Hesitation/Stuttering/Running a 15.0?

[93GSXCLIPSE]

All right, so ever since i bought my car ive had this weird problem. Whenever i punch the gas at around 5.5-6k the car starts having a bad hesitation.......almost like a fuel cut out, but the car will keep going if you keep holdin the gas.......it doesnt just cut out and stop, it cuts and then shakes back and forth really hard. Now, the only way for the car not to do that, I have to turn the boost down to 13 psi. Now, this doesnt seem right at all. I have 660's, a 255 fp, and a fpr, and with my afc, up to 5.5k its fine, but right after the car just bogs and hesitates. Before today, I ran a 14.2 at 98 and even that is WAYYYYYYY too slow for all the stuff I have done. I should be in the 12's with my stuff. My plus have around 6k on them, the wires too........on the street, the car feels fast as hell......but once it gets to 5.5k, it sucks........i dont understand how my car can be running stock times when I have around 6 thousand invested into it.....my 60fts also blow because of the boggin issue.......i get like 2.0-2.1's when i should be gettin 1.7-1.8's...........I am just stumped about what the problem could be......I know that the problem can be anywhere from a boost leak to fried piston rings, but ne help would be appreciated....also, it seems kinda weird to me that the way my afc is hooked up, it is set on 2cyl pointing up for it to display the right rpm's that my car is running......would this serve in the problem, the fact that the afc thinks im running on 2 cylinders or the fact that my afc is hooked up incorrectly? Please let me know what you guys think.....btw, I did a boost leak test and I did not encounter any.......thanks much guys

 

[DSMTalonAWD51]

u could easily check for compression issues with a compression guage but it really sounds like a boost leak

 

[Newlogics]

puffing black smoke down the 1/4 mile?

You're running way too rich. Have it wide-banded.
Big intake leaks will do that to you, as well as simply untuned afr.