I just got done with the vgs mod. It costed me $3.99, and about an hour's work (it was tricky trying to get at the hoses). I used "windshield washer and vacuum line" from kragen, which was 3.99 for 6 feet. I then found a drip irrigation tee, and a drip irrigation stopper for the BPV hose. i just went on a test drive, and woah! im really happy with how it turned out, best 4 bucks ive ever spent haha. the car pulls much much better, sounds way better, has better throttle response, and has more burble . I plan to mess around with the bpv soon too, to maximize the system. my other mods that pertain to this are: 15% pulley, and CAI, and my car is an 03 with 73,200 miles.

 

Use a wire to secure the lines at the ends to insure seal while on boost.

make sure that you remove the BVP to check if it seals properly. Use a light behind the BPV to see how well it seals. It must not allow any light to pass.


I recommend that you just buy the modified BPV from Detroit Motors.
http://www.detroittuned.com/shop/?productID=179

Yes, it is worth it. You want to try an OEM? At the time, I checked two dealers and out of 10 samples, 8 did not seal well, so this is a very common problem with the 02-05 S models.

Good luck.

Bomboasy

 

ok, ive got an update on my experience with vgs. So the other day, i adjusted the BPV to make it close all the way. This is a simple job, once you remove the BPV, you just have to back out the little screw on the side to make the butterfly close all the way. The funny thing is though, is that its a major pain to get the valve off. I had to remove the throttle body, and one of the intake manifold studs to get the manifold off. Right now that stud has been replaced by a bolt and nut, but i will replace it with a new stud soon. Anyways, im loving how the car feels with the vgs and adjusted BPV, it really runs great. sounds great too, the supercharger seems to be able to boost a little more than before. Very happy with the VGS. I strongly reccomend it to anyone. And if you aren't faint-hearted, adjust the BPV too.

 

I had done this about a year ago, and adjusted the valve close, It helped some with idle and off idle, I then thought my valve was leaking during a smoke test i had some coming from the Diaphragm area, truned out to be a loose fitting Vac hose, Long story short i have had the BPV off twice, Once to replace a leaky diaphragm / Hose,
And I just installed a Detroit tuned Valve, Awesome item Should had done it years ago,

Once i had the elbow from intercooler to intake off, i removed the studs So much easier to slid the elbow up and down and just install bolts

 

When testing my BPV, I actuated the linkage to test the spring. It did not seem to have a smooth feeling-gritty I would say. I would think this is not normal. Does yours feel like this?

 

Well, I took the VGS mod off a couple of months ago. I was tired of a terrible yo-yo effect that occurred once in a while at a slow creep in 1st gear. It would manifest after I briefly gave my MINI some fuel to get moving.

Since then, I've been slowly developing a slight yo-yo when doing a part throttle (i.e. like 2-4 lbs. boost). I'm curious as to whether I would have that problem had I never made the VGS mod in the first place (I did it for the boost-assist factor; I never had a yo-yo problem to begin with). So, I ordered the DT BPV last week and installed it today. Yes, definitely no more yo-yo issues. And the best part is I now have the benefits of the VGS mod without actually having it. A good quick push of the throttle, and it boosts right up and pulls good. It's now like a whole new MCS.

 

going to try this soon

 

I need help please! I just had my car worked on recently. I had the head pulled off. I was snooping around the engine just now and I smelt raw gas coming from my intercooler. So I popped it off and low and behold the vacuum line to the fuel pressure regulator is missing. I started looki.g around and found a vacuum line just dangling. I traced it back to the intake manifold. The line goes into the intake manifold on the pass side right next to the output horn of the supercharger. Is this the line that Is supposed to go to the fpr?

Here is a picture of the line I'm talking about:

 

Hey everyone, just wanted to let you all know that yes that is in fact the vacuum line to the FPR and it was indeed connected to the vacuum tee underneath the output horn and yes the mechanic did leave the vacuum that was supposed to be connected to that tee dangling in the wind. Put all the lines back on correctly started her up and she runs like a dream! If any of you know me from my rants about my hesitation problems I was having with my car for the past two years, they have now been all resolved! I'm so happy to have my car back and running right again!

Steve

 

Did this mod yesterday - definitely felt a difference. Feels much more linear... not a "whack" of power at once. Smoother and more drivable. Digging it.

 

Did this mod a couple of weeks ago. The power felt a little smoother off of idle and the delivery is a bit smoother. However, my mpg did decrease 1-2 mpg and up until the mod, I never had any "yo-yo" tip-in or light throttle issue, which I do now. I will be yanking this mod and installing a detroit valve instead.

 

I just did this mod. I'm getting a lot more power in 1st gear but can't get used to the heavy engine braking effect on throttle lift. I track my car and this kind of lift could easily put the car into a spin.

