Boost vs. Drive pressure and an external gate

[oldsmokey]

Ok guys I built a set of twins using an he351 and a bht3b with a 40 mm external gate. The gate on the 351 is not being used, only the external gate. At 52 psi total boost with 24 psi from the primary I see 70 psi drive pressure this is with my smarty beta 4.3 on lv 3. Currently I have a flow controled boost to the top of the gate a medium spring and full boost to the bottom of the gate. Shouldnt the 40 mm gate be able to keep dp and boost a little closer to 1:1? Im not sure if its opening all the way. I built my twins a little differently than most, I used a 3rd gen manifold flipped not a 2nd gener, and the adaptor has a 90 degree bend as it goes into the secondary. Could this be the culpit? Here are a few pictures to show what Im talking about.

Thanks for any help guys
Joel

 

[chrleb1]

Try to use the stock gate also. You are trying to flow a lot of exhaust through a 40mm gate and a 9 cm turbo housing.

 

[oldsmokey]

Thanks Erick, do you guys sell a wastegate spring for a clocked stock turbo?

 

[chrleb1]

No i don't. Check with Shane over at wicked diesel or Nathan at MPI. Both of them have stocker over 400 kits. I don't remember of both of them clock the housings or only one of them do. Shane is gone for 2 weeks though.

 

[patracy]

Drive pressure should be blowing that stock HE351 gate open past 30psi or so. I see the electronic solenoid is gone. But the plug doesn't look like a ATS plug. Is it plugging off the boost pressure to the gate? Also do you have the gate wired shut or anything? If you've got the gate disabled like that, drill and tap the compressor housing and install a boost elbow to see what things do.

Interesting design on the external gate adapter. If I build twins I might do that as well.

 

[oldsmokey]

Drive pressure should be blowing that stock HE351 gate open past 30psi or so. I see the electronic solenoid is gone. But the plug doesn't look like a ATS plug. Is it plugging off the boost pressure to the gate? Also do you have the gate wired shut or anything? If you've got the gate disabled like that, drill and tap the compressor housing and install a boost elbow to see what things do.

Interesting design on the external gate adapter. If I build twins I might do that as well.

Its not the ats plug, I found a different one that fit. The gate on the stocker is closed with a j hook so its closed. I was hoping to just use the external gate but that might not be enough. I think im going to try and build a bracket to use the stock wastegate actuator, hopefully that will work