Where do you install a performance chip on a 89 535i?

[repenttokyo]

I would hazzard a guess that most of those are knock-off's, prolly a Turner chip in disguise. Anyone with an eprom burner can clone them, cutting legitimate chip developers out of their rightfully earned sales.

i think most of them are actually devices that trick the computer into thinking the maf is getting more air than it actually is - at least that's how the cheap, fly by night guys do it.