GT500 bypas valve TECH question

[GreenTerror]

Hoping that a detailed routing and guide for this will be available soon

 

[v6tungsten]

so the vacuum side it the DS cam cover to the PS Supercharger connection?

putting a 3/8 reducer on that?

 

[Powered by Ford]

OK to clear up a few things on how the vacuum hoses should be routed I have created a vacuum diagram (attachment "slide 1"). We hooked up a DOB supercharger setup like this tonight. After studying both the GT500 and 3V PCV and vacuum systems (then double checking Roush) this is how it should be completed.

I will make a better diagram for Jason's instructions.

One note: you do not have to hook up the lower nipple on the bypass valve to the intake tube, it can simply vent to atmosphere if you desire.

I have also uploaded a PDF document that shows the PCV systems for GT500 and 3V GT. You will see they are very similar systems. For the GT500 you will not need the EGR vacuum lines since there is not one equipped. Also the passenger side vacuum fittings/nipples are not needed for DOB. They can be plugged.

DiMora - can you verify you have it routed/installed in this manner?

 

[DiMora]

OK to clear up a few things on how the vacuum hoses should be routed I have created a vacuum diagram (attachment "slide 1"). We hooked up a DOB supercharger setup like this tonight. After studying both the GT500 and 3V PCV and vacuum systems (then double checking Roush) this is how it should be completed.

I will make a better diagram for Jason's instructions.

One note: you do not have to hook up the lower nipple on the bypass valve to the intake tube, it can simply vent to atmosphere if you desire.

I have also uploaded a PDF document that shows the PCV systems for GT500 and 3V GT. You will see they are very similar systems. For the GT500 you will not need the EGR vacuum lines since there is not one equipped. Also the passenger side vacuum fittings/nipples are not needed for DOB. They can be plugged.

DiMora - can you verify you have it routed/installed in this manner?

No, not doing it that way.

We are doing it the Roush way, with one exception: Since we have the GT500 hose that hooks the lower bypass nipple to the air inlet tube, we are using it.

I am not a believer in using a T fitting to feed the upper bypass nipple a vac/boost signal from the DOB manifold, since neither Roush or GT500 use that routing, and I don't see why the bypass needs boost.

Our current connections are (BTW, this is identical to the routing on my Roush TVS setup on my GT, save for the lower bypass nipple to inlet air tube):

VMV to DS elbow
Brake booster to T fitting to supercharger elbow
The above T feeds the bypass valve upper nipple
lower bypass valve nipple to air inlet tube ( optional, not required)
DOB manifold to IPTS
air inlet tube to PS PCV inlet on PS cam cover
DS PCV outlet to PS PCV inlet on PS SC
vacuum caps on SC aft 90 tube and PS SC small nipple ( On my Roush TVS, the aft SC 90 is the "PCV bubbler" line)
PCV blocked off

Alternate routing we tried with no change to howling sound:

Same as above, but we routed the bypass valve upper nipple to the PS SC small nipple (same as the GT500).

Please note that in both the GT500 routing diagram you posted above, as well as on my Roush TVS, the manifold has an un-interrupted line to the IPTS with no additional T connections.

 

[908ssp]

Then DiMora you are choosing to do it wrong.

"That’s Fords PDF…..and it is misleading. A lot of the stuff on there is not “termed” as we understand it. Stoopid Ford.

A few hours ago I was surrounded by blown 3v’s, stock GT500’s, big HP big blower GT500’s and even a 1000hp GT Supercar with carbon fiber rims!!! They all had one thing in common. The bypass valve took its vacuum/boost signal from the manifold after the supercharger.

And all but one, a stone stock GT500 had the “non signal” side of the bypass valve open to the atmosphere. On the stock GT500 it was routed to the CAI before the TB. It doesn't need to go there, Ford does it so nothing is left "open".

I think I am going to have to officially classify the subject of where the bypass valve gets its signal from."

 

[Department Of Boost]

No, not doing it that way.

We are doing it the Roush way, with one exception: Since we have the GT500 hose that hooks the lower bypass nipple to the air inlet tube, we are using it.

I am not a believer in using a T fitting to feed the upper bypass nipple a vac/boost signal from the DOB manifold, since neither Roush or GT500 use that routing, and I don't see why the bypass needs boost.

