Wastegate Single turbo selection

[Ukfox89]

Genlteman

what size waste gates you guys running? i have C&G single turbo setup 7675CEA turbo. stock longblock and tuned the car on 22psi which was just wastegate spring, 19.5psi spring. has been very consistant all year with slight drift. last pass of the year i was pegging my boost gauge over 30psi which im assuming was due to the cold air and very very low DA. i have a single 46mm wastegate and im assuming the wastegate is acting as a restriction and causing the turbo to still spool.

boost reference on my turbo is going to the lower port on my wastegate. as soon as the wwastegate sees 19.5psi the wastegate is open, i can hear the gate opening, but its over boosting like crazy. enough to blow my elbow off the Throttle body.

Any help would be appreciated. Thanks,

 

[Nightmare302]

What brand is it? I've used a single 38mm and had no issues. The only time you should have issues is when you are trying to control it way down.

 

[crfrider16]

There's no way a 46mm gate is a restriction. Are you using a boost controller? I'd check the diaphragm and vacuum lines for leaks.

 

[Ukfox89]

its a precision 46mm wastegate. has a 18psi spring with a 1.5 psi spring, made 22psi all year with no issues. last day of the year at the track, 68 DA and cool weather, was pegging my boost gauge. no boost controlle rbut why would that matter. once the boost reference line sees enough pressure to open the wastegate, it opens. you can hear the wastegate opening. once the wastegate is open there should be no pressure int eh exhaust causing the turbo to not build anymore boost. boost reference line looks fine and wastegate diaphragm was all in tact and looks fine. i think the position of the wastegate and the size of it makes a difference. if the wastegate cant expell all the exhaust gases fast enough, it will cause the turbo to surely over boost. why else would it do it when theres very dense air?