I saw that you have the EBC, presumably controlled by the link as intended. If so, it should reach target boost. In my experience the link does a decent job of controlling boost.
If you can't reach boost with a decent EBC, then your turbo is choking on something -> the cat hopefully. It could also be blowing air somewhere else and not into the intake. But since the link uses the stock ECU and MAF when not boosting, and for part of the fuel delivery when boosting, it should also have bad AFRs which you are not reporting. So I doubt it's an air leak.

Extended Autobahn high-speed runs could also cause really hot combustion chambers and from that valve-failure. I hope that's not it, but if it's not the cat you may want to pull the head.

I have build the car together with Jasper. After his unfortunate run in Germany, I have helped him re-installing the couplers that were badly installed in the shop they took him to. We did not boost test the setup, looked at the couplers and they seemed ok. I also checked the torque on the manifold bolts and the down pipe, all tight. No visible cracks.

The cat was on my list of suspects too but since the car sounded not louder or muffled, I guessed it would be Oke. Think we have to check it just to rule it out.

Scott that is one scary picture!

that happened after I blew a motor and the cat got dowsed in oil...that was after trying to run the new motor and it just wasn't quite running well :)

Check the studs!!!!

studs are okay

yeah they are! wooo woooooooo

:makeout:

LOL , thats why I called them bolts in the first post

There wasn't enough change at idle on the car I heard for us to figure it out right away. I never drove/rode in it and on the track I had my own exhaust to listen to. Turbos are already muffled by nature so the exact same failure NA would certainly sound different.

It should be easy to unbolt the cat and look inside to check it's health.


If it looks fine, you could still have a boost leak. Also, check the wastegate actuator preload. If it was loose, it may not be putting the same amount of force on the flapper as it used to, meaning you might have lost your 1-2psi there. You could also have spike really lean and detonated really hard when the coupler popped off. If you haven't replaced the plugs and tossed the old ones yet, pull them out and check for detonation residue (tiny balls of aluminum on the insulator).

We checked the plugs, nothing that indicated detonation, new plugs are installed.
Haven't checked the preload on the actuator yet, it goes on the check list.

Wow, lots of replies! My notification system didn't work any more....
Henk is right, we've got to check everything step by step.

We're both quite busy so it'll take a while. ;-)

Pop the pipe going to the cat off and run it. It will be loud but if it works like normal its sledge hammer and jack handle time.

This Saturday i'll try to pop the midpipe out. My cat is clamped in between two pieces of exhaust (midpipe) with exhaust clamps... And I do not really want to take those clamps off. (We had a bit of trouble sealing them up)

So I'll probably remove everything after the downpipe... so the full midpipe+cat and possibly together with the muffler.

Took off the exhaust this weekend, right after the downpipe and flex piece.
Serious amount of noise that made us giggle like little girls. :giggle: Had a good time, lol...

Took it for a short spin while my friend was recording everything with his phone.

The cat looked better than I hoped, no big blobs or molten stuff, but it looks to be a bit off to the side and it also kinda looks like it's a bit clogged...

But like I said, we took it for a spin and although I think I had more power, it still wasn't nearly as good as it was before... So it can't be just the cat that's causing problems.

metal core?

Yeah, bought last year @ Flyin' Miata. You can't see daylight through the cat because there's a bended pipe after/in front of the cat.

Have you run a compression test yet? That would tell you what shape your valves and/or rings are in...