omgbossis21

Okay heres the deal... I have an apexi avc-r boost controller on my 98 hyundai accent (yes hyundai lol). When I turn it off my boost is fine at the set internal wastegate psi which is six. The problem is when its on.... I cant boost barely over 7 maybe 8psi... unless I turn it up to like 13psi then I might get 8.... Im not getting it until the high rpms as well.... I am also getting alot of oscillation in my boost which is bad. I turned the f/b speed down to 1 and it helped some but still undershooting bad... I turned f/b speed off same deal. I've checked over and over again to make sure its setup right and everything seems good. I've heard of installing a restrictor in the wastegate line and it working properly if someone has a problem like this... any ideas??

leed

My AVC-R can be a tad touchy as well; but only when I get past double the spring pressure. In my case, I was on a 6-7psi ish spring, and boost control would be very good untill I tried to exceed about 14psi. It would either overshoot, or go into huge 2-3psi oscillations. I shimmed my WG spring and got couple more steady psi outa it.
IMHO, the AVC-R has trouble once you exceed 2x the WG spring pressure.

Try setting it for like 11psi using only the duty cyle setting (w/o setting a boost target yet), then once its close, set the appropriate boost target. Then slowy add some boost by increasing the duty and boost target at the same time. (small increments)

Good luck.

omgbossis21

Okay well heres what I did today :

Replaced all the crappy autozone silicone vacuum lines with real rubber ones
Added a "restrictor" to the wastegate, its just a vacuum tee with extremely small ends in hopes of slowing pressure to the wastegate
Reset the ecu and apexi avc-r

I still need to drive it. If it doesnt work out I will try to set it the way you did. I have tried setting it anywhere from 11-13psi with the same results ;-(

jdm monkey

wanna trade with my Greddy profec B spec II?

omgbossis21

No im not going 2 trade, if anything I'lll sell this one and get a manual. Heres what happened after I drove it.... So I punch it 8psi YES 6psi NO 8psi YES 6psi NO etcetcetc STUPID POS @#*u@$)%_#$890 It worked fine like 2-3 weeks ago all I changed was some vacuum lines. I put them back to normal with better lines and this is what I get.... I played with the settings f/b speed off different target boost levels all I get is 2-3psi osciallation. This sucks ***.

leed

Dont get pissed yet. Have you tried setting the boost w/ duty cycle control only? (Dont set a boost target) Once its close then set a target.
If I were you, Id reset the AVCR, and start from scratch.

LateApex

Does the ECU use any kind of boost control solenoid that may still be on the car?

omgbossis21

I dont understand how you set the duty cycle w/o a target. I did reset the unit after I did all the vacuum lines and stuff.... When you reset it the unit goes back to .60 target and 30% duty cycle. I changed it back to 70 target and started messing w/ the duty cycle with no luck. Their is no stock actuator or anything (its a hyundai lol). I found the rpm wire had come loose and was constantly losing voltage today. I fixed that and checked the rest of the wiring and when i drove it the same crap happened. I didnt reset the unit again though, I will before work tommorow and see what happens. It was working fine 2 weeks ago =-( I was boosted at 2000rpm seeing 10psi until redline , this sucks.

robs99si

post up pics of your hyundai's engine

omgbossis21

These are pics when I first boosted it... Some things have changed with the apexi avc-r install, oil lines is now stainless and a few other things. Im running Tiburon mass air flow sensor and tiburon injectors (240cc better than stock 190cc), Malpassi RRFPR 1:1, Eclipse walbro 255l fuel pump, Unorthodox crank pulley, 8.5magnacore plugwires, Tiburon Throttle body (matched my IM port) and some other minor stuff. I just gotta figure out my current problem lol