Bypass Valve fix/Possible Boost Mod
10-08-2009, 01:00 PM
#76
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did you remove the tank? i did what u said and it worked but i didn't remove the tank and the spare hoses are just chillin there. the cel went away after i disconnected the negative battery. surge was reduced also. the cra seems to run better/smoother. i dosent buck between shifts and has more throttle responce. alot compressor surge was reduced
10-08-2009, 01:43 PM
#77
I have a couple pics about removing the tank. I got it out although it's a little bit PIA cause the oil dipstick is RIGHT in the way of one bolt. Then made a short vid just to explain what we're doing with the tank bypass. Working on getting them ready.
EDIT: Vid is still waiting for youtube.
REMOVING THE TANK. (assuming you've completed the vacuum tank bypass mod) Views in the pictures are the front of the car is the bottom of the pic and engine to the top of the pic. I'm laying with my legs hanging out under the front bumper.
1- Jack up the front of the car
2- Get underneath. The tank sits under the intake manifold, above the starter, behind the dipstick. (see pic)
3- Use a 10mm socket with long extension (I used my 6" but probably could have used shorter. I just couldn't find the other) and remove the DRIVERS side bolt first. (see pic)
4- Because it's a tight squeeze and the dipstick is positioned almost dead center of the passenger side bolt. Push up on the drivers side of the tank to tilt it. This will get the tank out of the way to give you more access. (see pic)
5- For the last bolt you don't need an extension. Just need to be a little flexible and be patient.
Vid just to explain what we're doing coming soon hopefully.
EDIT: Vid is still waiting for youtube.
REMOVING THE TANK. (assuming you've completed the vacuum tank bypass mod) Views in the pictures are the front of the car is the bottom of the pic and engine to the top of the pic. I'm laying with my legs hanging out under the front bumper.
1- Jack up the front of the car
2- Get underneath. The tank sits under the intake manifold, above the starter, behind the dipstick. (see pic)
3- Use a 10mm socket with long extension (I used my 6" but probably could have used shorter. I just couldn't find the other) and remove the DRIVERS side bolt first. (see pic)
4- Because it's a tight squeeze and the dipstick is positioned almost dead center of the passenger side bolt. Push up on the drivers side of the tank to tilt it. This will get the tank out of the way to give you more access. (see pic)
5- For the last bolt you don't need an extension. Just need to be a little flexible and be patient.
Vid just to explain what we're doing coming soon hopefully.
Last edited by Zander916; 10-08-2009 at 02:19 PM.
10-08-2009, 02:16 PM
#80
EDIT: CRAPPY VID BUT HOPEFULLY IT WILL HELP!
http://www.youtube.com/watch?v=8GrBO7LcvPg
10-08-2009, 02:20 PM
#81
Cold=less boost
10-08-2009, 02:42 PM
#82
10-08-2009, 03:06 PM
#83
Yeah, I really don't like loose things in the engine compartment, so I completely feel ya on that one.
10-08-2009, 04:15 PM
#84
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thanks a lot for the how to. now i will be doing this this weekend along with the infamous leak on my LNF motor. just got my S/C tune today, the car is so much faster now.
10-09-2009, 12:04 AM
#86
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I guess I forgot to mention the throttle body. If you let off the gas while under boost it will close. Then you have pressure in the intake tract, but vacuum in the intake manifold. So at the BPV then has pressure on one side of it's diaphragm and vacuum on the other cause the line is fed from the manifold and it opens to relieve pressure. The solenoid is just doing this electronically.
If you look at the diagram, the intake line connected to the solenoid would be under pressure. The intake manifold line would be under vacuum (if the throttle is suddenly closed). The solenoid is just the ECU determining when this happens rather than just physics. I didn't bypass the Solenoid although the Solstice guys did. I just bypassed the tank (which they didn't have in the first place unless the later models do)
I noticed you have an HKS BOV and Hahn block off plate. Yours might already be bypassed. Can you take a pic of yours and post it up?
I don't really recommend bypassing the solenoid like the Solstice guys did. (The pic with the 'T' connection) As someone told me, "it might save your bacon if something goes wrong."
Alright... hahaha.. I'm diagram happy and I suck at it! Here's another. This shows what I think the solenoid is doing. I could be wrong but I don't know what else it would be doing. It's just switching between positive and negative pressure to control the BPV.
I'm one line away from making a couple Swastikas!
If you look at the diagram, the intake line connected to the solenoid would be under pressure. The intake manifold line would be under vacuum (if the throttle is suddenly closed). The solenoid is just the ECU determining when this happens rather than just physics. I didn't bypass the Solenoid although the Solstice guys did. I just bypassed the tank (which they didn't have in the first place unless the later models do)
I noticed you have an HKS BOV and Hahn block off plate. Yours might already be bypassed. Can you take a pic of yours and post it up?
