So heres what happened, maybe someone else will find this helpful as well. So I installed the gtx4202r on the car and due to a bit of a time crunch and being worried about two wastegates hanging off my crossovers which are made of exhaust tubing I put a single 60mm wastegate on the turbine with a 4psi spring. got everything plumbed up and hooked up my laptop ready to go burn some tires off! apparently the car had other plans. I let it get to temp and drove up the street and stabbed the throttle, it pulled like a animal to 4 psi and then I here this loud fluttering noise that sounds like compressor surge and it is so bad that the car looses all power while still registering 4 psi. at this point it feels like im no joke driving a stock Volvo 240. so my brain froze at this point, the car ran absolutely perfect on the drive to the shop when I was giving the s366 its final beating. so I pulled over and disconnected the wastegate, still does it at 4 psi..... so now im frustrated, drive back to the shop and think maybe the bov is blowing open? so I take the bov off and stick an bolt in it to wedge it shut. still has the issue. I take the wastegate off the car and bench test it and it works totally fine, no leaks and free movement. so I put all the wg springs I had in it and test it, well its about 30psi opening pressure so this should be fun. I drive it and the car pulls like a animal to about 15psi then it does the same thing. falls flat on its face. so I park the car and think. Initially I started talking to some of my friends with turbo ls cars and the consensus was that you really cant over wastegate a car. I mean 60mm is big so I was thinking maybe its too big and letting to much volume out the exhaust? so I made a restrictor on the outlet of the wastegate thinking that may help. I restricted the outlet down to 35mm and drove it, same issue. Doing that and thinking that would be the same as running a smaller wastegate is where I kinda threw myself off the right track. so being the car has always had a extremely small intercooler I started to wonder if maybe it was now a restriction. I non intercooled the car and drove it, same issue. then I thought you know what Im just gonna pull the exhaust off since its a three inch turbo back, maybe that's my issue. NOPE with no exhaust, wg restrictor, 30psi worth of spring and no intercooler the car still makes 0 power and wont rev past 4k in boost. So at this point I'm so pissed off. I send logs to friends that know more about tuning the I do and no one can seem wrap their head around what's happening, it was mostly frustrating. Threw a fuel pressure gauge on, new plugs gapped to .025 and coil packs and wires off the Fairmont. Still no change and rock solid fuel pressure. So now I'm just thinking I better talk to DUDER, so I do and I have to say, it may be how I worded the question but it even seemed like he have been slightly confused as well. We went back and forth a little and he told me with the surface area of the valve being so big the back pressure may be pushing it open, and since it's so big it may not need to open the entire way. So I got a long bolt and cut the end off and cut 1/8th 27 not threads into it and screw it into the wastegate against the back of the valve to cram it shut. Well needless to say the car was immediately maxing out the map sensor and doing crash off the road burnouts. SUCCESS, it was that stupid fvcking wastegate being too big, backed the bolt off half a turn and blamo 10psi, which is what I resprung it too. So long story short, a 44mm wastegate in a gtx4202r is perfect. Lol