It goes without saying that for longevity, leave the car stock. For maximum fun and performance, go twin turbo. IMO, a centrifugal supercharger is sort of in the middle.

Just to clarify here... for the most part when you are looking at increasing an NA motor's output via intake or exhaust mods, you're going to be increasing combustion efficiency. i.e. allowing more fresh air in the cylinder during combustion. More air ==> more power ==> more combustion heat and pressure ==> increased wear on internal engine components.

Now, if you're talking about mods outside of the induction and exhaust systems (lightweight/underdrive pulleys, lightweight flywheels, etc) then you're correct. But there are some technical drawbacks to such items as well when you're considering engine harmonics and such.

Yes -- without question, FI will reduce the overall longevity of the engine (i.e., substantially greater cylinder pressure creates considerable additional stress on the entire motor -- especially rods, crank, and pistons).

On the other hand, with a bad tune, detonation and preignition can kill the motor in seconds.

Now will FI, even with a "perfect" tune, reduce longevity by 100K miles or 300K miles? That appears to be unknown.

Has anyone found something resembling the upper limits of what the motor will tolerate before breaking due to overpower -- as in, will break something even with a seemingly knock free tune?

Well even with a really good tune, fuel starvation can kill an engine in seconds. The stock fuel system sump design (ignoring having upgraded pumps, lines, etc) is not capable of fueling a car making 2x stock power. You really need a fuel accumulator or revamped fuel pickup design to safely run a ton of power over stock. I've yet to encounter any budget sports car that had such a fuel system design stock.

Evo's have this issue... my project car before that had the very same issue. I'm sure the 370Z is no exception. In fact, unexpected fuel starvation has always been the biggest engine killer I've come across while tuning turbo cars.

Uphill onramp + 0.7+ g's of acceleration = fuel starvation. Not to mention power under cornering on a road course.

^^^ I'm going on the assumption of all proper and needed upgrades for safe tune while leaving the motor untouched (i.e., larger injectors, bigger fuel pump).

I'm saying, given all that, at what power level is the motor likely to break something? I don't think that is currently known... the longevity at another 150 whp is also unknown...

Its all pretty much unknown at this point but anything that adds power will take away from the life, just jow much is the question. Full bolt ons IMO wouldnt cause any noticeable difference. A low PSI FI will take away some life but with todays cars going 200,000 miles on them would taking 20,000 miles, lets just say, really matter to most pepople? Not me as I dont keep cars much past 50 or 60K miles. The interior will degrade far sooner than the engine will.

I work for a Nissan dealership and earlier today I asked the same question to our master technician. He said that the vq motor has strong internals and that he felt a a supercharger with low boost 6-7 pounds would be ideal. He said TT is more fun but it will harm the motor/tranny in the long run. So I guess that leaves me with either supercharging the z, or bolting it up.

Go big or go home. ;)
Should know over the next 6 months what this engine can handle, especially when we see some bigger builds finish up.

There is a guy that runs the Z club here in Houston with a twin garett's putting out well over 400whp+. He has had 40,000 safe miles no probs and he by no means drives like a grandma and still curently has no issues.

Yep, if done right (from 350z research) the VQ engine does very well with forced induction. Just remember, do not go cheap when doing these types of upgrades.

And dont let dreamer play with your boost controller:shakes head:

You might go blind.

Are the VQ motors forged, or hypereutectic *sp pistons?

I have yet to touch yours boost controller yet, wait...does a turbo whistler count as boost controller? :ugh2:

Well, the unicorn blood coats the pistons,seals and rings. Also lowers the compression, so it should last at least 10 years.