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Helpp! 1.4 Bar Boost On Stock Gtr?

Yawn

By Yawn,
in Engines & Forced Induction

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Yawn Mentor

Yawn

Posted
Posted

Hey guys my gtr was running weak and it would take very long to spool up to 0.5 bar which im guessing is stock boost? took it to my mechanic, he found a leaking hose (wastegate one i think). He reconnected all the hoses with new ones and back to the factory boost controller and took it for a spin around the block. We friggin got 1.4 bar of boost at 8000 rpm??? Shouldnt the turbos have blown? Am i just lucky that the turbos didnt blow or is there something else im missing? The reading is definitely accurate, (defi gauge, reads boost consistently all the time before this) and the car was pulling like freight train all the way until the fuel cut. So basically what happened? Whats wrong? Mechanic thinks that another hose is leaking so it doesnt create enough pressure to open the wastegate? Coz now ive fitted a bleed valve and even when i turn it all the way down to minimum setting it still goes up to 1.3 bar?? Scared the sh*t out of me to be honest and im driving it really carefully now until i figure out wats wrong.. Anyone got any comments?

Thanks in advance :)

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1q2w3e4r Enthusiast

1q2w3e4r

Posted
Posted
Hey guys my gtr was running weak and it would take very long to spool up to 0.5 bar which im guessing is stock boost? took it to my mechanic, he found a leaking hose (wastegate one i think). He reconnected all the hoses with new ones and back to the factory boost controller and took it for a spin around the block. We friggin got 1.4 bar of boost at 8000 rpm??? Shouldnt the turbos have blown? Am i just lucky that the turbos didnt blow or is there something else im missing? The reading is definitely accurate, (defi gauge, reads boost consistently all the time before this) and the car was pulling like freight train all the way until the fuel cut. So basically what happened? Whats wrong? Mechanic thinks that another hose is leaking so it doesnt create enough pressure to open the wastegate? Coz now ive fitted a bleed valve and even when i turn it all the way down to minimum setting it still goes up to 1.3 bar?? Scared the sh*t out of me to be honest and im driving it really carefully now until i figure out wats wrong.. Anyone got any comments?

Thanks in advance :)

If your mechanic can't work that out for you, I reckon your best to be spending your $$$ elsewhere mate

paulr33 Grand Master

paulr33

Posted
Posted

misconfigured boost controller or actuator line isnt getting a signal, of a very very low one. so the actuator never opens, which means the wastegate never opens, or opens too late.

the result is too much pressure or unlimited pressure

the turbochargers will certainly fail, massive presure = massive heat

massive heat = exhaust wheel failure

Yawn Mentor

Yawn

Posted
  • Author
Posted
If your mechanic can't work that out for you, I reckon your best to be spending your $$$ elsewhere mate

Nah man, the mechanic i was referring to is sort of a friend and he was helping me out for free.. He doesnt deal with turbo cars that much so he asked me to take it to my normal performance workshop nearby just to double check. I will definitely do that but i just posted here in the mean time to see if anyone had any opinions or comments on wat had happened is all.

Yawn Mentor

Yawn

Posted
  • Author
Posted
misconfigured boost controller or actuator line isnt getting a signal, of a very very low one. so the actuator never opens, which means the wastegate never opens, or opens too late.

the result is too much pressure or unlimited pressure

the turbochargers will certainly fail, massive presure = massive heat

massive heat = exhaust wheel failure

Ah icic, yeah it did seem to have unlimited pressure, it just kept going. Im just lucky nothing blew.. :) phew.. really still on the adrenaline rush that it gave me.. heh. Also, btw is stock boost 0.5 bar? and at wat rpm should i be reaching peak boost? coz it still takes pretty long to spool up, like maybe 4-5k rpm for 0.5bar?

Oblivion Grand Master

Oblivion

Posted
Posted

well depends on the engine load i guess...should spool before 3000. if it is unlimited then there is an air leak as well....cause once the actuator reads .5 bar...then it opens and doesnt allow it to spool futher. so maybe the lines arent connected right.

ferni Grand Master

ferni

Posted
Posted

The turbos won't just explode at 1.4bar of boost, they will take it for a very short time... i'd be more worried about the damage it may have done to your engine, if you ran that much air with not enough fuel you may find it was detinating.... which could lead to rebuild time...

As everyone else has said, sounds like your wastegate isn't opening, probably because a hose is off or wired up wrong.... get the car to a workshop to get it fixed asap and don't come on boost while driving it there :ermm:

As for spooling up on stock turbos/stock engine i used to hit 1bar on my stock turbos before 4000rpm...

Beer Baron Grand Master

Beer Baron

Posted
Posted

i can tell you with a high degree of certainty that when he reconnected the vacuum lines he stuffed it up (or one hose is still leaking). basically your wastegate actuator is not getting a pressure feed like it should, so wastegate is staying shut.

wrxhoon Grand Master

wrxhoon

Posted
Posted
Ah icic, yeah it did seem to have unlimited pressure, it just kept going. Im just lucky nothing blew.. :pwned: phew.. really still on the adrenaline rush that it gave me.. heh. Also, btw is stock boost 0.5 bar? and at wat rpm should i be reaching peak boost? coz it still takes pretty long to spool up, like maybe 4-5k rpm for 0.5bar?

Do you know for sure that you have stock turbos ? 0.5 bar at 4-5,000 rpm in a healthy engine ?? Stock turbos should be 1 bar before 4,000 especialy in higher gears .

As for the high boost, obviously the w/gates dont open. Check with compressed air to see how much pressure they need to crack, you may have aftermarket actuators.

I wouldnt be letting it boost to 1.4 bar on a stock ecu, wont last long .

Yawn Mentor

Yawn

Posted
  • Author
Posted
Do you know for sure that you have stock turbos ? 0.5 bar at 4-5,000 rpm in a healthy engine ?? Stock turbos should be 1 bar before 4,000 especialy in higher gears .

As for the high boost, obviously the w/gates dont open. Check with compressed air to see how much pressure they need to crack, you may have aftermarket actuators.

I wouldnt be letting it boost to 1.4 bar on a stock ecu, wont last long .

To be honest, i dont know for sure if they are stock, but since they are low mount and everything else is stock, on top of the fact that the past owner didnt mention anything about aftermarket ones, my guess is that they are. Hmm now the main problem for me is the crap lag.. takes way too long to spool imo, even tho i havent sat in many stock gtrs. For the 1.4 bar that yesterday, i agree with all you guys opinions of the wastegate not opening, and im pretty sure the hose connecting to the actuator is leaking, causing it to not have enough pressure to push it open or sth. But because of the long period it takes to spool up to even 0.5 bar, nothing would be under mcuh stress as long as i dont fang it again until its all sorted heh. Also, i doubt the leaky hose connecting to the actuator would have anything to do with why my turbos are so laggy will it? Id be happy as if i could get 1 bar at 4000, as its really sluggish now.

Thanks for all the help so far guys :pwned:

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