Surge/Flutter

[tweedo]

Hey all

I\'ve just started experiencing what I thought what just wastegate flutter but after watching a compressor surge video on here I\'m rather confused and think it\'s quite possibly that now.

This never happened at factory but AFTER a tune it has started. Just noticed it the other day pulling up a slight incline in 4th and it started chuffing away. Managed to replicate it a couple of times... only seems to be in the higher gears, particularly 4th & 5th.

Btw, BP5 and only mod is a Subtech downpipe.

I don\'t know enough to take it to the tuner and say what needs to be done to fix it so any thoughts from you pros would be greatly appreciated!

Thanks to all in advance.

[Rosssub]

Chattering? (High Pitched Ticking/Tapping from the Turbo) - Is it only doing it when you first put your foot down? Then fading away as the Rev\'s/Boost rise?

You need to get your ECU\'s Waste Gate Duty Cycle or Gain adjusted. Guessing your running OEM Boost control? Do you have a Boost gauge fitted?

The tune has made your Duty Cycle more aggressive (Waste Gate opening less, so Boost Rises to Target PSI Faster). Also fitting the Subtech Down Pipe (no Cat?) has increased Spool up speed/Exhaust Flow.

Pretty much, the Back End of the Turbo is Spinning faster than the Front End can keep up with.

[tweedo]

It would just do it as I tried to give it some, could only get it in higher gears and each time was up a slight incline so higher load too.

Yep standard everything and no boost gauge yet but thinking of getting one sussed so I can keep an eye on it.

Just yesterday got it flashed back to factory and it hasn\'t done it at all since then so must be something tune wise not right eh, should I just say thats what I want him to focus on?

Also got a wee miss or surge going on at low revs in particular (1500-2000). Really noticeable when I\'m in traffic.

And if I bring the revs up to that just sitting it will fluctuate quite a bit. Any ideas what that could be?

[Rosssub]

 tweedo']

Just yesterday got it flashed back to factory and it hasn\'t done it at all since then so must be something tune wise not right eh, should I just say thats what I want him to focus on?

Yip, who did the tune for you? Did he test drive it afterwards?

When you say "Focus On", afiak that would be more for a Dyno Tune scenario. Small adjustments to fueling/Duty Cycle etc, throughout the rev range to maximise performance. Your flash tune is more likely just a Pre-Programmed/Pre-set Map. Just that the Map selected was too aggressive for you set up. Waste Gate Gain too high.

[quote name='tweedo said:

Also got a wee miss or surge going on at low revs in particular (1500-2000). Really noticeable when I\'m in traffic.

And if I bring the revs up to that just sitting it will fluctuate quite a bit. Any ideas what that could be?

Most likely a bad AFM. Is it idling fine? No actual Miss Fire, just Hunting?

Edit: The Tune/Map used would probably of been ok if you still had the OEM downpipe. With the Subtech Pipe, Boost comes up too fast. If you had a Gauge fitted, you might find slight Boost Spikes too

[tweedo]

Got it done at APET down here in Dunedin. Pretty sure its not a pre-set map though, he did it all on the dyno from scratch and pretty sure he did test drive it afterwards just maybe not up to boosting in 4th though where it actually started to happen.

The guy who did it and one of his mates are both running the same tune on the same cars but they are having no issues so my guess is the downpipe/extra flow is whats causing it for sure.

It idles all good just takes awhile to get there sometimes. It will drop right off when you come to a stop sometimes but then come right but I\'m not sure if that and the wee miss/fluctuate would be linked as it has only started doing the latter just recently.

[Marky]

As said it\'s just coming on boost a tiny bit faster than it needs to

You could have kept the same tune just with the boost dialled back a touch down low to get rid of it

It\'s an oddball problem, some cars find it chronically some avoid it altogether. You see it even on all kinds of cars and setups so don\'t think of it as a fault or bad tune as such, is you\'ve found it can be hard to get it to do it

The not-so-technical explanation is the turbo is spooling up and trying to force the air into the motor, then motor is not using that air fast enough, so it all backs up and "chuffs" back out through the inlet. Just needs that backed off a wee bit is all

[tweedo]

Mint so no need to touch the WGDC or will they both need adjusted?

And just dialled back at low revs or adjust the higher load boost too? That\'s where it seems to be happening.

At times when I give it some at around 3000rpm in a higher gear too it will stumble a bit before taking off, do yas think that could be related to either of the issues or is that something I will just have to live with?

Thanks again for the help.

[Rosssub]

 tweedo']

Mint so no need to touch the WGDC or will they both need adjusted?

And just dialled back at low revs or adjust the higher load boost too? That\'s where it seems to be happening.

Boost Levels/Gain/WGDC all related and sort of the same thing.

WGDC=Boost Level (how much Gate is opening, controlled by ECU/Boost Solenoid)

Gain=How fast Boost rises to target level

[quote name='tweedo said:

At times when I give it some at around 3000rpm in a higher gear too it will stumble a bit before taking off, do yas think that could be related to either of the issues or is that something I will just have to live with?

