Andy--
Thanks for this how-to! It made a HUGE difference on my '03 S. I ended up using a hybrid of the Alpha and Omega instructions, so we'll call it Pi (as in "easy as") and maybe I'll go have a slice later.... I removed the intercooler, cleaned it up a bit (it wasn't *that* goopy inside, but a little Simple Green shined it right up), and had wonderfully easy clearance for the Alpha method of teeing off the fitting at the end of the manifold.

You can count on it! I'm going to have to relearn the clutch/throttle interaction now that it's got torque....

My "butt dyno" says the 0-60 times are going to be a *lot* quicker....

C ya,
Dutch

 

This is an oldie, but a goodie of a thread... Andy doesn't post here much anymore..

Matt

 

True, it is an old thread, but I figure that thanks are appropriate....

Perhaps another n00b like myself will see this and get a better-running car out of the deal.

C ya,
Dutch

 

Dr. Obnxs,

Are still with Cisco? I left about two years ago. Nice to see that you are still around driving your Mini.

I still have this mod and it has been going fine for the last 5 years. My mini has only 54K miles, but it is a daily driver.

This along with the 4-2-1 header is a wonderful combination for Torque.

Bomboasy

 

and I think he's still there. I'm off to new things... www.fes-auto.com, and www.drobnxs.com. Check them out!

Matt

 

Well i gave 4 days of driving

I changed my Vac lines 4 or 5 days ago, First thing i noticed was smoother idle, Not sure if others have notice the clicking from the PCV valve, mine has smoothed out to gone, Makes sense if the BPV is changing the vac signal,

the rpm's do not drop off as fast during shifting. engine feels much smoother,

I have another track day the 19th, Curious to see how car feels when drove hard

 

and I guess it doesn't really matter which side you tap (pre- or post-SC), but it does make a difference and the results are personal taste. Andy first did this to poke the AGS name in the eye (Andy wasn't the biggest M7 fan) and also to put a dent in the yo-yo that some cars had. I think my car has been hooked up this way for years....

Some manufacturers do the bypass valve this way from the factory.

A good hint to anyone who does this is to wiretie the vacuum/boost lines so that you don't leak any boost when you're at high RPMs.

Matt

 

Holy resurrection Batman! Who woke this up from the dead?

 

I think it's the second or third hand owners getting into the game. Good thing too, there are some jems that are burried under 10,000 "what did you have for breakfast" threads!

matt

 

Nothing to see here, just move along Sir

Randy
M7 Tuning

 

You are correct, sir.

I got my '03 at the end of October with 36k miles on it. I checked the bypass valve and found that the spring in the diaphragm didn't come close to closing it all the way, so when I saw this simple mod to move the vacuum source for the thing post-supercharger and have the boost help close it, I figured that'd fix me right up. It did initially give me a bit of the dreaded yo-yo at times, but I stuffed a little bit of cotton in the line near the bypass valve end, and that got rid of it.

Eventually I'll get the Detroit Tuned replacement (or roll my own ), but this worked for now....

C ya,
Dutch

 

LOL...it's been so long that I've forgotten what this mod was...and it's listed on my mod list...uh oh...

 

Reviving this old thread. To begin, I never had any yo-yo effects with my old '02 MCS or my current '06 MCS. In fact, the '06 MCS starts to pull at 2,000 RPM, where the old '02 MCS would not start pulling until 3,000 RPM. The only condition I would experience with both is the hesitation when first letting out the clutch in 1st gear. Mechanically-inclined friends have explained the low torque of the motor causes this, which means you have to increase the RPMs to compensate.

I installed the VGS modification last night. I accidentally pulled the BPS valve hose off completely. It took over an hour to get a new piece on the brass fitting on the down tube. This required a combination of a mirror, the 45-degree angled pliers, and a flashlight.

Tapped into the vacuum line at the back corner of the intake manifold. It was still a little tricky to get the T-fitting and small hose extension in place. It was also easier to connect the BPV hose before I connected the T-fitting to the original vacuum line.

Went to reassemble the IC; dropped a seal bolt underneath the engine. Never could find it. I even took off the driver's side tire and tirewell. The only conclusion I have is the bolt fell inside the edge of the electric fan shroud. Thankfully, the bolts that hold down the IC cover have the same thread pattern, so I used one of them temporarily. Today, I went and retrieved the bolts from the IC from my old '02 MCS.

This job took me about five hours for two mistakes. I was taking my time. Not one of my better experiences.

Now, the analysis. Yes, starts in 1st gear are alot better. However, if you let off the gas in the middle of letting out the clutch, the engine will bog a bit because the BPV opened up. There is a definite defined on/off feeling with the BPV closing under boost. To get part throttles to work, I have to give a little extra gas to make sure the BPV closes, then let back off the throttle a small amount. It's still enough to keep it closed until I decelerate back into a vacuum mode.

If I do a hard acceleration and tack up the motor in 4th gear, to say about 4,000 RPM, then let off the gas, there is a definite defined bog or drop on the engine, as some have previously mentioned.

I have not hooked up my GReddy boost gauge yet. When I had it in my '02 MCS, under part acceleration, I would notice the boost go up to about 6-7 PSI, then start to slowly taper off without actually letting off the gas. I attribute this to the BPV acting under vacuum conditions. With the VGS method, I would expect the boost to be steady. I'm going to keep the mod installed for awhile, and I will post an update whenever I get the gauge installed.

For anyone that wants to know... my '06 MCS build date is 10/06.

