Try and catch that time with a Gallardo. Before I tinkered with the suspension, the fastest time I could get with the car was 55.4 seconds. It took a while before I could get it down 2 more seconds.
I just looked through the Apex Guide and it has suggested settings for suspension... that could have been helpful. It has general ideas, like if your having oversteer, stiffing up this. But, still, this Apex Guide has taught me SO much.
I got around 55 seconds with my 700bhp Skyline, and the handling on that thing is so messed up. I reckon once i've fixed all that i can give your time a shot