How To Drivetrain :: Operation Vacuum Gain System (VGS)
#226
Originally Posted by andy@ross-tech.com
The supercharger creates very little heat at low absolute pressure readings. It's only when boost is above 8 psi or so that you see temp increases become really significant. The VGS mod has no effect on this range compared to stock. I'd wonder if the poster has actually monitored air temperature coming out of the supercharger.
#227
The guy is just wrong.
Originally Posted by Profpatpending
anybody care to elaborate on the following statement,
BTW this statement aint mine,
here is where I got it from,
https://www.northamericanmotoring.co...ad.php?t=48792
"I wouldn't mess about with tying it shut all the time, beefing up the spring or doing the VGS mod which seems to keep the supercharger in action more than it would with the mod absent. This can run the charger much hotter in my experience (expensive mistake following a it's failure!)."
whats the chance this can lead to SC failure????
BTW this statement aint mine,
here is where I got it from,
https://www.northamericanmotoring.co...ad.php?t=48792
"I wouldn't mess about with tying it shut all the time, beefing up the spring or doing the VGS mod which seems to keep the supercharger in action more than it would with the mod absent. This can run the charger much hotter in my experience (expensive mistake following a it's failure!)."
whats the chance this can lead to SC failure????
If the guy really did have a hotter SC, it was from more power, and more heat carried out of the radiator! But what he's saying just doesn't make sense.....
But tying it open would effect gas milage the worst, as you wouldn't drop manifold pressure under engine braking, or with very small throttle openings. I didn't notice much if any difference between ryephixII and VGS. Maybe a bit improved with the VGS, because the spring isn't as aggressive.
Matt
#228
Its a good rule to assume a possibility that the last thing you did to your car caused the failure you see now. In his case, it is not the cause. I would imagine it was a less than perfect bearing that destroyed itself over time.
The space station could pay for itself if they would manufacture round ball bearings.
The space station could pay for itself if they would manufacture round ball bearings.
#229
Nothing short of turning it into a drug lab
Originally Posted by namwob
The space station could pay for itself if they would manufacture round ball bearings.
Matt
#230
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well it seems my gas milage is the same....i was messed up that nite i wrote that post.....i did go for a trip to CT this weekend and just got back....but half way up on the ride to CT my CEL came on but the car still ran fine....i got to my friends place and let it kewl down to take to IC off to inspect the hoses for the VGS.....i found out the FPR line came off so i put it back on and held it down alil better......i cycled the key a few times and the CEL went off.....15mins later it back on and i wasnt looking at it agian.....i just got in not to long ago so i mletting it kewl down again to tare it apart one more time to see wtf is goin on here.
I did manage to get 340mi out of th tank....And that was all highway mostly with alil rippin the street of CT up at the sametime.
I did manage to get 340mi out of th tank....And that was all highway mostly with alil rippin the street of CT up at the sametime.
#232
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Originally Posted by eMINI
I had the same thing. Try a zip tie on the bottom of the FPR to hold the vacuum line on.
#234
How about the motor mounts at the bottom of this page:
http://www.webbmotorsports.com/performance.php
http://www.webbmotorsports.com/performance.php
#235
Originally Posted by Originalhotrodder
How about the motor mounts at the bottom of this page:
http://www.webbmotorsports.com/performance.php
http://www.webbmotorsports.com/performance.php
Don't work on an '05. Passenger side motor mount is different.
#237
back to VGS
Just a simple testimony that my VGS mod to my '05 went like budder this morning. Total cost $7 since I had to buy 6ft of hose in a packet rather than the exact amount from PBoys. I have to add that the installation modification of moving the IC mounts out of the way to re-install the IC saved the day, and lots of swearing--I'd recommend adding it to the "official" method description.
I had the 3000-4000rpm flat spots (yo-yo) really bad, much exaggerated by lots of other modifications. First report this morning shows partial throttle response in that rev-range to be smooth as budder. Car is a little "smoother" on acceleration, and not so aggressive, but more time will allow me to better describe the change in driving feel.
Thanks so much for the solution to what was becoming my obsession!
