If you install a turbo on a gts4, you will need an aftermarket ecu to run it. Now from my experience; the second biggest noticable modification was installing an aftermarket ecu (the biggest came yrs later when i upgraded the turbo), as this free'ed up ALOT of mid-range torque and power. So you're really not comparing "apples with apples". Keep the same boost, mods, etc, but both cars need a/m ecu's to be on a level feild.
Still have my money on the 34.
You may not have originally discussed "twisties", but the topic has been raised in this thread.
PS: You are talking about installing a std rb25 turbo on the N/A, as this will also affect the outcome.
Also note that power variations also exist between std cars, especially when they get as old as ours, so blaming the variance due to modification is really irrelavent. If it is a good engine and makes good power, great. If it is a weak engine and is tired, too bad
Race with what you got, with the same level of modification.
Hope to see the challenge at Calder Park Rwy!!
If you do it on the street i truely hope you get caught.