Sometimes in town when i lay into her i can see boost spike up to 30 psi but it drops off fast. Is it safe to apply some brake pressure in town to simulate a load? or what should i see for boost. If im on highway and i lay into her should i see boost go 23,25,30,34,35,33,33,33,,33 etc...

or should it just go 23,26,30,20,16,10,etc.......

mine seems to do the ladder of the 2



"Sorry for the threads"

 

As soon as the t/C locks up, lay into it. If it goes to 35+ and drops off, your waste gate opened.

 

is that good? do you want your wastegate to open?i mean like you do want it to open later?

why is it that when i pinch my wastegate line i get more boost longer? doesnt it need that air in line to open it or to keep it closed?if i pinch line wastegate should never open right? or is it spring relief?

 

Unless you need more air because of a power adder of some sorts, then yeah you want it to open. It helps prevent a head gasket failure because the factory is to lame to put studs in right off the bat. When you clamp the hose, it blocks off pressure and prevents the waste gate from opening.

 

Wastegate will never open if you pinch the line shut. That is true until you are so severely overfueled that you make 60 psi of exhaust pressure and it overcomes the spring strength in the actuator and blows open.

When your wastegate opens naturally, or how it should under stock conditions, the ecm reads boost in excess of 26-32 psi and sends voltage to the black solenoid to start to pull back it's little rubber plug and allow boosted air to run down the silicone hose to the round actuator head. This air pushes an internal rubber bladder that relieves/ overcomes spring tension so that the rod starts to extend. The more the rod moves out, the farther the internal 1-1/4" round flapper opens. Keep in mind that exhaust has pressure too, and it pushes on the system by pressing against the flapper trying to open it as well. So, if you were experimenting with some regulated shop air and put say 26 psi into the little silicone hose and the rod started to extend, that is not necessarily where the wastegate will open. Remember there is exhaust pressure trying to blow open the wastegate so in the real world, your wastegate may "start" to open when only 20 psi is present in the silicone hose. And thus the exhaust pressure is making up the other "6 psi" worth of force required to make the rod extend. As with all springs, the more you compress, the more tension it takes takes to further compress. So, maybe the rod starts to move at 26 psi but it may take 34 psi to fully extend the rod. Under normal driving, the wastegate does not need to fully open because when it opens just a little, it bypasses exhaust driving energy and slows down the shaft-compressor enough limit boost.

But, lets say you have an older truck like me 99'. With the Quad Adrenaline turned up, my waste gate fully opens at 26 psi boost but the wastegate is too small to bypass enough exhaust, thus there is still enough driving exhaust energy to speed up the shaft-compressor even further and I can hit 40 psi boost, even though the wastegate is fully open.

Sallyman, I personally think that since you have high egts at normal boost/ normal HP levels, you either need to:

1. Get a rail pressure gauge to see if your pressure is too low and not atomizing the fuel properly.

2. Figure out how to check out your injectors to see if one or more of them has problems and is not fueling properly. There is no reason to have 1400* with an empty truck in the winter time. I have a hard time hitting 1400* in the winter time with my excessively overfueled setup. By hard time, I mean I have to break the speed limit to see high egts empty when it is below freezing outside.

 

And I'm pushing more HP than you with a smaller less efficient turbo! Something just doesn't add up. Did you buy the truck new? Does it still have stock injectors?

 

Maybe your lift pump went out and your CP3 is starving for fuel and is not keeping your rail up to snuff. Or, maybe your CP3 is bad. Or maybe you got some bad Canadian Diesel and you smoked an injector. Just ideas.

 

injector? its all electronic. if an injector wasnt working id get a code.what rail pressure should I have?23,000 psi and how much before cp3? 10 psi