Thanks Eric, if I was anymore computer savvy, I'd figure out a way to edit that stuff and just post it here as a write up. I certainly could use some help with that.
Sewerzuk, the first manifold I made, was fabbed out of regular exhaust tubing, and just couldn't take the heat or vibration. First time for me too, and I learned some important stuff, Like first, get the knowledge you need, then BUILD! Of course, the first install gave me valuable information on things like underhood heat management, vunerable components near the turbo, and general service issues that needed to be addressed.
The second build addressed all the issues I had with the first one, and included everything I had learned about weak areas, power needs, and serviceability. I really did a lot of research on materials for the manifold, and got ahold of a great guide for building turbos: Maxium Boost by Corky Bell. Covers everything from begining to end on turbocharging anything. The stainless steel manifold was determined to be the most durable, and stainless was also the best choice for heat retention, exactly what you need to run the turbine wheel. It is a bitch to work with though, cutting and fabbing all the joints requires lots of grinding and cut off wheels. Mine is made of Schedule 40 grade 304 stainless steel weld el's, and the main collector tube is 304 Sched 80, for ultimate strength, and maximum heat retention. I also found that SS is much easier to heat shield, keeps the engine compartment much cooler, and is very resistant to corrosion. It's virtually rust free, even after several years of use and being splashed with mud and occasionally being submerged as well.
The Turbo I used is an IHI RHB5 with an internal wastegate, blow off at 7lbs, common to the Ford Probe, Mazda 6, Suburu of late 80's early 90's vintage. Wildgoody gets the credit for finding the turbo and experimenting with it first. It's sized perfectly for this appliction, and only required some mods to the exhaust side flange to get it to fit. I did modify the intake side of the turbo (compressor housing) to make install easier, and to eliminate as many unnecessary clamps and bends in the air plumbing as possible, and simplify maintence. The system was built to fit into the stock location, with all the stock intake and sensors. This way, swapping back to stock would not be an issue, even on a long trip, if there were some kind of catistropic failure af any part of the turbo system.
As far as the ECU and fuel management, I used all the stock components, including the MAS in the airbox, and all the other stock sensors, and the stock ECU. I upgraded the fuel injectors from the stock 175cc to 210cc injectors out of a Nissan v6 pathfinder, which use the same electrical connectors and fit like the stockers. Eventually I also added a manually adjustable fuel pressure regulator and run 47lbs of fuel pressure as opposed to about 38 stock. Stock fuel pump. By keeping boost pressures to a conservitive 5/6 lbs, the stock engine internals are more than strong enough to handle the added pressure and power. I did retard the timing 2 degrees from stock, but that seems to be more related to ambient tempertures and fuel quality than anything else. I've found in the colder months, I can go back to stock timing, 5 Degrees BTDC, and have no pinging or detonation even under the heaviest boost conditions.
Before I actually got the turbo installed, I installed all the guages to get them working and have a way to get baseline information for comparison. The oil pressure readings were at first startling to me: up to 80+ lbs when cold, before warming up. At highway cruise speeds I was getting a consistant 60lbs +or- 3 lbs of oil pressure. This explained the oil draining problems I esperienced during the first build. The turbo only needs 25, anymore than that and it floods. I installed the scavcange pump, problem solved, but I did eventually get enough information about oil restrictors to figure out a way to put in a adjustable valve with a pressure guage inline to the turbo and get the pressure where it needed to be. I can probably eliminate the scavange pump, but it's already there and works fine. If / when it fails I'll go directly to the drain already fited to the oil pan.
The EGT's were another real eye opener. in stock form, with the temp probe mounted near the same location, about 6" after the collector, on the highway , STOCK, it ran in the 1200 to 1400 degree range. I thought this was pretty hot, but after talking to several experienced turbo builders, I was convinced this was normal. Once the turbo was installed and running , EGT's at highway speesd: 12 to 1400 depending on how long I was on boost, like going up a paticularly long mountain grade it'll get near the 1400 mark and stay there untill I'm off boost. Running down the highway ant normal speeds, 65/70mph, not on boost 8 to 1000. Pretty much the same as stock with a Calmini header.
I've been running this setup for over a year now with no problems, and it runs great. Plenty of power when needed, stock like normal operation when not on boost. Boost available anytime you step on the pedal, and surprising accelleration, just ask anyone who's been in it! If anyone has anymore questions I'll be happy to do my best to answer.
