There is probably is limited interest in this, but being an E34 M5 guy, this is actually quite spectacular. Main concerns with pressurizing an M5 is the the fact that the OEM compression ratio is already high. The E34 M5 is already considered at the ragged edge, with the gurus at the M factory really pushing the edge of the envelope to squeeze as much power out of the motor as reasonably possible - while still maintaining reliability and longevity. Aside from that, given that a new crate motor sets you back over $10k and a rebuilt one is still about $8-10k, it makes trial and error quite expensive. Rumors float around the internet about people having boosted an S38 motor, but one has finally been documented with photographs. This was just released earlier today. It will be interesting to see how the motor stands up over time, but given the low mileage, it should be good for at least a little while:
Supercharged E34 M5 Story
Supercharged E34 M5
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