^ damn skippy. I'm still sorting through some install fine tuning, but I'm feeling really good about the car right now.

Had a piping coupler that kept popping off, just had to reposition thngs a bit. Glad I took the time to roll beads on every joint.

Then this happened:
https://cimg3.ibsrv.net/gimg/www.mia...d9aec966c8.jpg

... which is because I'm a dumbass, and positioned the actuator port straight up. It was interfering with the hood. That's the first reason I kept slamming into the overboost protection at 12psi, I was basically running allofit. Which was fun until I hit the fuel cut.

So I rotated the wastegate actuator and fixed the signal line. Better, but still hitting the overboost protection due to boost creep. I had "ported" the wastegate before I installed it, but all I did was put a big radius on the edge and didn't touch the diameter of the hole at all. So this morning, I got out my new cordless Dremel (how have I lived until now without this thing?) and did some Extreme Wastegate Porting. Hogged that thing out as wide as I could.

Just took it for a drive- running like a champion now. Boost peaks around 9.2 @ WOT and 7200rpm. Intake temps are less than 20 degrees over ambient. I was going to figure out a better situation to get cool air in the turbo inlet, but I think I'm going to put that off. I need to make some heat shields to protect the brake stuff.

So excited about this car right now. MT.net, the place to hang out if you want to cycle between rage and euphoria every two days.

They do. Scared the tar out of myself when I managed to blow the outlet coupler off the super freereving to show how the system all worked...

Finally got around to doing some tuning and logging. Finally got a decent log of a WOT pull, so I could get some spool data.

https://cimg7.ibsrv.net/gimg/www.mia...c577f3b62b.jpg

Obviously a lot of room for improvement here. I can hear the wastegate sucking almost immediately after I put the hammer down, I think it's killing the spool. On a positive note, the boost creep is gone after I ported the wastegate; that last data point was probably just after I hit the rev limiter. I just ordered the EBC solenoid from DIYAutoTune.

Shouldn't hear wastegate sucking. Doesn't make that kind of sound. BOV, boost leak, or something else is the problem.

Thanks. Next project: boost leak tester.

Once you get in the EBC then this picture should help out a ton with wiring up both ports on the wastegate. You should be able to get a good bit more spool with that. Glad you are slowly getting the kinks worked out and enjoying the setup.
https://cimg7.ibsrv.net/gimg/www.mia...8f370b30db.png

Thanks Lars... solenoid should get here in a few days. Been reading up on tuning boost control.

Build my leak tester and put it to work. The POS Autozone tire pressure tester doesn't even work.

https://cimg2.ibsrv.net/gimg/www.mia...9c6d58a6e0.jpg

So it looks like I have multiple boost leaks on the cold side. Hard to tell exactly where with the car on the ground, so I'm going to have to get it back up on stands and take the bottom tray off again.

I did notice that the check valve that I put on the IAV is leaking quite a bit, so I've ordered a new one.

https://cimg1.ibsrv.net/gimg/www.mia...2dd4d6378e.jpg

You need to route the IAC back into the intake. No real way around that.

Even with the check valve? That may be my issue on my setup. I havr the same check valve...

This.

More stupidity left over from the supercharger. Running the IAT back to the intake pipe makes sense. Cancelled the order for the check valve. Will go to the hardware store to get a threaded 3/8" NPT fitting with a barb for the IAT hose, and hook it into the coldside piping.

Idle valve plumbed back into the intake pipe.

https://cimg1.ibsrv.net/gimg/www.mia...5663a7a7b7.jpg

Hooked up my leak tester, heard hissing from the hot side. After nosing around, found that the vacuum cap on the brake master cylinder was cracked and leaking. Replaced it.

https://cimg5.ibsrv.net/gimg/www.mia...34b4d1420a.jpg
https://cimg7.ibsrv.net/gimg/www.mia...5da0267dbe.jpg

Took it out for a drive and some tuning. Still making the hissing noise when the turbo gets going. Sometimes it starts when I'm revving up but still in vacuum. The more boost the turbo makes, the louder the hissing. Still slow to spool, almost identical to the other graph.

https://cimg0.ibsrv.net/gimg/www.mia...4b93a7707e.jpg
I've got a better tire pressure gauge coming to hook up to my boost leak gauge; I'm going to get the car back up on jack stands and remove the bottom tray, and see if I can figure out where the leak is coming from.

On a positive note, the knockoff Greddy Type S BOV I have is much quieter when I take the stupid trumpet thingy off the bottom.

Why is there a t in your vacuum hose? That should be just one hose from the pipe to the booster. It's just another point of possible failure

That is a very good point. I think the cruise control that I removed a long time ago used to hook in there... dunno. I’m learning that a lot of things that aren’t a big deal with normal Miatae can become a big deal with turbo Miatae. I will remove that T.

