HELP please very bad surging, run out of ideas.
 

Hi all,

I have a 2003 WRX STI UK, I have had full decat, K&N Typhoon, Walbro fuel pump, HKS ssqv DV valve, HKS EVC 6 and full remap for all Mods by ECUTEK by a reputable mapper down south.

Took the car out today on the motorway and when in 4/5/6 gear @ 3k revs and flooring it, it surges badly and sends shudders throught the car, on the boost gauge you can see the needle flying from 1.5-1.3bar rapidly. If i ease of the throttle and ease the power in then it smoothes it out a little, It has been doing this since i fitted the decat but have had it remapped after all the work.
I spoke to the mapper and he said it is the air backing up to the turbo because it cannot get it through fast enough. He suggested either changing the turbo or dropping the boost. I have dropped the boost to 1.3bar and it still does it.

Please can someone help me solve this I have checked for leaks on the intake system, I have dropped the boost, I have tried various things but with no joy. One thing i need to do is check the restictor pill is not in the regulation pipe as i'm not sure if I have took this out when fitting the Boost controller can some one point out to me where this exactly is.

Sorry for such a long thread but once this fault is cured the car will be perfect. Thanks Guys.
Dean. :notworthy

Ask your mapper to reign in the duty, that should resolve surging. What turbo is it?

Jay it's the standard turbo on a 2003 wrx sti uk. I the mapper tried turning down the duty cycling but it was still happening, So i fitted EVC to try and take control of boost regulation but no matter how much i fiddle unless it's set to something like 1.0bar max boost then it starts surging, should i have fitted the restrictor pipe with the EVC 6 or took it out i'm not sure if I have or not. Cheers Dean.

I wouldn't have thought a restrictor alone would resolve it. I'd be hassling my mapper on what to do.... didn't he suggest a restrictor?

Are you running a 2 or 3 port solenoid?

It's using the HKS EVC 6 solenoid/stepper motor. The mapper seems to think I have to live with it, He suggested lowering boost which I have done but still not resolved it failing that He suggests upgrading the turbo Which I will be doing but not till the end of this year.

What spark plugs would you guys recommend on my car?
Dean.

You must have a mechanical problem somewhere then because this isn't a common problem as far as I know. What are your boost targets and at what RPM?

This is a very common problem, even on the early PPP maps used by prodrive.

It sounds like more time needs to go into setting up the EVC 6 with a throttle and RPM dependant boost table. Although on a standard turbo car, I don't know why you even have an EVC 6 when the OE boost control offeres 3d boost control, temperature compensated and gear dependant and overall very good control.

The problem is as descirbed to you regarding too much boost/not enough flow, it is referred to as "compressor surge". Typically you would make sure that the boost doesn't exceed Xbar at say 3000rpm, at part throttle your HKS dumpvalve is making things even worse, and we can't be sure of how the boost control is wired in (ie can it currently be setup for throttle and RPM dependant boost).

A poor choice of mods for the hoped for result, and a boost control setup that is probably compromised by installation are probably the biggest issues rather than the map itself.

Resolution is ensuring correct wiring of the EVC6 and further setting up of it to ensure no compressor surge.

surge
 

hi there
first thing i would do is put the standard dump valve back on the car. should sort it out:thumb: ive got a 2004 sti type uk running 1.5 bar with no problems..i have the standard dump valve on mine. hope this sorts it.

Hi all mods were advised by the mapper otherwise i would have spent my money elsewhere, the EVC 6 is wire to throttle position via the sensor and is set correctly from 0%-100%, the rpm signal is set correctly too as it matches the factory gauge.
The idea is to change the turbo, injectors, exhaust manifold/headers and possibly the Intercooler.
As prevoiusly mentioned most mods were advised by the mapper, and has I will be changing the turbo in the future he advised EVC 6 to control it.
So basically should I map out the boost to the revs and input it to through the boost controller?
Obviously I won't be using this mapper again as it seems I have been a little
little misled.

Zen in future I will be looking for a decent mapper so you seem to be what i'm looking for cheers for your input.
Regards Dean.

I just basically want the car running right before I start spending X amount of money, upgrading.

I think your going to have to bite the bullet and take it somewhere decent. I'e the likes of zen above. I didnt have these problems using the factory boost control with and ecutek remap on a 35

Don't mind spending money as long as it sorts it or at least have an idea as to what is wrong with it. The guys who did it before are very well known and to be honest didn't really cure it, I know i should have taken it back to them but they are so far away and don't really trust them.
Maybe Zen is the way.

From what you've said, this can easily be corrected by altering the setup of the boost controller, which is best done via a laptop. The EVC6 has a comprehensive range of options, so many infact that it's difficult to setup via the hand controller to get the best out of it. But it has a serial interface that allows you to very quickly alter many settings at once without struggling with the button interface, trying to setup RPM dependant control without this is a pain. As good as the controller is, without the laptop interface, an AVC-R is much more straightforward to setup. It' also worth pointing out the standard turbo is very prone to compressor surge.

But I don't know of any boost controller that is temperature compensated for duty cycle to stop overboost in very cold ambient conditions. However the factory setup is limited if you want run say 1.7 bar in the future, which is where the likes of the EVC6 comes in.

Zen i do appreciate your comments and have order HKS easy writer today enable easier programming, the plan is to change the turbo in the very near future hence the EVC6, I understand the low temp boost control and would not hit full boost in cold conditions, maybe an idea is to set boost map B at a lower target setting for colder weather conditions.
Zen as this is not your problem you have proved more helpful than the original mapper, so will be calling you in the future with regards to the turbo, injectors and headers to get 400+bhp.
Thank you Dean.

At last after 3 days solid of playing with the boost controller I have cracked it,No surging at all nice smooth power, peak boost @ 1.5bar and holds boost best the car ever as.
The instructions that come with the EVC are very poor and not as they read.
I am so happy this as sorted this niggle.
Anyone need a hand setting up HKS EVC 6 give me a shout and will guide you through. :-)