Past Issues:
Stuttering power
Turbo exhaust leak
Low power
Unable to hold boost

Resolutions:
Just installed EU
Tighted loose and missing bolts around turbo
Installed Greedy boost controller

Now:
Over all much better response and performance but still have some issues.
HP 338 TQ 360
Can't hold boost at higher RPM
Stalling often and takes several attempts to restart. ??
SES light (not sure cause yet)

One day everything will just work, One day...

 

how much boost are you running? 338 is low
alot of APS ST cant hold boost, on 350zmotoring.com, theres alot of APS ST guys
the ses light is from getting dynoed (have nissan reset it, theyll tell you its a sensor thats messed up, just reset the light)
stalling ide check the vaccum -20-25 is good, Did you get rid of the MAF? i dont know lot about APS, check the BOV for a leak (my friends had a leak). My friends with a APS ST have none of these problems

 

hope your not using that exhaust converter/restrictor. i just put on the APS exhaust and makes a HUGE difference in holding boost to redline.

 

I got the jic single side, i dont have any of those problems. who installed it? oh yeah, my hp numbers were about the same as yours until i put a 3 inch exhaust on the car. sux that aps didn't just say that in the first place. if you got any more problems hit me up. the ses light is probably a misfire, most turbo guys regardless of brand get them. i stuck with the unichip and i'm about 15 hp away from 400. you just need to find the right tuner.

 

My boost peaks around 10psi but doesn't hit that until around 4500 rpm. I am not able to post the dyno as I don't have a copy yet.

 

I am using part of the Y pipe from the evo2. I hear others saying that will cause restriction issues but its hard to believe.
My vacuum is around -24
I want to replace the BOV. Any recommendations?

 

Who did your install? Were they an authorized aps dealer?
You will need someone who can tune the kit to straighten out your problems.

 

That's why I switched to the EU so anyone (almost) can tune it. I have to say the EU made a big difference in the performance and stuttering power issues I had.

 

Did you know there is an unichip tuner in florida? I understand that but if the car was stuttering some thing wasn't done right when it was installed. It should run fine out of the box. At worse case the only thing I've seen is boost tapering off. Other than that 99% of the time it's an install issue.

 

There was no UniChip dealer at the time. Even if everything ran perfectly I didn't like the fact that I had to find some out of the way shop to tune the UniChip. As far a the install, if the instructions are correct and followed correctly it shouldn't matter who does the install. You just mounting hardware to the car. I feel there is a boost leak still though.

 

not to sound like a smart alec but if you still have a boost leak then the install was'nt done correctly. tig488 did a turboxs rfl on his aps st and capped off the recirculation pipe. i'm guessing you want something louder because the aps bov is pretty effective at our boost level. i would take your car to someone that has done a couple of these installs to troubleshoot these issues.

 

i along with several other people think the boost leak is caused by the wastegate. maybe they had a bad batch or something, some people have it and some dont, GRD put on a stronger actuator and it held boost. i wired mine shut and it holds boost. i am now waiting on my stronger actuator. believe me, ive rebuilt this kit from the ground up searching for the boost leak problem, i retorqued all my bolts, pressureized the system, resealed all the flanges, changed bov, welded egt bung, took off exhaust completely, then installed JIC single 3" exhaust, disconnected the unichip boost controller and used a mbc. you name it and think it, ive done it. so far the only thing that helped is changing the actuator. good luck.

 

Tig,

Thanks for the help. You and I seem to have a faulty product. I will try a new wastegate too. At this point, what the hell.

 

Hey Tig,

BTW I had the same loose bolt you did. Actually mine came off.

 

its a PITA getting that bolt tight.