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Boosting Problems With A Highmounted, Externally Gated Rb25det

zacy-g

By zacy-g,
in Engines & Forced Induction

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zacy-g Newbie

zacy-g

Posted
Posted

Hey guys,

Just joined up to see if anyone can help with a problem I'm having my 25det in my passage. It is a highmounted td06-19c, with and 50mm (unsure of brand) wastegate. No other modifications done to the motor yet. I brought the motor from a guy who had it in his written off hr31 coupe. I saw the motor running/turbo spooling in the car before we pulled it out...

Now the problem is that since we have put the motor in (day before yesterday) and got the car driveable after completing the s13 coilover conversion etc.. the turbo does not spool (cannot hear air being sucked in/wastegate not working). I am thinking that some lines are plumbed up the wrong way on the turbo??

If anyone has any starting points for me to start troubleshooting from would be a great help :cool:

The car idles and drives fine, although is excessively slow, due to the turbo not working. The car is also getting extremely hot (water bubbling in radiator after 5 minutes of normal driving).

Any help would be appreciated!!

THANKS!

TiTAN Grand Master

TiTAN

Posted
Posted

the turbo has oil feed and return, they need to be facing straight up and down respectively it may also have water feeds on the sides of the core it doesnt matter as much which way they are connected.

are you sure the wastegate isnt stuck open? is there a spring in it?

jarrod83 Community Regular

jarrod83

Posted
Posted

what lines do you think are wrong? they are pretty straight forward.. maybe a photo of your setup may help us ? also what ecu is it running.. have the afrs been tuned? and can u check to see if the turbo can spin freely?

zacy-g Newbie

zacy-g

Posted
  • Author
Posted

thanks for the replies guys, will check to see if there is a spring in the wastegate in the morning..

the afr hasn't been tuned and is running a standard computer, so should make 5-6psi..

will also grab a pic in the morning for you to have a gander at, the engine bay is a real mess at the moment though lol. i did this afternoon remove the pod and afm from in front of the front turbo housing to see if the compressor wheel could spin freely - it definately can..

:sick:

R31Nismoid Grand Master

R31Nismoid

Posted
Posted
thanks for the replies guys, will check to see if there is a spring in the wastegate in the morning..

the afr hasn't been tuned and is running a standard computer, so should make 5-6psi..

It will make whatever the wastegate is SET to make.

If there is a 20psi spring, it should make 20psi if all things are correctly done.

It is not controlled by the ECU, rather the gate - that afterall is what the gate does :)

Sounds like you have installed the lines incorrectly onto the ext gate.

zacy-g Newbie

zacy-g

Posted
  • Author
Posted (edited)
It will make whatever the wastegate is SET to make.

If there is a 20psi spring, it should make 20psi if all things are correctly done.

It is not controlled by the ECU, rather the gate - that afterall is what the gate does :)

Sounds like you have installed the lines incorrectly onto the ext gate.

http://img687.imageshack.us/i/img0444q.jpg/

The blue line with the t piece out of it (running to the manifold) is the only line running to the gate. It is running from the front housing to the gate, with the t-piece to the manifold...is this incorrect?

But even if the spring is a 20psi spring as you said, shouldn't the turbo be working atleast?

Edited by zacy-g
PM-R33 Grand Master

PM-R33

Posted
Posted (edited)

The problem is definetely in the wastegate staying open and not letting the turbo build boost.

So the wastegate vacuum line is being split to go to the compressor housing niple AND the intake manifold?? Why is it being split to run to both? Why is it not just being run from wastegate to compressor housing?

Easy way to test it, disconnect the vacuum line from the wastegate and plug the lines up so there isn't a vacuum leak and take it for a carefully drive to see if it starts to build boost. If it doesn't you know the wastegate is screwed and staying open, it it starts building boost you know its simply a vacuum line problem. However back of as soon as it builds boost as with the wastegate shut it will run maximum boost possible.

Edited by PM-R33

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