Our current connections are (BTW, this is identical to the routing on my Roush TVS setup on my GT, save for the lower bypass nipple to inlet air tube):

VMV to DS elbow
Brake booster to T fitting to supercharger elbow
The above T feeds the bypass valve upper nipple
lower bypass valve nipple to air inlet tube ( optional, not required)
DOB manifold to IPTS
air inlet tube to PS PCV inlet on PS cam cover
DS PCV outlet to PS PCV inlet on PS SC
vacuum caps on SC aft 90 tube and PS SC small nipple ( On my Roush TVS, the aft SC 90 is the "PCV bubbler" line)
PCV blocked off

Alternate routing we tried with no change to howling sound:

Same as above, but we routed the bypass valve upper nipple to the PS SC small nipple (same as the GT500).

Please note that in both the GT500 routing diagram you posted above, as well as on my Roush TVS, the manifold has an un-interrupted line to the IPTS with no additional T connections.

The official DOB recommendation is to signal the bypass valve with post supercharger vacuum/boost (supplied by fitting next to IAT sensor). And leave the other port on the valve open to the atmosphere.

It is the owners choice to plumb their supercharger however they want. But if they do, their performance/results are their own.

 

[v6tungsten]

I tried the reducer on the DS vacuum line that connects to the PS Supercharger and also the removing the oil cap. Mine still howls...any more suggestions?

 

[Department Of Boost]

I tried the reducer on the DS vacuum line that connects to the PS Supercharger and also the removing the oil cap. Mine still howls...any more suggestions?

All of them have a honking/howling noise at idle. In most cases hardly noticeable.

Alan’s car (the one DiMora is working on) is INCREDIBLY loud. I saw a video of it (that I can’t find, maybe he can post it). The normal intake noise is nowhere near as loud as that car. In addition to that there is something goofy going on with that car. It made over 15lbs of boost with the 12lb pulley and only 450hp. At 15lbs of boost it should be making 550+. So something is clearly not right. Is it related to the intake noise? I have no idea, there are about a million variables to work through. Until the boost issue is resolved going after the noise issue could be a waste of time though. Solving the boost issue may solve both.

With an open element air cleaner there is no way to make the intake noise “silent”. Every blower makes noise at the air filter.

There are far more cars with DOB manifolds out there not making noise than there are cars that do. And the only logical conclusion that can be drawn is that there is a variable in how all of the vacuum lines are hooked up and where. They all have the same blowers, same manifold, same elbow, same TB, etc. If most of the cars are not making noise its a reasonable conclusion that it is not because of the proceeding list of parts.

I’ve been working with a local customer on his blower install and documenting it so instructions, diagrams, etc can be made. They will be completed by the end of the week. I’m hoping that if everyone is hooking everything up the same way they will all get the same results.

Of course the use of different CAI’s will change things a bit, but I’m guessing that will effect tone more than actual volume.

 

[v6tungsten]

Last week u said it wasn't my jlt intake since yours didnt make noise. I have my vacuum lines connected correct. I've seen several post talking about it. My previous post on this discussion has my layout. I do have acatch can on the intake but it was there before withk an opken intake. my khowl is coming from the back OK the super charger. I have no problem changing intakes if it will reduce or remove the howling

 

[Department Of Boost]

Last week u said it wasn't my jlt intake since yours didnt make noise. I have my vacuum lines connected correct. I've seen several post talking about it. My previous post on this discussion has my layout. I do have acatch can on the intake but it was there before withk an opken intake. my khowl is coming from the back OK the super charger. I have no problem changing intakes if it will reduce or remove the howling

That still leaves about 14 million variables. Maybe lots of pictures and some video would help???

 

[v6tungsten]

That still leaves about 14 million variables. Maybe lots of pictures and some video would help???

happens at 25/26 sec. This is the car idling no throttle input. It gets louder on the road with throttle input.

http://www.youtube.com/watch?v=LNF-vXLc1s4&feature=plcp

 

[Department Of Boost]

happens at 25/26 sec. This is the car idling to throttle input. It gets louder on the road with throttle input.

http://www.youtube.com/watch?v=LNF-vXLc1s4&feature=plcp

I can hear a little intake noise, but that is nothing like Alan’s car was. His was LOUD!

