Free boost modification

[ZO6 Bryan]

Originally Posted by DeSH

Why would you not just adjust the set screw? Seems to me that's what it is there for instead of loosening the three 10mm bolts and twisting the valve at an awkward angle. Any explanations to the contrary?

You are exactly right. The bolts are for gross adjustment to get it close. Then the set screw is for fine adjustment.

[NicKey]

"If the bypass valve closes too tight it will jam in it's bore and get stuck. The set screw is there to prevent that. The set screw should barely touch when the valve is closed tight. "

The above is correct. While we have seen some stock LSAs out of adjustment not all are out of adjustment.

[STUNNAH]

I just did the adjustment by hand...Loosened the two bracket bolts pushed the valve slightly forward and tilted about and 1/8th inch...Gap is now just a little less than 1/8th inch, that's just eyeing it...Let the car warm up hit a couple of straights and jumped to 14pds on the stock boost gauge...Boost is very responsive and does not take as long to build up as it did prior to the adjustment...Still on stock GY's broke loose mid 3rd gear, needless to say I was not expecting that...WOT 2nd, 3rd, 4th boosted fast to 14pds and held...So much going on needed a co-pilot to help watch the gauges...I believe I had full boost at about 5k, didn't redline...No problem with temp either...This is with just a stage one kit 2.55 upper pulley...Things just got nasty round here...Very happy with the mod...Mod should be moved to the info section where it is immediately accessible...

[DeSH]

Originally Posted by STUNNAH

I just did the adjustment by hand...Loosened the two bracket bolts pushed the valve slightly forward and tilted about and 1/8th inch...Gap is now just a little less than 1/8th inch, that's just eyeing it...Let the car warm up hit a couple of straights and jumped to 14pds on the stock boost gauge...Boost is very responsive and does not take as long to build up as it did prior to the adjustment...Still on stock GY's broke loose mid 3rd gear, needless to say I was not expecting that...WOT 2nd, 3rd, 4th boosted fast to 14pds and held...So much going on needed a co-pilot to help watch the gauges...I believe I had full boost at about 5k, didn't redline...No problem with temp either...This is with just a stage one kit 2.55 upper pulley...Things just got nasty round here...Very happy with the mod...Mod should be moved to the info section where it is immediately accessible...

How many pounds boost did you gain compared to before the adjustment?

[STUNNAH]

Originally Posted by STUNNAH

I just did the adjustment by hand...Loosened the two bracket bolts pushed the valve slightly forward and tilted about and 1/8th inch...Gap is now just a little less than 1/8th inch, that's just eyeing it...Let the car warm up hit a couple of straights and jumped to 14pds on the stock boost gauge...Boost is very responsive and does not take as long to build up as it did prior to the adjustment...Still on stock GY's broke loose mid 3rd gear, needless to say I was not expecting that...WOT 2nd, 3rd, 4th boosted fast to 14pds and held...So much going on needed a co-pilot to help watch the gauges...I believe I had full boost at about 5k, didn't redline...No problem with temp either...This is with just a stage one kit 2.55 upper pulley...Things just got nasty round here...Very happy with the mod...Mod should be moved to the info section where it is immediately accessible...

Originally Posted by DeSH

How many pounds boost did you gain compared to before the adjustment?

At least 4 or close to 5...My guess is that since my car had the basic mods that a good deal of air was seeping...With that being said I didn't really look at the stock vs modded threads for any comparison...So in theory if a stock car picks up 1.5 to 2 pds, then my numbers should be very close to correct with the CIA delivering more air...This is just my theory and solely based on my car and the out come...Prior to this adjustment my car was making a little over 9pds, now it's steady at 14pds...

[STUNNAH]

Originally Posted by Emvici

I am making 15 lbs of boost with only a 2.55 upper pulley, after doing the boost bypass adjustment!.

Here is another example, with apparently basic mods...

