It has a 3 port boost solenoid. If I take off the pipe to wastegate actuator, how do I tell it's boosting OK? Just by driving? It there an rpm I shouldn't go beyond, or should the system cut out if it overboosts?

I'll check if the restrictor is there. At this point I can't remember if the rebuilders replaced pipework or not.

Yes, I can't help thinking someone's not been on the ball. I know I'm not on the ball but it's not my job.

Ah ok, well I think with a 3 port you don't normally use a restrictor so unlikely to be this.

To test what the turbo is capable of you can just pull the pipe off the wastegate and stick a bolt in the end of it to prevent a vacuum leak. But I'd recommend using a boost gauge and delicate throttle control to see what happens rather than relying on the overboost cut on the ECU. Really without a boost gauge you can't prove a lot as you have no idea what the boost cut was set to, and could be dangerously high.

What part of the country are you from Davoid

Lancaster

Find a decent subaru specialist near you ask on here for recommendations if you have to and take it to them. Who built the turbo by the way

turborebuild.co.uk

Worked out it's not the wastegate actuator. Can BOV cause boost problems? Oddly, before turbo change I couldn't hear BOV but now I can.

Just name the mapper ffs, save us all the same kind of headaches, would you protect samsung if your phone blew up and gave you third degree burns? Would you protect asda if one of their pizzas gave you the runs or contained glass? No you wouldn't, so why protect a mapper that sounds inept and could potentially ruin other people's cars or make boat loads of money for a service he can't even genuinely provide... More to the point, why should he earn money for something he's not actually capable of. .

because the fault may not lie with him and it won't go an inch toward solving my problem. The most useful thing I've seen in the replies was someone who'd had almost identical symptoms and the problem was exhaust-related. If I provide a name, blame is seen as implicit to some people. If it gets fixed, or if the mapper behaves badly toward me, then I'll be inclined to supply a name. But otherwise, as I said, no good can come of it.

The mapper is very experienced and well known on the forums, and generally, well regarded.

Blocked cat ?

Resolution? Updates?

Low Boost Try checking the Uppipe
 

"from memory it just wouldn't boost to more than about 1 bar"

I'm going to throw this in as a lot of people have already tried to help but we don't have a resolution.

I have a suspicion that you have this problem due to a boost leak in the Uppipe.

Some years ago I had my WRX mapped by Simon Roe ( JGM) and I think everyone on here had a very high opinion on his work.

He did a road map for me on a china built TD05 16G , despite his magic he was unable to pull more than 1.0 bar from the system ,
even with the ECU calling for 1.2 bar he didnt take the map higher as it made no sense to him to do so. His comment's at the time were that
PRC turbo build tolerances might make it difficult to reach higher pressures but he felt some other problem existed in the boost control.
Changing to a 3 port might help , and he wanted to have another go at that, sadly he died a couple of weeks later.

I subsequently changed the std actuator to a Kinguwa ( exchangeable spring system ) with which I was able to induce 1,2 bar
( as the JGM Map originaly had called for ) never the less I had always felt that the low end torque was never very good.

More recently May 2018 I took the car to SRR and had a remap done following a bottom end rebuild and as I had made some head gas flow work.
and needed to remap for the changes , the results continued to be somewhat disappointing in the torque , and to be honest nothing special for 1.4 bar in peak power either.

Frustrated I finally decided to get rid of the China TD05 and replace it for a reworked Blouch design but while I had the engine out, I also discovered a problem with the uppipe.
This was a aftermarket decat two piece sleeved design, and to my horror I found the two sectioned pieces were able to wobble,
clearly it was no longer fully gas tight in the middle. Hence the reason why boost had been hard to develop at lower revs and why 1.2 bar boost
had previously only been possible to achieve at all by use of a higher wastegate actuator spring.

So clearly you need to be very sure after fitting any new turbo , that you do not damage the uppipe when doing so.
I remember I had experienced quite some difficulty to mate the aftermarket uppipe to the TD05, and most probably had subjected it to a lot more stress
than was good for the joint.

The PDF map curve shows the old TD05 and the uppipe that leaked. below 4000 and it drove like a sack of potatoes.

I now use a Harvey design Uppipe and together with the SC360 have obtained a pretty decent boost climb.
No curve available yet though.

Hope this helps

Yeah that was kind of my thinking as well. It was the only thing that made consistent logical sense. The mechanics charged me a lot for fitting the turbo and i sensed it was a pain of a job for them. Previously it got 1.2-1.3 bar and afterwards no more than 1.0.

I'm tending towards getting one of those up-pipes and having it fitted by cotcomp, along with a few other jobs.

So I have no useful news yet but you've helped me make my mind up about what to do.

By the way, did the lack of up-pipe cat have much effect on MOT/emissions?

Finally, do you have a torque curve from when it was still crap?

Like Linksfahrer, I have a Harvey's up-pipe. It's now been MOTed twice since the up-pipe was fitted and there have been no issues with emissions.

