Northern's Sterlingsilber M52 Turbo 325is

[Northern]

It looks like it was a spot of corrosion. I couldn't find another early e39 M52 rail, so I ordered some injector hats and a clean looking OBD1 rail from socal, and then use my pitted OBD1 rail on my 4dr.

The standalone question is a long one...
I've thought about buying a Link E36X a few times, (previously about an ECUmaster EMU Black + EDL-1 logger/bt unit) but the E36X is cheaper (and newer) by a bit.
The PNP aspect is my least favorite part of the E36X, because it's OBD1 pinout, but also because adding/removing pins is painful vs say an AMP Superseal motorsport connector on a MoTeC or Haltech.
It would give me live tuning, failsafes, and let me run an e-throttle, traction control, closed loop boost control, etc.

I haven't considered anything cheaper because I don't think it's worth it. Any ECU with poor or non-existent knock control isn't for me, Speeduino and a lot of stuff like lower tier Haltech/Link doesn't do knock, and the M52 on stock CR and 91 is so knock limited on boost that I pretty much have stock timing up until boost hits and then I've fine tuned it using logs of MS41's knock retard and some MLVHD tables.

I think I kind of have the learning curve out of the way with MS41, all the deletes I need are done, MAF hack+ HPX MAF let me deal with the extra air, spreadsheets and MegalogviewerHD views give me the info I need to do quick revisions. The only painful part now is physically removing the ECU to bench flash it instead of live tune. I don't think I have any plans to ever make more than 500whp on this chassis, and even 400+ is unlikely so this is probably how it will stay.

I have probably spent the same amount as an E36X costs, between software, MAF, MAP, EBC, other loggers, so I probably would more seriously consider a standalone if I did it all again and had today's options available. Might still consider it for my 4door if/when I turbo it.

Another big part of it is being part of the MS41.3 beta ( https://sites.google.com/site/openms...-code---ms41-3 ) which has been interesting. The goal is to let this be a public thing once everything has been confirmed to work and there isn't a big chance of adding things (for example, the items in yellow are new since the version I'm running, so that removes the MAF hack and dividing all tables with load by 2 so the variable doesn't overflow, which always raised the question of "what tables have we not found in the ECU that use load")


That exhaust heat shield, I just bent that piece up from a masking tape template of the original, had to make some compromises on shape since I was using a brake for the bends.

Funny to see that engine bay again, I'm probably going to eventually rebuild that turbo (again) for my other car.

[moatilliatta]

Was the fuel leak from the spot weld or corrosion?

Hope you can get the car sorted out soon. Have you though about just going standalone if you're trying to use a map sensor?


That turnout quite well! I may have to do the same, I always hated how heavy that panel was. Some cars seem to have steel or aluminum heat center heat shield. I think it maybe and early early car vs late


Hah, this is great. A local at the time, I helped him build the car in his garage. The gold old days..

[Northern]

Small update just to remember what I did from Jan-Feb

Replaced my Wideband O2 sensor again (warranty). It's an NTK Xref of a Bosch LSU 4.2.
Apparently that's what my innovate LC-1 shipped with in the first place, so I don't feel sketchy about running it.
The fact that I've burned through 4 of them in 2020 is probably a sign that I need to delay the O2 from starting until the car is actually running.


I finally got my MAP sensor working, turns out there's something with the rear O2 sensor's sensor ground in the ECU that stops it from being used for anything else, so I spliced into one of the large ground splices in the engine bay:

My Revised setup is:

+5V from Tank Pressure Sensor (X8000 Splices into TPS +5V fed from the ECU X6000-44)
Signal Input to Post Cat O2 #1 Signal IN (X6000-77)
GND to BR/OR Chassis GND Engine Harness Splice (X6459)

X6459 is the large splice of Brown/Orange GND in the engine bay.
No reason I chose this one in particular, other than that I found it quickly visually and in the ETM, and confirmed it went to the strut tower GND on the RHS of the car.

I Noticed it read ~6kPa high at atmospheric, so I used my boost leak tester to pressurize the intake and hoped to use my EBC to get a reading.

I didn't think far enough ahead because as soon as my EBC saw positive pressure it went straight to flashing "LEAN" since the car wasn't running,
then when I passed the 10.5psi boost cut, it started flashing "CUT" at the same time as "LEAN".
After I lowered the pressure, the gauge permanently read "17.5" and after calibrating the MAP I thought I had somehow broken it until Harrison from GFB told me that I had just switched the readout to AFR mode by holding the settings button as I freaked out the lean message.

Anyway, I used my analog boost gauge to correlate with voltage in my romraider log. Despite how sketchy it felt, it worked to make an adjusted scalar that looks correct.


Then I spent 3 attempts at fixing a fuel leak at the fuel rail.

I thought it was something wrong with my 3d printed spacer arrangement, since the fuel rail didn't look to be sitting straight, maybe the spacers were too long (they were, and we also crushed).
I replaced the spacers with shorter/unsquashed ones, and the rail still leaked.
I replaced these spacers with harder HDPE ones, and the rail still leaked.
Then I replaced the top Orings on the EV14s, and the rail still leaked.
Then I noticed the top of the rail was wet when I was priming the system. I just happened to look under the rail and saw:

[Northern]

Might need to open this pic in a new tab for it to show a decent resolution...

