did my 1st AX with the 914 GT clone today Options

[rfuerst911sc]

Today I took the 914 GT clone to her first autocross. I posted here rather than the paddock as I'm just getting my feet wet with the 914. Overall for the first time out I think I did good. I was 5 seconds off TTOD and this was on 5 year old Yoko ES100's. Here's a little rundown on the car before I ask some questions.
3.0 stock 911 engine with Weber 40 carbs.
911 Front struts with 3 inch ear calipers. Standard Boge inserts.
911 M calipers on all four corners. 20mm vented rotors all the way around.
Rear Koni shocks set to hard with 140 lb. springs.
Stock 901 transmission with stock 4 cylinder gearing.
Front 19mm sway bar no rear bar. Standard torsion bars.
Car corner balanced at 2100 lbs.
16x7 + 16x8 Fuchs with 205/55 + 245/45 tires.
19mm master cylinder.

Now the questions. The car seemed to be well balanced but I really struggled with rear traction. Coming out of turns it was very easy to spin the tires. And launching from the start was either spinning in 1st gear or a slight bog starting in second gear. And I quickly found out that stock street brake pads are not up to snuff for aggressive driving. I have some Porterfield R4S that I'm going to try. So you guys that have more power than me how are you putting it down ? I know better tires will make a big difference along with me learning how to drive the 914 vs. my 911SC but any tips to pass along ?
Overall I had a blast as I always do (IMG:style_emoticons/default/biggrin.gif) .