Thanks Dutch for attempting to explain it to me... I'm still confused, though: did Mini simply include a vacuum nipple (or a pair, given the short loop) on the BPV for the sole purpose of "sucking" the BPV closed should the user decide it might be better off that way?

In a driving report, this mod does...something. I'm not sure what. It definitely makes the car feel faster. I can't describe it much better than that! It also makes a funny noise, especially at WOT. Why would a 10" length of 5/32" hose make the car sound so very, very different, especially across the powerband? (i.e., it's not just different in the region where the BPV is actively closing or opening.) Sorry to sound so incredulous...but I am!

 

Actually, the vacuum sucks the BPV open, not closed. Its purpose is to dump boost pressure as soon as you let off the throttle. This helps with deceleration and doubtless makes it easier for the ECU to maintain useful air/fuel ratios during these transitions. The short loop on the BPV pulls vacuum from just inside the throttle body and uses it to pull the BPV open on light throttle and at idle.

Capping the vacuum port off and instead using boost/vacuum from the output side of the supercharger to operate the diaphragm allows the boost to push the valve closed when the spring has given up or is otherwise weak and not closing the valve soon enough or completely enough.

HTH!

C ya,
Dutch

 

I've read this entire thread and I must say that there are some pretty damn good ideas out there. I've already done the chrome "Blackout" with Plasti-Dip and Electrical tape as well as the LED Bulb install. I've gone as far as replacing the headliner with a black and grey Union Jack flag and spray painted all the plastics matte black with a matte clear coat. Before I swapped out the "little kitty" and stock BPV under the bonnet for the Spintex, I looped a wire to the BPV and brought the other end to the front left screw of the intercooler diverter plate in order to keep that damn valve closed. Then I reset the ECU. Cost me $2. The results were amazing.



~Joe

2003 Mini Cooper S
Chili Red w/ Black Roof, Caps, & Interior
"Make it whine like a puma in heat"

 

Has anyone tried setting this up with a re circulation valve or bypass valve that does opporate under boost and vacuum?

So effectively going with a BOV but the recirculating type vacuum holds it open to allow bleed off back to intake after TB as normal?

 

If you are referring to the 2nd-Gen turbo models, they are designed for and are better suited for the recirculation valve. Way sells the upgraded valve. Supposed to be a good bang-for-the-buck part.

 

No talking about the R53
I've looked at the theory on the VGS and Ryephix methods along with the DT bypass
And just thought to myself a recirculating valve or diverter valve would do the same job and truly be able to use generated boost to close properly but under vacuum light throttle - idle will open the same way?

 

The idea behind the DT BPV is to alleviate the need for doing the VGS mod. I tried the mod about three years ago and actually created the condition it's designed to correct. So much for converting the stock BPV from vacuum-activated to boost-activated.

I don't think a BOV is effective on a supercharger setup. Never heard of anyone using one when I used to go to the hangout, and I would see plenty of roots and centrifugal setups on a wide variety of old-school American muscle. Superchargers quit applying boost the instant you let your foot off the accelerator. Turbos take longer to spin down, which is why some kind of recirculation/blowoff is effective.

These two threads explain where others thought of the same thing:

https://www.northamericanmotoring.co...rged-mini.html

https://www.northamericanmotoring.co...ve-on-r53.html

 

just so I'm understanding this, but this method doesn't work anymore for fixing the yo-yo effect?

 

If you are referring to my last post, that is not what I said. I did not have the yo-yo problem to begin with. The VGS mod attempts to fix the yo-yo effect and converts the bypass valve from a vacuum-operated device to a boost-operated device. I wanted to do the mod so I could get the valve to close faster. However, as a by-product, I created the yo-yo condition. My solution was to go back to the stock configuration, then purchase and install the Detroit-Tuned bypass valve. It has a different spring in the vacuum modulator and slams shut at the slightest tap of the accelerator.


The benefit of the VGS mod it it's a very low-cost, low effort solution. It does change how the engine responds and requires a bit of getting used to. If you do in-fact have the yo-yo condition, give it a try. The alternative is to get the DT BPV, which was $125 the last time I checked.

 

Just to chime in on the VGS mod vs. the DT spring. The "getting used to" issue related to the VGS mod comes from the introduction of a rather binary throttle response produced by the boost actuation of the BPV -- feathering the throttle becomes a more difficult (but doable) exercise. There is a very abrupt transition from no SC to full SC. The DT spring, however, produces a nice linear response and allows feathering of the throttle with predictable response.

I don't track my '04 MCS JCW any more so I have kept the VGS mod active. If I had continued to drive the track, I would have switched over to the DT spring for finer throttle control.

FWIW,

Theo

 

Jus did this mod and wow what a difference. Car is much smoother and more fun to drive now. Thanks for the tip!

 

 

Any long term feedback on this.... Is this still a good idea, in light of th DT-valve, on our W11's ??

.

 

Read my previous responses. Still stands it's not worth it. Better to stay stock or get the Detroit Tuned BPV.

 

Just done this mod on my 2004 R53, with a tuned BPV. Got it first time, no codes or issues at all. Amazing difference, so responsive. Car is 20 years young!
I left the intake manifold end of the stock hose attached, and attached the other end (originally attached to the fuel pressure regulator) to the T.
Bit tricky getting the vacuum hose on the BPV and on the fuel pressure regulator nipple, but a drop of isopropyl alcohol for temporary lube and some wiggling with needle nose pliers and clamp scissors helped a lot.

To note, 4mm ID hose seemed too loose on the fuel pressure regulator nipple, so used 3.2mm ID for that, and forced on a 5mm brass T. Then used 4mm ID for the other pieces which worked great.
Also the rubber right angled piece on the stock hose (coming from intake manifold) is a little delicate, would connect that to the T last.

Highly recommend 🇬🇧