Ok, but those are the ones we KNOW to avoid...
If I were to start with a blank slate for rallycross, I'd want something in the 3000lb range for stability over rough sections (light cars bounce too much, bouncy bouncy = no control), an effortless 400hp turbo or 300hp N/A, decent diffs that can put the power down but still allow you to turn, and suspension that won't fold the first time you slam into a rut at the top of 2nd gear because lifting sucks.
I'm not sure this car actually exists 
Evos seem to be the easy button. Subarus have cornering issues because Subaru diffs aren't as good, they don't allow the car to corner as well. A steering quickener on a fast rack would definitely help compensate. At the end of the day an Evo is still cheaper than buying a Subaru and fixing the deficiencies, from a dispassioned viewpoint.
Whats awd out there that ISN'T front biased??
In reply to kevlarcorolla:
Subaru STi, GD Impreza with automatic, all BMWs, a few more I can't think of off the time of my head. The BMWs and STi use planetary center diffs, kind of a neat idea. The planets are the input and the sun and shell are the output. So you still get proper differentiation but there is a torque difference between the two outputs. The trans in the GD Imprezas (turbo and non) have a very slight rear bias due to the bizarre center differential used. Seriously, look up cam and pawl differential.
Anything with a bevel gear or Torsen center differential by definition cannot be biased one way or the other.
In reply to Trackmouse:
The Pontiac 6000 STE definitely did NOT suck. In its day it was a pretty well regarded vehicle.
Subaru's with a stick are supposed to be straight 50/50 torque splits, so not biased either way.
In reply to NGTD:
Not exactly. They have open bevel diffs (which are by definition 50/50) but they also have viscous couplers stuck on the end as a limited slip device. This alters the torque split so more torque goes to the wheels that can use it. This is where the 12kg/16kg/20kg numbers come from, that is a number that defines how much it can transmit before breaking free. Kilogram isn't the only number but it's the shorthand, like when people say X pounds of torque (inch-pounds? foot-pounds? furlong-pounds?).
A locked differential can be 0/100 or 100/0 depending on which end has grip. Think about if one end was completely off the ground, that end is transmitting 0% and the other end is getting 100%. If it was a 50/50 diff (or better described, 50:50) then if one end can transmit zero ft/lbs, that is all that will go to the other end too.
I don't know why anyone thinks "fifty fifty torque split" is a good thing...
In reply to Knurled:
Lots of cars with a 50/50 split are only 50/50 when static. That can change greatly front to rear depending on conditions, and how much the viscous coupling can transmit as you mentioned. DSM's, and Evos up to I believe the 8 (at least 8's in the U.S.) had very strong viscous couplings that could send most of the power to the rear under acceleration. Here's a video of DSM's and EVO's launching in slow motion, you can see the power being sent back and forth. Note some of the cars have locked center diffs, you can easily tell which...
On loose surfaces when turning, most of the power will go to the rear, especially if the car has an open front diff. When the inside front tries to spin, that power is sent rearward.
In reply to Boost_Crazy:
Yeah, that is the beauty and the bane of limited slip diffs. They allow torque to transfer to the slower moving output. The downside is they prevent differentiation, which doesn't sound bad until you try to turn without upsetting the contact patches.
However that isn't quite the same thing. A planetary differential will provide more torque to one output even when everything is happy traction-wise. Translated linearly, it's like putting a board across two bathroom scales and standing off to one side. One scale will read higher.
I'm also only taking about vehicles with differentials. Anything with a purely clutch pack interface from one end to the other (electronic, viscous coupling, whichever) will always be 2wd until there is a speed difference.
Pretty much all non-supercar AWDs are forward biased when it comes to weight distribution, and that has a way bigger proportional impact then the actual power distribution on how the car acts. AWD doesn't do anything good for you unless you're in a situation where one of your wheels would otherwise be spinning. In other words, you have to be under power. On corner entry most AWDs are just going to act like front-heavy FWDs that are just slightly heavier overall. It certainly helps once you start trying to put power down on corner exit, but once you get up to a speed where your non-supercar wouldnt spin 2 wheels anyway, it stops helping again.
I think the merit of AWD depends more on the racing venue and your expectations for the car then it does on the actual system architecture. If you are driving only a mildly powerful car on pavement, weight distribution is going to have a way bigger influence on how you perceive performance than whether power is distributed primarily to the front or rear. On dirt, where even slow cars can spin tires constantly and it isn't particularly difficult to get ANY type of car sideways, i think you will appreciate ANY type of awd more then you might care about the vehicle's overall weight or power distribution.
Just my .02.
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