First time posting, so "HI!". There got that out of the way.
Anyways, the majority of the posts by 'me' are not the truck owner. I'm his computer guru friend, but I am also a car nut so fear not! He's a big mechanic as well. Just to get all the FYIs out of the way!
(M5 5spd btw) We're not quite sure what's going on with the truck, it's just gutless. And while it is quite heavier than your avg PSD due to being a Tow Truck, but this slow just doesn't seem right. The oddest bit, is that there seems to be no change in performance with the Superchips programmer that a friend gave him. Few days ago I replaced the EBV sensor and pipe, since the pipe was plugged solid (no surprise!). Then we made a 10K mod (we decided to go with 6.9k since people reported down to 5.6k before idle problems) and installed it today with the tune set to stock. Small bit of smoke, compared to virtually non any other time. Stopped and tuned it to 'performance' and smoked quite a bit, but in the upper Rs (probably 2750-3K+) it was gutless. There was a noticeable change in the exhaust tone as well, it was kind of raspy.
Short of going out and driving it again to get these numbers, all I can tell you is that the MAP PSI is around 28 and khz around 110-125. Highest boost we saw was 16psi.
Mods so far are just a straight pipe, kicked out mid-box through a 3" can. The 10K Mod (again we did 6.9K).
Replaced the EBV stuff as I mentioned, and the CPS. 4 new injectors with the other 4 tested and were good. Glow plugs replaced. Harnesses for the glow plugs and injectors were replaced, as they were not in good shape. He told me there's such a list that he can't even think of it all right now
But if you think of anything I'll ask if it was done.
I plan to do the regulator screen cleaning and the BB spacer. I'll see if he wants the regulator rebuilt since it looked cheap ($15-30). He's asked me to make a list of stuff to buy for performance, but I have a feeling there should be other things done first before that. I managed to talk him into doing the free mods first, and then progressively get more expensive. Found a 3" mandrel down pipe for $89 so that's on the list, and to make a better air intake with the bigger NAPA filter. Plan to do a mechanical "MAP fooler" to blow off pressure over 20psi (or less if you recommend it). The TW chip is on the list after all that, and he really would like to slap a turbo on it too and we found a nice place on eBay that has the Garrett ones for $550 (shipped), non waste gate model with ported and polished inlet @ 1.10 A/R, Banks compressor wheel, 1.15 A/R turbine housing with the stock turbine wheel. No core charge so that price is what it costs.
Only question, obviously above the "wtf is wrong with this thing?", is the downpipe. It all shows a single down pipe, but when we had this thing in the air removing the muffler, there were 2 of the flattened pipes, on each side of the motor. Do you remove all of that, and then it's a single 3" down pipe? If so, how can that be better than 2x 2.5"? And then is the exhaust back 3" or 2.5"?
Thanks for bearing with me on this!