The second cat is directly under the turbo , and is on its own capable of holding the requirements for the German Abgas TÜV so I don't see you having a problem for a MOT emission test. I already posted the curve in my earlier post .

The very poor pick-up can be clearly seen in the area measured from 1500 rpm-3500 rpm. Ignore the headline 310 bhp it says nothing about how the car drives.

In my view the 2.0 needs to be very carefully boost / timing / fuel controlled in the 1500-3000 rpm area , and Subaru clearly thought the TD04 was going to produce the best torque curve , so a Hybrid version of it , a uppipe cat delete and the bigger injectors from the Sti improve's on power output through out the power band without adding the dreaded lag. A well developed TD04 hybrid should make 300 bhp , but what makes them impressive in day to day driving is the turbine effect from low down.
On a TD05 16g you do sacrifice a lot of that driveability , however car was transformed by Simon in a road mapping session,

At a subsequent later build on a re.-installation I had clearly damaged the uppipe and although the tune you see was an improvement , compensating slightly for the lack of boost produced at low revs , it just goes to show how very important it is to get every single connection gas tight before going to your engine mapper. The capability of turbo X or Y to make finally 1,5 or more bar at 6500 rpm as a headline figure is really of secondary importance , even the best map engineer can do little to help a poor installation.

Next time when I am back in the UK I will be road mapping , the car now is with the Forged E207 block, (Blouch) SC360 Turbo the Harvey pipe (midsized) and a 3 inch bore sports cat , three port boost controller , together with 550 cc injectors and careful gas flow workings done on the WRX heads I'm really hoping for far better torque delivery. In a sense its essential when I move to Cornwall , the peak power is no longer relevant for me. And to be honest driving the WRX at speeds over 150 mph on Autobahns is not a very rewarding experience all it does it drain your pocket of Euro's and doing so in UK would probably give me a stretch at Dartmoor.

Best of luck to you in finding the cause of your poor toque delivery its unlikely to be the Hybrid Turbo's fault.

were up pipe and down pipe gaskets changed when the new turbo was fitted genuine subaru ones

In my particular case yes ,

The real problem is however to get the exhaust / uppipe components successfully mated to the manifolds, it is physically very tight down there.
joggling , rotating the various bits together , requires some planning and invariably skin knuckles and cursing.

Question was aimed at the op 👍

dunno. But just ordered an up-pipe with all gaskets and will ask subaru specialists to install, and to do a before and after boost reading. AP performance said it could possibly be wastegate 'penny' valve, due to bad adjustment or gasket compound sticking in there. I'll ask them to look at all that..

Hopefully you will have a positive outcome keep us posted

I had a boost issue(a standard td04) as well..wouldn't go above 0.9 bar
i made a pressure tester at work,pressurised the intake to 1.1 bar,checked every hose with a leak detector...nothing showed up....
thought.....ffs....sprayed the leak detector on the vacuum hoses by the air box then found the filter for the boost gauge was expanding under pressure ....and bubbling like mad
replaced the filter......
and bingo.....boost is back :luxhello:

This posts a little old now, but I have hybrid TD04 running 305bhp/lbft on original 1997 380cc? injectors. Before doing so though I changed fuel pump to high flow Walboro and increased fuel pressure. As an alternative to changing the injectors.

Got a Harvey (AS Performance) up-pipe fitted by Cotcomp, who checked boost after and boost is back! 1.34bar. Thanks to everyone for help. Car feels nice. I'll take it back for a final map tweak and see what we end up with. Again thanks to all for helpful suggestions and I think BrownPantsRacing gets the gong for spotting boost leak first.

:luxhello:

Glad it's fixed bud. Big relief. :thumb:

Well done

yeah well done BrownPantsRacing :P

:lol1: Yep, I'm still claiming that one bud! :D

Well done, OP for coming back and updating with the eventual fix.
Solution chasing threads like this work best when the OP returns and lets us know how the problem was fixed.

final map
 

Final map. TD04 hybrid now doing what it should be doing i.e. bringing on torque 4-500rpm earlier than before and not running out of puff after 5200rpm. I've seen a number of dyno plots but only one (vf28, which I found not believable), gave 150lbft at 2000rpm. To recap: previous traces (in blue) represent TD04 remapped. At that stage it had a panel filter, 200 cell sports cat and I think that was it. Peak power was 262. Now it's got a Harvey up-pipe, Deatschwerks fuel pump and TD04 hybrid. I will admit, with slight shame, to being disappointed not to have hit the magic 300 but it's only at 1.2bar, and it drives great. Got an AP clutch which is really nice and I think I'll leave it alone now except for better rear brakes. It does develop some issue at just before 4000rpm although this might have been driveline, transmitted to dyno. We had no clue. Not really evident on the road. Any suggestions welcome.

https://cimg6.ibsrv.net/gimg/www.sco...24a884103f.jpg
https://cimg9.ibsrv.net/gimg/www.sco...4e98134ed7.jpg
https://cimg1.ibsrv.net/gimg/www.sco...264bdc2147.jpg