Just got my motor! Now some questions. OBDI or OBDII, eh?

[MIKe30]

As of today, I'm officially in the project-24v-club! Now I'm working on getting into the Running-Properly-s52-Club :mrgreen:

96 m3 s52 and trans, and other tid bits arrived today.

Right now it's all on a pallet, and some in boxes - I need to get a stand.

I've turned wrenches on my car before, but nothing to this extent. I'm excited to learn and go through the journey. I'm not sure where to start other than get a stand, other than make sure I have a plan and a direction. I'm hoping you guys can help me find my direction :)

The motor has 83k, and was pulled from a rolled e36. Seems to be in good condition, all stock with the exception of obd1 manifold.

Whenever I had visions of s50/s52 swapped e30, I always envisioned a complete obd1 conversion - but it's been a while since I've read up on the 24v swap threads. I've started reading again this week - and I've re-read the wiki articles, but the sticky at the top of this forum is just too long and scattered. Also, I know new solutions and methods pop up all the time and some of the material is dated. So my first question is:

Do I keep my s52 motor obdII (with swapped obd1 manifold), or do I do full conversion to obdI?


I'm guessing stay obdII as i've already got the obd1 goods in the mani, but I'd like some reassurance. Will power be affected? Will cost be different? Is the tuning available that is on par with obdI that's already out there?


Also, I believe I've got all the ews goodies I need - and I like the idea of an automatic cut-off should someone try to steal my car. Do I have to delete it, or can I make it work and keep the fancy key? :mrgreen:


Thanks all for your time, and I look foward to making this thread grow, full with progress and questions and answers. Ultimate project goal is completion by first day of spring with 250whp minimum!

-mike

[318isbmw]

I'd say obd1, there are a few people who have pulled off obd2 but still vast majority run obd1 because its easier from what I know. You still have to have the key and such from the original car so its just easier to convert it over to obd1.

By the way, congrats on the purchase, I'm sure along the way you'll get super pissed off cuz its not going as planned, but just be patient and don't give up and it'll be one hell of a fun car when done.

[erik325i]

Also, I believe I've got all the ews goodies I need - and I like the idea of an automatic cut-off should someone try to steal my car. Do I have to delete it, or can I make it work and keep the fancy key? :mrgreen:

-mike

You do not have to delete it. There are people (myself included) that have working EWS.

[DaN]

With obdII, you'd have to keep the secondary air pump and plumbing, and 4 o2 sensors, to keep off the check engine light.
I don't know if they have software to delete that.

[rThor432]

I've got the full OBD I conversion on my S52. My boss bought a wrecked M50 325i because he wanted the cylinder head. I just scavenged everything else I needed from the car before we scrapped it. You can buy a complete M50 for nothing, so might as well do that if you have the space to swap the stuff from one motor to the other.

[BigD]

You don't have to do OBDI but if big power is your goal, and without FI, you'll want the OBDI manifold, and the adapter kit is expensive... it's up to you.

For what it's worth, if the car was really a 96, you'll have an easier time installing the S52 than anyone else, because your engine should still have the hole for the second coolant temp sensor, plugged with a bolt. The later S52s don't have this hole and we either had to drill/tap the boss or find another way.

[rThor432]

or find another way.

Turner Motorsport sells a nice plug for this application, it's $45. That's what I did, no drilling/tapping needed.

[BigD]

Turner Motorsport sells a nice plug for this application, it's $45. That's what I did, no drilling/tapping needed.

Or you can simply rethread the sensor and put it into the throttle body warming nipple hole, $0.

[rThor432]

1 sensor>2 sensors. Weight savings ftw. I just want plug-n-play, no rethreading sensors for me. $45 is nothing compared to the cost of the everything else involved in the swap.

[PiercedE30]

Stay OBDII. Send the ECU to get a tune and have them delete the air pump, and both rear O2 sensors and have them disable the EWS, if you want, and badabing. Running car.

[MIKe30]

You don't have to do OBDI but if big power is your goal, and without FI, you'll want the OBDI manifold, and the adapter kit is expensive... it's up to you.

For what it's worth, if the car was really a 96, you'll have an easier time installing the S52 than anyone else, because your engine should still have the hole for the second coolant temp sensor, plugged with a bolt. The later S52s don't have this hole and we either had to drill/tap the boss or find another way.

