper S R53 JCW – Vacuum Gain System VGS Modification

As usual, the Mini Cooper S with the Eaton M45 supercharger also has a bypass valve, which helps with fuel economy and lighten the load on the supercharger during idling (for instance). On NAM (North American Motoring forum) I noticed a popular mod, which is also known as the VGS or Vacuum Gain System modification.

Basically, the VGS mod changes the way the Bypass valve is operated. From indirect vacuum to direct vacuum, allowing faster response of the butterfly valve, but also keeping it shut better so no boost is lost.

I liked it in the beginning, but it makes for a rough driving experience. So in the end I reverted and never went back. Thats why we experiment 🙂

Source: https://www.northamericanmotoring.com/forums/how-to/38268-drivetrain-operation-vacuum-gain-system-vgs.html

Changing the vacuum line routing.

Mini Cooper S R53 JCW Bypass Valve VGS Mod

Mini Cooper S R53 JCW Bypass Valve VGS Mod

Brand new Bapmic Compressor Bypass Valve (CBV).

Mini Cooper S R53 JCW Compressor Bypass Valve

Modifying the bypass valve.

Mini Cooper S R53 JCW Compressor Bypass Valve


Volvo S80 2.4T ProPerfekt CBV / Diverter / Blowoff Valve

I actually wasn’t planning to upgrade the OEM Compressor Bypass Valve (CBV), but I am glad I decided to do so with this ProPerfekt piston type Diverter Valve (DV).

The rubber rings don’t leak (so much) boost, which means the power output is better (and faster) compared to the stock CBV. The stock CBV has a rubber outer ring (diaphragm) and a plastic ring on the inside (this is the flaw in the design).

The ProPerfekt DV is a known mod with the Renault Megane RS drivers, but I haven’t seen it before on another Volvo forum. The results are clear to me, the boost buildup is quicker, which means the car is faster. I would recommend this mod to anyone who has a TD04 turbo (who is still using the stock CBV). My S80 has the TD04HL-13T turbo, but will also fit the TD04HL-16T. Please note that the CBV I had fitted is quite new, so no ruptured diaphragm or something.

Volvo S80 2.4T ProPerfekt Diverter Valve
Volvo S80 2.4T ProPerfekt Diverter Valve
Volvo S80 2.4T ProPerfekt Diverter Valve
Volvo S80 2.4T ProPerfekt Diverter Valve

And this is how it compares to the stock CBV.

Volvo S80 2.4T ProPerfekt Diverter Valve
Volvo S80 2.4T ProPerfekt Diverter Valve
Volvo S80 2.4T ProPerfekt Diverter Valve



Volvo S80 2.4T Fitting a new Compressor Bypass Valve (CBV)

I noticed some strange behaviour when lifting the throttle and decided to service the CBV aka Compressor Bypass Valve. I was right, car drives a lot better after replacing it with a fresh CBV / DV (Diverter Valve).

I went with an aftermarket TRITDT K5T09671.

Volvo S80 2.4T New TRITDT Compressor Bypass Valve (CBV) repair kit

Volvo S80 2.4T New TRITDT Compressor Bypass Valve (CBV) vs Old

Volvo S80 2.4T New TRITDT Compressor Bypass Valve (CBV) vs Old

Volvo S80 2.4T Fitting a new Compressor Bypass Valve (CBV)