well....don't know if you were looking for suggestions, but....
the header pipes are doing a pretty hard angle change there. A few more cuts and welding would have softened the angle change to make it less severe. It'll still work fine as it is, but the sharp bends will act as a baffle to the exhaust pulses, which will effect spool time and peak efficiency.
The charge pipe coming off the air box looks awfully small, what diameter is it?
the intake diameter is small, but it is the same size as the outlet of the compressor, so i didn't think that that would really affect anything since the air had to already go through a passage that small. yeah, those are some sharp angles, but i am probably going to go to t3/t4 sooner or later, so it will suffice for now. i am not too concerned about spool time since i dont really want a huge ammount of boost at lower rpms. if i was going for more than my goal hp of 250-275hp, i would probably change it, but i am too excited about it too even think about taking apart something and redoing
the smaller the pipe the larger the pressure drop from point a to point b. The higher velocity creates more friction on the pipe walls, and is overly sensitive to directional changes (pipe bends)
There is no hard rule on what diameter the pipe should be for a given setup, but I would at least go over the compressor housing exit ID by 25%. IE, if the ID is 1.5" go with 2"
larger pipe, at an extreme would slow down the boost hit, because the vollume of air takes longer to pressurize, but it takes a lot of excess to be noticable. Where as, if you are too small and have a large pressure drop, you are moving the compressor further up the compressor map, causing more heat in the intake and possibly pushing the turbo out of its efficiency range (that is the extreme of course). The heat in the intake is very bad. More heat = detonation, which is how you blow up motors.
i didn't like the style of the log exhaust. the log plenum is not too different from a normal plenum. it is just shorter. a log exhuast though is very diff from a normal header. the angle is wierd on the tire and there is a piece of plastic there too that makes it look closer than it is. i lowered it like 3 inches and it still has plenty on clearence.
so i shortened the header today just a little less than an inch or so. helped a lot it looks like. just finished that up, so i will need to wait for it t cool then put it back on.....should be ok too for oil drainage issues now as well.
and yea, those are zip ties holding the boost gauge on...i needed to finish fast in order to try and make it to the last track day, and that could be hack....oil lines and stuff couldn't, so the gauge will be dorky for now, but hey, it is a BOOST gauge none-the-less