OBD1 Vs OBD2 Argument with Dynos...

[328ijunkie]

Customer Car came in as OBD1 S52 with M50 manifold and a off the shelf Name brand chip for said setup i wont name. OBD2 headers and a cone on the MAF. Brought car to shop, threw OBD2 harness/ecu/sensors on it, changed nothing else and results are below

Did 3 runs, based my other comparisons off the middle of the 3.



Stock US Tune vs OBD1. Dip is from vanos shutting off early because of missing VSS...


OBD2 Base vs OBD2 tuned


OBD1 vs OBD2


Here is the revisions on the OBD2. Playing with vanos after flashing my Off the shelf tune and tweaking slightly (bringing timing down as far as possible without affecting power). Back to back to back runs other than the ~1.2 min flash time.


So basically ~10w/tq from going to OBD2 with no other changes. My off the shelf tune vs fine tuning it on dyno changed nearly nothing (other than fixing vanos bomb) as ive gotten the off the shelf tune pretty down after a while.


Again there is the obvious possibility that the OBD1 tune could have been revised further to make the same numbers but my point still stands. This will be more reliable, smoother overall, and when it does mess up, give you meaningful feedback as to whats going on.


Bring the fire! ;)

[ForcedFirebird]

It's kind of not a fair comparison if you used a shelf chip. ;)

Also, you posted on FB that the VANOS wasn't working correctly due to the VSS.

You have seen it, but here's a direct comparison from a popular companies shelf tune vs live tuning.

[328ijunkie]

Vanos wasnt working correctly due to VSS on OBD2, OBD1 doesnt care in that regard... OBD2 Ms41.2 uses VSS as a axis for vanos engagement map...

[surebimmer]

Awesome. When my car comes up due for smog this year think i'm going to swap over to OBD2. I like the fact that you get much better info from the OBD 2 system. Plus two pre cat 02 sensors should give a lot better sample for the ECU.

[328ijunkie]

^Something 99% of the E30 swap 'kids' dont seem to get thats important :P :(

[nando]

did you ever figure out how to get the OBD2 computer the right VSS signal? or does it end up not mattering?

[328ijunkie]

Steve sent me a signal converter for free :( and its still sitting on my desk ( i suck). As far as it mattering, yes it does in many places, i just tune around it... The E30s spitting VSS is so inconsistant. The Car i dynoed here would do ~155 on the dyno and VSS signal wouldnt break 3mph cause cluster was outputting crappy signal. Thus throwing vanos into fail mode. The shutoff point on ms412 changes based off VSS+RPM. For whatever reason MS41.1 doesnt care and does it solely off RPM.

[nando]

the circuit board is pretty crummy. the 30 year old capacitors are probably starting to fail, as they weren't very good quality to begin with. the PCB itself literally looks like something made at home with one of those self etching kits, only lower quality.

pretty easy to rebuild with modern components. I think the VSS chip itself isn't a problem.

[DesertBMW]

The shutoff point on ms412 changes based off VSS+RPM. For whatever reason MS41.1 doesnt care and does it solely off RPM.

Why not try using Alpina B3 flash on MS41.1 for S52 then scale MAF map for 3.0"? I bet it is more superior program than ms41.2. I have the full 256kb flash if you want it contact me via PM.

[nando]

Steve sent me a signal converter for free :( and its still sitting on my desk ( i suck). As far as it mattering, yes it does in many places, i just tune around it... The E30s spitting VSS is so inconsistant. The Car i dynoed here would do ~155 on the dyno and VSS signal wouldnt break 3mph cause cluster was outputting crappy signal. Thus throwing vanos into fail mode. The shutoff point on ms412 changes based off VSS+RPM. For whatever reason MS41.1 doesnt care and does it solely off RPM.

just a thought, why don't you modify the VSS axis on that map so it basically doesn't use it? set them all to 0 or something. or is that what you're doing already?

[328ijunkie]

The Alpina flash is based off '804' which i dont have an XDF well defined for and dont feel like redoing an entire XDF for one. The 806 411 file works fine (and i have the alpina ;)), appreciate it though

Thats basically what im doing nando.

and the chip isnt a problem as much as the speedo itself and the connections from the plugs at the rear to/from the speedo.

[fresh_TD]

S52 obd1

results from dyno are 223whp/211wtq.. first run was with the SSsquid chip I was running and then final run after dyno tuned.. the peak numbers were not a huge increase as you can see, but the overall power curve is much better and so is the AFR

Mannys dyno before after by bluebelt00, on Flickr

[328ijunkie]

Are those AFRs correct?

[fresh_TD]

Are those AFRs correct?

According to Forcedfirebird, they are..am I missing something here? Are they not correct?

Sent from my Samsung Note 4

[328ijunkie]

I was specifically looking at the OTS chip AFRs. Crazy Rich. Did squidddd do the dyno tuning or was it ForcedFirebird?