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R33 Pfc Boost Controller Issues

dangerman4

By dangerman4,
in Engines & Forced Induction

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dangerman4 Mentor

dangerman4

Posted
Posted (edited)

im running a 18 pound actuator and a brand new PFC boost control kit.

attached is a dyno print out showing the wave.

i have installed a 2mm restrictor in the feed line to the solenoid and the results are on the printout.

before i installed the restrictor it was even worse.

the boost settings are on 1.6 kgm cm

and the duty cycle is on 83 %

its a built rb25det with the new gt3540-iw

if i go any higher with the boost the wave gets bigger, and longer.

does any one have any other solution?

cheers Darren

post-24852-1163580810.jpg

Edited by dangerman4
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dangerman4 Mentor

dangerman4

Posted
  • Author
Posted
how are the results varied when you adjust the duty cycle?

how is the solenoid connected? (draw a diagram)

where is the map sensor connected to (diagram would help)

the map sensor i joined with a T fitting into the line to the EBC from the plenum

and the wires plug directly into the pfc

the solenoid is wired up as you suggested in your pfc thread.

and checked with a multimeter.

if i go any higher with the duty cycle it becomes even more unstable.

Sydneykid Grand Master

Sydneykid

Posted
Posted
the map sensor i joined with a T fitting into the line to the EBC from the plenum

and the wires plug directly into the pfc

the solenoid is wired up as you suggested in your pfc thread.

and checked with a multimeter.

if i go any higher with the duty cycle it becomes even more unstable.

What Paul suggested plus.......

Since you aren't using the EBC, reduce the amount of vaccum tubing, it's just buffering the signal to the PFC map sensor.

:O cheers :)

dangerman4 Mentor

dangerman4

Posted
  • Author
Posted
What Paul suggested plus.......

Since you aren't using the EBC, reduce the amount of vaccum tubing, it's just buffering the signal to the PFC map sensor.

:O cheers :)

Sorry Gary you have lost me.

i have a bad headache.

what ebc are you talking about?

where do you recomend running the lines from for the ebc?

should i get a fitting put into the outlet of the comp cover?

or what?

also should i plug the map sensor into the bov instead?

cheers

paulr33 Grand Master

paulr33

Posted
Posted

also to note the FC has a boost cut protect mode which may be activating, if the boost spikes 0.25kgcm2 over the value you dial in under SETTING, BOOST it will perform boost cut and back itself off. you may be hitting this, i would expect the engine check light to come on however

Leadfoot Enthusiast

Leadfoot

Posted
Posted

Looking at the boost curve it appears that the initially required duty cycle (at 3500 rpm) is not set correctly to meet your boost target of 1.6kg/cm).

1) At 3500 rpm your turbo is finally making enough pressure to overcome the actuator spring pressure. Prior to this your 2mm reducer and bleed off valve have no effect.

2) The sudden reduction in boost pressure after 3500 rpm is due to the solenoid bleeding off too much pressure. The duty cycle is too low at this point (even at 85% open) and the waste gate has opened too much due to too much pressure on the actuator. This suggests the reducer is incorrectly sized and you need to reduce the duty cycle (overall) in order to gain some control at the onset of boost - 3500rpm. My guess is that a bigger reducer would give you better control of boost at this point. The 2mm reducer cannot relieve enough pressure fast enough at this point and the waste gate is opening too much.

3) The boost response from say 4500 rpm to 6000rpm is fairly normal.

4) To retain a flatter boost curve after 6000rpm a multi channel boost controller might be needed to pull down the duty and open the waste gate as this turbo really starts to come on steam. A simple proportional controller as per the PFC may not be able to act fast enough in this sort of situation.

dangerman4 Mentor

dangerman4

Posted
  • Author
Posted
Holy f**k Sticks Batman!

Have a look at the boost of the Gizzmo!!

It's almost vertical!

What was that like to drive?

as its my wifes car she loves it, and my 2.5yr old daughter squeals out "More Boost Mum"

Being a auto it gets very interesting very quickly.

Cubes Grand Master

Cubes

Posted
Posted

Steve might be able to shed some light as he made 320 something rwkw through a HKS3037 + all the nice bits to get there with 20 something psi with perfect boost control

You 'may' want to give Shaun a buzz as he tuned Steve's many years ago and knows them like the back of his hand.

Just like the AVCR they can be a hassle to setup.

J34 Proficient

J34

Posted
Posted

Can anyone post the top attachment as I can't seem to view it. I also have the PFC boost kit and my boost curve is also like a wave and its affecting the whole power graph, im not sure if the self learning thing has changed it since the tune ill have to get it on a dyno again to check it out.

paulr33 Grand Master

paulr33

Posted
Posted

are you referring to 255 on the boost screen? its not used but apparently its part of the logic control. the manual doesnt say shit about it, datalogit cant touch it and the hand controller cant touch it

dangerman4 Mentor

dangerman4

Posted
  • Author
Posted
also to note the FC has a boost cut protect mode which may be activating, if the boost spikes 0.25kgcm2 over the value you dial in under SETTING, BOOST it will perform boost cut and back itself off. you may be hitting this, i would expect the engine check light to come on however

as stated in the original post the boost is set at 1.6kgcm2

yet boost is only making 21 psi! how would boost cut be activating?

does anyone have english instructions for the pfc boost kit?

i have posted the dyno graph in the original post

cheers

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