when i am in pretty much any gear when i get to 3750-4250 RPM the car will boost with a jerk instead of a smooth boost thru the whole gear... and if i have the RPMs fluxuating in between 3750 and 4250 the car with jerk with the fluxuating RPMs... i have a boost Greddy Profec B electronic boost controller with the ability to choose low or high boost and how much of either you give it... and an Apex'i S-AFC... I dont know much about either.. any help on the settings???

What is your boost set at? Maybe you should consider taking out the profec-B until you are completely familiar with the SAFC. Pick up a cheap Manual boost controller, set your boost low and learn how to use the SAFC. Get the boost up to where you want it with results you are happy with on the SAFC and then convert back over to the profec-B. That damn thing is tricky to set the boost, gain, blah blah. I had one on my car for a week before I totalled it and I haven't installed it yet on my new DSM just because it was a mega-pain in the ass. I might get back around to it, but I might just sell it and keep using my Dejon Tool MBC from RRE.