I guess I understand the sentiment (too much power), but it’s hard to make a blanket statement, even regarding the purpose of these cars.
I was out for a bit last night, just cruising in the early evening, and 125 hp would have been just fine. But I’ve also hustled my car in haste on mountain roads (east and west), and was thankful for every last pony under that deck-lid. I’ll readily agree that with a flexible frame, ancient suspension (see the recent thread regarding swing-axles vs IRS), and stockish brakes, 125 hp IS about the limit. Moving the capabilities of the car requires a complete rethink of the entire vehicle, but it’s not like every car represented on the SOC is a pan-based car with drum brakes.
I can guarantee that Jim Kelly’s car is up to the burden of 300 hp, and that Marty’s is able to handle his 200+.
A fully loaded Speedster is not THAT light. Nobody has any problem with a stripped-down early 911 making 250+ hp and weighing a couple hundred pounds more.
Modern sports-cars weigh a bit over 3000 lbs (1.5-2.0x as a speedster) and make 400+ hp. “Too much power” is more a function of too little effort planned on other parts of the car. A fox-body Mustang was a death-trap with 200 hp. A modern GT500 is in no way “overpowered”.
Everbody has an opinion, here’s mine: if you want to cruise, El Guapo style— 125 hp, a swing-axle, and front discs/rear drums will be just fine. There is more than enough to keep a guy occupied in his garage just trying to keep everything working.
If you want to hustle a bit through the mountains, you really do want IRS 4-wheel discs and 150 hp (+/-), along with sway bars (front and rear) and some work on the front end.
If you want to run with newer sports-cars, it’s going to take money. Lots and lots of money.