I'm going to try the cotton in the line trick; if that doesn't work I'll need to go to a Detroit Tuned bypass valve, or return to the stock vacuum/boost line configuration... :-(

 

I did this mod and now my boost gauge never reads over 10PSI. It used to read 17 or 18PSI (I have a 17% pulley). It's not a delay issue because it never goes above 10PSI no matter how long I stomp on the gas.

I teed in the boost gauge at the fuel pressure regulator end, together with the bypass valve hose.

The car feels like it's actually getting the correct amount of boost, it just seems like the gauge is wrong.

Has anyone else had this issue?

 

Maybe in installing the mod you jostled the tee for the gauge, and it's now leaking a bit?

HTH!

C ya,
Dutch

 

I doubt that because I reconnected all tees and everything looked really tight. The gauge is also reading correct vacuum. But I plan to doublecheck everything...

 

Doublechecking is good. I didn't mean to impugn your ability to hook up a vacuum tee. I was just offering the suggestion of where to look since it was presumably the last thing touched. I've seen one-way leaks, also, which hold vacuum but leak pressure (or vice-versa), both in vacuum lines and radiator hoses. They can be a royal pain in the posterior to find....

HTH!

C ya,
Dutch

 

I just took the car apart and checked. Everything looked good. I put zip ties on the hose ends. Same result.
I took it apart again and rigged up some hoses to enable me to go back to pre-VGS mod without removing the intercooler each time. When I went to pre-VGS mod, the boost gauge returned to normal.

Could I have a leak under boost only in my bypass valve? Vacuum readings are good, both with and without the VGS mod...

 

It's certainly possible, and all evidence points that way. Do you have a hand vacuum pump? If you isolate the line going to the BPV and apply vacuum, does it hold it? The springs on those are prone to breaking (which mine did, BTW), and leaving a pointy end, which, if you're not lucky, could have made a hole in the diaphragm that opens/closes the valve.

Might be time for a Detroit Tuned valve in your case....

HTH!

C ya,
Dutch

 

Did the VGS mod. My car doesn't seem to build boost, it goes and then BAM at 4k rpm it takes off. However, the yo-yo affect seems to have died down but there is a little stumble around 1k.. I'll have to give it a little more time to really get an idea of how it feels.

 

If OE works = the BPV is working = no leak.
How is the boost gauge hooked into the system? If the hose connected to the BPV is disconnected & plugged, the valve will be closed, see if this has any effect with your gauge......

 

I think I'm going to give this a shot on my car this weekend. Will keep you posted on whether the VGS works for me.

 

just wanted to give the thread a bump for new owners like me...i just did it today and def have smiles...will see if any of the complaints surface as i use the car more, but initial impressions look real good..and the price is right!!!

 

I did this mod a couple weeks ago. last week the CEL came on. Uh oh!
lifted the IC and found the hose had detached from the FPR.

I used a zip tie to secure the hose to the FPR nipple. Had to put the tie on the hose and squeeze the hose down just a bit and then work the hose back onto the FPR nipple. Been on a week now and seems to be holding.

 

OK... I did the VGS modification, complete with proper vacuum tube and barb, and zip-ties on all fittings. What did I just do? Sorry to ask such a stupid question; I'm not super automobile-literate. But I'm learning! What, exactly, does the VGS do? I don't understand where the small loop of hose on the BPV comes into play at all, nor what vacuum directed at/from the fuel pressure regulator into/from the BPV does. Can someone shed some light in laymen's terms on this supposedly super-duper-awesome bang-for-buck mod? Thanks!

 

The fuel pressure regulator needs to pay attention to the amount of boost in the manifold after the supercharger, so that it can regulate (or adjust) the pressure of the fuel entering the injectors, which allows them to spray the right amount of fuel into each cylinder when opened.

The VGS taps into that boost pressure line in order to put boost pressure on the diaphragm that opens/closes the bypass valve (which is supposed to open at light throttle or idle, and dump the boost made by the supercharger). This helps it close more quickly and as completely as possible.

The factory BPV can have a problem with closing properly (or at all) due to a weak/broken spring and the valve's set-screw being poorly set so that the valve never quite closes all the way. Even a small misadjustment of the setscrew at the BPV fairly effectively neuters your boost and your engine's power, and when the diaphragm spring's broken you lose most of your boost, since the valve never closes past the point where the broken spring will close it. Even a small amount of boost on the diaphragm will push that valve as closed as the set-screw will allow and give you as much boost as you can get.

I had this on mine and it worked well, but I eventually found a used Detroit Tuned BPV (which has a stronger spring) and removed the VGS. The DT BPV closes as soon as the vacuum drops below idle levels, and lets the supercharger start boosting lower in the RPM curve.

HTH!

C ya,
Dutch