i just finished rebuilding my B18 and for some reason it wont rev past 4500-5krpms and if it does then the engine dies and shuts off. I cant downshift either or the same thing will happen... But i noticed when im in the freeway in 5th gear the car will drive just fine till about 5500rpms. i havent taken it past that tho... Here are my mods: 84mm wiseco pistons eagle rods darton sleeves micropolished n balanced crackshaft inline four crack pulley Extreme P & P head brian crower stage 2 boost cams brian crower dual springs + retainers 1mm oversized valves w/3 angle valve job STR cam gears sk2 intake manifold sk2 70mm throttle body 3 bar map sensor 255lph walbro fuel pump automotive fuel filter automotive FPR automotive fuel gauge AEM fuel rail 275cc injectors (no boost yet) external msd coil MSD 6AL ignition box apexi neo fmu (upgrading to s300 once i start boosting) ram exhaust manifold 44mm tial wastegate T4 custom turbo 3inch downpipe 3inch cat back 31x12x3 front mount I only have about 200 miles in it since i rebuilt it and ive been driving it slow with no boost, but i noticed the other day that the car started holding back once it past 4kprms..... i really dont have any ideas at the moment of what it could be.... if you guys have any ideas or if anything like it happened to you, please let me know.... Thanks!