222rwkw On Stock Boost

[tigermm]

Finally got my R on the dyno today.

All i have done is 3" cat back with a cat removal pipe (yay nz)

It came up with 222 at the rears on 16psi. Now I know thats not really stock boost but it still has the restrictor in it and removing it only got me 2 psi and 8kw.

Is it normal for boost to be this high with just the exhaust fitted?

[R31Nismoid]

You are running GTR turbos @ 16psi?

That is not normal.

Power is a bit low, generally 1bar (14.7psi) will usually see 240-250rwkw. So considering you are running a bit more... not so good.

Start off by back the boost off to a safer level, 12-14psi max for GTR turbos (if one dies, it generally will kill your motor).

Then get some cam gears and a front pipe (fine with stock dumps), and then you should see a better result or similar, with less boost.

[The Dan]

Boost is controlled by the wastegate actuators. If you have aftermarket 1bar actuators then 16psi is certainly possible.

[The Dan]

You are running GTR turbos @ 16psi?

That is not normal.

Power is a bit low, generally 1bar (14.7psi) will usually see 240-250rwkw. So considering you are running a bit more... not so good.

Start off by back the boost off to a safer level, 12-14psi max for GTR turbos (if one dies, it generally will kill your motor).

Then get some cam gears and a front pipe (fine with stock dumps), and then you should see a better result or similar, with less boost.

I would assume by his post that he does not have a boost controller. He won't be able to back boost off

[R31Nismoid]

Well he removed the restrictor and gained another 2psi (18psi peak), is what i took from the way he worded it...

If there is a hole/split in the line then it is entirely possible to have increased boost without adjusting the actuators or a boost controller of some description.

[tigermm]

Well he removed the restrictor and gained another 2psi (18psi peak), is what i took from the way he worded it...

If there is a hole/split in the line then it is entirely possible to have increased boost without adjusting the actuators or a boost controller of some description.

Yeah thats right, 18psi with the restrictor out. No other boost control system. What size is the hole in the restrictor meant to be?

Its weird tho, the dyno graph starts with boost already at 2psi at 40kmh in 3rd, so Im wondering if his sensor is a bit out and its actually running 14psi. Will have to get my own gauge and double check it.

How come one turbo dying takes out the motor?

[Brandon]

Probably the ceramic dust from the turbo. Read a lot about them but dont know if anyone's actually got a f**ked motor because of that reason.

[R31Nismoid]

ceramic exhaust wheel, usually the rear turbo.

wheel shatters, sends ceramic shards/dust back onto the piston - do a search mate, plenty of detailed threads with pictures etc etc.

basically the older the turbos, the more risk you run when going over 12-14psi

[Sarumatix]

I tried to find an answer to that very question Brandon and no one came forth as such. Still it appears to be common knowledge so it would be highly recommended to make sure you are running safe boost levels for stock turbos.

[Brandon]

I tried to find an answer to that very question Brandon and no one came forth as such. Still it appears to be common knowledge so it would be highly recommended to make sure you are running safe boost levels for stock turbos.

Yea, same here. Not that it affects me but whenever someone ask what pressure should they be running for stock turbo, I'll just reply 12psi to be safe. Some lucky ones may have gotten away with 14psi or 15psi for years but you cant expect every single turbo's the same. Morale of the story is, I rather be safe than sorry. You've got no one else to blame but yourself if it does shits itself.

It'll be a very costly experience or lesson to learn.

[Sarumatix]

Actually I reread the thread and the data is fairly conclusive. Dead turbo results in ceramic dust being embedded in the piston on the exhaust side, check the photos out .

http://www.skylinesaustralia.com/forums/De...ad-t283890.html

[R31Nismoid]

I was gonna say - its pretty clear and conclusive what can happen, pictures are clear evidence of it occuring despite the what the "theorists" might tell you about it not being possible.

[The Dan]

I was gonna say - its pretty clear and conclusive what can happen, pictures are clear evidence of it occuring despite the what the "theorists" might tell you about it not being possible.

Not to doubt anything you are saying but can you PM me links to at least one of those threads. I would like to do some reading on the topic and find where they have had the 'dust' tested and confirmed it is actually ceramic

[R31Nismoid]

There is one linked above already?!?!

Considering it is on the exhaust side of the piston, what else is it honestly going to be after a turbo has let go?

Dirt? Sand? Come on...

EDIT: i know, they must be tiny rocks that started off as big rocks that made it past the air filter, were minced up by the compressor wheel, sent through the cooler and TB's and then somehow ended up soley on the exhaust side!

[tridentt150v]

No, if its dust or rocks then its drugs! nothing to do with ceramics. If you have negative pressure in the motor compared to the turbine or exhaust then the air will flow to that negative pressure...simple really.

[Birds]

Any hard and non combustible object entering the combustion chamber = bad. Ceramic turbos are a time bomb for your engine if you're overboosting them...might aswell take off your air filter for better flow too

Also note it varies from compressor to compressor and engine to engine how much psi you can get away with on stock ceramic turbos.

[STATUS]

Finally got my R on the dyno today.

All i have done is 3" cat back with a cat removal pipe (yay nz)

It came up with 222 at the rears on 16psi. Now I know thats not really stock boost but it still has the restrictor in it and removing it only got me 2 psi and 8kw.

Is it normal for boost to be this high with just the exhaust fitted?

yep soon as the restrictor is removed the std ecu pours in the fuel and dumbs it down. Most GTR's will pull around 190-200rwkw with a stock ecu, with a mines ecu they will pull around 220 (loads more timing about 29 degrees peak but still rich) a remap will yeild 230rwkw at less boost or 240kw with the restrictor removed and the remap controlling boost.... Sarumatix yours still has the highest reading on my dyno for a std rb26 so dont worry..... yet

Edited November 20, 2009 by URAS

[R31Nismoid]

250rwkw is easily doable on the factory ECU trent - ben has done it on countless cars

[Turbz RB-25]

GTR running simular setup to yours at about 14 PSI pulled out 229 rwkw here in canberra.

[The Dan]

There is one linked above already?!?!

Considering it is on the exhaust side of the piston, what else is it honestly going to be after a turbo has let go?

Dirt? Sand? Come on...

EDIT: i know, they must be tiny rocks that started off as big rocks that made it past the air filter, were minced up by the compressor wheel, sent through the cooler and TB's and then somehow ended up soley on the exhaust side!

ROFL.

Yes, not saying it isn't ceramic but no one has actually proven it to be that.

Keep in mind that you are talking about dust, not chunks, and when a turbine wheel comes off, what happens to the comp wheel? It starts machining the housing away at the front. This creates dust also. What happens to alloy dust when you burn it? It looks like what you'd imagine ceramic to look like.

Theories of engines sucking blades back into themselves is a bit far fetched. Can happen, I'm sure, but you guys all make out like it's going to happen to every single GTR turbo that ever existed.