The video/audio is not too clear. From what I can hear I would call that normal. It will never have zero intake noise with a CAI and open air filer. At the end of the day you still have two rotors spinning very fast (even at idle) at the end of a large tube. There is no way it won’t have sound coming out of the air filter.

We are working right now with a local car on a “official” hose routing recommendation. It will be done in a few days. If you want to explore reducing the intake noise as much as possible let me know. I can see from the video that you aren’t hooked up quite like we are.

 

[v6tungsten]

I can hear a little intake noise, but that is nothing like Alan’s car was. His was LOUD!

The video/audio is not too clear. From what I can hear I would call that normal. It will never have zero intake noise with a CAI and open air filer. At the end of the day you still have two rotors spinning very fast (even at idle) at the end of a large tube. There is no way it won’t have sound coming out of the air filter.

We are working right now with a local car on a “official” hose routing recommendation. It will be done in a few days. If you want to explore reducing the intake noise as much as possible let me know. I can see from the video that you aren’t hooked up quite like we are.

I do want to reduce the howling or "honking" as I call it. what about my hookup is different? The the noise I'm complaining about is only at the 25/26 second mark and sound like a honking noise. Its louder in the car while driving. It's not the intake noise during the complete video i'm worried about. My carpool buddy doesnt think its normal either. I had a V6 mustang with the xcharger and open filter and never has that howling/honking.

 

[PLee]

What confuses me is that here in THIS very thread, alternative suggestions to the hose routing have been provided, which JUST MIGHT solve this rare howling problem. WHY NOT TRY IT? Is vac hose made of unobtanium? Last time I checked it sure wasn't expensive. If nothing else is working, seems to me it's time to try something different.

Second thing- I noticed while installing mine that the blower gasket is a tough son-of-a-gun to get fully seated into the machined groove- just a tight fit by design. Sure, it rests in the channel nicely, but it should be seated firmly all the way down into the channel. I'm wondering if you're experiencing any sort of leak?

 

[Department Of Boost]

I do want to reduce the howling. what about my hookup is different? and the noise I'm complaining about is only at the 25/26 second mark.

I heard it, but as far as intake noise goes that is by no means loud when you factor it in with all the other intake noises out there.

My carpool buddy doesnt think its normal either. I had a V6 mustang with the xcharger and open filter and never has that howling.

Different blower, different CAI, probably different hose routing, etc, etc, etc. Your comparing apples to oranges. My KB makes all sorts of noise out of the air filter, a different noise, but a lot of it. I heard a Terminator with a 2.3 Whipple yesterday at my tuners and it made all sorts of noise through the intake too. Different than my KB and different than the GT500/DOB setup, but a lot of noise. Different combo’s, different noises.

I’m working on that local car and experimenting with different hose setups for the best sound. Once it is completed I will have a diagram made up in CAD so it is easy to follow (thanks to Matt T) and you can give that arrangement a try. It will be done in a few days.

I doubt there is anything “wrong” with your setup right now. But it wouldn’t be a bad idea to check that blower O-ring/gasket, make sure it is seated correctly and lube it before you put the blower back down. Then you should check for vacuum/boost leaks with the old school “carb clean” method or the “smoke” method. There are potentially 20+ points where there could be a leak. And one could make for some weird tones/noises. They need to be checked.

 

[v6tungsten]

What confuses me is that here in THIS very thread, alternative suggestions to the hose routing have been provided, which JUST MIGHT solve this rare howling problem. WHY NOT TRY IT? Is vac hose made of unobtanium? Last time I checked it sure wasn't expensive. If nothing else is working, seems to me it's time to try something different.

Second thing- I noticed while installing mine that the blower gasket is a tough son-of-a-gun to get fully seated into the machined groove- just a tight fit by design. Sure, it rests in the channel nicely, but it should be seated firmly all the way down into the channel. I'm wondering if you're experiencing any sort of leak?

The only thing different is the brake boost and DS connected to the elbow in this post. I connected mine as directed on the other forum months ago. I guess i can try to move the hoses. My supercharger gasket was installed with a screen door tool so i'm guessing it was and seated completely. Actually i've removed the supercharger once already to check that gasket. also used Gasket maker on the two front bolts holes as directed.

 

[DiMora]

All of them have a honking/howling noise at idle. In most cases hardly noticeable.

