RomRaider

howdy, i was wondering if y'all had any insight:

i can't reach my 24psi target boost:

no leaks
wgdc % makes no difference
tightening actuator arm makes no difference

boost holds steady at 22psi consistently and tapers to 20 by redline. is there anything in the TD tables that could be preventing my boost goal if my initial and max wgdc tables are maxed?

i'm using a grainger/perrin 3-bort bcs. i was able to boost 24psi successfully before (colder weather), but since i've put in a new block and a fmic and have been stuck @ 22psi.

please let me know what i need to post to provide more "meat" (logs/setup info).

thanks in advance!

what turbo?

if it helps, fp green

***edit***

just seems strange that i'm hitting a wall. could anything with a tune (specifically Turbo Dynamics) cause this if both WGDC tables (initial and max) are maxed out (100)?

Something leaking on the intake side after the turbo?
BPV\BOV not holding pressure?

i'll do a pressure test this weekend, but all seems well. i've reclamped all connections and the bpv is crushed to keep it closed.

besides mechanical issues, is there anything with the Turbo Dynamics tables that could affect target boost provided the WGDC tables are maxed out? too high this, too low that will cause me not to hit target boost. anything like that? if so, what can i change?

if your values are 100%, you have a mechanical problem somewhere, you should be overboosting like crazy.

check your wg actuator?

well, i haven't actually tried 100% wgdc, i'm just assuming based on the fact that i saw no change from 60% bumped up to 85%.

mechanical, eh? hmmm... is there any way to tell if it's exhaust or intake?

***EDIT***

actuator seems to be functioning ok.

which value did you change? only the initial wastegate duty cycle? or both the max wgdc and the initial? did you log both 60% and 85% to ensure they were actually running that high?

What are you reading boost with? You do know the stock MAP has a max limit right?

both initial and max were adjusted. went as high as 85 on initial and 90 on max if i recall and there was no significant change (maybe held higher at redline by 1 psi vs. max at 75). duty cycles were actually that high when logged.



i've read that, but not sure what the limit is. do you happen to know the limit of the stock MAP sensor? i'm reading boost via romraider. i also have a stock (lamco) boost gauge which doesn't help much at that pressure. i HAVE been in the 24psi range before, but lots up upgrades and hotter weather have come into play since then.

according to the gauge, it appears i'm boosting higher when in 4th/5th (didn't have my laptop with me), but can't be certain. i will unbolt my header/uppipe tonight and retorque it. if no change, i'll pressure test the intake this weekend.

Once you hit 95% on a 3 port in interrupt on a single port wastegate (internal gate), you're about out of options as far as the tune. I'd just make sure you actually log primary wastegate duty that high. It is the "actual used" WGDC, so if there was misstep in one of the other maps it would show up in the primary wastegate duty log.

Your BOV may not be holding. I've used TXS BOVs on several cars running 20+ psi. They work great, though I suggest adding 1-3 washers. Perrin makes a "rotated" BOV that uses boost to hold it shut, no way it could leak. One local car would not boost past 16.5 psi on a stock BOV. We tried an 04 and 05 STI BOV, both crushed. Would not hold. That was a 3" inlet 8cm FP green on a 05 STI, FMIC, catless exhaust, stock header. Find someone with a BOV you can borrow, swap it out, see what happens.

I think the standard spring on an FP green is ~11-13 psi. You might do better with a 15psi spring. I think FP sells them.

as a matter of fact, i have a greddy bov sitting around. i'll give it a go and see what happens. as for the actuator spring, there's no changing it unless i do a whole new actuator seems like the unit is not made to be taken apart. at that point i may as well go EWG.

i'll try the greddy and see what happens, although the current crushed sti bpv was able to hold 24psi+ in the past. the greddy was removed because it was failing to open quick enough causing surge at lower pressures. we'll see what happens.

thanks again everyone! if there are any more suggestions out there, please don't be shy and post them up.

cheers!

Yes you cannot replace the spring, the entire actuator has to be replaced. It would still be 1/4 the cost of an external with a atmosphere dump. I believe FP offers them.

If your logging with rr and the stock map sensor you can only read up to 22.? at sea level.

If you log 'Manifold Relative Pressure (Corrected)' that is true. However, if you log one of the direct parameters - 'Manifold Absolute Pressure (Direct)' or 'Manifold Relative Pressure (Direct)', there's no effective limit (the latter assumes sea level pressure).