Need Help With Boost Controller - Rb25det

[nismoCat]

I have here a R31 GTSX which has had a RB25DET put into it out of a 97 front cut, so the problem is it's only running 4 to 5 psi when boost gauge was put on, i also know the 2 stage boost is not there either, so i went and got a bleed valve type boost contoller and it tells me to put it on the hose that comes from the actuator to the front of the turbo, Well the hose coming from the actuator goes to the plenum, i put the bleed valve there and it did nothing, i had a good look and i can't find any hose coming from the front of the housing at all?!!

Can someone please help me with this as 4-5 psi is no good, Might as well had the old RB20 in it still!!

Thanks in advance!!

[(B1) MR_fanny]

from memory its the hose from the stock IC pipe to the bleed to the actuator? theres a third hose that gets blocked off. maybe someone can clarify. obvious question but you are adjusting the bleed valve correctly yes no?

[nismoCat]

from memory its the hose from the stock IC pipe to the bleed to the actuator? theres a third hose that gets blocked off. maybe someone can clarify. obvious question but you are adjusting the bleed valve correctly yes no?

As far as i know i am using it correctly, But the point is the only hose coming of the actuator goes to the plenum, no t-piece just one hose?? Do you think the the sphincter of the universe who did the conversion (which i won't name) has connected everything in the right place??? As you could imagine this is very frustrating, the actuator arm has no thread on it, thats why i am trying to do it this way.

[cheez]

all the 'the sphincter of the universe' who installed ur engine has done is eliminate the stock boost controller. normally the line from the intake plenum goes to the top of the standard solenoid and then a t piece from the bottom of the stock controller goes to the consetina pipe near the turbo and and the wastegate.

for installing a boost t, run the valve in the correct ditrection between the plenum and wastegate. by doing this u are regulating the pressure u need for the gate to open thus adjusting boost

[RandomHero83]

If you are located on the northside of brisbane drop me a line I can look at it for ya if i have the time spare.

[nismoCat]

I don't need to know how it is stock, i just need to know if i have the bleed valve in the right spot and if not where to put it, i had a look at the old rb20 turbo from the old motor and it has the hose coming straight of the actuator into the front housing of the turbo, is assume this is where you put a bleed valve on that yeah?? But on the 25 in the car now the hose runs from the actuator all the way over to the plenum, so we put the bleed valve on that hose and either gives no boost or just the 4-5 psi that we can't seem to get past???!

And RandomHero83 i am located in northern sydney.

Thanks heaps for everyones help so far.

[blind_elk]

The only difference between your current setup and the RB20 is that your current setup gets its boost signal from the inlet plenum, so it is measuring boost at the inlet valve. The RB20 is measuring boost at the compressor wheel, and as such is subject to significant spiking of the signal as you build initial boost.

Your new bleed valve has to T into the line going to the wastegate actuator (regardless of where that line comes from).

[smidy]

hey m8,

i am rather inexperienced when it comes to moding my car myself but heres a pic i used kindly posted by another member. no complaints just need power fc now!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! hope this is of use

[nismoCat]

So is anyone elses hose going to the plenum from the actuator??

I might block that and see if i can find somewhere to put on the cooler pipe, like shown above, Hey for all i know the bleed valve might be faulty?? If i knew a good mechanic i would take it too him, but i don't and and gettin ripped off any more! If the 2 stage thing was there i would just hook that back up at least i would have 7psi high in the rev range then, i'm sick of stock cars blowing me off!!

Surely it can't be that to hard to up the boost now cmon!

[nismoCat]

Ok, Well it still aint working, I took the ball and spring out of the bleed valve and nothing still, i also took the hose of the actuator and vented it to atmosphere and still nothing, i thought that should make it boost infinate??? No matter what i seem to do i can't seem to raise the boost?? Could my plenum (a hose or something??) be leaking?? Could the wastegate actuator be screwed? Next i am going to try putting the hose from the actuator before the throttle body, inbetween the cooler and the throttle body rather than after the throttle body on the plenum...........??

Please help me if you can! PPPLLLEEAASEE!!!!!!!!!!!!!!

[jryc888]

are you sure you installed the bleed valve in the right direction? as someone previously pointed out the valve only goes in one way, i.e. the input nipple (the small tube where you attach the hose) with the small hole at the end should be facing your throttle body/intake manifold while the nipple with the bigger hole should face the actuator. there's a very good diagram of this in the turbosmart website regarding their "boost tee manual boost controller" installation instructions.

the factory setup is connected in such a way that the pipe from the intercooler output (i.e. after the intercooler and going into the manifold) has a small tube which is then connected to the boost controller and actuator via a tee pipe (refer to previous picture showing blue intercooler pipe). this tube from the intercooler pipe is therefore located before the throttle body and plenum on a standard setup.

the picture of your engine shows that your intercooler pipes are not original (maybe explains why there is no small tube for the boost controller) because its diameter is smaller than the intake manifold pipe to which it is connected by a big rubber hose. you can clearly see it because the big rubber hose has a reducer (one end is bigger than the other). in my engine, the hose is one size (intercooler pipe size = manifold pipe size). this small intercooler piping may be a concern if you jack up the boost as this restricts airflow to and from the intercooler....

Ok, Well it still aint working, I took the ball and spring out of the bleed valve and nothing still, i also took the hose of the actuator and vented it to atmosphere and still nothing, i thought that should make it boost infinate??? No matter what i seem to do i can't seem to raise the boost?? Could my plenum (a hose or something??) be leaking?? Could the wastegate actuator be screwed? Next i am going to try putting the hose from the actuator before the throttle body, inbetween the cooler and the throttle body rather than after the throttle body on the plenum...........??

Please help me if you can! PPPLLLEEAASEE!!!!!!!!!!!!!!

[J3TR33]

hey mate, i didnt have the standard boost controller on my car either and i dont have a boost controller on it atm... i had a line running from the wastegate actuator to the inlet manifold.. but what i did is, i tapped and screwed in a nipple on the intercooler piping before the throttle body. connect a hose from this nipple to the wastegate actuator and run your boost controoler in between the wastegate actuator and this nipple.. and make sure the nipple on the intercooler piping is fairly close to the turbo and it doesnt leak.. there is a D.I.Y thread about FMIC installation and people having to install one of these nipples as FMIC's intercooler piping dont come with it.. il try get a pic for ya of myne.. oh and it has improved lag by a fair bit.. boost comes on alot quicker..

i think there is something about installing a boost controller after the throttle body that doesnt quiet work.. not sure on the technical side of it.. jst read it somewhere