or are certain ones better than others? I need a cheap option to replace my n75, as it may be on its way out (i have no way of swapping it to test it).

 

for a stock turbo, a bleed valve is better because it will be far smoother than a ball and spring mbc.

incabin mbcsmooth and only $22
combo mbc (ball and spring/bleed valve) spool faster and still make it smooth with no high spikes $44

I have a real combo mbc from turboxs and i enjoy it very much. my brother uses the incabin one and is extremely smooth. Pics of both installed are in my sig.

 

I found the Modshack Boost Machine to be easily tunable-- with two different valves to modulate (one controlling the onset of boost and one controlling its release). A little pricey but it certainly modulates spikes, and thus prevent me from going into limp mode, as well as let me hold boost 2-3 psi higher and for a longer time.

www.modshack.info

 

so its just like a normal mbc....neat.

Its just a really bulky, overpriced ball and spring/bleed valve that can be had for $50-100 that will take up 1/8 the space.



wow, look how massive thats not, AND it fits under the engine cover.