You probably skipped in my novel length OP (sorry), but the previous owner already swapped the manifold to an obd1 mani. From what I've read in the past, that is the only physically power restricting part of obd2 vs obd1. Please correct me if I'm wrong. Also, I'm not familiar with what software is available for obd2, and if it is restricting in terms of power compared to obd1 software available.

And thanks, I didn't know that about the plug. I was actually a little worried I may have been forgetting something when it came to purchasing a motor, since afaik it's the first production year of s52's. (for ex, I stayed away from 95 m3 s50's due to the lifters, iirc)

Stay OBDII. Send the ECU to get a tune and have them delete the air pump, and both rear O2 sensors and have them disable the EWS, if you want, and badabing. Running car.

Nice, I like how you make it sound so simple. Who does this kind of obd2 tuning and does staying obd2 limit my options for tuning post mods?

[BigD]

You probably skipped in my novel length OP (sorry), but the previous owner already swapped the manifold to an obd1 mani. From what I've read in the past, that is the only physically power restricting part of obd2 vs obd1. Please correct me if I'm wrong. Also, I'm not familiar with what software is available for obd2, and if it is restricting in terms of power compared to obd1 software available.

Yup, you're absolutely right. With the OBDI manifold there is NOTHING you can gain from the conversion, so it makes extra sense for you to stay OBDII (it's a much more advanced system - which makes tuning harder because it's so smart but there are many tuners now who can do it, it's just $$$ from what I've seen).

[MIKe30]

Yup, you're absolutely right. With the OBDI manifold there is NOTHING you can gain from the conversion, so it makes extra sense for you to stay OBDII (it's a much more advanced system - which makes tuning harder because it's so smart but there are many tuners now who can do it, it's just $$$ from what I've seen).

Hm, I'm happy to be reading this kind of stuff. One thing that gets me curious is, there has to be tuners out there for the e36 guys. Are we e30 guys just not familiar with them because we're so used to staying obd1? Or is it because they really are much more expensive?

I hope those who have stayed obd2 chime in on their experiences (especially with tuning) and what kind of numbers they're putting down.


Seems to me (only a hunch and hope people clarify :D) that power wont be affected, just money and time. Like it's going to be cost effective to physically build/prep the motor to be put in, but it'll cost more to get it tuned properly. Which outweighs which is still a mystery!!! :hitler:

[mongule]

The problem with OBD2 is the no chip factor,

You either
1. Send your DME to the tuner
2. Get it tuned by someone local who tunes OBD2 bmw ( which for most, is not an option)
3. Get a shark

For normal tunes IE: cams, euro maf etc, Option 1 would be the cheapest and probobly equal in cost to OBD1 tunes or very close .

Bimmerworld quoted me $350 for a tune. ( including rear 02 delete, air pump delete and EWSII delete). I just went with stock tune because I just want it running first and next year i will do m3 cams and the rest.

EDIT: I should add the $350 was for a tune with stock motor ,cams and stuff would probobly mean more $.
Its when forced induction comes into play where the OBD1 conversion has its merits in terms of cash and and availability.

But like you said e36 guys dont convert to OBD1 from what i've read and they still run FI.

For the record I am swapping an M52 and keeping it OBD2.

[BigD]

Hm, I'm happy to be reading this kind of stuff. One thing that gets me curious is, there has to be tuners out there for the e36 guys. Are we e30 guys just not familiar with them because we're so used to staying obd1? Or is it because they really are much more expensive?

I hope those who have stayed obd2 chime in on their experiences (especially with tuning) and what kind of numbers they're putting down.


Seems to me (only a hunch and hope people clarify :D) that power wont be affected, just money and time. Like it's going to be cost effective to physically build/prep the motor to be put in, but it'll cost more to get it tuned properly. Which outweighs which is still a mystery!!! :hitler:

Well no one can answer that other than you and your wallet. Until not long ago, tuners wouldn't touch OBDII BMWs. It's possible now but it's expensive. The problem is that with OBDI, the tuners just fudge around with the fuel maps, burn a $2 chip, charge you $200 and make their money. With OBDII they have to buy a programmer which costs thousands (maybe it was over 10k even, I remember hearing the cost somewhere but I can't remember now - it's expensive, leave it at that), so to make it financially feasible they have to transfer the cost over to you...