Overboost with HKS EVC4,SSQV,Greddy Gauges.

[EK97GST]

I have an HKS EVC4 that I finally dinked around with and got things working on last night and to my surprise when I set it to 1 bar, in D1 with overdrive off I floored it and the initial boost I got rocketed up to 1.5 bar before calming down to one about 3.5K rpm into the gear, when shifting up I get little tiny spikes that go to about 1.2-1.3 bar and then immediately plop back down to where they're supposed to be at 1. I have the SSQV, Greddy Electronic Boost Gauge, and a stock turbo. I have K&N FIPK, and a 2.5 inch UICP.

Any clues what is causing this? Could it be from the T-25 spooling up too fast for the wastegate to go off quick enough? I really like the horsies I am getting at this level but I am concerned the overboost will hurt things. Opinions on this last statement?

Any help or suggestions would be much appreciated.

 

[EK97GST]

I was perusing other threads and someone with a similar problem & running really rich initially had a reply about the blowoff valve letting go too early. Could this be it? I'm going to try to tinker a little, but feedback would be nice regardless

 

[EK97GST]

I messed around with the nut on the blowoff valve and it cut it down a little, but I'm still getting relatively monstrous spikes for only boosting at 1 bar. I tightened it almost all the way it would allow and it still only affects it marginally. I don't get backspin but it is pretty tight on there. It still overboosts to about 1.5 bar in first and spikes a little when shifting to each gear beyond that, I'm out of ideas and I don't want my engine to explode, but I don't want to have to set normal boost at .7 bar/10 psi just so the spikes won't pass a safe place. ANYONE with a clue?

 

[Mitsuturbo]

Stupid question, but did you make sure you're set up for single port, not dual port on the EVC IV. I know when i got mine used, i had to reset it.. but dont remember what exactly it did when it was on a single port as a dual port config.

 

[EK97GST]

No it's on the right setting. I clipped the lines to be as short as they could be for where the stepping motor is mounted (under my K&N on the front passenger side) so it's kindof far away from the turbo and wastegate actuator, would this have anything to do with it?

 

[Mitsuturbo]

not really... mine is mounted to my fuseblock under the hood... works great.
have you tried tuning your offset differently? is your EVC working AT ALL? have you tried elimination the evc from the equation? take a hose and run it from your manifold directly to your wastegate actuator.. if you get low boost levels, then try just turning your EVC off and see if you get the same boost.. if so, then try re-tuning your evc... you did tune it in 3rd gear, right? your bcs is out of the works, right?

 

[EK97GST]

How do I tinker with the offset. Yeah the unit is working, it runs stock boost with a tiny spike when the unit is off. It also goes to the level I want after the initial spike is gone regardless of where I set it. I have an auto, so I just put in the stock boost that the car ran without the unit on/with the unit put to .2 bar of boost. (it read the same result on the gauge, spike and all) is the BCS the same thing as the waste gate solenoid (thingy to the outside of the coolant reserve tank)? If not I've been trying to find out where the hell the bcs is online but all I get is the stuff on the wastegate solenoid that I disconnected already.

 

[Mitsuturbo]

bcs is wastegate solenoid.. yes

 

[Mitsuturbo]

maybe you should try putting the evc in learning mode, and staying out of boost til' 3rd gear at a somewhat reasonable speed where when you get on it, it will hit passing gear, and thus start your stock boost curve so the evc can "learn" it.

i had to tune my evc 2 or 3 times before, to get it right.

 

[Mitsuturbo]

One last thing... i am assuming you are running a vacuum line from your manifold to your #1 port on the evc... then one off the j-pipe to the #2 port, and #3 to gate... right?

make sure you are not tapping a blue striped line (fuel pressure regulator) sometimes it will play havoc with your evc

i prefer to use my BOV line for boost monitor signal to the evc when running a stock, unmodified manifold

 

[EK97GST]

I ran the line that originally went from the intake manifold to the stock BoV into A T that goes into my SSQV and then into the EVC. Thoughts?

 

[Mitsuturbo]

that's your boost monitor line, right?

i say re-tune it... sometimes it takes a time or 2

if you hit MOD and see the number 100, you can turn it up to lower your boost... see if that helps

 

[EK97GST]

Yeah it's at 100 now. I'll mess around with that stuff for awhile and get back to you, thanks for all the advice man

 

[myblack98gst]

do you have full 3" exhaust behind it.... if so you will never get rid of the creep and spikes.


I have a big 16g with 3" turbo back and a Profec B. the boost is set for 15 psi and that held there perfect with stock exhaust but with the 3" it starts creeping around 5k and ends up at 20 psi by 5.7k.

If I install the super silencer into the muffler it will hold a constant 15 - 17 psi again....

 

[EK97GST]

I did a little tweaking with learning mode and whatnot and now my "spike" is actually probably under 1psi and then it chills where it's supposed to be until about 5.6K and then it drops a psi or two, but I've been told that's because the T25 can't keep stuff like that up in the high end. Regardless, I'm happy now

Peace

 

[Mitsuturbo]

good to hear. if you tune in learning mode at different ambient temps, you will get different results... if you're overboosting, then you should probably tune it when it's cold out... when it warms up, it will lessen the spike & creep