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Looking to get the new turbo setup buttoned up this weekend, then tuning to follow. Updates and pics to come, though I won't have much useful data until I've dialled in the tune, which could take me a week or so.
It's something like 2.5" coming out of the turbine housing outlet (63mm turbine wheel?) into the downpipe. The downpipe transitions from 2.5" to 3" during the first bend, straight after the turbine flange.
I've welded shut the iWG flap and inserted a blanking plate to separate the iWG section of the turbine outlet from the circular 2.5" turbine wheel outlet. This provides a near circular tube for the exhaust flow as it exits the turbine wheel into the downpipe. Should help to reduce turbulence during high exhaust flow.
Blanking plate location illustrated in red in the pic below (not my turbo).
We're all back on track now, but I've had the following set backs this past week:
During the re-installation I finished bolting everything together, then decided to swap out my custom stainless engine mount bracket for the factory aluminium one. This gives me less options for installing a larger compressor inlet pipe in the future, but makes the paperwork easier for getting my car back on the road right now. I misplaced the bolts and they're an uncommon size (in NZ at least), so I had to make up some new ones. M12, 1.5 pitch, 35mm length for future reference. Damn it was hard getting the factory mount bracket in!
Also, the OMP position sensor plug was damaged, so I stripped and reconnected a spare unit I had. It'll take away the risk of the OMP flaking out in the future.
Everything addressed and buttonned up now. Just need to start it.
Last edited by JimmyBlack; 03-18-2018 at 05:12 PM.
I need to order a 1.5" stainless flex pipe so I can plumb it back into the main exhaust. In the meantime I'll get my wish of a louder exhaust note under boost lol
In the weekend I took the car for the first drive in 12 months, filled it up with good quality 98 octane (common NZ octane ratings are 91 and 95), and gave it a decent wash.
The only incident during the shake down drive was that a charge pipe silicon joiner blew off. Easy fix - replaced a shitty worm drive clamp with a t-bolt clamp.
That screamer pipe is really bad lol. WG cracks at about 5psi, and just ramps up in noise after that.
Edit: Just picked up a 1.5" flex pipe. Will post pics once I've finished plumbing the WG outlet back into the exhaust.
Last edited by JimmyBlack; 03-25-2018 at 06:17 PM.
Reason: Update
Next step is merging the wastegate outlet back into the exhaust midpipe.
I have the BHR midpipe with resonator and cat. I gutted the cat during the turbo build, but didn't bother replacing the oversized cat housing with straight 3" pipe at the time. I need to do that now, as the space is needed for the wastegate outlet piping and flex pipe before it merges back into the midpipe.
Original BHR cat housing:
Cat housing compared with 3" exhaust compared with 1.5" flex pipe:
Exploring a few fitment options now that the cat is removed:
Had a busy weekend routing the external wastegate outlet back into the exhaust.
Mock up with with EWG outlet tacked onto midpipe:
After trial fitment I broke the tack welds at the midpipe, drilled the hole in the midpipe then re-welded it permanently.
The front end of the WG pipe that mounts onto the WG outlet uses a v-band flange. I re-used most of the stubby screamer pipe I made earlier and added small sections between there and the flex pipe to get a nice fit. Once it was tacked and fitted I welded it permanently:
Final outcome with it fitted on the car:
The car passed the legal inspection this morning (warrant of fitness), so it's now a legit road car again, 15 months after I took it off the road.
The previous tune seems pretty good, though I haven't gone above 5psi yet. I'll be doing a thorough tune when I have time next weekend. If there's any performance gain from this external wastegate, it'll be visible after that, when I push the car to high rpm with a target boost of 11psi.
Quick update. The car is back on the road and I'm enjoying daily driving it at about 9psi. I need to locate and fix an exhaust leak, which may be on the exhaust manifold, and therefore impacting performance. Having said that, performance is very similar my previous internal waste gate setup. A bit disappointing as I was hoping this new setup would see some gains in the upper RPM range, thinking the small t25 turbine housing was a bottle neck for the exhaust gas that was going to the iWG and turbine wheel.
Once the leak is fixed I'll log some 10psi WOT pulls to compare with previous logs for the final result.
11-21-2017, 02:25 PM
