Hello Haruna, hello all,
 
from my experience while the championships 2008 I have to say, that most of the cars are very close together, if an optimized setup is used.
Even with different robots (usr/simplix) we had time differences down to 0,01s in qualifying (street-1).
Ok, with other tracks, we had greater differences, but if you look to it over all tracks, the used cars are nearly balanced (car3 wasn't used, car5 only with old robots).
 
> Please note that I was using default setups
I assume you are talking about the "official" TORCS(-NG?)-default-setups (Not the simplix-default-setups).
With the "official" setups, some cars are not competitive!
It would be good to have it compared based on a human driver and the simplix(/usr) based on the default setups of the robot.
 
> any chances to stay with any rivals at the start. For some odd reason, the same can't be said for the TRB1s driven by SIMPLIX.
I tested a car1 with the same "official" setup for me (as human driver) and simplix.
The result on a track where I just had to press down the throttle for the first 100 m, I checked the time needed for this distance.
Human driver (using automatic transmission): 5,4 s
Simplix (using it's default startautomatic): 5,7 s
With a modified Human driver (using a startautomatic "a la Eric = rpm based" with optimized parameters): 5,0 s
With a modified Simplix (using it's startautomatic( = rpm based) with optimized parameters): 5,0 s
With wdbee_2008 (using it's default startautomatic( = time based) but a car6): 5,0 s
 
So you can't say, a human driver doesn't have a chance against a "default" simplix while start.
 
> and the powerband stinks horrifically (car3) ...
Most robots/drivers are using a fixed scheme to switch to the next gear, based on the rpm correlated to the current speed.
With cars having a more sinking torque characteristic, it may be better to shift gears earlier, because the next gear would have already more torque! This was used with wdbee_2008 and the car6 to help against it's problematic torque characteristic (yes, it helps in the first five gears only).
 
> Top tier (Best of the best) (car1) :
This car has a higher rpm-limiter-value, a good aerodynamic and much power. On fast straights this car has a build in advantage. The problem: All tracks have a "long" straight needed to realise the pitlane.
 
Cheers
 
Wolf-Dieter