long pull boost drop off?

[Beauford t]

I set up at 16psi boost, hits it at will, trail up, boon-docking and not too long climbs no problem!!
On long hard pulls it will drop off to 10psi? I was even turning the boost controller up as I climbed but it wouldn't move on the gauge?
After I came back down it was hitting 16 again.
Under normal conditions turned right down I only get as low as 12psi.

Would heat soaking the turbo cause this?
Something cracked or lose?? but why only on long pulls?
I noticed the muffler outlet was sorta half closed off, could that cause too much back pressure and kill the boost?

Any ideas would be great!!

Thanks

 

[Wheel House Motorsports]

that my friend is called an exhaust leak, pressure test everything turbo intake to downpipe and start sealing.

 

[Beauford t]

So the best place to start looking is from the head to the turbo?
Pull it all apart and reassemble with some sort of goop ??
Whats the best sealer to use?

 

[Wheel House Motorsports]

the red silicone RTV works good for normally gasketed joints. cap the turbo inlet and downpipe, add air pressure to the system and hold it at 10psi and listen for all the leaks,

im betting you have a pipe crack or something stupid. also, if exhaust donuts are worn down to the wires they leak like crazy.

 

[Iceman56]

http://www.snowestonline.com/forum/showthread.php?t=162905

This thread might help ya make one. You almost have to do a pressure test or you won't be able to guess where it is leaking. Best to cap or plug the exhaust side too so everything in the system is plugged and should be air tight. Use soapy water and spray bottle spray on all boots and every exhaust connection once you have it pressurized.

 

[Beauford t]

Thanks!
That looks good for intake tract leaks!
I'll use some reverse engineering to check the exhaust side. Pull the muffler off and clamp the valve stem plug there?
Valve over lap should get the pressure to the gauge...right??

Does any one know if there is any place that is prone to cracking on a powderlites stage two? Where on the header? Air to air??

I need a new TAPP so I'll call them today and see what they think?

Kevin

 

[Iceman56]

Thanks!
That looks good for intake tract leaks!
I'll use some reverse engineering to check the exhaust side. Pull the muffler off and clamp the valve stem plug there?
Valve over lap should get the pressure to the gauge...right??

Does any one know if there is any place that is prone to cracking on a powderlites stage two? Where on the header? Air to air??

I need a new TAPP so I'll call them today and see what they think?

Kevin

No, just either plug or cap the exhaust where you take the muffler off. Pressurize at the turbo inlet like in that thread, the air will travel in the motor and out the valves, through header and exhaust side of turbo. pressurizing the whole system from turbo inlet to exhaust.

 

[Beauford t]

Got some new gaskets coming.
Thanks powderlites! Great to deal with on the phone!!
I think the turbo flange was slightly concave when I had it apart last summer,I didn't think anything of it at the time, but I bet the (used) gasket failed there as there are a few cases of turbo flanges warping....

 

[Beauford t]

What is the fastest drying sealer to put on the gaskets?
I wana do the job the day I get home and ride the next morning??
How would gasgacinch hold up to the heat??