drewblueeye

If you are reading this then more than likely you have the same problem that i have been dealing with for the past year. That is that you bought an aftermarket LICP and installed it. Then 'T'ed into the hose from your BOV to the Intake manifold. So then you notice that if you WOT there is no problem, but if you try to slowly build boost or try to hold your boost above 7psi but not WOT, then you get a BOV flutter and you lose all boost in a matter of seconds.
Well the reason is because you 'T'ed into the BOV hose and the bleeder valve on the MBC is releasing air.
OK let’s skip the turbo lesson and just fix the problem. Now this is what I did to fix it, I took the advice from another EvolutionM.net member, I did what they said they did and it worked. So I thought I would share with a How to.

First go out and buy some supplies. buy Red Loctite, a 7/16" Drill bit, a 1/8" NPT Tap, and a 1/4" ID Hose Barb X 1/8" M NPT Solid Brass Fitting (it sounds confusing, but go to your local hardware store, they should have it).

Here are the steps; Pictures are attached below, in order

1. Remove the Aftermarket Turbo outlet pipe (Part of your LICP)

2. Mark a hole on your Aftermarket Turbo outlet pipe, in the same place that your stock nipple is located on your factory turbo outlet pipe.

3. Take a punch and a hammer and center it on the mark you just made and tap it until it makes a small notch, just deep enough to keep your drill bit from sliding off the mark.

4. Drill a 7/16" hole in the pipe. You want the hole a little smaller than the hole you are tapping so that you get some good threads.

5. Take your 1/8" NPT tap and tap the hole. When tapping the hole you should only run your tap in about half way (about an inch). That way your barb fitting doesn’t bottom out.

drewblueeye

6. Take a file and file off the rough edges around the hold you just tapped. Once they are smoothed out it would be a good idea to run the tap in again to clean up the edges. The same distance about an inch.

7. Now take a rag or a shop towel and wipe around and inside the tapped hole. Just make sure the metal shavings are gone. (It would probably be a good idea to clean out the turbo outlet pipe, to make sure all shavings are gone)

8. Ok, now take you Red loctite and coat the bottom half of the threads of the Barb fitting. (Make sure to only do the bottom half of the threads because when you thread in the barb fitting there will be a lot of extra loctite)

9. Thread in the fitting into the hole that you tapped inn the turbo outlet pipe. Once hand tight then take a wrench and turn it about 1/2 a turn more. Just until it is snug, the loctite will hold it in. DO NOT OVER TIGHTEN THE FITTING OR YOU COULD STRIP OUT THE THREADS YOU JUST TAPPED, AND THAT WOULD BE BAD!!

10. Wipe off the extra loctite on top of the pipe.

11. Now take it inside your house or keep it somewhere warm for 24 hours. I put mine on one of my vents in my house. Just keep it at around 70 degrees or more.

12. When 24 hours is up. Install the turbo outlet pipe back on your car. Do a boost leak test (which you should be familiar with). Once there is no leaks go have fun boosting at any psi you want to again.

Roldy

I don't understand how this fixes that problem? Can you please explain.

superscout03

iTrader: (3)

Its alot better if you weld it on, so you dont have half of the threads from the nipple on the inside of the piping. The thickness of the piping is not good for threading, after time from heat expansion its going to be leaking. I would take it to a good welder and get a steel nipple welded on. it only takes a few seconds to weld it on first and then drill out the hole.

whitey4d

iTrader: (1)

Instead of doing all that work I just used the nipple on the turbo outlet thats stock.. then I used the BOV line for my MBC. That way there is no drilling tapping etc etc. Also for the second Q. Greddy valves and some others have 2 vacuum ports one for manifold vacuum/boost and the other just for a boost source with out vacuum. It works alot better then that stupid Single Spring Mod.

Evoryder

iTrader: (55)

I have both the single spring + the pressure source mod...this is a little much...but nice write up

AfireINSIDE

iTrader: (10)

Will this help me?!?! I have a ATP GT3076 turbo, Forge BOV, stock upper ICP, Custom licp, and I dont have the nipple on the turbo that most people use for their source because it is a Garrett GT30 series. I have been using the intake side vac line so far but feels like its hard to build boost and flutters like crazy at low rpm/boost. Is this what I have needed all this time??

drewblueeye

People wondering why exactly this can fix the sputter.


