I was wondering if anyone could direct me towards a cold air intake system for my '91 525i M50. I haven't been able to find anything of the sort. I would really appreciate any help.

Not worth getting.. you gain a little up in the higher rpm range but you loose a lot of low end torque..

What would you suggest for the best performance gain? I am currently looking at Dinan Engine and Transmission Chips. I'm not looking to spend over a grand though.

I found one on ebay for 60 bucks, it's nothing but a piece of pipe with a filter on the end (something cheap) with an adapter and a brace. I decided to try to install it, I had to rig it, but it's on for now. Seems to have given my '90 a jump, and a good growl but only when you stomp on the pedal.

It may help a 90 but with a M50.. it just loose bottom end.. save the money invest in a EAT chip. and dinan tranny chip.

After I installed my CAI on my M50, I thought it had considerable jump off the line and high end compared to stock. Just my 0.02

After I installed my CAI on my M50, I thought it had considerable jump off the line and high end compared to stock. Just my 0.02

Maybe at wide open throttle there is a little gain. but at times when you are driving in traffic using lower and mid range rpm without wide opent throttle. the car is slower. It bothered me enough that I put the stock airbox back on.. However if you are on open road all the time it may work out for you. In Los Angeles Traffic.. it didnt work out so well.

Yeah that is true, im usually not in traffic so i open it up quite a bit

drop-in panel filters work much better.. but ill let you know after i go this route. Go for the afe if they have it otherwise it might be best just to stick with the stock setup and oem type filter.