A slow but well driven street car should hit low 1.40s high 1.30s on a decent tire. A fast street car (eg, Ferrari, Porsche, et cetera) should high mid 1.30s. A race car should be in the high 1.20s and below.
I used to run low 1;40's at Riverside in my 275 GTB/4. Back then times at Riverside and Willow were very similar. Four Cam is long gone, but I run high 1:36's in my daily driver non supercharger Lotus Elise on street tires. About 165 hp at the wheels. It really is my daily driver, but it is also very dialed in. Also, I used to run IMSA in the 80's and still coach, so am reasonable, but not magical, as a driver. Breaking into the 30's is not easy for an average driver, no matter what street car he is in.
