[Nick M3]

I started this process a few weeks ago and figured I'd log some updates here.

After the long restoration on the M3, I ended up throwing in the S50US out of the yellow car in order to get it driving. This had the advantage of being a very cheap, easy swap that I could do basically for the cost of building an exhaust, and providing a cooling system. I had pretty much everything else in hand.

That said, I've never been particularly satisfied by the S50US. It doesn't rev the way I want. It doesn't quite make enough power. It doesn't have enough throttle bodies. It looks quite utilitarian in the engine bay. You know, because it is. It's just a mildly built M50. It was never a long term answer. It just got the car on the road.

I dithered for a while on rebuilding the S14 vs. putting in the S54. Ultimately, though, the cost of rebuilding the S14 and the insane cost of replacement motors if I blew it up (think comparable to the 993TT) pushed me towards the S54.

At this point, figure $15-20k to do a home assembled rebuild of the S14 to a spec that would put down about the same power as the S50US. WAY more interesting motor. A little shy on power. VERY peaky. If only I'd bought half a dozen S14s when you could buy them in good running condition all day long for $3-5k.

S54s are about $4k in good shape. They made tons of them, so it'll be a while before they get scarce. They're actually quite reliable. They'll spin 8,600 to 9,000 RPMs. And 300whp is a baseline expectation. And I already had one in the basement.

Photo courtesy of clyde.