LS conversion for a three series BMW

[73 L92]

Good afternoon,

New member here.

I've been lurking around the forum and following the BMW conversions on LS1tech.
I'm pretty well versed in LS swaps. I've done 6 in various cars and Jeeps.

I'm trying to decide between 3 series cars for a LS swap. Either 1999 and older body style or 2000 and up body style.
I know header clearance is tight on the 1999 body stlye. Is 2000 up any better? It looks like there's a bit more room on the 2000 up body style.

I haven't bought anything yet. It will be a convertible either way.

Any other good or bad issues for 1999 to 2000 body styles? I like the idea of an 1999 M3 vert with the posi rear end but the 2000 body style is a little smoother but I don't think I can find a 2000 up M3 vert in my price range.

I'm considering a 4L60E instead of a T56. Has anyone done a LS1/4L60E swap into a 1999 or 2000 body style? Tunnel looks a little tight.

It's going to be a 2013-2014 project. Already hve a nice LS1 on the engine stand waiting for the right car.

Regards,

[erikerikerik]

Now There a few things you have going on.

1999 M3 = E36 (old style)
1999 Normal = E46 (new style)

Not having done this my self but lurking on the engine change threads, its still a bloody tight fit on the E46 platform.

[73 L92]

Thanks for the model numbers. As I was typing the questions I could not recall E36 or E46. Last winter I built my first set of headers for my 67 Nova. It has a 6.0 LS sleeved and stroked to 427 cubes. The headers don't scare me there're just time consuming.

Another question. Budget cost to add limited slip to a E46 rear end? As I understand only M3's came with limited slip rear ends. I may end up with a non M3 E46.

[BigC986]

Thanks for the model numbers. As I was typing the questions I could not recall E36 or E46. Last winter I built my first set of headers for my 67 Nova. It has a 6.0 LS sleeved and stroked to 427 cubes. The headers don't scare me there're just time consuming.

Another question. Budget cost to add limited slip to a E46 rear end? As I understand only M3's came with limited slip rear ends. I may end up with a non M3 E46.

May want to look at some of the 330i zhp's. i believe some of them have lsd. Eitherway im pretty sure the m3's arent the only ones that have lsd. Some of the auto e46's i know had it. Should be pretty cheap/simple to install even if its from and m3

[hefftone]

What do you mean by "issues"?

Biggest thing to me, is the E36 was probably designed in the late 1980's...... I have an E36 M3, and it drives great. But sometimes I can just feel the age. And automatic E36 M3 will be much cheaper than any E46 M3.

It sounds like you are pacing yourself on this project. If i could build a set of headers, i'd definitly be looking at the E46. Thaniel is making strides on the electronics, which has really been the primary reason people have'nt messed with E46s.

[73 L92]

Just asking to anyone that may have done a LS swap to both a E36 and E46 about any issues they can relate to having done both swaps. I have 98 Wrangler with 2000 LS6/4L60E swapped in. That swap is similar in some aspects to the E36/E46 LS swap. From what I've researched I will keep the original BMW computer and let it run it run what it needs to. The LS computer just runs the engine and possibly the trans if I go 4L60E. Transfer the oil pressure, temp any other BMW sensors to the LS engine. Looks like it's possible to mod the the tach signal from the LS to run the BMW tach. Couldn't do that in the Jeep. Let the LS computer/harness run the BMW fuel pump. I ended just pulling the check engine bulb in the Jeep. The LS harness comes with a check engine light at the computer connector.
I'm really leaning towards the E46. I'm kind lurking in the shadows with cash in hand looking for a distressed seller or a really cherry car I can snap up at a reasonable price. Verts are always cheaper at the end of the summer.

[hefftone]

The E36 has been figured out and done. There are a few options to buy a swap kit, mounts headers. Several folks have built their own.
The E46, there is only a few of those swaps completed, kits are in the supposedly "in the works", and work arounds for electronics are still being explored.
In the mean time between E36 and E46, quite a few guys have jumped in E39 five series cars, and made some really badass stuff!

[Thaniel]

I'm trying to decide between 3 series cars for a LS swap. Either 1999 and older body style or 2000 and up body style.
I know header clearance is tight on the 1999 body stlye. Is 2000 up any better? It looks like there's a bit more room on the 2000 up body style.

