Hks Gt-rs Wastegate Issue

[W1ngnut]

Background info:

S2 R33 GTST RB25DET (unopened bottom)

HKS GTRS Kit (brand new)

Bellmouth Dump pipe 3" exhaust

JJR FMIC with enclosed POD intake

PowerFC

eBoost2

I have had some really annoying issues with controlling boost on my GT-RS. I cannot for the life of me (or my tuner) get any less than 1.3bar (~19psi) of boost once you are above 5000rpm.

Our troubleshooting started at thinking it was the eBoost2 causing issues so we isolated any boost control and ran the feed from the intercooler to the wastegate directly. This caused a 0.9bar boost from low revs to 1.3bar for anything above 5000rpm. So this eliminated the eboost as a suspect.

Then we figured if it was still overboosting on 'wastegate pressure' then it is something to do with the wastegate itself. We thought, perhaps it was the JJR Split Dump I had installed, causing the wastegate flap to get stuck and not fully open. We have changed this to a bellmouth dump (HKS dump) and looking at the JJR Split dump, there was definetly SOME restriction (with all the carbon build up). We took it for another run and we still hit 1.3bar (a little less about 1.25 - 1.3) instead of 0.9bar.

So we are now at an end, we cannot think why it is boosting so high. The boost gauge is fed of a T-Piece from the Fuel Regulator and the eBoosts feed runs off the standard boost gauge in the dash (but the eboost is currently bypassed till we can get wastegate pressure).

Has anyone else come across this or does anyone else have any troubleshooting options? Its an unopened bottom end and whilst I have no worries running 1.2bar, I am very very susceptible to cold day boost spikes to 1.4 bar etc..

Thanks in advance for any advice you can give, and if you need more information, i'll be keeping track of this topic to respond.

Cheers

Sam

[PM-R33]

Mine used to do this when the GTRS was running off the stock ecu, would just keep making a shit load of boost no matter what we did. Once the microtech was tuned the problem was gone...

Mine is set up to about 19psi at the moment, and holds it fine. However i can run in it as low as 14psi with the profec setup for it.

When it hits 5000rpm, does it just violently spike, or does it slowly keep climbing in boost?

[W1ngnut]

It just climbs at a steady rate, not a quick shoot up but not overly slow either.

I wonder how the Standard ECU affected yours PM-R33?

We have also since tried to play with the wastegate actuator itself and it appears to only really change how fast the boost will build but not dramatically affect final boost.

[W1ngnut]

Just from your post in the other thread PM-R33. This is the dyno sheet.

What I cannot understand is that this is from about a month and a half ago and the boost looked perfect. No issues at all. Yet once I got behind the wheel, I had nothing but trouble with it. Absolutely nothing has changed in the setup since this dyno (apart from a new bellmouth dump today).

[evil_weevil]

My GTRS was overboosting - found out last night I had a split boost hose....

stock wastegate which is 14psi went upto 19...

but got a new hose and fixed

[sl33py]

I have a similar issue with my car, exact same combo as the OP, but greddy profec boost control. Rev too high and the boost alarm goes off. It's limited to 1.2, but goes up to 1.6 (not spiking, goes up and stays up). My engine check light also flickers (possibly just showing knock? I dunno). It was also perfectly fine for one month after the GTRS was installed (just recently), and now I'm getting this 5h1t. I hate not being able to put my foot down

My car goes in for looking at (Trojan too!) very soon, I'll keep you up to date. John already had a fiddle with the boost, but it made no difference. Strangely, he says he has no issues with it on the dyno, yet I can make it happen whenever I want (ie rolling in 4th doing 60kph, then put your foot down - BAM, warnings/alarms). I'm sure he'll see it this time around. I'll be watching this thread.

[W1ngnut]

It is VERY odd Ben. As the Dyno sheets show, the dyno is having no issues, but once moving, it overboosts, and like you say not a spike and back down, it does in fact stay up high.

evil weevil, i was thinking a busted vacuum hose and they have been replaced once, but I am happy to replace them again just to make sure.

[PM-R33]

Hmmm very strange....

Bit off topic, Sl33py on your profec when it goes over the maximum boost and the screen turns red, does yours actually make like a warning sound? Because mine never did but i swear its ment too...

