and help me in the process, of course .
Well I did the following mods on my MY00 ex-PPP
full 3in GGR catted exhaust
Walbro fuel pump
VF29 turbo
Apexi AVC-r boost controller
and.. M48 MoTeC

before everybody jumps at me yes the AVCR gives superior boost controlling due to ots 3way solenoid and you can fiddle with it without a laptop!

Went for an initial setup spin with laptop+lamda sensor etc car was absolutely stunning up to 5800 (+/- 50) rpm (on all gears) after which it became a NA engine! It turns out boost from 1.2 steady went to a 0.30 dive!
Actions:
Put back (different) PPP ecu same problem
Changed fuel pump same prob
Different AVCR unit same prob
Different AVCR solenoid same prob
Can it be a turbine fault
Ideas?

 

Check that you haven't split the pipe between the turbo and intercooler and that it is still securely in place.

If is OK, then its time to look inside the turbo.

 

Stelios

Could it be compressor choke? You appear to be running with both a large amount of boost and a free breathing exhaust, so it is possible that your approaching the limits of the compressor evn on the VF29. Has anybody got a compressor map for the VF29 to check this theory?

Duncan

 

Have you checked the system for leaks?
Couldn't it be a dodgy BOV as well?

Still...it sounds a tad iffy if the same thing happens on all gears at ~6k rpm...

Weird...

/J

 

Can you just clarify if you can still make boost up to circa 5800, or now it will only make .3bar ?

Mark.

 

Hi Mark,

I'm quite sure that Stelios makes the boost to 5800rpm and it is after this that his boost dies off. I'm replying for him coz he hasn't got computer access till Monday, erm when he goes back to work, if you know what I mean

Cheers,

Wrexy.

 

I can't think why the turbo would be able to make boost up to 5800, but not at 6000. If the turbo was damaged, I don't think it would react like this.

When you refitted the PPP, was it used with the boost controller, or the standard solenoid ?. Try the stock set up, PPP, solenoid, etc', this will eliminate the turbo.

I suspect it may be the way the controller has been set up, but even then, I would expect you to make about .6bar, which is the normal actuator cracking pressure.

Mark.

 

Well I tried all this

I run with the PPP ECU up to 1.1 bar with 2nd gear boost dropped from 1.1 -> 0.1-0.2 at 6700 rpm 3rd gear 1.15 ->0.1-0.2 at 6100 rpm. Up to then car was boostting fine and below those figures car is *stunning* its just boost cuts off at some point at high revs

Removed wastegate control run the car with wastegate spring loading, car boosted up to 0.7, again boost droped to almost zero at 6800 at 2nd

All hoses are checked, fuelling continues normally after boost drop (just NA engine!)no overboost ecu thing or fuel/ignition cutout. With MoTeC the diagram is clear injector duty at point of boost drop is 70% and fuelling is compensates the boost drop even MoTeC australia are mistified!

It all adds to a turbo problem by process of elimination (even disconnected car alarm!)
Re-fitting original turbo just to make sure it is the turbos fault
Can it be turbine stall/choke? but the VF29 is a stock replacement in aussie tuning and larger than the std MD04. Note turbo was brought "brand new" with IHI guarantee from www.dieseldistributors.co.nz (and v. cheap)

 

This sounds very weird, my VF24 (a smidge larger than the 29 IIRC) has *no* problem whatsoever to deliver 1.2 at 6500 rpm....

:confused.

 

Update
Re fitted original MD04 turbo no loss of boost whatsoever through the entire rev range so I guess it was the turbo, now trying to sort it out with the supplier.

 

Hi Stelios!

Glad you narrowed it down to the turbo. It's a start

As for compressor choke, that would not cause this kind of behaviour.... it sounds more like a problem with the wastegate or there is a serious problem with the bearing core...

It is possible that the wastegate actuator is insuficiently strong to hold the button closed, and as you approach 5800 RPM the volume of gas gets so great that it is just blowing the wastegate open. I've seen this happen many times, but generally it is still making good boost when it does happen (12 to 18 PSI).

If there were a problem with the bearing core, it may be that it only manifests itself when the radial load on the bearings exceeds a certain threshold, at which point it no longer runs true but slightly eccentrically, thereby vastly increasing the bearing loss, and also reducing the turbo speed thus reducing boost. When you come off the throttle, it allows the turbo to spin down sufficiently for it to recover and run true again...

The odds of you hitting the choke line on a VF29 with the boost you are running is minimal, indeed almost impossible. It is possible, though, that there is still a problem with boost being leaked via the dump valve, and that because the TD04 is giving a less dense charge, it can't blow it open whereas the VF29 can.... You could try blocking it off to verify this theory.

Hope this helps,

Pat.

 

RE: "before everybody jumps at me yes the AVCR gives superior boost controlling due to ots 3way solenoid and you can fiddle with it without a laptop!"

The M48 will drive a 3 way solenoid quite happily, as on my car. You have a point about the laptop though.

 

MMc
AVCR has also learning curve capability (thenew M800 has it) and looks good
Pat,
Thx for your help I needed to know if the VF29 compressor map is Subaru compatible.
As for your wastegate actuator theory I beg to disagree as with no actuator (disconnected line) and max 0.7 bar boost due to wastegate spring only the same behaviour was excibited and also boost with wastegate wide open is still a good 0.7 bar not 0.3-0.2.
The bearing theory seems a good one friction due to bearing misalignment as the rpms load increases but can it be so abrupt?
My theory is turbine blade stalling in the compressor side
as this comes abrupty an is a function of both pressure difference and gas velocity (rpm and load dependance)
This was a brand new turbo and looked it (or wasnt it?)so Ill take it up with the supplier
Thx all for your assistance i dont know what id have done without scoobynet.