Here is what Mike@forge wrote me:

Here's a little tidbit for you guys to chew on:

If the boost controller and bypass valve share the same reference from the intake manifold, you can figure that they are essentially sharing the same volume of air (pressure/vacuum).

When the boost controller (lock-ball-and-spring type) actuates, meaning when the spring allows the ball to come off of it's seat and send the pressure signal to the actuator or external wastegate, some of the "shared" pressure helping to hold the bypass/blow-off valve closed under boost is now momentarily diverted to the actuator or wastegate potentially causing a "flutter" in the seal surface of the bypass valve and a slight loss of boost pressure altogether within the system.

When the boost controller and bypass valve each have their own individual reference from the intake manifold, the possibility for this flutter is greatly decreased, however, it may still exist to some extent because both references are still sharing a given volume of intake manifold pressure.

It is always highly recommend to ensure that any boost controller is referenced from the turbo outlet nipple where available, or from the intercooler piping before the throttle body if no turbo outlet nipple exists.

This is also important in that the boost controller only ever needs to see a positive pressure reference, and never vacuum.

Boost Controller
Positive Pressure Only
(Turbo Outlet)

Bypass/Blow-Off Valve
Positive Pressure AND Vacuum
(Intake Manifold)

drewblueeye

Also the reason i didnt take it to a welding shop to get a nipple welded on is because every shop i called said they wanted to keep the pipe for 3 to 5 days because they are all backed up on work. I am from Sioux City, Ia, there isnt alot of welding shops that will/can weld intercooler piping. And i did a boost leak test and there was no leaks, and the person that shared this with me did this to his and he said he hasnt had any leaks. Hey i am just giving people some options.

MitsuJoe

iTrader: (133)

So the MBC should use a pre throttle-body boost source

And the BOV should use a post throttle-body boost source


Is this what I understand here?

Tapeworm

I have this exact same problem as well. I have Buschur stages 1-3, and their LICP doesn't have a nipple like the stock one does. I didn't use their MBC controller though, opting to go for a Greddy Profec Spec II instead so I can adjust the boost while driving. One advantage of the Greddy is that it keeps the wastegate bypass closed valve to minimize 'spool up' time until a certain boost pressure is reached - in my case, I have this set for 15psi.

I get bad flutter in high gears when you slightly let off the gas after boosting less than about 5psi, but I don't understand how your solution would help me? The Greddy controller won't start cycling it's boost control valve until it senses more than 15psi, so in effect, in my car the BOV is connected directly to the same vacuume source it would be in a stock car - the boost controller should not be affecting this as it has not started cycling at such low psi.

Because of this, I wonder if BOV flutter is a more subtle problem, like hose diameter, mounting position of the BOV, horizontal vs. vertical mounting, restrictors being required in the hoses etc...? Even if I had a nipple welded as you have done, I can only see this affecting the BOV by being more accurate at maximum boost (as it's not seeing a fluctuating air pressure being caused by the boost controller cycling). I have read elsewhere on this board that when people have BOV flutter, some have tried unsuccessfully multiple vendors adjustable BOV's and still had the problem - so I don't want to go down this route either.

I'm having a hard time believing that respectable component suppliers who have access to dyno's and can fabricate parts easily have not identified and found a 100% fix for this problem yet.

One other data point - My car is a 2006 IX MR, so it's BOV is already 'one of the good ones' and the car never had flutter as stock, when I added all the components (intake, exhaust, intercooler and piping) the problem started and was initially pretty minor. I then got my ECU flashed and the problem is *much* more pronounced. I'm not saying the flash is responsible, I just believe that the engine running more 'efficiently' (ie: with a better tune) has the ability to make this problem worse.

Andy

Evotech8

iTrader: (4)

Nice write up ....I did the same thing to my BR turbo outlet pipe.
After two years of boosting 26psi no leaks with this simple mod.

AfireINSIDE

iTrader: (10)

I may have to do it this way...... I can only find the 1/4 fitting in aluminum (not able to weld) and brass (have to braze) I just dont like the possibility of leaks..........

AfireINSIDE

iTrader: (10)

ok why use the RED lock tite?

blackbichGSX

iTrader: (19)

I did the same thing, but I went to a hydrolics line place and bought a 1/8 NPT SS coupler. Then I had cut it in half and made a bung (lathe), you dont have to cut it in half if you dont want to. Then welded it onto the pipe. This way I have tons of threads instead of having 2 on the pipe. Nice write up. I did not know this was a common problem.