In my opinion the interior of the E46 is more dourable and prettier than the E36 (I own 2 of each right now and the interior by far is my least favorite thing on the E36). From my research the E46 only comes with LSD in the M3. Some have put in complete M3 rear assemblies and if one can be picked up inexpensively then that'd work great. Retro fitting an LSD into an E46 (non M) differential housing is expensive currently (3K?) I've seen some possible DIY ways to retrofit and I may try that some day. The E46 engine bay is like 1" wider than the E36. But I think the engine fits fine in the E36 so it's no big deal either way.

Availablity of parts and kits is different. I missed if you are wanting a bolt in kit or are planning a make from scratch install.

Either car is great.

Thaniel

[73 L92]

In regards to a kit for the swap I'm a bit torn. Looks like the LS only fits in one place in either the E36 or E46. Either centered or slightly to the passenger side. Remove the six cylinder and slide the LS in, level it at about 2 degrees and fabricate some engine mounts. Trans mount looks to be fairly simple.
My biggest hurdle is I don't have a hoist so all under car fabrication is on a creeper.
I understand the work that goes it a install kit and headers but during the winters here in MN what else do we have to do?
Today was the first day I had my 73 camaro with the L92/tko600 out because the winter here has been never ending. So much fun to run it thru the gears. My 67 Nova has a 6 liter LS sleeved and stroked to 427 cubes. It's truly a blast. About the same weight as a E36 or E46.

[BikealarmBlair]

I can't speak for yank cars but UK/Euro cars only the M3 has an LSD but the whole subframe etc simply bolts in to a normal E46 only thing you may have to re use is your original ABS sensors and allow time budget for a renforcment kit.




I don't seem to have many close ups of the headers






i don't personally understand why people are scared of the wiring its very simple as I've said too many times and now Thaniel seems to have an interface that does the job for you.

[Thaniel]

in MN what else do we have to do?

I know what you mean.

allow time budget for a renforcment kit.

Very good thing to point out. Both cars have a relativey weak mounting system.

[Ebola21]

Ive been toying/researching the idea of putting an LSx in an E46 coupe as opposed to buying an E46 M3 coupe lately.

If I did it, it wouldnt be a requirement for it to have power windows, ac, original BMW instruments, radio, etc. But it would be nice to have all/some of those. Id be using it more as a track car than a road car.

[73 L92]

That's what my research leads me to believe, E46 is the only one with limited slip and bolting in the subframe, center section and half shafts are the way to go. Still looking for "right"convertible. I almost got derailled by a nice Trans AM project car but luckily it sold before I could take a look at it.

As I keep looking at the swap threads I'm inclined to build the engine mounts along with the headers. They are the major cost of a kit. The engine mounts I may try to design something that uses something other than ureathane just to reduce vibration. On my Camaro swap I'm using standard interlocking rubber motor mounts and the motor rocks left or right very little.

[Matt Cramer]

Just asking to anyone that may have done a LS swap to both a E36 and E46 about any issues they can relate to having done both swaps. I have 98 Wrangler with 2000 LS6/4L60E swapped in. That swap is similar in some aspects to the E36/E46 LS swap. From what I've researched I will keep the original BMW computer and let it run it run what it needs to. The LS computer just runs the engine and possibly the trans if I go 4L60E. Transfer the oil pressure, temp any other BMW sensors to the LS engine. Looks like it's possible to mod the the tach signal from the LS to run the BMW tach. Couldn't do that in the Jeep. Let the LS computer/harness run the BMW fuel pump. I ended just pulling the check engine bulb in the Jeep. The LS harness comes with a check engine light at the computer connector.
I'm really leaning towards the E46. I'm kind lurking in the shadows with cash in hand looking for a distressed seller or a really cherry car I can snap up at a reasonable price. Verts are always cheaper at the end of the summer.

Truly bizarre trivia: The later LS series with the 58X crank trigger uses a very similar (but not quite identical) crank trigger pattern that might allow the stock BMW computer (for some reason, Bosch calls it a DME) to use the GM crank trigger to get an RPM signal. I'm not sure if it could use the GM sensor, however, or if you'd need to add some sort of mount to let a BMW sensor read the trigger wheel. The cam triggers don't match, however.

[V8Z4]

E46, no question