why no S50 in the States?

[swamper]

having read the new thread by Ibanez ...got me pondering why they didn't start out with the S50 over their.
in my mind the States is the place for muscle cars and lets be honest have a wide range to choose from.
as well all know the S50 is a stonking bit of kit...and after 5000 rpm..well things start going blurry lol.
is it to do with emissions ?
the S52 is more likely to be closer to its claimed 240 bhp than the S50 to its 321 bhp....but even so it just seems to me that when BMW where going into a market where the customers could already buy a rag top with some very serious grunt...they kinda missed the chance to jump on board.
theres probably a very simple explanation.....but then they brought out the S54......so..???

then that got me pondering what british cars from the same era could come up with that kind of performance ?
now im not that well up on these kinda matters ....but im struggling.....TVR..the odd Jag ..????

anyway its my thread so heres a pic of the swamp buggy ...!!

 

[hard top]

The best bit of info I could find Swamper is this....

1998-2000 models use the drivetrain of the E36 M3. Therefore, the European-spec model is fitted with the 321 hp (239 kW) S50B32 engine and the North American-spec model uses the 240 hp (179 kW) S52B32 engine.

The gearbox is a ZF Type C 5-speed manual, but the North American version is the only one fitted with BMW’s ASC+T traction control system (as of 9/98 production) until the facelift. The final drive is either 3.23:1 (S52) or 3.15:1 (S50 and S54). A limited slip differential with a maximum locking of 25 percent is standard.

The European-spec M roadster is electronically governed to 155 mph (249 km/h), while the North American version is limited to 137 mph (220 km/h).

2001-2002[
2001-2002 models use the engine from the E46 M3. Therefore, both European and North American models use the S54B32 engine.

The only accurate way to determine differences in the engines outfitted in each years production is to refer to the VIN. Using the labeling on the valve cover may prove inaccurate as some early 1998 US M Roadsters shipped with valve covers inscribed with BMW MPower vs. the simple M logo.

The other major addition to the revised M roadster is an M-tuned version of electronic stability control (called "DSC" by BMW). DSC intervention can be reduced or disabled via a console-mounted button.

 

[GazHyde]

I had it in my mind it was down to emissions, but I can't remember where it got that from. I do know that the S52 is a higher performance version of the M52 which was designed for the North American E36 M3.

 

[swamper]

cheers chaps....it is a bit of a puzzle.
the normal Zed is fitted with an emission control for the american market....so surly they could have fitted it to the S50..hmm