How To Drivetrain :: Operation Vacuum Gain System (VGS)
#101
5th Gear
iTrader: (2)
Join Date: May 2003
Location: Illinois
Posts: 1,030
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by DunWaiten
andy@ross-tech said
It seems that a failure of the bypass valve diaphragm and/or housing would open a path from the intake manifold to atmosphere through the vacuum line installed as part of the VGS setup. I think that would act like a vacuum leak under low boost conditions, and would cause idling problems. Of course, the stock setup could also fail, causing idling problems.
It seems that a failure of the bypass valve diaphragm and/or housing would open a path from the intake manifold to atmosphere through the vacuum line installed as part of the VGS setup. I think that would act like a vacuum leak under low boost conditions, and would cause idling problems. Of course, the stock setup could also fail, causing idling problems.
#102
#103
#104
I currently have my MINI disassembled to complete the VGS and I hope one of the experts is on line. Here are my current questions: 1) the vacuum line connecting the diaphram and the bypass valve appears to be 5/32". I pulled off the end at the bypass valve and sealed it off. I connected a long section of 5/32" hose to the bypass valve and this is where I am now. The hose that connects the nipple on the intake manifold to the FPR is a much smaller diameter. Can you tell me what size this is? Would it be OK to cut into this hose closer to the FPR than at the intake nipple? Thanks for your help.
#105
Originally Posted by JPit
I currently have my MINI disassembled to complete the VGS and I hope one of the experts is on line. Here are my current questions: 1) the vacuum line connecting the diaphram and the bypass valve appears to be 5/32". I pulled off the end at the bypass valve and sealed it off. I connected a long section of 5/32" hose to the bypass valve and this is where I am now. The hose that connects the nipple on the intake manifold to the FPR is a much smaller diameter. Can you tell me what size this is? Would it be OK to cut into this hose closer to the FPR than at the intake nipple? Thanks for your help.
you put your T piece on the end of the FPR hose (the grey rubber piece)
you connect one of the other ends of the T to the long hose connected to the bypass
put a small piece of vaccum hose on the manifold nipple where the FPR hose came from and pipe this to the last place on the T piece
#107
#108
#109
#111
#112
#113
Stock vs Ryephix II vs VGS
I've had teh VGS on for about two weeks now. Here's what it seems like.
1) Stock sucks. And you have to ajust the butterfly stop at least, so why leave it stock?
2) Ryphix II is definantly the most aggressive. It switches like a hammer, and makes very light throttle driving a bit of a pain in the butt, but it sure put the power down early! I'd go this way if I were a track rat.
3) VGS gives back a lot of the arount town light throttle drivability back. Gas milage improved 1-2 mpg as well when compared to Ryephix II for sure. Since I only do 2-3 Mini track events a year, I'm gonna stay with the VGS.
Also, for more drammatic effect, you can stretch the stock spring a bit. This will increase the force that the diaphram will have to act agains (close earlier as vacuum decreases) and the spring constant will increase as well, making it open slower as vacuum increases (close slower as well, but as the manifold pressure will increase as it closes, the rate that it closes should increase via posative feedback). By stretching the spring different ammounts, one ought to get any behaviour you really want.
The RPII is a little different, less turns of thicker wire (much higher spring constant), but you get the idea.... I stretched mine about 1/4-3/8 of an inch.... Just guessed.
Matt
1) Stock sucks. And you have to ajust the butterfly stop at least, so why leave it stock?
2) Ryphix II is definantly the most aggressive. It switches like a hammer, and makes very light throttle driving a bit of a pain in the butt, but it sure put the power down early! I'd go this way if I were a track rat.
3) VGS gives back a lot of the arount town light throttle drivability back. Gas milage improved 1-2 mpg as well when compared to Ryephix II for sure. Since I only do 2-3 Mini track events a year, I'm gonna stay with the VGS.
Also, for more drammatic effect, you can stretch the stock spring a bit. This will increase the force that the diaphram will have to act agains (close earlier as vacuum decreases) and the spring constant will increase as well, making it open slower as vacuum increases (close slower as well, but as the manifold pressure will increase as it closes, the rate that it closes should increase via posative feedback). By stretching the spring different ammounts, one ought to get any behaviour you really want.
The RPII is a little different, less turns of thicker wire (much higher spring constant), but you get the idea.... I stretched mine about 1/4-3/8 of an inch.... Just guessed.
Matt
#117
Andy,
Thank you so much for giving us this great mod.
I have a 2005 MCS, with v39.2, and approximately 6200 miles.
I have driven many stick cars in my life but this MCS was like no other.
From the day I picked it up new, no matter what throttle/clutch technique I used, I could not get a consistent, smooth start unless I brought the rpm to 2000 or so before releasing the clutch. Also, unless I up-shifted at 3500 rpm and > the clutch engagement was never as smooth as I am used to. Another thing I noticed with this car is that the throttle response has always been delayed (as when blipping the throttle from idle). I began to theorize that the throttle hesitation was due to the drive by wire throttle and that there was nothing that could be done about it.
Since reading of your VGS mod I've wanted to install it.
Today I started at 5:10 PM and was wrapped up and putting my tools away by 6:10 PM.
I drove to our local pizza place to pick up dinner and I was amazed and very pleased at the new throttle response. Now the car has butter smooth clutch engagements and solid, smooth low rpm power and up-shifting is smoothed out as any normal car should be.
I highly suggest this mod to all MCS owners. It’s excellent and really easy to incorporate.
Thank you again for sharing your knowledge with us Andy.
Thank you so much for giving us this great mod.
I have a 2005 MCS, with v39.2, and approximately 6200 miles.
