Cliffnotes:
The MAP downpipe is a pretty nice downpipe! It arrived safely, and included all of the parts that I needed, including bolts, spacers, gaskets for the exhaust as well as the turbo, all neatly packaged up.
Install went well, I did it without removing the exhaust manifold or radiator. The most difficult part was getting to the factory bolts after removing the heat shields, and then fitting the downpipe onto the two studs on the turbo. This DOES require you to remove the a/c compressor to fit the downpipe on, but then you can place it back when you are done. It is impossible to clear the studs on the turbo without removing the condensor.
Fitment is VERY tight, but it seems to clear everything. There is between 1/4 and 1/2" gap around the oil pan, subframe, and a/c compressor. Nothing rubs though, and it seems very sturdy.
The exhaust sounds amazing, pulls hard, and it makes an extra 2 psi at WOT, without changing anything. The exhaust should flow a lot better, since there are no sharp bends in the new "o2 housing" section, and there is no turbulance from the wastegate since it is externally gated. I am very happy with it!
The only negative I could find, other than the unexpected need to remove the a/c compressor during installation is the coating. MAP claims it to be ceramic coating, but it really seems just like some high temperature grill paint. It rubbed off very easily in a few places during installation. They did warn this on the MAP website, but it is impossible to not bump it at all during installation. Still though, it is a great downpipe.
I recommend this downpipe to others
The whole story:
Started progress on the exhaust system last night. Big props to emery who helped me get to two "impossible" studs, and got the lower heat shield off for me, which normally requires you to pull the top of the manifold off. :tup:
Started out by blocking the radiator off with cardboard, so we didnt' damage it. Then cut a slit in the lower heat shield to allow the o2 sensor wire to pass through, and then with lots of force and pulling, we were able to remove it from the bottom. Next, pulled the DC Sports downpipe I had on there, as well as the lower IC coupler, so that we could access the factory o2 housing.
The factory o2 is held on by 3 bolts and 2 studs. The 3 bolts were pretty easy to get too, the 2 studs are next to impossible. The easier of the 2 studs we were able to get a closed-end 14mm wrench on it, and then throw some body weight into it to loosen it up. The other stud was up against the block, and we had to go from below with a 14mm deep socket, and move it about 1/64th of a turn at a time, until it was loose, and then I was able to get the nut spinning with my hand. After only about an hour or so, we got the o2 housing off.
For a factory peice, it is a pretty well designed peice :tup: Its matched up nicely to the factory turbo, and its pretty big inside, and no major sharp edges inside. If you look at the flow, there is quite a bit of turbulance inside from a quick turn, and the way the exhaust has to cup back into the downpipe off off the wall of the o2 housing. My words may not explain it properly, but there is definitely room for improvement in the factory o2.
The new dowpnipe came safely, packaged in a big box. They even included new hardware and new gaskets for both ends of the downpipe. I ended up getting the 2.5" - 3" transision in the o2 housing section of the downpipe, because of fitment issues. The people at MAP told us that the full 3" section requires you to remove the a/c to fit it, and I still have mine. This 2.5" section matches up perfectly with the outlet on the factory turbo though, so it should flow pretty well out of there, not to mention that it has an extra 1.5" of open dump to free up the exhaust flow there!
Tonight (weather pending), I am going to finish this up. Due to the design of the tubular o2 housing vs. the factory cast housing, I think the bolts should go in quite a bit easier. Time will tell :eekdance:
I have more update for the downpipe. It's on, and now we are just waiting for the flanges to come for the test pipe. The snow storm haulted some shipments today :spank:
The day started off a little bit rougher than planned. It was thought that we only had to move the a/c compressor if I had the 3" o2 housing, but you can not get it in place, even the 2.5" o2 housing, with the compressor there. Its just too tight of a fit because of the studs in the turbo. Instead, we just pulled the accessory belt, and then pulled out the 4 bolts holding the compressor to the block. With this extra room, we were able to get the down pipe up against the turbo flange, but not without scraping quite a bit of the downpipe up. Its not bad, but i the future, I would put tape on some of the spots that rub easy, so that it would not rub through the coating.
After that, the bolts and nuts went on pretty easy, and it slid right into the exhaust hangers with the help of some WD40 on the rubber hangers. The fit is great, there is about a 1/4" around the flex joint and the oil pan, but since its solid mounted up to that point, it won't ever hit it. The lowest part is the dump tube, and that is fine. The dump tube clears the a/c compressor by about an 1/8th of an inch, and clears the charge pipe just fine. The o2 sensor would have been much easier to tighten when the downpipe was out. Its almost impossible to get to now
Overall it was only about a 3 hour job to do the entire thing, and that was a lot of bull****ting around, doing things that weren't planned on. About an hour to remove the heat shield, old down pipe, and o2 housing, about an hour to mount the new stuff, and then an hour doing things like the a/c compressor and accessory belt, tightening charge pipe clamps, etc..
Here are some pictures of the final product:
And for the record, the smears all over the downpipe are from the anti-seize. I had it on my hands when I was trying to get it in the first time, and now its all over the pipe :roflpicard: I figure a heat cycle or two and it will burn off anything left on the outside, or I won't care!
--mark