 

Hi Stelios!

I'm thinking of buying a IHI VF29 of the supplier you mention.
Would be nice if you could update me on your turbo-problem with this supplier.

Hope everything works out for you!
(my email: lars_olof_Strid@hotmail.com if you have any good or bad experience with the supplier)

regards,
L-O

 

L-O
U got mail

 

Have not received any mails yet....

 

L-O
your email above is it correct? i get undelivered notice

 

yes, it should be: (LARS_OLOF_STRID@HOTMAIL.COM)!

I'm not shouting, just trying to avoid misspelling...

//L-O

 

I had a similar issue with a turbo car once, check your air filter / airbox or cone assembly and connecting pipe.
On my car the increased flow of the new turbo was enough to suck the pipe sides together virtually cutting off the air flow but only at 6000+ RPM ! Close the throttle and it popped out again leaving no evidence !!
Try a short run without filter and hose fitted

CC

 

Pats could be right, with the actuator limiting to 0.7 bar as standard then the wastegate is not wide open at all, barely cracked in fact, its more than possible that the wastegate is getting blown wide open and hence the boost. It won't be bearings, if it was you wouldn't have a turbo left to do anything and it certainly wouldn't partly seize so specifically and repeatably.

just my two penneth

 

Hi there Stelios!
I have not received any mail from you, are you still having problems sending to my mail-address?

//L-O

 

Cosie
nice one! But i have SAMCOs all the way and ramair induction
Bob
Thx for your help
Are you suggesting that the wastegate actuator is blown open at higher revs?
I measured a brand new VF22 actuator and rate was same. Also with the actuator disengaged with prodrive ECU it boosted up to 0.7 and then to approx zero when approaching 6700. Also from motec data file drom is dramatic!
Ill send the turbo back for inspection

 

Well ive got an update on the matter:
Turbine was sent back to diesel distributors in NZ and they checked/dismantled it and found nothing
BUT they volunteered to send me a new VF22 as replacement!
So here goes my individualistic VF29 !

 

Sounds a good car, but when u own "easyjet" i expect ur loaded... haha.

 

Sorry if i tired u with the subject but problem was resolved happily Cosie Convert was right. A defective brand new SAMCO intake collar(which costs also a fortune) was very weak and was sucked together.
My turbo supplier www.dieseldist.co.nz very kindly and unecessarily as it turned out swapped my VF29 for a brand new VF22 free of charge!! even after inspecting the returned VF29 and finding zilch.
Car now very linear to the end just revs and revs reminding evo delivery. Lamda still very rich and advance very conservative some tuning to be done. Suprisingly car is NOT laggy (maybe thts MoTeC for u and it ought to for the dosh! and no FMIC ). VF29 had savage low end though!
Thnks you all your help!
Stelios

PS nope i dont own easyjet (id buy MoTec for everyone in here if i was!) but we studied with that Stelios in London at the same time and we used to hang out together! (Yes i know big fat hairy deal)

 

Glad you got it sorted Stelios.

Would have been nice to see if the VF29 went as good up top as it did down low. I suppose we will have to wait till I get mine now. Probably be a while too.

When are you going to come around to take me for a wrap in it?

Cheers,

Wrexy.

 

Stelios/Cosie Convert, I too have recently seen the same issue with my Samco Turbo inlet hose being sucked in at circa 6000rpm!
I first noticed it upon the road, where at about 6K rpm, my boost would drop from 1.3bar to 0.8bar instantly!
Had my Link ECU, Wastegate on my VF23 checked out etc etc. Couldn't suss out what the hell was wrong. Sort of ignored for a while...until I had my 1st RR day at PE the other day.
Had it on the Dyno and after 2 power runs, and a quick look under the bonnet at 5500rpm onwards...BINGO! Fudging Samco Hose
This only occurs when using standard airbox (HKS panel) as it causes a depression (i.e. throttling the Turbo!). I proved this theory by replacing the airbox with a GGR induction cone. Problem gone! But I don't like the noise!!!
The answer for me, is to replace the GGR induction kit back with the airbox and replace the Samco hose back with the OEM one. The OEM one is a bit more restrictive but doesn't collapse. My VF23 will have to work harder to maintain my 1.3bar but least it will hold!!!
Bottom line....In my own opinion, don't use a Samco inlet hose unless you will be using an induction kit. The Standard airbox has too much of a pressure drop, therefore throttles the Turbo at high RPM. I may of course have had a faulty part, but then again, I have had 3 of these, one on the car, two on the shelf that don't fit!!! Quality

Jacko.


[Edited by Jacko - 1/28/2002 1:30:30 PM]

 

Jacko,

Stelios didn't post this in his first post where he had included his mods, but he does have the GGR induction cone with the K&N filter on his car and he had this on the car when he had the problem.

Cheers,

Wrexy.

 

Jacko,
Yep XREXY is right it was a faulty SAMCO when i put another one hey presto problem solved! Upon inspection the old hose was very wobbly. Some people put a cylindrical wire mesh to ensure rigidity