I had the 3000-4000rpm flat spots (yo-yo) really bad, much exaggerated by lots of other modifications. First report this morning shows partial throttle response in that rev-range to be smooth as budder. Car is a little "smoother" on acceleration, and not so aggressive, but more time will allow me to better describe the change in driving feel.
Thanks so much for the solution to what was becoming my obsession!
#238
Hello everyone, I just got around to doing the VGS mod, I suppose later is better than never. Initial impressions are positive. I had a mild occelation in the supercharger between 3K and 4K which has completely vanished, the power comes on a few hundred rpms sooner, and I am very satisfied at the $ per achievement ratio. Thanks Andy, this was a great idea. I'm looking foreward to more miles of smiles.
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well i had the VGS setup for a while now, like 2000+ miles, and recently i have been experiencing the "yo-yo" affect. i have felt it on my car before, but it was very very subtle and "once-in-a-moment" occurance but this one is happening often and the power going off and on again is very pronounce. i had a 15% pulley installed around 500miles ago... so really i have no idea what could gain this affect. any thoughts from you guys how i gain this?
#240
#241
Originally Posted by eMINI
Have you checked all the vacuum line connections made when VGS was installed? If one of the lines has slipped off, the yo-yo could become more pronounced. That would be the first step.
Check your BV it sounds like it's sticking. Do you have a boost/vacuum gauge? They are a great trouble shooting aid.
Last edited by norm03s; 09-13-2005 at 07:36 AM. Reason: spelling fix
#242
Flat spot at 3000 RPM's
I did the VGS mod last weekend and the yo yo is gone now but I have a flat spot at light throttle around 3000 RPMS. I also noticed the vacuum readings are different now. At idle I get 20 to 22 in Hg compared to previous 18 in Hg. I tee'd into the boost gage line which is tee'd off the vacuum line just before the fuel pressure gizmo. This seemed to be the easiest way rather than adding a second tee to the orginal line going to the fuel pressure gizmo. Any ideas/comments out there?
Thanks
Thanks
#243
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i'm with saddan as well that i experience the flat spot too, well not really flat, more like its only using 80% of the power even the pedal is nearly to the floor. i can notice it when i accelerate out of a corner. so would the throttle body spring would cause both the pronounced "yo-yo" and the flat spot? or is it the hoses getting soft that i heard around the forums a while ago? but i'll check if any lines has gotten loose, which would kinda suck if it did because its been only 2000-3000 miles since i had it.
#244
#245
When you do it....
Originally Posted by dotBob
I have that flat spot, and I've still got Sly ('04 MCS) stock. I think it's typical, and you just happen to notice it more with the added boost.
One of these days I'll actually do the VGS and bypass valve mods. I've had the Detroit Tuned bypass valve for months..
One of these days I'll actually do the VGS and bypass valve mods. I've had the Detroit Tuned bypass valve for months..
Also, get a spare hose clamp to replace the one that will be trashed as you take the hose off the bypass valve. If you do put the car into service mode, you can pull the TB-SC duct and clean out the glue flash (poor man's AGS, thanks SFJAMES).
I was intimidated by doing all that stuff to gain access to the front of the motor. After doing it for another project, I wish I'd done it for the VGS and bypass work I'd done in the past.....
Matt
#246
#247
It allows you to pull the radiator forward a bit.
Originally Posted by gandini
Sorry for my ignorance, but I did a search....what's the service mode, and how does that make access to the engine easier?
thanks,
thanks,
Matt
#248
I have read the Stumble and YoYo threads and completed the VGS modification on my '04 MCS. When the weather is warm I only get a slight stumble in the morning, then it runs fine. But now that the weather is getting colder (40 degrees last night) I get the stumble everytime I accelerate until it warms up. Any ideas on how to solve this? Thanks.
#249
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Have been reading the VGS post - very impressive and I would like to try it. The thread as you all know has gotten rather extensive and there are several drawings. It appears that the hook up changed inside the thread or I just confused myself.
long story short - Which is the FINAL diagram I should be following?
long story short - Which is the FINAL diagram I should be following?