After tracking CTSC cars as well as stock suspensioned 02+ cars, my personal recommendation (for what value that's worth, and not to have anything negative to say about the other posts) would be to go with suspension. Your car has 1/13th the miles of mine and the bushings are in much better condition and the deflection is minimal even in my car with suspension. IMO, suspension with a good track alignment will make the nsx easier to drive and more predictable on track ESPECIALLY since you have a CTSC. Since you have that much more low end torque, its even more crucial to have a suspension and alignment that won't have you fighting for rear grip. So a suspension with a proper alignment will be a far bigger fference in safety and predictability than reducing slight deflection alone, especially on such a new car.
What tire size and model (Z1 starspec?), and tire pressure are you running front and rear again?
Stainless Steel lines do make a diffeence in feel but since ur car is so new, just put good fluids and pads in. Most people (even those sho track a lot) are still very innefficient under braking and don't brake hard/late enough to need upgraded brakes. A proper racing school will teach you how to use them properly and how to corner faster. So especially after a school - GET A BAFFLED PAN!!!!!!! Or risk losing a rod bearing which is possible ON STREET TIRES! There is absolutely no reason not to invest in a baffle especially since the NSX dosnt have any factory baffling. STMPO has a great baffle and ill have track data to provide a review soon (I have it on my personal car/FXMD test mule. PM me for pricing on the STMPO baffle.
At a minimum, invest in a baffle, brake fluid and pads, racing alignment, and a racing school. Afterwards I say go for the suspension/corner balance/and alignment (which we can provide for local people in Southern California/Las Vegas area).
The CTSC puts you in a unique position since you have the power but not the suspension or brakes to match the increased performance capabilities of the car.