Thanks again for the help.

No worries ;D That again points to a faulty AFM, maybe worth trying another known working one or just replace it?

[tweedo]

Hey all just a quick question on the potential afm issue.

Going to swap it out for a mates one tonight but have no way of resetting ecu after... Is it necessary to do so or will it be fine without doing?

Cheers!

[Rosssub]

Will be fine with no reset.

You can reset by connecting the Green and Black Plugs under the Dash (D-Mode) and going for a short (5min) drive. CEL will start flashing constantly when ECU is reset. Then jus stop and unplug.

[tweedo]

Thanks again Rosssub but it\'s back to the drawing board or, more specifically, the garage!

Tried the other sensor to no avail, maybe even ran a little worse for a start... Would that be usual?

Anyways don\'t think that is it after trying that out so maybe IACV? But that wouldn\'t cause flat spots at 3-4000rpm though so leave it to the pros I think!

About the reset too... Does that method work with the newage\'s?

[Rosssub]

I think that ECU trick only works up to 07ish? Not sure on that one?

But at least AFM is ruled out.

When you say "ran worse for a bit", was it missing or just low revs that then came right? No Vac Leaks? Like you said maybe IACV, give it a good clean and see if it helps at all?

Hunting/changing or low idle could be your IACV? Vac leak?

Flat spots around 3-4000rpm could be Coil Packs/Plugs/Plug gaps?

[raijin]

 tweedo said:

Thanks again Rosssub but it\'s back to the drawing board or, more specifically, the garage!

Tried the other sensor to no avail, maybe even ran a little worse for a start... Would that be usual?

Anyways don\'t think that is it after trying that out so maybe IACV? But that wouldn\'t cause flat spots at 3-4000rpm though so leave it to the pros I think!

About the reset too... Does that method work with the newage\'s?

Hi I\'m not sure where you\'re based but if you are in the Auckland area you\'re welcome to bring in the car for a free diagnostic session. Cheers. Alistair.

[Swindog]

You have to be careful with the stumble. Could be anything. Plug going bad, coil or AFM. Does the computer show any log of faults? Do you have access to a code reader?

Does it ALWAYS surge or miss at that particular rev range or when you slowly apply throttle?

Had a similar issue in my father in laws BH5 not so long ago. Replaced the coils and new plugs and issue solved apart from some cold idle issues which was sorted with new AFM. I noticed it logged an o2 sensor fault too so im replacing that this weekend.

Stumble or misses or surges that are minor are generally those 4 things. AFM, o2, coils or plugs. Does it fart around when its cold?

Your searching idle could be your TPS not set correctly also. Be the easiest and cheapest thing to check. Its free with a multimeter.

[tweedo]

Hey guys thanks for your replies.

Took it into the outfit that did plugs for me awhile ago and told him what was going on... he was almost certain from my explanation that it would be an o2 sensor. Getting it checked out and sorted next week and can\'t wait!

Never had any codes show up... would signs of this failing show up when logging?

Thanks for your offer too Alistair but unfortunately I\'m at the other end of the country in Sunny Dunedin!

 Swindog said:

Stumble or misses or surges that are minor are generally those 4 things. AFM, o2, coils or plugs. Does it fart around when its cold?

Your searching idle could be your TPS not set correctly also. Be the easiest and cheapest thing to check. Its free with a multimeter.

It does fart around when its cold but I thought that\'s just these newages did so as you can\'t get them assholes from cold?

And what am I meant to be doing as far as the multimeter test goes?

Thanks!

[raijin]

No worries re the offer. All the dodgy O2 sensors I have seen on newage cars result in a CEL which causes the ECU to disable air to fuel correction learning (but we learn new things all the time about these marvels of engineering).

Whoever mapped the car for you in the first instance should really be trying to sort this for you, however rather than swapping sensors on and off the car with the hope identifying the issue, I\'d recommend the quickest way of sorting this is to take the car to someone who can log the channels on the ECU whilst you drive and replicate the condition.

For example all the sensors can be working fine but the ECU can make massive false knock correction adjustments due to unusual mechanical noise which causes the car to run poorly and the only way to diagnose this is to plug in the laptop and get a mic onto the engine. Hope you get it sorted. Drop me PM if you need any help.

[tweedo]

I\'m taking the mechanic for a ride while it does it not sure if he\'ll have it plugged in or not though.

This issue doesn\'t have anything to do with the tune I don\'t think but I\'m sure the wastegate flutter or whatever it may be does!

I\'m back at factory tune atm and thinking of just staying there tbh. Either that or get a cable do some logs and go with Cryotune... there seems to be some very positive reviews on his work!

OR ... Do I get the tune put back on and then go with an outfit like Cryotune to smooth things out a bit more? Just not wanting to completely waste what I spent on the tune or would it be better just starting from scratch?