im not trying to get flamed, and im not an expert so i am going to ask here. been driving my evo around. my boost kicks in around 2.8-3k rpm pulls nicely i believe in 1st and 2nd gear from what i remember. i noticed in 3rd, and up around 5.8-6k rpm feels like i cant go any farther like the boost just got dumped, and all the power is lost.(i cant even make it near redline). if this a boost leak possibly? i bought my evo 8 used, so im wondering maybe it could be tuning with the previous owner, and maybe he took out some stuff before he sold it ( and kept the tune). tell me what u guys think, or if you ever heard of something like this

 

If you don't have a boost gauge, get one! If you do have a boost gauge, then tell us how high you boost in lower gears and at what boost level it feels like it goes flat on you in third. Does the car have a manual boost controller? Does it have the stock diverter valve or an atermarket BOV?

 

do a boost leak test

get a boost gauge if you don't have one