I have driven many stick cars in my life but this MCS was like no other.
From the day I picked it up new, no matter what throttle/clutch technique I used, I could not get a consistent, smooth start unless I brought the rpm to 2000 or so before releasing the clutch. Also, unless I up-shifted at 3500 rpm and > the clutch engagement was never as smooth as I am used to. Another thing I noticed with this car is that the throttle response has always been delayed (as when blipping the throttle from idle). I began to theorize that the throttle hesitation was due to the drive by wire throttle and that there was nothing that could be done about it.
Since reading of your VGS mod I've wanted to install it.
Today I started at 5:10 PM and was wrapped up and putting my tools away by 6:10 PM.
I drove to our local pizza place to pick up dinner and I was amazed and very pleased at the new throttle response. Now the car has butter smooth clutch engagements and solid, smooth low rpm power and up-shifting is smoothed out as any normal car should be.
I highly suggest this mod to all MCS owners. It’s excellent and really easy to incorporate.
Thank you again for sharing your knowledge with us Andy.
#119
So far I have put about 75 miles with the mod, most of it has been in and around the city, a lot of shifting, and boy what a difference, it is much crisper and smoother going through the gears, drivability has improved significantly.
This may be premature but my initial reactions to the VGS modifications are very positive. Throttle response has changed I had to adjust my driving style to accommodate the change. After nearly 14,000 miles of either Yo-Yo or sluggish starts (V39 helped a lot with the Yo-Yo) I found myself having to adjust to the now liner acceleration, that was never there before.
This morning I decided to do the modification, I studied the photos and diagrams supplied on this thread, purchased the necessary parts from a local store yesterday and made sure the car was cool before starting the mod. All together, including painting the IC shroud, it took about 2 hours to complete the job and cleaning up after. Like everyone before who said it was a tight fit, I agree!
The only hose that was difficult for me to identify was the hose that attached to the black plastic plunger of the bypass valve, it didn’t seem at first that the hose could be removed, but was actually very simple to remove with a little tug. Then came the most difficult part, reinstalling those hoses to the bypass valve, I never actually saw where the hose attached to the other part of the bypass valve, the one that was blanked off, I just felt it, that was a “beach” to put back in and probably took me the longest time of any single task with the mod.
Interesting thing, there was a puddle of oil on both sides of the IC laying in the groves of the rubber seals. I think they were from my Alta air filter?
Is that a problem?
Anyway
Andy: Thank you for this great little mod, and spreading the word.
This may be premature but my initial reactions to the VGS modifications are very positive. Throttle response has changed I had to adjust my driving style to accommodate the change. After nearly 14,000 miles of either Yo-Yo or sluggish starts (V39 helped a lot with the Yo-Yo) I found myself having to adjust to the now liner acceleration, that was never there before.
This morning I decided to do the modification, I studied the photos and diagrams supplied on this thread, purchased the necessary parts from a local store yesterday and made sure the car was cool before starting the mod. All together, including painting the IC shroud, it took about 2 hours to complete the job and cleaning up after. Like everyone before who said it was a tight fit, I agree!
The only hose that was difficult for me to identify was the hose that attached to the black plastic plunger of the bypass valve, it didn’t seem at first that the hose could be removed, but was actually very simple to remove with a little tug. Then came the most difficult part, reinstalling those hoses to the bypass valve, I never actually saw where the hose attached to the other part of the bypass valve, the one that was blanked off, I just felt it, that was a “beach” to put back in and probably took me the longest time of any single task with the mod.
Interesting thing, there was a puddle of oil on both sides of the IC laying in the groves of the rubber seals. I think they were from my Alta air filter?
Is that a problem?
Anyway
Andy: Thank you for this great little mod, and spreading the word.
#120
The brass vacuum nipple on the downstream side of the BPV is definitely the hardest part to get to. For easiest VGS installation, I'd recommend the following procedure:
1) Disconnect the short rubber vacuum hose from the diaphragm of the bypass valve, but leave it attached to the lower brass vacuum nipple. Cap off the now-loose end of that hose.
2) Disconnect the (hard plastic with rubber caps on each end) vacuum line from the intake manifold but leave it attached to the fuel pressure regulator.
3) Install a tee in the now-loose end of that vacuum line.
4) Install a short length of vacuum hose between the tee and the nipple on the intake manifold.
5) Intall a long piece of vacuum hose between the remaining branch on the tee and the diaphragm of the bypass valve.
6) Make sure everything is snug and that all your tools are accounted for.
7) Enjoy.
Using the above method, it should be possible (in fact it's definitely possible) to install the VGS without removing the intercooler.
1) Disconnect the short rubber vacuum hose from the diaphragm of the bypass valve, but leave it attached to the lower brass vacuum nipple. Cap off the now-loose end of that hose.
2) Disconnect the (hard plastic with rubber caps on each end) vacuum line from the intake manifold but leave it attached to the fuel pressure regulator.
3) Install a tee in the now-loose end of that vacuum line.
4) Install a short length of vacuum hose between the tee and the nipple on the intake manifold.
5) Intall a long piece of vacuum hose between the remaining branch on the tee and the diaphragm of the bypass valve.
6) Make sure everything is snug and that all your tools are accounted for.
7) Enjoy.
Using the above method, it should be possible (in fact it's definitely possible) to install the VGS without removing the intercooler.
#123
#124
#125
I took out my BPV after I set-up the VGS, and it the stop screw needed adjustment, as well as the butterfly plate. With those three mods (stop screw, butterfly, and VGS), the car is considerably faster, both in terms of throttle response AND boost. I should have used a boost gauge to measure the delta before BPV adjustment and after, but alas I'm too poor and also stupid.
Marty
Marty