REALLLY annoying "binary" feeling throttle problem, please help!

[thomasK(austin)]

ok my rb25 240sx has this really annoying problem. what is does is this:

ill be accelerating throu, say, 3rd gear up to about 4k rpms with about 75-90%throttle, i let off the throttle and it feels as if my car hits a wall, a very binary feeling. my acceleration is either OFF or ON. what usually causes this?

i currently have a recently tuned powerfc and a blitz bov vented to atmosphere, but it cant be that because my friend ran this exact bov on his car before he gave it to me and his car didnt have the binary throttle feeling.any ideas?

i attatched a pic of the engine, i think everything is set up ok.

[180fan]

Checked your TPS? Other thing is your blitz bov could be leaking. It's very common for those to leak boost.