I've increased the rev limiter and fuel restore rpm to around 8000 cut / 7963 restore. This helps for smokey burnouts and sounds cooler. The car can bounce of the rev limiter pretty quickly. It's fun, but Michelin's aren't cheap. Without other mods, I'm doubtful of squeezing 20-30HP out of the VQ37VHR. The factory tune seems to run rich, so the car is mod friendly without a tune, up to a point. You could try leaning it out a touch, but you won't find the 30HP you are looking for there. Cam timing is complex and hard to tune without a dyno. Power gains from the factory tune will be limited to finding mistakes make by Nissan that you can find and correct to find the missing horsepower.
Burnout instructions:
(Disclaimer: what your do with your car and your life is your own choice. You agree to accept any and all consequences for your actions.)
Start by finding a good spot to practice burnouts. A well-lit, wide-open lot is best. Access to a hose or other water source is highly recommended. I suggest wetting down some smooth concrete or asphalt first, then rolling your back tires into or just though the water. Try not to use too much the water as it can make a huge mess and is unnecessary. You could also use water in a spray bottle to wet the rear tire directly. Drive your car over the wet ground. After exiting the wet patch, pull forward and stop. Defeat VDC, then stomp the brake. Stomp the gas until the RPMs stop climbing. From here you have two choices, a stationary burnout or a flying burnout. I'd start with the stationary (missionary) first. Release, the brake, then as the car starts to leap, reapply the brake just enough to stop the car. Still holding the accelerator to the floor. You rear wheels should start to spin wildly. Try to modulate the throttle so you don't bounce off the limiter continuously but keep RPM high. Let off the gas after the desired effect has been achieved. For a flying burnout, keep holding gas and release the brake. Make sure you enough runout as to not crash into anything. Reverse or loop back around and repeat until your tires beg for mercy or the police are called.
Posted updated with my current tune:
If anything, my tune may be down on power compared to stock. I've tried to tune for smoother throttle response and gas mileage when under 50% load and 3900 RPM. I've completely remapped the open loop fueling table, changing RPM axis and engine load. This makes a big difference in how the car runs. Everything I've done has been butt-dyno tuned only. I'm still not satisfied after 2 years of adjusting, but that's why HP Tuners is the best. Looking that the NISMO map, they start at 2800 RPM and go up 7200. Probably a good choice when tuning for max power, not sure about the loads. They go from 20.3 -> 129.7. I've never seen 100% load, let alone anything over 100%. I've reclaimed the extra load columns and picked new RPM points based on my preferences. Mine focuses more where you drive under normal conditions. Load from 17.2 -> 93.8, RPM 1000 -> 7400. I have 3 "high rpm" levels, 3900, 5250, 7400 for adjusting fueling targets. I've gained more adjustability based on load by doing this. I've tried to mimic the NISMO map under full load, but I can only estimate since my loads and RPMs don't match. I also have an automatic, I've modded the estimated torque map slightly at high RPMs and high load for quicker shifts. It's very touchy, so this table has minimal changes. Been playing with this one a lot, I have "race maps", but they're a bit too clunky for daily driving. I get the traction control light to flash when hitting second with VDC on. At some point I was going to fully remap the estimate torque table, reclaiming the columns about 100% load. This will be very time consuming; I'll likely need to use excel of something to get something close to stock, then work from there. Here's my tune, it's still a work in progress...