The Official OBD1 vs OBD2 argument thread.

[328ijunkie]

The speedo speed? Cluster being old/broken.

[craiggroves91]

The speedo speed? Cluster being old/broken.

Speedometer yes. Fixed that haha

It is old. 21 years old to be exact. But the speedometer is fully functional so I don't really think it's broken

[spice boy]

This thread is very interesting... I do have 1 question though...

You see everyone scrambling to convert from OBD2 to OBD1... What about the other way around? Converting an OBD1 engine (M50B25TU for example) to OBD2?

I understand that there would need to be several items flashed out (EWS, SAP etc) but it shouldn't be too difficult, right?

[Wanganstyle]

This thread is very interesting... I do have 1 question though...

You see everyone scrambling to convert from OBD2 to OBD1... What about the other way around? Converting an OBD1 engine (M50B25TU for example) to OBD2?

I understand that there would need to be several items flashed out (EWS, SAP etc) but it shouldn't be too difficult, right?

Many are actually for more brainpower- smarter brain is better when tuning a turbocharged engine.

The obd2 usa engine has a hall position crank position sensor in the rear of block; European spec model obd2 cars have the updated hall position sensor mounted in the front like a obd1 crank position sensor- they are different style sensors so not compatible but easy to order online or at bmw.

With this crank sensor any obd1 engine can natively be ran on obd2 electronics.

I know of a few cars that have upgraded obd1 turbocharged electronics to obd2 for smarter tuning and troubleshooting. The processsor is also more powerful and the same engine will run cleaner and more reliably on the newer electronics

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[328ijunkie]

I've done this on two customer cars. Both s50's

[spice boy]

Many are actually for more brainpower- smarter brain is better when tuning a turbocharged engine.

The obd2 usa engine has a hall position crank position sensor in the rear of block; European spec model obd2 cars have the updated hall position sensor mounted in the front like a obd1 crank position sensor- they are different style sensors so not compatible but easy to order online or at bmw.

With this crank sensor any obd1 engine can natively be ran on obd2 electronics.

I know of a few cars that have upgraded obd1 turbocharged electronics to obd2 for smarter tuning and troubleshooting. The processsor is also more powerful and the same engine will run cleaner and more reliably on the newer electronics

Sent from my GT-N7100 using Tapatalk 2

I've done this on two customer cars. Both s50's

These are both music to my ears!

Yes I did hear that there is a front mount hall sensor from the euro e36 323/328 that can be used, thank you for confirming it!

The main reasons I'm looking to convert my 1994 E34 M50B25TU from obd1 to OBD2 are:

Looking for better mappability
Fitting a twin screw charger
Fitting E46 330 m54 internals and cam
I want a live port in the car for easier diagnostics and live data whilst I'm driving

Those are the main reasons that I can remember right now but I'm sure there is more reasons...

Can I use my obd1 loom or will I need an OBD2 loom like off an e36 328? I already have the correct Siemens ecu in hand

Apart from the hall sensor and I think the temperature sensors, is there any other major changes I would need to do? I would just happily bring my car to one of you guys but I think it would be a little far lol

[Leo_328i]

Covering some more things that have not yet been mentioned, regions and flexibility.

I thought I'd throw my 2c into this discussion.

I've currently got an E36 328i which I daily, M50 intake manifold, exhaust and CAI, nothing special at all - very stock.

I've got an E30 318iS and an euro aluminium block M52 2.5l in my garage which I am prepping up to drop in. I am using OBD1 due to cost considerations. Now believe it or not, it sounds very dumb at first, but I do actually have a full set of OBD2 sensors, coil packs and harness lying around which I can also use for this swap.

In Australia we have a different situation with our ECUs, all of our M52 engines run MS41.0 whilst you guys in the US run MS41.1 for M52 and MS41.2 for S52 engines. You guys are really lucky to have such fantastic tuning support with guys like TRM and Market Motor Works - we don't have this level of service available in Australia.

I was going to purchase an MS41.1 (Siemens E36 328i US spec) ECU and have it sent over to a tuner to be flash tuned and have EWS deleted but I have never been able to confirm whether the wiring harnesses between USA and Euro specification cars are identical, the pinouts for the ECU would need to be identical for it to be plug and play - if anyone has info on this please let me know! And even if it were the case it that it would work, tuners in the USA have very little knowledge about how to tune MS41.0 because they were never released in the US market.... The guys in the UK seem to have a lot of trouble as it is.

In addition to that, there doesn't seem to be any sort of hardware which you can plugin to an OBD2 ECU to adjust things easily like ignition advance, fuel load, etc etc. I'd like some flexibility in my stock ECU and this is where Miller WAR comes in for OBD1.

I'm building a unique build 2.8l high compression alloy-block engine with longer rods, lighter pistons, high compression and even hope to replace the single VANOS unit with double VANOS from an M54 motor using Hoveringuy's VANOS controller which is designed for 413 ECUs. Although I could go to a standalone ECU at this point or Megasquirt - both my funds and technical ability (for Megasquirt) are lacking for this.

