Did the install, everything was easy. Did the mods to the rom. Switched to direct boost control (vice load-based). Went out and had Base WGDC at like 50%. Did not make much boost at all.. Like 12psi. Then i slowly started adding it back in. My target is 27psi peak, sloping down to 25 until about 5.5k then taper to 19psi. So i got it pretty much dialed in, but im using like 100% WGDC!!! At 3500, i drop to 94% duty, then 5k + is about 80% duty. It is normal to push the stock turbo that hard with a 3-port to achieve my target boost? I know the stock VII dv leaks a ton, so i have increased the spring pressure on it (cheap screw mods). Im awaiting my forge rs next week, but i wanted to get a jump on the tuning. Here is my best log from the night. Only 2-cts of knock

Side note: Boost leak checks were performed a few months ago. Could my crappy crush bent local exhaust shop cat back be blocking up that bad? And the stock plastic seat DV be leaking that bad (the spring is real tight on it, it flutters pretty bad some times, so the point of stalling out).

Edit : I keep reading about how people are using 50 and 60% WGDC and i just feel something is wrong somewhere.

 

similar here i need to push WGDC to 100% @ redline to get 23 psi or so.

at 80 @ 3500 rpm i hit 26 easily though. check for a leak!

also the WGDC controls the WG, basically so check your stock WG settings.

all my experience is on a IX, with 100% WGDC @ 3500 rpm i hit 29psi. so for a stock VIII turbo u seem right on track.

 

stock plastic BOV will severly limit your boost, and require much higher dutys on a 3 port to get even mild boost levels. swap out the BOV with something stronger and be sure to turn the duty cycles down a bunch before you do a pull. you'll find that the stock 9 valve (metal) is also limited beyond 28psi.

 

When I changed out my stock plastic dv for a synchronic I accidentally spiked to 37psi. I had even lowered the boost limit on my ebc just forgot to change the set and pow... I saw 32 and stomped on the clutch but the ebc said 371

 

Ok, my forge arrives tommorow. It has been very hard to get boost to stay constant. Last night it was about 50 deg outside and i kept overboosting. I lowered WGDC to the 80's and drove home this morning and had it back under control. The Forge RS should help stabilize my WGDC settings. We'll find out tommorow.

 

KevinD speaks from experience. We had the stock 9 DV at 85% WGDC and anything over wouldn't hold build anymore boost. We swapped to a Forge and noticed 2 things -

The 9 I had, maybe all?, wouldn't hold more than 28 even at 100% WGDC
The response of the Forge was amazing on my car

Get rid of the 8/9, get something heavy duty (Synapse, Forge) and don't look back.

 

just boost tested my stock IX DV/BOV it leaked @ 10 psi.....

and from i could feel leaked bad!

swapped it out i will try to tune my 3 port today but there is a lot of rain

 

Well the forge is amazing. It eliminated my low-rpm DV flutter stall out issues. And it holds boost like a champ! I havent had a chance to get back in and try to use the boost error correction table yet. Here is another question: My 4-bar map and my boost gauge differ by a LOT! I used the formula

0.238683*x-14.7

I changed 14.7 to 14.5 because im about 300 feet here. The MAP reads 0 at engine off. about -8.9 to -9.1 at idle (should be about 20 in Hg.) My boost gauge reads 25 in Hg at idle. Now on to boost. At 10psi the boost gauge and map are dead on. At 15 psi, the boost gauge reads about 1 psi higher. At 20 Its about 2psi higher. And if i get to like 25 on the MAP the needle is pretty much stuck at 30psi on the gauge. Now, this gauge was a bargin e-bay deal so i dont have a lot of faith in it. Its reading HIGHER than actual boost? If the burdon-tube is worn out then it would have less resistance to pressure and cause the needle to deflect more. Anyways, thats the idea, now which one should i trust? The gauge or the MAP? I dont really like running the gauge to 30PSI even though the engine is NOT knocking and the MAP says 27psi. Any ideas?