the timeless question, how much boost can I run without breaking ****?

[Skym]

Downunder your looking at around 1 grand, which includes Nissan repair gasket kit (intake, exhaust, camcover, oilpump, turbo, etc gaskets) that cost's half of 1 grand, skimming + checking head for leaking valves and correcting, crack test, etc, labour to remove and install head.

Then add cost of 80.5mm bore (stock 78mm piston) 1.2mm thick Tomei metal headgasket -

http://www.tomei-p.co.jp/_2003web-catalogue/e105_RB20_gasket.html

And cost of ARP headstuds.

That's not taking into account any intake or exhaust manifold studs that might snap due to age. Any intake, exhaust studs over 10 years old are known to snap.

[GavinJohnson]

i blew up 4 rb20 turbos and 1 rb25 turbo at 15 psi, made 275rwhp and 235 rwt oh and blew a bottom end with stock tune

[exxon]

Here are some general rule of thumbs. You can go beyond but these are proven safe levels of boost

rb20 turbo = 14-15 pounds
rb25 S1 = 14-16 pounds
rb25 S2 = 11-12 pounds

Hey brian. Do you know the visual differnece between the s1 and s2 turbos? Like model number on the compressor housing? Trying to figure out which one i have.

[Skym]

Lack of engine oilcooler when thrashing (high oiltemps = coking, which starves turbo bearings of oil), high km (out of balance compressor, exhaust wheel due to bearings) is what usually destroy's stock turbo. My stock turbo bearing collapsed on intake side after thrashing and started to whistle (touch housing), then wack the housing after a while before I could replace it with a new turbo.

[BrianV8]

Hey brian. Do you know the visual differnece between the s1 and s2 turbos? Like model number on the compressor housing? Trying to figure out which one i have.

sure do, S1 had a steel compressor wheel, looks like steel lol

s2 has a plastic one, should be pretty apparent

[mitch32]

I say run it at the max if it blows you can pick up another turbo for 200$. Headgasket might go but I think you'll be ok.