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Think my wastegates are too small?
LS1 stroked to 383, stage 3 turbo cam, lsxr102, etc..
Twin Garrett GTW3684R's (62mm) .83AR housing
Currently I have 2 Tial MV-s 38mm
took for first run this weekend... 7lb spring in wastegate and got to 26lbs twice before blowing charge pipe off
My goal was going to 20 tops - good news it lived and hauled *** at 26lbs for the first 200 feet So thinking my wastegates are too small and pondering what to get next. Thinking 50mm per side? Keep in mind space is limited under the engine.
Turbos are Vband mounted direct to the manifolds pictured and tucked under engine
Wastegates are placed as in picture (purple)
And the datalog is from one of the runs with exhaust backpressure, dome pressure and boost... Target dome was 0psi but guess the solenoid was holding some pressure, but not much
Update.. pulled gates and tested.. I had a plug in top as I am running CO2.. well it was stopping gate at about 1/3 travel. Think this will fix it.
I hope that helps. Looking at the position/angle of the wastegate, it's not going to get much priority and would tend to not open reliably with anything other than a super light spring. On my own twin setup, due to space restrictions, I had only a slight angle off the manifold. The boost went up to near 30psi(29.5 is all my boost controller will record) one of the first times I took it out with 14# springs in each of the Tial 38mm wastegates. I eventually went down to 3lb springs and a 3 port MAC to keep the boost as safe levels.
I hope that helps. Looking at the position/angle of the wastegate, it's not going to get much priority and would tend to not open reliably with anything other than a super light spring. On my own twin setup, due to space restrictions, I had only a slight angle off the manifold. The boost went up to near 30psi(29.5 is all my boost controller will record) one of the first times I took it out with 14# springs in each of the Tial 38mm wastegates. I eventually went down to 3lb springs and a 3 port MAC to keep the boost as safe levels.
Crossing my fingers on placement because there aren't many other options at this point.. it is a little lower than my drawing as my goal was at least 2 of the cylinders had a straight shot out wastegate as opposed to turning to turbo.. all theory
i am running a 7lb spring with CO2 on top and holley to control so assuming they vent ok I should have plenty of range.
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Help with wastegate diagnosis - found it 