[WARLORD]

i never had any problem with mine at all ever....

pm-r33 mine makes that warning sound.

Edited August 7, 2008 by WARLORD

[PM-R33]

Really? I swear i never heard mine, unless its muted or something. Might have to test it out. Thanks man.

[tp1gts2]

It just climbs at a steady rate, not a quick shoot up but not overly slow either.

I wonder how the Standard ECU affected yours PM-R33?

We have also since tried to play with the wastegate actuator itself and it appears to only really change how fast the boost will build but not dramatically affect final boost.

i found that my hks gtrs wastegate/actuator setup did exactly what your talking about when i had no boost controller inline

unplug your boost controller and put it straight on your wastegate actuator and see if its any different, if it doesn't change then maybe your boost cotroller is the problem

maybe rig up a simple bleed valve and see if you can control the boost with that to eliminate your boost controller

[sl33py]

My profec makes the warnings noises when it goes red and the stock check engine flickers on and off at the same time. Very unnerving, as mine's been specifically tuned to run very safely, but I'm getting all the bells and whistles in my face when I just blat it a bit in traffic to get around someone!

[W1ngnut]

My profec makes the warnings noises when it goes red and the stock check engine flickers on and off at the same time. Very unnerving, as mine's been specifically tuned to run very safely, but I'm getting all the bells and whistles in my face when I just blat it a bit in traffic to get around someone!

On my eBoost i get audible alarms saying i'm overboosting, but that is only because my eBoost is very very VERY inaccurate. It says i'm running 21psi when i'm only running 17psi. I am starting to think that it is because the standard boost gauge line off the back of the manifold is just too small and isn't giving its true reading to the eBoost.

I got my car back last night supposedly all fixed, but I am yet to be able to confirm or deny if it is due to the wet roads. It definetly feels better and stronger.

We changed the dumppipe and took the cat converter out and took some preload off the actuator, the lowest setting we could achieve was 15psi. 17psi low boost and 19psi high boost, supposedly no longer climbing any more. Will update the thread when the raining stops.

On a side note, is there anywhere else to plumb a boost gauge? I have one boost gauge (accurate) running off the FPR line, and the eBoost running off the standard boost gauges line but its quite small, is there anywhere else to move it to?

[evil_weevil]

when I was at WSID the other week thats when mine went apparantly.

Allof a sudden around 3rd gear the profecII flashed red and beeped also.

The highest knock I got on that run as low 30's

I got mine back the other day, given it a drive to mum n dads today and watched the boost gauge and just wastegate sat flat on 14psi, low boost on 16psi so, so far so good with mine.

Hope everyone elses is a simple fix too,

Cheers,

Chris

[sl33py]

Turns out my boost controller was completely dead and doing nothing to control the coost - simply displaying current boost. Mechanic said it's usually caused by giving/receiving a jump start, which can short out the controller if you don't turn the parking lights on (to get shorted out first), but I'm pretty darn certain I didn't do either.... But with a new controller, it drivers perfectly again Funny thing is, as I was about to leave, one of the guys at the workshop on the phone was asked the person on the other end "... did u recently jump start it??" and nodded to me "yep... same issue" hahah. Weird... gonna keep an eye on it!

[W1ngnut]

Thats crazy Ben! Glad to hear that you have it sorted though. Uncontrollable boost is such a worrying thought, mine has settled on 15psi wastegate 17psi low and 19psi high.

Just getting a Metal Cat delivered tonight as at the moment, its a little empty inside. Hopefully it won't make a huge difference to the tune or the boost!

[PM-R33]

Ok i for the love of god cant get my profec to beep when it over boosts. Whats the secret? I cant find any setting in the book that talks about turning it on or off

[Swink33]

When I got my highflow I was having problems with boost spiking despite having an AVCR working properly. My tuner immediately thought it was the actuator so in went an HKS heavy duty actuator and I have had no problems since.

[bubba]

Ok i for the love of god cant get my profec to beep when it over boosts. Whats the secret? I cant find any setting in the book that talks about turning it on or off

Mine doesn't beep either

[sl33py]

Hrmmm mine's a Profec B-Spec II ... are your controllers the same? I think there's a few revisions?