In the end, I'll have an OBD1 E36 328i with a custom tune installed in a Miller War Chip and also an OBD1 E30 M52 2.5l with generic performance available locally.

I'm definitely not advocating that OBD1 is better, it seems that the truth is very much the contrary to this. But, if a little flexibility is needed without going standalone or megasquirt, OBD1 still has one saving grace. Having said that, when somebody does a product similar to Miller WAR chip in OBD2, OBD1 no longer has a purpose.

[Wanganstyle]

These are both music to my ears!

Yes I did hear that there is a front mount hall sensor from the euro e36 323/328 that can be used, thank you for confirming it!

The main reasons I'm looking to convert my 1994 E34 M50B25TU from obd1 to OBD2 are:

Looking for better mappability
Fitting a twin screw charger
Fitting E46 330 m54 internals and cam
I want a live port in the car for easier diagnostics and live data whilst I'm driving

Those are the main reasons that I can remember right now but I'm sure there is more reasons...

Can I use my obd1 loom or will I need an OBD2 loom like off an e36 328? I already have the correct Siemens ecu in hand

Apart from the hall sensor and I think the temperature sensors, is there any other major changes I would need to do? I would just happily bring my car to one of you guys but I think it would be a little far lol

The looms are slightly different- obd1 has vr crank sensor (2 wire) and obd2 id hall type powered sensor (3 wire).

You will need to fit a obd2 loom to your e34; it has been done in e34 both with trm goods and technica goods (brain/engine/turbo kit)



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[Wanganstyle]

I thought I'd throw my 2c into this discussion.

I've currently got an E36 328i which I daily, M50 intake manifold, exhaust and CAI, nothing special at all - very stock.

I've got an E30 318iS and an euro aluminium block M52 2.5l in my garage which I am prepping up to drop in. I am using OBD1 due to cost considerations. Now believe it or not, it sounds very dumb at first, but I do actually have a full set of OBD2 sensors, coil packs and harness lying around which I can also use for this swap.

In Australia we have a different situation with our ECUs, all of our M52 engines run MS41.0 whilst you guys in the US run MS41.1 for M52 and MS41.2 for S52 engines. You guys are really lucky to have such fantastic tuning support with guys like TRM and Market Motor Works - we don't have this level of service available in Australia.

I was going to purchase an MS41.1 (Siemens E36 328i US spec) ECU and have it sent over to a tuner to be flash tuned and have EWS deleted but I have never been able to confirm whether the wiring harnesses between USA and Euro specification cars are identical, the pinouts for the ECU would need to be identical for it to be plug and play - if anyone has info on this please let me know! And even if it were the case it that it would work, tuners in the USA have very little knowledge about how to tune MS41.0 because they were never released in the US market.... The guys in the UK seem to have a lot of trouble as it is.

In addition to that, there doesn't seem to be any sort of hardware which you can plugin to an OBD2 ECU to adjust things easily like ignition advance, fuel load, etc etc. I'd like some flexibility in my stock ECU and this is where Miller WAR comes in for OBD1.

I'm building a unique build 2.8l high compression alloy-block engine with longer rods, lighter pistons, high compression and even hope to replace the single VANOS unit with double VANOS from an M54 motor using Hoveringuy's VANOS controller which is designed for 413 ECUs. Although I could go to a standalone ECU at this point or Megasquirt - both my funds and technical ability (for Megasquirt) are lacking for this.

In the end, I'll have an OBD1 E36 328i with a custom tune installed in a Miller War Chip and also an OBD1 E30 M52 2.5l with generic performance available locally.

I'm definitely not advocating that OBD1 is better, it seems that the truth is very much the contrary to this. But, if a little flexibility is needed without going standalone or megasquirt, OBD1 still has one saving grace. Having said that, when somebody does a product similar to Miller WAR chip in OBD2, OBD1 no longer has a purpose.

Not sure about pinouts between euro and usa harness; but a usa harness can be adjusted to work RHD not that difficult.

The 328i obd2 harnesses are dime a dozen and you can purchase one with dme easily- you could even buy the harness/dme/custom tune for high compression/cams and AUS petrol from Market Motorworks if needing a set from one source.

War is good but obd2 is not any worse; id prefer not tweaking anything myself unless working with a full standalone

If desiring a double vanos setup then perhaps buying the entire m54b30 engine as a unit and running the oem m54 double vanos dme+e throttle would be the smartest/cheapest/most reliable option.

The m54b30 e46 dme is hacked already and its a complete alloy engine with the disa and dual vanos already setup to work.

Why use a hodgepodge of wrong version oem electronics and aftermarket tuning for higher cost when a genuine bmw dme with bmw factory software is availible to run for very low cost?

