Nice truck man.... Hope you get it worked out !

Pitt

 

Just wondering if you figured anything out with it.

 

x10 That is a great looking truck. Love that body config.

 

the way i am thinkin is the turbo cant be a restriction cause he is making more boost now than before. think the right idea has been mentioned with the exhaust side, particularly the housing. maybe he needs a larger exhaust housing to flow more air. could be reaching a flow limit causing backpressure buildup. as we all know, boost is merely a measure of restriction. supercharger still pushing boost in but cant get exhaust out pass restrictive turbo. just a theory but something to look into

 

i can't beleive the 70mm will flow that much, My 6l and front mount 70mm gets real inefficient over 13-14psi - intake temps start to climb like crazy...

 

compound boost is the way to go

 

I really just haven't had time to even order the 2nd waste gate. I see where you and others are coming from but all I see is that regardless of what one would think would happen with the small turbo- it still makes to much- so I only see the problem amplifying with a bigger turbo. The supercharger also never loses its ability to suck through the turbo either, and the turbo is only needed to generate 5lbs itself. I changed to the 5.5 lb wastegate spring and it helped, just not enough. I will take it out but I think KB is right it will need a 2nd wastegate. I dropped my car off at the tuners yesterday and my goal is to have the truck ready when its time to pick up the car.

 

Did you measure back pressure?I'll bet its through the roof probably about 4 to 1.High back pressure will cripple flow.Flow makes power not boost.In all honesty another wastegate will be a bandaid of sorts you really need a cutout adjusted to allow for good spool time but, also flow enough air to keep back pressure at a minimum.

You got any specs on the cam? I.E valve events not the standard numbers people give out.

 

I took the whole 5 minutes today and totally removed the wastegate spring and to my surprise it only makes 4 psi so I assume that is only blower boost with the 5" pulley. The truck has never been so slow ! So with the blowers 4 psi and the turbo's wastegate spring only 5.5 psi it compounded to over 20 psi. Now I think Im going to try to find 1,2,3,4 lb springs for my wastegate. Does anyone no if they even make them that low or who has them? My wastegate is a Tial Sport.

 

Hummm.... That's VERY interesting. Go to you local hardware store like ACE and find the softest spring you can get to fit in the WG, just to hold it shut. Then hook you boost controller to the top port and use it to control the boost pressure and see where that gets you. You have me wanting to play with compounding again, just happened to pick up the "H" version of your blower this weekend too,