[ZO6 Bryan]

Originally Posted by STUNNAH

At least 4 or close to 5...My guess is that since my car had the basic mods that a good deal of air was seeping...With that being said I didn't really look at the stock vs modded threads for any comparison...So in theory if a stock car picks up 1.5 to 2 pds, then my numbers should be very close to correct with the CIA delivering more air...This is just my theory and solely based on my car and the out come...Prior to this adjustment my car was making a little over 9pds, now it's steady at 14pds...

8 or 9 lbs boost is stock level. If that is all you had after a 2.55 pulley install someone screwed up the bypass valve adjustment when they removed the snout to do the job.

[STUNNAH]

Originally Posted by STUNNAH

At least 4 or close to 5...My guess is that since my car had the basic mods that's a good deal of air was seeping...With that being said I didn't really look at the stock vs modded threads for any comparison...So in theory if a stock car picks up 1.5 to 2 pds, then my numbers should be very close to correct with the CAI delivering more air...This is just my theory and solely based on my car and the out come...Prior to this adjustment my car was making a little over 9pds, now it's steady at 14pds...

Originally Posted by ZO6 Bryan

8 or 9 lbs boost is stock level. If that is all you had after a 2.55 pulley install someone screwed up the bypass valve adjustment when they removed the snout to do the job.

I doubt that the valve was adjusted during the snout removal...Since the stock gauge has only two markings "press and 15" it's a bit difficult to make an exact reading while driving with no other markings or any other device monitoring the system...So I guess that my post regarding my cars boost level prior to the valve adjustment could have been wrong and the car could have been making 10, 11, or 12 pds...But now the needle sits just above the 15 pd marking and holds there...So if I only gained 2 pds or a slight bit more I'm quite happy with the increase...Do you think my gains in my signature are consistent with a stage 1 kit on a M6, and what do you think the pressure should have been???

[Bosse'sBoss]

Great free mod
What about keeping the warranty, do you think this could be detected at the dealer?
Anybody try it with the CAI & lower pulley mod?

I agree that is dumb that we don't have the boost gage at our dash or hud.

[ZO6 Bryan]

Originally Posted by STUNNAH

I doubt that the valve was adjusted during the snout removal...Since the stock gauge has only two markings "press and 15" it's a bit difficult to make an exact reading while driving with no other markings or any other device monitoring the system...So I guess that my post regarding my cars boost level prior to the valve adjustment could have been wrong and the car could have been making 10, 11, or 12 pds...But now the needle sits just above the 15 pd marking and holds there...So if I only gained 2 pds or a slight bit more I'm quite happy with the increase...Do you think my gains in my signature are consistent with a stage 1 kit on a M6, and what do you think the pressure should have been???

To remove the snout the bypass has to come off. Therefore it has to be set-up when you put it back together.

[STUNNAH]

Originally Posted by ZO6 Bryan

To remove the snout the bypass has to come off. Therefore it has to set-up when you put it back together.

Ok, that makes sense but the bypass is only held by bolts...So you remove the bypass lay it away from the snout, remove the snout, reverse the process bolt the bypass back on without making any adjustment...More likely than not...This is just speculation on my part...I am not mechanically inclined, but I did do this mod and now have 14pds of boost...

[Can'tHave2MuchHP]

14 PSI on a 2.55" and this mod? You better be careful, that is really really high.

[ZO6 Bryan]

Originally Posted by STUNNAH

Ok, that makes sense but the bypass is only held by bolts...So you remove the bypass lay it away from the snout, remove the snout, reverse the process bolt the bypass back on without making any adjustment...More likely than not...This is just speculation on my part...I am not mechanically inclined, but I did do this mod and now have 14pds of boost...

Yes the same bolts you loosened to adjust it are the ones removed when the snout came off. Therefore it needs adjustment when put back together.

[STUNNAH]

Originally Posted by ZO6 Bryan

Yes the same bolts you loosened to adjust it are the ones removed when the snout came off. Therefore it needs adjustment when put back together.

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