Hi guys.

checked the below:

1) The red wire is connected to the unichip right.
2) double checked vacum lines for any leak.


Test1:

-Disconnected the vaccum lines from the boost solenoid and connected the togther with a T bolt.

Result: The same boost level: 0.4 bar max . and boost constant till redline

Note: some of you said maybe the solinoid is faulty, my tuner had one from another APS ST. and i tried it and same results.


Test 3:

- as Zivman Suggested: Disconnected the vaccum lines from the boost solenoid and pinched the and made sure no leak

Result: Boost went to 0.6 bar constant.




any ideas??????!!!!!!

 

Good luck

 

Now that you got your exhaust, the easiest way to obtain 0.7~0.8bar of constant boost is to invest in a quality electronic boost controller. Get rid of the APS boost solenoid.

 

Update:

- Installed Forge actuature with yellow spring.
( as per the research i have done in here, i understood that if u have 11to 15 psi spring [yellow], you wont be getting hire than 15 psi, but u can get lower than the 11 psi. correct me if i am wrong )

Installed EVC 5, and set the max boost to 9 PSI.


went for a test drive.
wooooooooooooooohooooooooooo. boost is going high ..

but..

its going to 0.8-0.9 BAR = around 11 to 12 PSI ... ..... :S

what is the max boost that a stock engine can handle with APS ST ????
tomorrow i have a retune appointment, on which PSI is should set the EVC ???

any ideas ??
EVC 5 is easy to install so i dont think the install is wrong...



appreciate all the help and support from all of you guys.. u all are great.

 

Your spring pressure is the minumum boost that will be made.... basically your baseline. so if you are running an 11 lb spring, 11 lbs is your base boost (give or take) and you use a boost controller to go to higher boost levels.

With what you posted here, I firmly believe you had an issue with your boost control with your previous actuator. You were in need of a tune, your solenoid was broken, or most likely had your solenoid hooked up incorrectly.


Now you have another set of variable to contend with. You have a strong spring, and are using a boost controller, pushing the boost to levels that are dangerously high.

If it were me, I would put the old actuator in, and use the EVC, now that you have it, and adjust the boost upwards towards your target. I would do this under the supervision of a trained set of eyes. You really need to get your car on the dyno by a competent tuner and have them set your boost levels and tune.

 

i got the actuator from forge UK. and they confirmed that the spring is the yellow one and its rated from 5 to 15 psi...

i double checked it with them and they confirmed its 5-15 not 11-15.. any ideas.. ???

 

Turn the boost controller COMPLETELY off and see what boost you make. If it is still too high, you need to reduce preload on the actuator arm and/or get a lower rated spring.

My advise is to use the orignial actuator and use the EVC and adjust boost upward

 

i have tried the boost controller on the stock actuator and boost never went up.


what is the max boost (safe) on stock block with APS ST ??

 

I would shoot for about 10 lbs max.

 

5-15? ive never seen springs measured that way normally springs can hold up to twice their normal spring rate with an ebc.

 

So in the end you solved your problem by exactly following my solution and setup. As I mentioned in the old thread of mine, I had the same experience with HKS EVC+APS actuator. HKS EVC+ Forge actuator is the solution.

If you play around with the offsets on HKS EVC and the length of the actuator arm you should be able to get 9~10psi. That's how I set mine up for normal driving. Then 12~13psi for drag. My unichip map did just fine without any tweaking, but if you have a unichip tuner, go ahead and get it retuned for safety.

 

i am facing a wired thing guys ,,,,, every time i think i solved a problem another thing comes up.. but i wont give up...

took the car to unichip tuner,

the boost was not going more than 6.5 PSI. stable to red-line ( and got 420 bhp )

we have tried almost everything.

1) EVC ( ON ) and set to 70KPA =~ 10 psi

-car never boost more than 6.5 psi on the dyno.

2) EVC ( ON ) and set to 100KPA =~ 14 psi

- car never boost more than 6.5 psi on the dyno.

3) EVC (OFF) (it should give the spring pressure)

- car will boost till 12 or 13 psi and drop to 7 psi. by redline.

4) EVC ( ON ) and set to Zero KPA.

- car will boost till 12 or 13 psi and drop to 7 psi. by redline.

5) Tuner suspected that the EVC installation was wrong, and luckily i had the manual with me and we double checked the wiring and installation and everything is perfect.

so we decided to un-plug the EVC 5 buy removing the vacuum lines and check.

- connected the vacuum lines from the intake and actuator and result was: steady boost till redline, 6.5 psi
( i thought the spring pressure is 12 or 13 psi according the note (3) )


what do you think guys..??? any ideas ??

thanks all, appreciate ur support.

 

what are you using for exhaust. do you have the aps external wastegate or the crappy internal one.

 

APS ST exhuast
APs internal wastegate + forge actuatore ( yellow spring )

 

Was the dyno load based dyno? I experienced similar thing when I dynoed on non load based dynojet. My boost wouldn't go up above 7.5psi no matter how I adjusted the HKS EVC. I suggest you do a road tuning instead. APS ST is weird like that...

 

it is a load based dyno..

and i got same results on the street.

 

What? Didn't you said you were getting stable 11psi on the street?
Recheck the HKS EVC installation. See if any vaccum hoses are leaking... Also, there is a reset function for HKS EVC. Reset it. I think something is messed up with the HKS EVC.

 

NO.. on the street the same results as the dyno.

 

im afraid its the downpipe. its a poor design. most internal wastegate setups do better when the exhuast gases are divided after the turbo. on my setup i welded a piece of steel in the downpipe. what happens is the exhuast gas causes the internal wastegate to stay open longer than it should causing you to lose boost. i noticed that when i divided the downpipe boost held longer but still tapered off.

 

like below. back when i had my kit i tried my best and changed everything on the kit but still had problems. i also found an old picture that APS released of the kit and the downpipe WAS divided in the early pics. but for some reason they ditched the idea. probably because they kept saying they wanted to make it the safest kit on the market.

so instead of making a kit that would perform great, they sold a kit they knew would perform this way and not cause engine damage. they (APS) sucks.