I just put in my order for one of CFD's turbo kits. I'm going with a s363 with twin scroll housing. I still haven't decided on whether or not to get the max effort tuning. Justin says it's hard on the cp4 and I certainly don't want mine failing. I'm going to start a separate thread about this topic, and another for the actual review of the CFD kit.
Here is a little bit more info on my situation: My POS ford garbage turbo failed at the end of April with about 56,000 miles and I've been tuned since 25,000. I've had lots of time to think about the current kits. I haven't used this truck for towing very much yet, but that's going to change. I bought a 25,900 pound gooseneck trailer in march. I'm getting better wheels and tires for it because on very rare occasions it will be loaded to about 31,000 pounds. Please don't derail this thread with over-weight comments though. This is not what this thread is about. I know the downsides. The rest of the time it will weigh between 8100 (empty) and its normal max gvwr of 25,900. I plan on towing about 5-10% of the time I use my truck. The rest of the time it's just a big car. Another reason for selecting this turbo is that I live at 6000 feet elevation and the 366 would have way too much lag. I may even change to a s360 later if the 363 is too laggy.
I've thought long and hard about which kit to go with and I'll share my thoughts on the current kits. All of this is just my opinion and from my "armchair engineering" perspective. I'm not a real engineer, nor do I play one on tv.
SPE: I think their kit looks great and has the lowest chance of having any problems on the exhaust side. I think the oem exhaust manifolds are probably going have a lower chance of cracking than any aftermarket welded manifold. The possible downside is a little more restriction with the oem exhaust manifolds. Is this significant? I dunno. The turbo mounting looks solid. They have the lowest priced kit. Dan has tuning for their kit to work with the emissions components. That's a major plus for those who live where emissions testing is done. Their turbo oil feed line looks like is the least susceptible to damage and possible rupture. Rupture in that line would be very bad. CFD initially said this oil source is from a cam bearing like it apparently is in the duramax engine. According to Dan and the ford coffee table book, this oil source is direct from the main oil galley, so it should be sufficient. Justin says the opening in the block where the oil comes out of the block and into the pedestal is still pretty small for an oil cooled turbo. I'll report back what i see regarding the size of that hole after my install. If it's big enough, then the SPE oil feed line is definitely the best imo. Dan really seems to me that he knows what he is doing and I'd trust his tuning. The intake tubing from the intercooler to the throttle body that they leave in their kit has me worried a little with the heavy loads I'll be towing on occasion. If anything can saturate the oem intercooler with heat and blow that ford garbage plastic tubing, it's going full throttle (on the stock fueling level) up a long steep hill for 20 minutes. They say a replacement for those tubes is on the way, but not available when I called. Another thing that I don't understand is why Dan said their tuning only makes about 30 psi of boost. It's true that (in a sense) boost is a measure of restriction. However, the restriction of a fixed-geometry turbo is, well..... fixed. So that leaves what for the reason for lower boost? I dunno, that's just a just minor detail though. Another thing I prefer about the other kits is the availability of turbos. The SPE turbo will have to be ordered from SPE because the exhaust housing is machined for a different (but better) style of downpipe clamp. The inlet to the compressor is also machined for clearance. That makes replacement turbos only available from SPE and more expensive than a generic "out of the box" turbo should I need a replacement or want to try a s360.
MPD: These guys definitely have the best looking kit so far. The exhaust and especially the intake look awesome. The obvious downside to their kit is the price, and they say the final price will be even higher. If you look at how much it costs to replace an oem turbo with an aftermarket on a 6.7, it's already ridiculous compared to any other diesel engine I know of. The oil feed line comes from a possibly insufficient source and it is not a solid steel line like SPE uses. I know, it's a detail, but think about how bad failure of that line would be. You're stuck wherever it breaks unless you have extra oil and the parts to fix it. I take my truck to the middle of nowhere sometimes and failure could have the potential to be life-threatening. Turbo mounting in this kit uses the manifold from one bank of cylinders to support the mass of the turbo. I personally don't like how this looks and it doesn't seem as strong and reliable as a pedestal. Cummins use the exhaust manifold for mounting, but it's bolted onto 6 ports and it's a big beefy cast iron manifold. There is also the question of these manifolds holding up and not cracking over time with hundreds or thousands of heating/cooling cycles. The thermal stress in combination with the stress of supporting the turbo has me a little concerned. I asked RCD about this and they didn't respond. They probably think I'm nuts for worrying about it. I think they are using a standard turbo, so replacement availability and price is very good.
H&S: Not much is known about their kit yet, but we have a basic drawing of the exhaust and pedestal. What I can see looks like a very clean design. I have a lot of respect for the folks at H&S regarding their electronic engineering and tuning ability. But, I don't like that the exhaust is routed through the pedestal. That means any fluid contacting the pedestal will get very hot and possibly burn during a long, full throttle hill ascent towing way, way too much like I plan on doing sometimes. The answer H&S gave in another thread did not satisfy me in the slightest. A the small volume of fluid flowing through a part of the pedestal is not comparable to coolant flowing through large cooling passages in a head. If the entire pedestal is cooled, that will take care of the overheating of fluid, but will also cool the exhaust prior to it entering the turbo. That's bad from the perspective of efficiency and performance. Maybe this is all paranoia on my part, but that's still my opinion.
Confederate Diesel: The exhaust manifolds are larger than stock and can flow more volume, or flow the same volume with less restriction. I don't know if they will be as reliable as the oem manifolds in terms of not cracking. Nobody will know until they have lots of miles on them. The pedestal looks strong and reliable. I was concerned about them only using a flexible coupling on one side, between the exhaust manifolds and the turbo. Justin says they are now using one on each side so that's ok. I'm also concerned about the weld beads right beside the holes for the mounting bolts on the manifolds. The bolt heads should contact the surface of the flange all the way round the holes for maximum fastener strength. It looks like some could get only one edge of the bolt head putting pressure on the weld bead instead of the flange surface. This is not ideal, but they said they'd make sure it isn't an issue on mine since I'm concerned about it. Confederate seems like they are very willing to accommodate customers' needs. They are the only ones so far to use an oil feed straight from the main part of the galley. This ensures plenty of oil will be available for the oil cooled turbos. The downside is that they have the longest oil feed line with the greatest chance of it rubbing somewhere and failing. They said they can also make a solid steel line like SPE does, from the pedestal, but it might not feed enough oil. So I decided to go with their regular line. I'm going to be very, very particular during install about making sure it doesn't contact anything it shouldn't and it's well protected. They are also sending me a heat sleeve to put on it to appease my paranoia. This kit uses a standard, out of the box turbo so replacement cost and availability is very good. The intake looks fine and they can do any color so that's a bonus for the custom look. They are also willing and able to send me replacement parts to rid my intake of all ford garbage plastic tubing. It costs a small amount extra, but my paranoia is appeased. You have to modify your own downpipe with this kit. The oem downpipe is double-walled according to the coffee table book and it sounds like it would be a pain to modify because of this. I'm getting a replacement downpipe from CFD so I don't have to fuss with it. You also have to cut a little off your oem pipe going from the turbo to the intercooler. That's no problem for me, but some people may not want to fuss with that.
Those are my thoughts, feel free to post up what you think. Feel free to tell me I'm full of cow excrement. It's all good.