 

I had some weired driveablity issues, i thought i had every thing hooked up right,
BUT
The hose i had got was thicker walled hose it fit snug into the BPV on the hood around the nipple, But was not sealing on the nipple it self, But from where i had room to push it on it felt right, it was later on found i was leaking at this spot,

Just some thing to check

 

that's why the factory hoses are the funky things with the big rubber ends. When using more conventional hoses, I also use wireties to make sure they seal under boost.

Thanks for reviving and oldie, but a goodie, of a thread!

Matt

 

I have not used any wire ties yet. The only end I'm concerned with coming off is the vacuum end that is on the "T" fitting. It does appear to be slightly larger. Just gonna keep an eye on it; at least it's easily accessible at the back of the manifold.

 

Just did this mod tonight and the car felt really good afterward, it seems to rev up faster and feel a little more lively. I think I'm going to disassemble the throttle body area later and cap off the original vacuum line at the source. Makes me wonder why the engineers didn't do this from the factory?

 

This does take me back. Good to see you still around Dr. Obnxs.

JJF, Have you ever inspected your BPV for a good seal? If you BVP does not seal properly, it might explain some of that hesitation. I was the first one to post this problem and Ryan developed the Detroit Tuned Valve on my suggestion to provide both, his modified spring and properly closing valve in a single product. I have the first sold sample.

I am one of the few who did both modifications: Ryephix #2+VGS! Look for the Yo-Yo Chronicles and enjoy the long read. The combo takes away some of the negatives of each mod and gives you most of the benefit of each. This has been in my car for 30K for over 4 years.

Regarding the need to raise your RPMs to compensate, that is not something that I need to do. The MINI was designed with as much HP possible and weak in the Torque department. Changing the header from a 4-1 to a 4-2-1 header changed the torque/HP map and made my MINI a real pleasure to drive in an uphill or at low speed in a parking lot. Maybe that change will also help.

Bomboasy

 

Did not see you there MSFITOY, this feels like a reunion party!


Bomboasy

 

maybe a dumb question (probably is) but would I, with an 06 MCS see similiar results as described in the thread?

I only wonder because most of the people who posted had '02 and '03's. I'm quite the newbie and wouldn't mind trying this mod out as I feel even I could pull it off Plus I would love to see less hesitation off the line, thanks in advance!!!

 

This is funny stuff to say the least. My by pass valve went bad a few years ago. I shut the valve off by removing the set screw and zip tied the arms so that they can not move. Best thing I ever did. I may have lost a mile or two in gas mileage but the all the problems that thing caused all went away. And I have to say that the throttle response was improved. What was mini thinking about with that anyway.

 

the Ryephix I, I think.... That goes back a very, very long time....

Matt

 

this VGS should work for Automatics too, right?

sorry! someone posted my question earlier. imma try this tomorrow

 

Yes, it should work for automatics, too. I'm still split about making the change myself. I never really had any yo-yo issues to begin with. It's really more effective on my MCS if I stay in the upper RPMs, like above 3K. But I just love the instant shut of the BPV when I give her some pedal. Makes driving in 3rd and 4th gear so much more fun in the twisties.

Like Bomboasy suggested, I probably need to check and make sure my BPV has a good seal. It just takes some practice getting used to the change.

Be prepared to take longer than just an hour like some mentioned here. The hardest part will be getting the new hose on the BPV. Get a pair of 45-degree 12" long needle-nose pliers. You should be able to pick up a pair at your local Autozone or Advance Auto. And don't use larger fittings and hose. Stick with 5/32 for the entire line. Autozone sells a multiple fitting kit for like $10.

 

Yes, I agree--it's a *lot* more fun to drive with the VGS than stock. Most of our twisties out here are a bit tighter, so it's 2nd/3rd gear, but the same thing applies....

Actually, when I did mine, it *created* a yo-yo issue that didn't previously exist. Luckily it was very easily fixed. It seems that the dreaded yo-yo problem is related to the weak stock spring in the diaphragm. During the transition between mostly closed and closed the vacuum/boost oscillates at a low frequency, since there's no resistance whatsoever to that last little bit of open/closed motion thanks to the weak and slightly compressed spring. The valve's throttle plate is just wagging in the breeze, and can instantly respond to what the diaphragm is telling it to do.

The fix--I simply pulled a small wad of cotton off a cotton ball, and shoved it into the vacuum line (using a jeweler's screwdriver) at the bypass valve end, and it created enough restriction on the vacuum going there to dampen the vacuum oscillation. Just like tuning an RC oscillation in an electronic circuit - increase resistance in the circuit, and the oscillation frequency is reduced. Increase it enough, and the frequency drops to near zero....

I think that the bypass valve is also responsible for that little power surge when throttle-off coasting and dropping through the 1200-1500 rpm range. I bet it's caused when the vacuum to the bypass valve drops below the threshold of holding it open, allowing the super to boost a bit for a split-second, thus creating a short, small power surge.... In my car, the VGS made that quirk a little more defined and pronounced. It's like the car's kicking and griping about having to go slow or stop....

In summary--the VGS is a really good solution overall to getting the weak stock bypass valve to perform better very easily and on virtually no budget. With the little bit of cotton shoved into the line, it has served me well since November sometime, but ultimately a Detroit Tuned valve is the best fix. It needs no boost fed to the diaphragm to fully close the bypass valve, as the spring holds it closed by itself, and it closes fully. This is (according to what I've read) an improvement over the stock unit, which is adjusted to leak a little boost even when "closed". I can't wait to get mine on....

C ya,
Dutch