Alan’s car (the one DiMora is working on) is INCREDIBLY loud. I saw a video of it (that I can’t find, maybe he can post it). The normal intake noise is nowhere near as loud as that car. In addition to that there is something goofy going on with that car. It made over 15lbs of boost with the 12lb pulley and only 450hp. At 15lbs of boost it should be making 550+. So something is clearly not right. Is it related to the intake noise? I have no idea, there are about a million variables to work through. Until the boost issue is resolved going after the noise issue could be a waste of time though. Solving the boost issue may solve both.

With an open element air cleaner there is no way to make the intake noise “silent”. Every blower makes noise at the air filter.

There are far more cars with DOB manifolds out there not making noise than there are cars that do. And the only logical conclusion that can be drawn is that there is a variable in how all of the vacuum lines are hooked up and where. They all have the same blowers, same manifold, same elbow, same TB, etc. If most of the cars are not making noise its a reasonable conclusion that it is not because of the proceeding list of parts.

I’ve been working with a local customer on his blower install and documenting it so instructions, diagrams, etc can be made. They will be completed by the end of the week. I’m hoping that if everyone is hooking everything up the same way they will all get the same results.

Of course the use of different CAI’s will change things a bit, but I’m guessing that will effect tone more than actual volume.

The honking /howling is not caused by the vacuum line routing. Go look at any GT500. We duplicated that routing identically, and we also duplicated the Roush routing.

We can try the DOB boost/vac method, but I am positive it will not stop the honk. I'll report back if we try it and I am wrong. Don't guys who have the bypass hooked up to a T off the manifold still have noise?

One theory I have, besides the manifold itself, is to make sure the EGR blockoff is sealed. Alan may add some RTV to his.

I'll contact Eaton /Roush this week and inquire about bypass valves receiving boost.

Alan's car is fine now on the 3" snout pulley...it makes low 400's and peaks at 12-13 PSI.

The low power at high PSI was due to too small a snout pulley with stock exhaust, and the tuner kept it very rich with low timing to keep it from detonating - 15 PSI is a time-bomb on stock internals. As you know, you cannot tune boost down on a supercharged car - you must swap pulleys.

The honk is much better; a lot of it on the first-start video was because the start-up tune wasn't quite right (tuner didn't account for GT500 throttle body); once it went into closed loop and the ECM took over it sounded a lot better.

I'll post the vid next week ( on vacation now).

On the subject of pulleys: There is no such thing as a "12 pound pulley"; the boost you make is a function of your other mods. In Alan's case, his car was bone stock, so he made 15 pounds with a 2.65" pulley. With longtubes and no cats or hugh-flow cats, yes, he would have made 12.

Anyone adding a DOB to a stock car needs to order a 3" pulley unless you want 15 PSI.

 

[DiMora]

What confuses me is that here in THIS very thread, alternative suggestions to the hose routing have been provided, which JUST MIGHT solve this rare howling problem. WHY NOT TRY IT? Is vac hose made of unobtanium? Last time I checked it sure wasn't expensive. If nothing else is working, seems to me it's time to try something different.

Second thing- I noticed while installing mine that the blower gasket is a tough son-of-a-gun to get fully seated into the machined groove- just a tight fit by design. Sure, it rests in the channel nicely, but it should be seated firmly all the way down into the channel. I'm wondering if you're experiencing any sort of leak?

It's a closed system: It is simple vacuum and boost. Air is not flowing rapidly through any of the vacuum connections, nor the bypass actuator.

I'll ask Alan to try the DOB method just to put this one to bed. I'll bet you a Fresca it makes zero difference in the howl.

 

[v6tungsten]

I installed the new vacuum routing as directed and removed.reinstalled the EGR block off with gasket maker.

NO change in the honking noise. Looks like I might go back to stock after August. Not messing with the car in 105 degree temps.

 

[Department Of Boost]

I installed the new vacuum routing as directed and removed.reinstalled the EGR block off with gasket maker.

I haven’t completed the hose routing and just as important “construction” diagrams yet. Until you try that combination and done it exactly as directed I wouldn’t call it quits.

NO change in the honking noise. Looks like I might go back to stock after August.

That’s just silly. You will find out what is making the noise and it will be something stupid. I'll get you figured out if it kills me.

Not messing with the car in 105 degree temps.

I agree with you there. Putting a trans in a car that gets driven/heat soaked first tomorrow. It's going to be 100. Oh joy!