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

[Chewy]

So, onto the details- I've got a pretty good idea of what she can run, but extra input is always nice. Currently running .85bar@3800 rpm. Thinking about turning up a bit, but I'm also happy with how she runs and the insurance factor of a safe boost(for the time being).

internally stock rb20
r33 rb25 turbo
trust vspl fmic
trust 13 row oil cooler
2 core aluminum rad
bcnr33 fuel pump
stock injectors
stock fpr
stock ecu (as far as I can tell)

I've really gotta get the gauges back that were ripped off from the car too, since it has wat. temp, oil temp and egt (which would all be paramount for safety)

Thanks in advance for any input.

[Snow]

If the R33 turbo is ceramic exhaust wheel I wouldn't push it past 1 bar (14.7 psi?) at most. They're known to be easy to explode after 1 bar (without water/meth), unless you lucked out and got a steel wheel (which I think mine is ). I wouldn't necessarily recommend going past 1 bar without fuel upgrades either, but an AFR would be better suited to monitor that. If you were running an AFR, got an aftermarket FPR to squeeze a few more lbs out of the stock injectors, and a warlbro 255 (not sure what the R33 pump is rated at) I would say 18psi max. Stock head gasket would probably hold up to 20psi if a lean AFR didn't kill the motor first.

So in essence, in anticipation of boost spikes, I say stay where you are now, or bump up just under 1 bar, or do what I suggested (AFR, FPR, FP etc with steel wheel) and stay at 18. If you want more, A/M head gasket and fuel upgrades (injectors, pump) would be essential on your list of things to do.

That's my input/understanding/opinion on the situation. Other people may have other points of views, so take it with a grain of salt.

[Chewy]

Good to hear another opinion. Think I'll wait until I can grab a nistune and a wideband so I can see/change what's going on. pulls really hard as is, I highly reccomend a Blitz SBCR to anybody thinking of going EBC btw. No spikes, spools noticeably faster.

[89Baysideblue]

Not sure on RB20's but as far as my RB25 goes....
to beyond 12 PSI where fuel-cut takes place /limiters come to a Max-out at this point.

http://www.skylineowners.com/forum/showthread.php?t=77441

[Paradis]

hmmm, well for the record i ran 22 psi for a summer on an rb20 and it held up. eventually an exhaust valve went, but i've got reason to believe that was related to something else entirely

[Chewy]

I'm with Paradis, the 20 is a hearty little motor, and I'm figuring it's probably just down to fuel/ig management and some further instrumentation for safety/tuning reasons. I'd like to be putting 250-280 to the ground since I'm not really a drag monkey and my car isn't a moneypit.

[love_boost]

run 14psi if you want.
but best to get it tuned. i learnt the hard way.

[Paradis]

ya, like chewy said. Personally, i wouldn't dare or dream of running more than 1 bar without having some engine managment in place. Its the just the sensible thing to do. Honestly, after buying the obligatory intake and exhaust mods, EM should be your next item.

[BrianV8]

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

[whiteboy87]

what about stock head studs? i remember reading somewhere that they dont hold up that great against higher boost. anyone have input?

[Skym]

Stock GTS-R RB20DET with basic fuel, ECU, desrestriction mods can handle 22psi from it's stock T3/T04E turbo and produce 440hp at engine. Roughly 284rwkw or 381rwhp. Look in SAU RB20 dyno result thread.

I wouldn't think R32 RB20DET would be any different if you keep peak hp rpm lower (6000-6400rpm) and use boost instead to make up for not reving engine higher.

Here's a RB20DET in Canada with close to 400whp and GT3076R turbo (similar in size to stock GTS-R turbo) -

http://www.youtube.com/watch?v=X_mibuiFSuk

And is driven hard -

http://www.youtube.com/watch?v=ak1dJrSgJqo

So RB20DET is a tough engine as long as it has a good ECU tune, fuelmods, metal headgasket.

Don't think stock RB25 turbo would push a RB20DET close to what it's capable of handling. I would look at ECU retune, fuelmods, headgasket (more for reliability when running higher boost levels). Poncams or reground stock cams (cheaper) would be next to get the most hp from RB25 turbo at same boost level.

Stock RB20DET turbo is capable of 268rwhp at 1 bar / 14.7psi (actually 14.5psi).

[Chewy]

I'm running the R33 (late) turbine. Yay for nylon compressor wheels, I guess I'll see how long she takes to melt

[BrianV8]

rb20 head studs are usually good for 1 bar before lifting and blowing out the head gasket,

rb25 head studs are usually safe to about 18 psi, again before lifting the head and blowing out the gasket

[whiteboy87]

anyone ever get their head studs and head gasket changed? how much time approx by a shop? im in calgary so autodream is probably the best option, anyone ever get them done there? orrrrr better yet, anyone do their own? and if so how long did it take you?

[BrianV8]

haha umm in the car good luck, probably quicker to pull the motor by the time u get those hidden 6mm bolts at the back.

If your going to do it too the head has to come off, get surfaced, and best bang for buck use a factory head gasket and ARP head studs and you will be bullet proof. Did that with my rb25 had it up to 25 pounds, worked fine