So tonight I hooked the pressure tester back up, and I just couldn’t make sense of it. Couldn’t get the system to pressurize at all, all the air I put into the compressor just disappeared. So I looked around the back of the turbo compressor and found this:

https://cimg8.ibsrv.net/gimg/www.mia...8923c151d.jpeg

If you look just past the oil line, one of the housing bolts that holds the actuator bracket was gone. Air was rushing out of this hole rapidly. I don’t know how the bolt came out, but I replaced it with another one and pressure tested again. Everything is tight as a drum, it holds pressure for days. This is a relief, because I couldn’t figure out how my intercooler piping could have been leaking. I spent an assload of time fussing with those pipes and getting everything perfect.

Took it for a drive. Spool seems much better. I’ll catch some logs tomorrow. I also noticed in that picture above that I’m losing a tiny amount of oil at the -AN connector, so I tightened it up.

The actuator shaft is up against the side of the hole in the bracket, and appears to be wearing a little groove. I think I should probably bend that bracket back a bit so the shaft is centered. It seems to be working just fine, but no sense taking chances.

EBC solenoid came today. Maybe a weekend project.

Took the actuator and bracket off and bent the bracket back a bit. Actuator lines up much better in the hole now.

https://cimg6.ibsrv.net/gimg/www.mia...8fdede1e0f.jpg

Since I still wasn't sure how the bolt backed out the first time, I turned them down good and tight this time. Yep, good and tight...

https://cimg8.ibsrv.net/gimg/www.mia...7b44366b12.jpg

DAMMIT. Unfrozen Caveman Mechanic stripped the thread right out of the aluminum compressor housing. In retrospect, I probably partially stripped the threads when I put it all together the first time, which is how the bolt got lost. Not to be outdone, I cut another bolt that goes three threads deeper, and tightened it down gently. It's holding strong for now. Then I ordered another ebay turbo, that's what I did. I'm not going to mess around with trying to rescue the threads on this one- if this car's going on the track, I need to remove all traces of jank. We'll call it a $112 learning experience. Ladies and gentlemen, this is why you don't get a Borg Warner for your first turbo project.

On a positive note, now that I've eliminated my HUGE boost leak and the actuator binding against the bracket, I found my spool. Finally did a legit 4th gear pull this morning.

https://cimg3.ibsrv.net/gimg/www.mia...6034e86eab.png

I've got a bit of compressor surge down low, which was predicted by the turbo map and my puny 1.6L motor. The good news is that I don't plan to spend a lot of time WOT at 1700rpm, and aside from that it's like a totally different car now- POWAAAAAA....

Can't wait to get the EBC installed, there should be more spool on the table. I'll swap in turbo #2 this weekend then get about it.

For the record, a turbo 1.6L may not be as good as a turbo 1.8L. But it's still a damned fast, fun car. I'm amazed to be honest.

So much boost it blew the bolt out of the compressor housing...


That would be my story.

That is an interesting spool map. Shouldn't it hit peak and level out?

Like this?

http://i158.photobucket.com/albums/t...psjbjyn4ha.jpg

Yes it should, I’m still troubleshooting boost leaks. Took me a while to get a strategy with the test fixture where I could see the pressure in the intake tract. I still can’t hold more than 5-6psi with the air compressor. Biggest issue right now is the turbo itself; I still have a big leak around the compressor, where the housing meets the back plate. My new Ebay turbo came in over the weekend, I need to port the wastegate then I’m going to swap the whole turbo out to see if this one also has the problem. If it does, I’ve got a can of copper RTV spray sealant that I’m going to try.

New turbo came in. Since it was only the compressor housing that I buggered up, I just took the compressor housing off of the new turbo. I’ll save the rest as parts for future service.

Removed the old/buggered housing. While it was off, I removed my oil fittings, cleaned everything up, and used Permatex high-temp thread sealant to put it all back together. Hopefully that will be the end of the oil leaks.

Put the new compressor housing on and bolted everything up. Put the pressure tester back on. Still won’t hold more than 5 or 6psi. Still hear air rushing around the turbo. Stumped. Then I noticed the smell.

Turns out that this whole time, the air has been rushing out of the crankcase vent, not the turbo. I feel like this probably isn’t good news. I compression tested the engine a few months ago and it was 180ish in all cylinders. I don’t have the time or the motivation to test it again right now... I’ll do it over the weekend.

May be headed towards the 1.8 swap sooner than I had anticipated. Which sucks, because I’m also on a Lemons team and we have to get that POS done in November.

You need a better PCV or a check valve that keeps boost in your intake manifold from pressurizing your crankcase.