12th Lipo a possibility ?

I'm just come home after my "testing" night at my local club... the results are very interesting.

I have the following electronics installed in the car:
Speed Passion GT LPF Speedo
Speed Passion 10.5 Motor
Futaba 603FS Receiver (2.4Ghz version)
Futaba 9650 Servo
MRT PTx transponder

Run 1: without an rx pack to see if
A) it would work
B) there would be any problems.
I ran the car for 6 and a half minutes before pulling it off but everything worked fine. There was a noticable lack of kick from the car, but I didn't have to let off as much for the corners.

Run 2: with an rx pack to see the differenceI ran the car for a few minutes (3 or so) before it cut out completely and wouldn't respond to any input. I believe this was because the car was trying to take power from the rx pack instead of the battery. This was the last time I ran the rx pack for the evening.

Heat 1: Lipo (no rx)
Gearing and Setup on the car were as I normally would have it when running 4-cell nimh packs.
Result: 30 laps in 305.442 (quick lap: 9.475, avg: 10.181)
Used Capacity: 1358 mah
Battery voltage: 3.9v (0.3 loss from fully charged)

Heat 2: Lipo (no rx)
Same gearing and setup (~57mm/rev). I had two screws come loose in the rear pod so didn't finish this run, but quick lap was 9.671, avg: 10.338
Used Capacity: N/A

Heat 3: 4-cell Nimh
Same gearing and setup (~57mm/rev)Motor moved in the mount meaning I didn't finish the run, but quick lap was 9.040 avg: 10.187

Final: 4-cell Nimh
Same gearing and setup (~57mm/rev)Result: 31 laps in 309.958 (quick lap: 9.264, avg: 9.999)

Overall the car felt like it had a lot less of a kick when running the Lipo, but there was no dumping sensation and the car was actually EASIER to drive around the track for me.

I will do some more testing, including the possibility of an 8 minute run, but things look encouraging so far !