Um well god didn't intend my Non turbo to have one so thats a no no and if you look at the cluster I'm pretty sure that 4,000-4,500 is a doted red for the red line then after 4,500 its a solid red I'm sure mine cuts off at the solid red.
whoever told you its not safe to turbo a n/a, is WRONG
ive turbo'd atleast a half dozen different n/a's, and it works just beautifully..
if your not out for alot of horsepower, then a n/a is perfectly fine to add a turbo to. you can add a turbo to a COMPLETELY stock n/a, with stock fueling, and increase power quite a bit, just from the boost of the turbo. you can crank the fuel up a bit and double your power quite easily too..
anyways, there are LOTS AND LOTS of n/a long blocks running around with turbos.. no issues.
i have probably 50k miles on my n/a engine converted to TD, and it has a VNT turbo on it, so it boosts even lower than a stock turbo, and my engine has had zero issues. im still running a stock head gasket, and stock gasser stretch bolts..
god didnt intend my engine to have a turbo either, but that didnt keep me from adding one.. turbo = happiness!
again, my car has a bone stock CS vanagon engine in it. with a VNT turbo, intercooler, TD fuel pump, and 20 psi boost..