Everyone I talk to says torque is the name of the game. Horsepower must be balanced with weight to meet class rule requirements and given the 818's weight, HP is no problem and durability should not be either.
In regulations, torque is unrestricted. I also hear suggested that torque, building early and sustained as long as possible is best for a road racing motor.
My whole experience with Subarus and working on turbo motors can be condensed into the last three years and is solely with the EJ257 DAVCS motors of 2008+. I really like the dual variable timing design. There are those of you that seem much more knowledgeable about the motors and their eccentricities than I. I would like to hear from you about ideal designs and combos that result in a high torque race motor.
Stroking a 2.0 liter motor gets you more CCs, less oversquare and potentially more torque, but is that better than what you can accomplish by stroking a DAVCS 2.5L motor with it's variable intake valve timing added in to the equation? Do choices that some make have anything to do with availability and cost?
I know that turbo choices and designs of exhaust and intercooler plumbing have a significant effect on torque. I hope to keep those as separate factors when we discuss the real or the theoretical designs and the pros and cons of making a big torque race motor.
Is this illogical to want to consider the shortblock as the one main building block, the cams and valves another block and the turbo another?
  • Flow volume is driven by displacement
  • Compression VS Boost: what balance is better for a track motor?
  • other components should be matched accordingly so as not to be a bottleneck
  • tuning of the intake and exhaust to enhance power in specific RPM ranges
  • turbo matched to spool up fast at low flow rates, but not so quickly as to not have anything left at higher RPMs...

Anyway, please excuse my stream of consciousness style. I hope in this thread we can discuss these concepts specifically as they apply to Subaru EJ motors (and individual components) and their strengths, weaknesses and eccentricities.