very strange, but i figured it out... towing the 5ver, in OD running around 60, start to go up a hill.. the boost goes up to 20 psi... very noticable "fluttering", and then the boost drops off to 10 psi and NO POWER..! but.... i heard it... the VERY loud hissing as most of my boost is dumped out of the wastegate...! i stoped on the way home, reset to "stock" setting... ugh...! no power...! but it didn't "dump" the boost, mostly because the truck downshifted before it made enough boost to dump... so i stopped again, reset the "tow" tune and plugged the wastegate acctuator back in... and it was better... the acctuator started to dump the boost sooner, less flutter, but it still did it... so.... i think i have to leave the acctuator hooked up... don't go into od unless i am running 65 or better mph, (probably much higher), and maybe look at tightening up the acctuator rod... anybody have any more suggestions...?

btw... cool temps tonight towing home... thanks to the tru-cool, the tranny temp NEVER got above 140*...! mostly ran around 120*.... and cooled right down below 100 once i stopped for a few minutes...! nice...!

 

sitting here thing about it... is it possible this is a back pressure tube/sensor problem..? if it was, wouldn't i get a trouble code..? and if it is... what is the loud "hisssssss" that i am hearing...?

 

Well John......I'm going to ask this question rather gingerly, because I havn't experienced it myself.......but have read Kwik describe it. So bear with me. When you say flutter.......did it sound like "a flag flapping in the wind"?.....or are you describing the sound from the exhaust? If it was a flag flap sound.....you may have experienced a turbo stall. It may be time for a wicked wheel. Common problem with the 99.5 to 2003 when we are moded heavy, and want to work the truck on a grade. Kwik will have to fill you in on that one.
I don't think you should have been opening the wastegate at only 20 psi. You mention that you have the wastegate mod in your signature......so I assume that you had the hose disconnected.
Another source for a hissing noise with a noticable reduction in boost.....would be a boost leak. Either a hole in one of the boots, or other kind of leak in that area. Just some thoughts.

 

If you think of the Banks kits and what they have done, it does make sense that they are used to cure the symptoms you discribed while towing with high performace tuning. Bighead actuator, wicked wheel, transcommand, zenor diode, intake, exhaust. We got around the Bighead actuator by unpluging it, and preload the actuator rod. So that leaves the wicked wheel. But as mentioned by touchofgray, it could be a simple boost leak. All you need a is WOT empty run to see if it is indeed a boost leak. If not, then the wicked wheel mentioned by our gurus may be your ticket. Again look what Banks with their tons of research has come up with for driveability with high performace chips.

 

Johnny8 you'll never hear the wastegate opening. It's port is part of the casting in the exhaust wheel. All inside of the housing. You have a boost leak.
That doesn't mean that you don't need a Wicked Wheel. TouchofGrey hit it on the head with the flag in the wind description. The WW will get rid of that and replace it with a nice big rig turbo whine. You'll still get exhaust flutter out the tailpipe.
But for now, your biggest concern is a boost leak. I would guess that one of the clamps on the orange boots has worked it's way up and partially off and the boot is only able to contain your 10psi.

 

You are definitely experiencing compressor surge, and pretty bad from the sound of it. You may also have a boost leak. You'll need a wheel or a housing or a bigger turbo to get rid of the surge.....

To check for a boost leak, go down to Lowes or Home depot, TSC, Orschlin's...wherever, and get the parts to built one of these:



Connect the big end to the intake at the CCV fitting, apply 20-25psi shop air to the fitting, open the valve and check it. If it spins the turbo you'll want to cut the air after about 20 seconds, it's not good for it t spool it up dry.

 

i agree with you guys.. i think the wheel is my big problem... what i don't understand is this... how can i run empty and get up to 27psi boost with no leaks and no letup on power or torque, but running with my 5ver she gets into it a little bit... that flag flap sound starts, gets worse and worse and the "SHHHHHHHHHH..." and half my boost, and i don't get it back till i completely letup on the throttle.... could i have a leak of some sort that seals back up...? if so, why can i run 27psi when empty and no leak... isn't boost boost..? or is there a difference between boost at higher rpm vs boost at lower rpm...? this just seems strange to me... i don't understand what is happening so it doesn't make much sense to me...

 

Now you're making me think that you have a very bad case of compressor stall and it's all just blowing back out the intake. Get that WW! You won't regret it at all.

 

is that possible...? to have your wheel stall out so bad that you loose half your boost and you can't get it back...? can that be all that is happening here, because it ONLY happens when i am running high boost at lower rpm... high boost at higher rpm is not a problem... is this stock wheel that bad...?

 

I agree......once the turbo looses the ability to make boost (stalls)........the preassure that is built up in the intercooler is blowing back out.
When you do get the wheel.......go up on Blackcloud's website, and get the instructions on how to install it WITHOUT removing the turbo. Will save a ton of time.

 

Your fuel demands are a lot higher when loaded. That means the turbo spools up at a much faster rate due to the increased drive pressure created by the extra fuel.

You know how when you're driving a screw into wood with a big power driver, and if you aren't careful instead of bottoming out the screw will just blow right through the wood and spin in place? That's kinda what happens with the turbo. It spools up so fast and hard that the intake wheel loses it's grip on the air and overspeeds

When that happens with a boat propeller it's called cavitation, we call it compressor stall, but it's basically the same thing.

At any rate, you already know what it's going to take to fix it.

 

here is what black cloud diesel's site says

We reccomend installing a high performance compressor wheel in your turbo when adding a turbo air guide to avoid turbo surge/stall.
The performance compressor wheel will Reduce or Eliminate Turbo Flutter/Surge in your 1999.5-2003 Ford Powerstroke.
Increase Airflow
Lower Exhaust Temperatures
Increase Low-End Throttle Response
For use in 1999.5 - 2003 Ford Powerstrokes <TABLE width=388 border=0><TBODY><TR><TD width=290 height=64>Superior Compressor Wheel 99.5-03 7.3L </TD></TR></TBODY></TABLE>
installation instructions- http://www.blackclouddiesel.com/Tech...on%20Guide.pdf

 

one last question then... what is this doing to my stock wheel... having all that boost running back through the compressor wheel when i'm trying to tow up a hill...? can't be good...

 

The wheel is designed to take more stress than it will ever see in normal use. Since your creating the boost pressure with the turbo.......it isn't hurt by being exposed to that same pressure coming back out. The turbo does this very same thing every time you get on it, and then back off to a lesser demand. It won't hurt it......you just need a wheel with more "bite" is all.

 

yes... i believe you are correct... too bad the wheel doesn't perform as well towing as it does when my mule is empty... just tromped on it coming home... 0-60 to going up an on ramp... my truck is faster than my old v-twin motorcycle..! of course i do have the 85hp tune loaded... wow..! that's power..! i'd love to see what this girl could do at the track..!