peak boost problem

[cyman]

i have a problem with reaching peak boost. the car was setup by re worx and runs around 370 bhp in low setting 12psi and runs 400bhp in high setting 15psi.
 
the car is non sequential twin setup with a greddy profec 2 boost controller,power fc ecu and everything else to go with it (to much to list)
 
the problem i am having is that in low setting its only boosting to around 10 psi instead of 12 and in high setting its only boosting to 13 instead of 15 these figures match on both the greddy and on the power fc hand set.
 
ive removed and checked the silicon flexi pipes and cant find any splits or cracks.
 
removed all the vaccum pipes to check and replaced a few with silicon ones just to be safe. took it for a run after this and still no difference on tht run the water temp was 87,inlet temp 39,inj duty went to 89% in high but it didnt boost past .84bar or 12psi.
 
now the strange bit is if it was a boost leak why would i be able to change from high to low settings and actually get an increase and decrease in boost?? if it was a boost leak surely it let it reach so high then leak and stop any further boost???
 
only thing i can think of is either greddy solenoid issue or actuator failure. causing the wastegate to open to much or to early stopping peak being made??
 
anyone had anything like this or got any ideas as to what it might be???
 
any help is much appreciated
 
si

[cyman]

update :
 
checked the actuator for the wastegate and that is working fine with no leaks, replaced all the flexi pipes on the inlet side, popped upto rx motors and they gave it a quick look over and cant find any boost leaks anywhere.
 
am pretty stumped now as to what the problem is.
 
has anyone not had anything similar to this??

[HaywardRotary]

Speak to ReWorx.
Boost settings do not allways correspond with actual boost.

Regards
Carl

[cyman]

i already have. the car was mapped and setup in feb by them and i have talked through everything i have done with them. they arent sure now as i have done everything they wouldve done. the only way for them to sort it is to put it on dino.
 
the boost gauge is backed up by the commander on the pfc its just they are now lower on both than they were say a month ago...
 
i was hoping some people may have had this before and could point me in a direction i hadnt thought of yet

[BlitzBoy]

Points to something with the wastegate actuator( eg the spring have become stiffer or one of the signal vacuum lines has become pinched maybe), if you know how to operate the Profec dial a couple of percentage points on the high boost setting and see if the boost increases

[cyman]

did a full check of the actuator this morning. it opens the wastegate at 7-8psi and only drops 1 psi over a minute. i tried to increase the percentages for the boost in both settings low and high and saw some small increases in both but then they dropped back down again and didnt hold a stable boost........
 
 
its all very strange.
 
the only things i can think of now are a tiny boost leak maybe from a gasket somewhere but this wouldnt explain why it can boost to 13 psi in high settings and only goes to 10 psi in low....  the other thing that may be a possibility is if my greddy profec b solenoid is on its way out??

[rx jamie]

might sound silly but...cant you just set the boost at 17 psi so that you actually get 15 psi, and likewise set the boost at 14 psi so you get 12 psi?  thats i did on my pulsar and escort turbo.

[BlitzBoy]

yes silly jokin lol. You adjust the duty of the solenoid which on the profec is done on percentage of duty. The controller does not have the option settings to set a 15,14 psi boost level etc etc The only PSI setting is the SET GAIN, but I dont want to write out the profec controller manual on here and explain it lol

So for example it might be set at 28% duty which might have acheived 15psi on this set up for example, I am saying to set the percentage increase by two - three points to 30% say and see if the boost increases

[arrouk]

could this be due to it been setup and mapped in feb, ie cold damp air and now we are in \'summer\' its warmer and not so damp?  i only ask as the profec is adjusted via duty cycle not pressure.

matt

[BlitzBoy]

Yes that is a possiabilty Matt
Right here is the manual on how to adjust the duty of the Solenoid, dont say I dont do anything for you guys lol

//www.alamomotorsports.com/greddy/PROFEC_B_SPEC2.pdf

[cyman]

did a full check of the actuator this morning. it opens the wastegate at 7-8psi and only drops 1 psi over a minute. i tried to increase the percentages for the boost in both settings low and high and saw some small increases in both but then they dropped back down again and didnt hold a stable boost........
 
 
its all very strange.
 
the only things i can think of now are a tiny boost leak maybe from a gasket somewhere but this wouldnt explain why it can boost to 13 psi in high settings and only goes to 10 psi in low.... the other thing that may be a possibility is if my greddy profec b solenoid is on its way out??

as i pointed out here have already tried to increase the percentages in both low and high and got a samlle increase in boost before it dropped back down to where it was previously.  i went up 5% in the low setting 1% at a time and 3% in the high setting 1% at a time.

[BlitzBoy]

sorry didnt read your latest post dude, do you know anyone local near you who runs the same boost controller and try their solenoid?

[BlitzBoy]

Also check the Limit option on the controller is set 0%

[cyman]

yeah there is another rex owner who has one i can get to to try the sol. i am thinkin its the most likely thing now.

[arrouk]

did the change happen all of a sudden or a gradual drop in boost?

have you done any other mods since mapping exhaust, intercooler or pipework?

how old are your tubs? could they be getting a little worn?

these are all just ideas I\'m throwing out.

matt