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[Leo_328i]

The main problem is bringing stuff into Australia, 2nd hand car parts get quarantined really harshly and its very possible that a harness could have dirt (yes I know its ridiculous) on it and get held up at customs.

If the pinouts of an MS41.0 are the same as MS41.1 then we're talking.

With M54 - the reason is purely due to better flowing head of NV and single vanos heads and the fact that the 3.0l crank in the alloy block seems to have harmonic issues if constantly seeing over 6000rpm.

[TNTDONYUTE]

whewwwww

WOW....page 1-9 a lot of info.....
thx to all

[Skafrog]

I look forward to discussing this in person at the march Peachtree event, but I just want to start with two points.
1) You can and have been able to get live data off an obd1 car. Even in 2003/4, I used to drive new swap cars with a scanner plugged into the diagnostic port and read temps, throttle positions, etc.
2) OBD2 doesn't necessarily mean more power, driveability, or less emissions. Like the gentleman said a few pages back, there is no hard evidence of this. I want to see the exact same engine on both obd1 and obd2 with factory and aftermarket tunes before I give up on obd1.

-Rob

[nando]

well, if you spend any time actually hacking these computers - the OBD1 computer is like 8-bit Nintendo, or even Atari. the OBDII computer is like upgrading to a Playstation. it's just better - there's no subjectivity or fuzzy math. It just is.

Motronic 3.3 is basically the same thing as what runs the M20 with a few extra injector & coil outputs. it's literally 1980 technology. actually the origin of it is even older, Motronic is just Jetronic with spark control added on.

if you already have OBD1 it's probably not worth all the work to swap, the engine will still run fine. but if you have an OBDII motor you are swapping, it just doesn't make sense to convert it now.

[328ijunkie]

I look forward to discussing this in person at the march Peachtree event, but I just want to start with two points.
1) You can and have been able to get live data off an obd1 car. Even in 2003/4, I used to drive new swap cars with a scanner plugged into the diagnostic port and read temps, throttle positions, etc.
2) OBD2 doesn't necessarily mean more power, driveability, or less emissions. Like the gentleman said a few pages back, there is no hard evidence of this. I want to see the exact same engine on both obd1 and obd2 with factory and aftermarket tunes before I give up on obd1.

-Rob

Rob i look forward to meeting you and chatting more about this in person!
1) Yes OBD1 does have the capabilty to spit out live vehicle data. The problem with it is, you basically have to have extremely specialty scan/diagnostic tools (IE: factory BMW stuff, or MODIS or something of the sort). On top of this the refresh rate is abysmal. with OBD2 the 'layman' can grab a generic OBD2 scanner at the auto parts store and watch live vehicle data at a 'good' referesh rate.
2) Just to put it breifly, OBD2 has extremely supierior diagnostics, adaptation values (ST and LT) and is overall more relilable. Granted there are alot more OBD1 swaps to sample from but there are tons of OBD1 guys that are constantly posting here and what not saying help my engine runs like poop and i dont know why. Crank sensors die and leave you on the side of the road, ECUs are questionable sometimes, knock sensors die, etc. Vac leaks are prevelent in many cases and the ECU simply spits a MAF or O2 sensor Code and so on.

OBD2 has readable adaptation values that can more clearly indicate vac leak/fueling issues. Only OBD2 sensor ive ever seen die for the most part has been cam sensors and when they die the ECU clearly yells about it..

Having worked on hundreds of swaps over the years i have grown to absolutely hate OBD1 for its annoying old age and temperamental. I have had so many OBD1 swap cars come through the shop that have required 5-10 hours of diagnostics to figure out why they dont want to run 100% perfect or start or pull strongly, etc. All the OBD2 swaps ive done and seen just 'work' for the most part or at the very least yell at you why they dont want to work. "Hey dude im idiling like poop because you made a vac leak by the ICV, code for BANK 2 fuel trims maxed." for example ;)

well, if you spend any time actually hacking these computers - the OBD1 computer is like 8-bit Nintendo, or even Atari. the OBDII computer is like upgrading to a Playstation. it's just better - there's no subjectivity or fuzzy math. It just is.

Motronic 3.3 is basically the same thing as what runs the M20 with a few extra injector & coil outputs. it's literally 1980 technology. actually the origin of it is even older, Motronic is just Jetronic with spark control added on.

if you already have OBD1 it's probably not worth all the work to swap, the engine will still run fine. but if you have an OBDII motor you are swapping, it just doesn't make sense to convert it now.

This :P

[DesertBMW]

OBD2 doesn't necessarily mean more power, driveability, or less emissions.

Maybe no more peak power, but siemens system is far more superior on other like fuel economy, emissions, drivability, diagnostics. Siemens uses 0-5v 02 sensors that have much better sensing range than a single 0-1v bosch sensor. There are many more improvements. It is shallow to think that system is no better than bosch because it does not make you more peak power.