boosts very slowly till 10psi if i get any boost. i boost leak tested and no leaks. I tried a diff N75/mbc, i replaced my r1 with a forge 004, nothing fixed it. Ivaggedand no codes so its not in limp mode.my boost goes to 5 psi no problem, but struggles to 10psi, but sometimes it goes to 15psi no problem when cold mostly. when i let off the gas at full wot it kinda jumps up a few psi.
if anyone has any ideas let me know plz..
also, with the forge 004, my idle when cold is kinda funky, its up and down and then fine after a few mins.
thanks

 

I was having similar issues I thought it was a leak or MBC/N75 was junk. Check your wastegate actuator and make sure it's working. Mine was stuck closed so it kept boosting up to 20psi and I ain't got no chip. My turbo compressor housing wasn't clocked right so the waste gate actuator rod was of center which caused it to stick. Check out my thread "overboosting with n75 and mbc" the link is below. And yeah it could cause your boost to be low if its stuck open. Where did you get your turbo?


https://www.audiforums.com/m_815999/tm.htm

 

so your main problem is when the car warms up?


if i am reading right and that is the case, might be one of your hoses have got a leak, but isn't noticeable till the car is warm....... that is what my problem was.....

 

^^^^^^
i boost leaked tested in -10 weather. think boost leak testing when the car is warm andwamer weathermight help?

turbo is stock k03

 

i didn't even have to boost test mine......... i looked at the hose i thought was it...... when i did my boost guage i t'ed into a hose and it was junk so kept part...... it frayed some and i replaced it, but it was actually the rubber hose that my boost hose was run into.... so i replaced it

it would shrink when cold and expand when warm/hot...... that cracked it

here is a pic of hose i was talking about, circled

 

all my hoses are less than 8 months old as i replaced them all, will take alook again..
i think the forge 004 is causeing me some issues. first my CEL came on and it sounds funny during idle. and now my EPC turned on....EPC=Stupid. i had no power what so ever. lucky i was taken a right onto a small street and not a left on a busy street. would the forge 004 cause a CEL and the EPC to come on?

 

the rubber hose attached to the brass fitting was 8 months to a year...... it is supposed to be pliable rubber, but was actually hard

 

it never has on mine. if you've ruled out the n75 and there are no leaks, i would think its the wg

 

and if you are right chaos, that is going to suck

 

While you car is running have someone open the throttle while you check if the wastegaterod moves. It's probably better under load to see it move a lot. Have some put it in gear and press the brake and accel pedal at the same time and watch it. (Do this with safety in mind)If it does not move then its your wastegate. If it moves alot then it's got to be a vacuum issuebutcouldbea wastegate vacuum issue. If it does move try to move itwith a pry bar or something. If you push it out hold your finger on the vacuum tube to the wastegate and see if it holds pressure. If it doesn't you wastegate is junk.If it does hold pressure and you have a hard time trying to move it open yourself it may be sticking or like myold turbo has got a hole around the wastegate flap in the exhaust housing hope this helps.