[Northern]

Not much going on with this car. Drove it a bit but I have no reason to leave the house.

Still trying to get the MAP working.
wideband O2 sensor died again, so I warrantied it but have yet to install the new one.


Pulled out Ye Olde Fender Roller to try to lower the car down again. I don't know if it made much of a difference, but it let me lower the car an inch or so.



Also lets me take pictures at utter degenerate levels of stance



I bought this kit for the S2.93 I'm building. I honestly though there would be more to it for $100. Would not recommend, just buy everything separately.
Hell, you don't even need the axle clips and I don't know why there are two cover gaskets.



MAP progression. Bought a third sensor, AC Delco 4bar for some LS variant. It also has a bosch part number.
It's supposed to mount to a flange, so I had to adapt it for a hose barb.





Much smaller than the old one. Probably will reuse the old one on the other car, since I think the issue is from trying to use the post cat O2 ground.



Really want to be able to log MAP because my EBC just flashes "CUT" over 10psi and it seems that the 7.5psi spring wants to live somewhere north of 10psi.

I reenabled VANOS and load comes up faster. I have the modifier tables changing fueling/timing much less than stock.

Engine seems happy with a bottle of VP Octanium per 35L of fuel. Hitting a hair above double the stock load numbers (since the MAF and Load in this graph are half the true number), but since this is a different MAF, something could be off.

[Northern]

Been a while since last update, nothing crazy to report.

started running VP Octanium octane booster with my crappy 91 AKI gas and it seems to have a good effect on knock.
I'm not sure how quickly the octane rating decays as the car sits, but I had zero knock under boost for the first few weeks and now I'm up to 1 degree at times.
Might be something else, but I think for this specific application, this specific octane booster does work.

I've been trying to diagnose a clunk in the rear, seems to be from one side of the back. I went under and checked everything a few times and I found the subframe mounts were loose? I managed to get 2+ turns before I reached spec. They're garagistic riser mounts FWIW, not sure if they deform over time or if I simply forgot to torque them last time I installed the subframe.
The driveshaft (or trans?) also seems to have some sort of play, but I don't want to drop exhaust/heat shields to mess with it right now.

Other than that, I found nothing wrong back there other than that my rear Koni Sports (top adjust mustang) had un-adjusted themselves? I only checked that because the rear seemed bouncy.
I set them both to 1 turn from full soft and it's much less bouncy now, but I might try another 0.5 turns and see how it goes.


Here's an engine bay pic because it's been a while

[Northern]

yes, at least 12 pops and 3 bangs.

I will share them with all the kids who post "pls gib popcorn tuen" on romraider, so that they can go on to drive noise legislation in a more restrictive direction in their locale.

[ba114]

loving the build! will you have hectic pops & bangs when you're done? :P

[Northern]

Used my gopro for the first time in years. Here's a quick 1 minute video with an engine bay mic:
(also I'm still overboosting to ~11psi...)

https://youtu.be/tJzrilZ7d7Q

[Northern]

^ does an M52 reach atmospheric at WOT in NA form?

Definitely an optimistic number either way.

[varg]

Yeah, seems pretty high. Quick estimate; saw a dyno of an M52B28 with M50 manifold and a tune and it was 196whp, 7psi of boost so 1.48 atmospheres of manifold pressure; 290whp/322hp. Drivetrain loss estimated by typical stock M20 dyno numbers (150whp) at ~11%.

[Northern]

Dont forget to multiply this by 0.8-0.85 to take into account drivetrain losses

It's saying 395hp@6509 and 325 ftlb @ 5800.
at 0.8 that's still 316whp, but I'm just skeptical of it adding that much from just 7psi.

[ba114]

...I also made a calculated column in megalogviewerHD for estimated HP based on MAF*0.3472 but it also seems like 25% high....

Dont forget to multiply this by 0.8-0.85 to take into account drivetrain losses

[Northern]

Thanks! I like that I've managed to keep the exterior reasonably stock looking, but I really need to do some bodywork at some point soon...


Small updates:

I made a new spreadsheet to compare timing maps, resulting knock, and update my timing map with the info. I think it has helped me start to dial my timing in.
With the 7.25lb spring, and timing adjustments over the past bit, I'm down to a maximum of 1.5 degrees of timing being pulled at WOT (down from like 7 at one point)

Car pulls nice, drives nice but has a few quirky spots in the fuel map still that I need to work on (Example: If I am idling and continuously stab/release the brake, load jumps up a bit and it goes very lean. My idle point is between 4 cells and I think the lower cells are too rich/the upper cells are too lean, so I'll slowly shift them until it works right.)

I'm curious to know what the car makes for power but it's hard to judge. It topped out at 1002mg/stk load and 1150kg/hr of airflow, which is not quite double a stock M52. I've thrown pulls in virtual dyno but it seems far too optimistic.
I also made a calculated column in megalogviewerHD for estimated HP based on MAF*0.3472 but it also seems like 25% high. I imagine I'm in the 300hp neighborhood just from the ~0.5bar

[zwill23]

I’m in Texas so pretty lawless as far as older vehicles go... I appreciate the feedback! I figure I’ll just run with it and worst case scenario plumb it if need be. It’s pretty nice that you can seem domestic cruising around town without attracting attention. Self control is also a big factor lol.

Digging the evolution of this car, it’s very unsuspecting.