All of the power made on the Honda K20 setups is with tuning. You have to be very carefull with ignition timing and not going anyleaner than 12:1 on them. All these Kits that I have tuned are all in RSX type S's and K20A swaps in the 01-05 civic. most of these are off the shelf Full-Race kits with the exact same turbo you are running, a .63 GT30R. these make 300lbft TQ at about 4500rpm and stays pretty damn flat to about 8000rpm where they set the limiter because of the stock valvetrain and rods. These are equal length manifolds, yes, but on these motors, because of their design, running this same setup with a Log would yield too much backpressure and retain too much heat in the combustion chamber and lead to early detonation and much lower power.
The GT30R is not considered a small turbo with high backpressure so your VET cams should not make more power than sr20ve stock cams for your given setup. This again is where i'm going to state about tuning cam gears on the dyno. you will be suprised about how much power AND spool you can get by having the right exhaust valve opening and correct centerlines. I have done consulting for several drift teams and built several motors for them as they all want the fastest spool and the most power as fast as possible. This is very hard to come by for the average builder with these motors. I always find the last 10% of power to be had with the cam gears. I do have a "recipe" for a 400lb ft 500whp sr20 at 20psi and does not have to be rev past 7000rpm. This is with a DET low port head ( S14) WITHOUT the NVS gear on it.
2.2L ( i've done 90mm bore and 91mm stroke setups)
Ported head flowing 280cfm IN 255cfm EX
C2 cams
Cam gears
ported S14 intake manifold
9.5:1 compression
Tubular ( non equal length) T3 divided manifold with 1 1/4" sch10 pipe
3.5" down pipe and exhaust
GT3071R .82 Divided turbine housing 60mm turbine
typical 22x11x3 FMIC tube and fin
2" hotside, 2 1/4" cold side charge piping
i have built 3 of these setups now and would love to build this as a street turbo setup. This motor makes 400lb ft TQ at 4100rpm and 500whp at 7000rpm and goes linear to about 8000rpm at 20psi (1.4 Bar) With the cams straight up at '0' on both i was only able to get 365tq and 460-470whp at 22psi boost ( 1.5bar). after spending about 1-2hrs on the dyno just messing with the cam gears, the rest of the powerband comes together.
The DET/ VE-T motors are much like the honda motors WITH SIMILAR PARTS. There are DET setups with Log manifolds making 500whp, but if they swapped to a tubular, then yes they will make a lot more power. A log is just for a simple turbo setup, not for a high power, high efficiency setup. The Fluid flow of the Log manifold ( or lack there of) really increases backpressure. and very high backpressure can lead to reversion and even engine damage and excessive wear. I do agree with Andreas Miko about the large turbo setup on the street with small cars. A fast spooling turbo setup that makes a lot of midrange torque and power early and carry's the powerband to say 7000-7500rpm will be much more fun on the street, and sometimes faster on the track, than a 800whp GT40R setup that makes full boost at 6-7000rpm. On a drag car, maybe, but on the street its totally different. The other factor to think about other than the transmission and clutch is traction. I have had a few of my own turbo setups on the street and i have found a few tires that do stick the power to the ground but they are about $240-260 a tire and you have to have enough clearance to run them. a 195 or 205 just wont stick it.
I have a Civic Hatch street car ( more like a race car though just street legal though) with about 360whp and 240lb ft TQ and the car weighs about 2100lbs, with a 235/40zr17 tire you dont get any traction untill 4th gear. This car runs mid 10's in the 1/4 on 100 octane on the street it's fun only on the freeway. I dont get how some of these people want to run a 800whp GT40R setup on the street. unless you want to go 200mph which i think is stupid.
-Ted