I don't really recommend bypassing the solenoid like the Solstice guys did. (The pic with the 'T' connection) As someone told me, "it might save your bacon if something goes wrong."
Alright... hahaha.. I'm diagram happy and I suck at it! Here's another. This shows what I think the solenoid is doing. I could be wrong but I don't know what else it would be doing. It's just switching between positive and negative pressure to control the BPV.
I'm one line away from making a couple Swastikas!
10-09-2009, 08:10 AM
#87
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i didnt this yesterday. i didnt notice anything huge but im deffinetly spiking 24lbs and holding 21-22lbs where before i was only holding 20lbs third also feels a little bit better too
10-09-2009, 10:08 AM
#88
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10-09-2009, 11:58 AM
#89
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We need a good name for this mod so we don't lose face infront of other car geeks, instead of calling it a "bypass valve boost vacuum tube delete mod" which sounds like we have no idea what we are doing.
I suggest "Loop-back mod"
I suggest "Loop-back mod"
10-09-2009, 12:22 PM
#90
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It's basically a Vacuum tank bypass.
10-09-2009, 12:46 PM
#92
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someone needs to put vids up of the sound difference/ reaction time difference
and how will this react with the dejon spring and a tune?
and how will this react with the dejon spring and a tune?
Last edited by purplehaze03; 10-09-2009 at 12:46 PM. Reason: Automerged Doublepost
10-09-2009, 02:34 PM
#93
I took a mini-trip yesterday. Drove about 4 hours. To me it seems like it has more power down low at part throttle (ie - 2K rpm) and the power is smooth.
10-09-2009, 02:39 PM
#94
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I did this to my car an hour ago but I have not driven it yet. If it works great I am going to permently remove the Vacuum cannister. Why did GM put it there in the first place on our version of the LNF? Were is Bill the engineer when we need him?
10-09-2009, 02:46 PM
#95
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i did this and the check engine did not go away p2261. do i have to take off the tank completely, or do i need to put the stock bpv spring back in because i have the dejon spring and i am running a hks and it makes weird noises. after i change the hoses around the car did run better!!
10-09-2009, 02:48 PM
#96
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i did this and the check engine did not go away p2261. do i have to take off the tank completely, or do i need to put the stock bpv spring back in because i have the dejon spring and i am running a hks and it makes weird noises. after i change the hoses around the car did run better!!
10-09-2009, 02:55 PM
#97
i did this and the check engine did not go away p2261. do i have to take off the tank completely, or do i need to put the stock bpv spring back in because i have the dejon spring and i am running a hks and it makes weird noises. after i change the hoses around the car did run better!!
Do we really need to shorten the hose? Or just take one end off the tank and just use the existing longer hose?
Or would it be better to get new hose at O'Reilly or Autozone?
Last edited by umrdyldo; 10-09-2009 at 02:55 PM. Reason: Automerged Doublepost
10-09-2009, 03:40 PM
#98
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I just used a 6 inch piece of 7/16th's and was done in less than 5 minutes . If you want to use one of the hoses off the tank it shouldn't make too much of a difference.
Last edited by rukkee; 10-10-2009 at 02:36 PM.
10-09-2009, 04:18 PM
#100
I always wondered where that line went under the intake.
I did this to my car an hour ago but I have not driven it yet. If it works great I am going to permently remove the Vacuum cannister. Why did GM put it there in the first place on our version of the LNF? Were is Bill the engineer when we need him?
I did this to my car an hour ago but I have not driven it yet. If it works great I am going to permently remove the Vacuum cannister. Why did GM put it there in the first place on our version of the LNF? Were is Bill the engineer when we need him?
I think the EASIEST way would be to just buy a small chunk of hose. It'll be extremely easy to reverse the mod that way too.
i did this and the check engine did not go away p2261. do i have to take off the tank completely, or do i need to put the stock bpv spring back in because i have the dejon spring and i am running a hks and it makes weird noises. after i change the hoses around the car did run better!!
You have a lot of aftermarket stuff. I'm guessing either something is not connected correctly or you have a vacuum leak and it's not pulling enough vacuum to open the BPV.
You should get a pic up so we can have a look.
EDIT: on second though I'm with umrdyldo. I had the spring for a while and it didn't cause problems but I had everything else stock. I'd put the stock spring in like umrdyldo said and see if that takes care of it.
Last edited by Zander916; 10-09-2009 at 04:22 PM. Reason: Automerged Doublepost