I have a question. I have a 94 M50B25 engine which I'm soon going to be putting into my 316 coupe. Still not quite ready for the transplant because need to buy my coilover kit that would take the weight of the big 6 pot block. And decided that while I'm doing all this, might aswell use the time and recon all other parts, new powerflex bushes for the 325 back end that I have living in my room corner at the moment.
I will be having to buy a new exhaust, so I thought, while it's out and not yet on the car, I would decat it. But! before go deep into the woods and make a lot of problems for myself I need to find out this.
If I decat the standard exhaust, cut the cats out and weld straight through pipes in. Would this: 1. give me any power gain? 2. Would I need a remap or a different chip since there is no cat.
I'm asking this, because as far as I know, the lambda probes sence the oxygen levels but since they are positioned before the cats, they must be sencing the built up gases due to the backpressure generated by the cat.
So if I decat the exhaust, will this not tell the ecu that there is too much flow and esentially kill the power?
Another part of this question. If a different chip or a remap is needed, then would it be possible (if i can somehow find one) plug in a pre 92 ECU from a M50B25 engine because as I read on this forum, all pre 92 BMW came to this country with no catalytic convertors.
Thank you for having the patients and reading my longwinded question and thank you for any replies.