So what makes the E46 M3 LSx swap so difficult?

[KarlSpackler]

I mean you never see them

Is it the drive by wire?
Getting the cluster to work?

So what is it?

This is coming from someone who knows nothing about E46s.
I know the E46 bay is larger, tranny tunnel I assume is larger, rear diff ratio should be closer as it came with a 6 speed.

Thanks
James

[Kaane]

Canbus is used on all the interior accessories. So getting AC, dash or anything else to work will be very difficult without the factory ecu in place.

Also since no one is selling a kit, you will need to fab all your own mounts / headers.

[birdman2447]

plus the limited amount of e46 m's on the road makes doner cars hard to find, But a built ls7 in an e46m would be amazing.

[KarlSpackler]

Canbus is used on all the interior accessories. So getting AC, dash or anything else to work will be very difficult without the factory ecu in place.

Also since no one is selling a kit, you will need to fab all your own mounts / headers.

Well, I was thinking with the bay being about 2" wider you could get by with some "hugger" GTO headers which are tighter than standard Vette headers

[M5Hunter]

Vorshlag is comming along nicely on thier E46 LSx kit, keep an eye out for that as an option here soon!

[MPD47]

plus the limited amount of e46 m's on the road makes doner cars hard to find, But a built ls7 in an e46m would be amazing.

There were ~26k e36 m3's imported into North America. By Comparison, e46 M3's had almost 44k imported. If you wanna tack base models on e46 was easily the most popular bmw ever when production ended. There is not a shortage of donors. As stated above, there is a kit coming out shortly.

[Jesus Freak]

http://ls1tech.com/forums/conversion...-357ci-v8.html

[BikealarmBlair]

http://ls1tech.com/forums/conversion...-357ci-v8.html

Or http://forums.bimmerforums.com/forum....php?t=1673679

[modernbeat]

The hardest part of the swap is the new, more integrated electronics. All the hard parts (the metal parts) are just as easy to make the kit for as the E36. Maybe even easier since we have more experience.

When these were first started guys wanted a better engine for their track car. And the E36 is a good chassis for that. But when we started talking about doing an E46 more guys wanted them for GT cars. They wanted to keep all the luxury that the E46 had.

Small things like AC (mandatory for a street car in Texas).

So the swap was going to require us to keep the fully integrated ECU, which means making it think the LSx V8 is actually a BMW straight six. It also means that the sensors have to talk "BMW" to the ECU so the ECU can talk to the gauges correctly. We're working on a solution that isn't kludged. Something elegant that won't be an embarrassment.

[BikealarmBlair]

The hardest part of the swap is the new, more integrated electronics. All the hard parts (the metal parts) are just as easy to make the kit for as the E36. Maybe even easier since we have more experience.

When these were first started guys wanted a better engine for their track car. And the E36 is a good chassis for that. But when we started talking about doing an E46 more guys wanted them for GT cars. They wanted to keep all the luxury that the E46 had.

Small things like AC (mandatory for a street car in Texas).

So the swap was going to require us to keep the fully integrated ECU, which means making it think the LSx V8 is actually a BMW straight six. It also means that the sensors have to talk "BMW" to the ECU so the ECU can talk to the gauges correctly. We're working on a solution that isn't kludged. Something elegant that won't be an embarrassment.

No idea what you said but mine all works

[modernbeat]

It's easy enough for us to do a one-off. But we have to be able to sell the parts and the instructions to make it work with an E46 that will face US style 49-state inspections. And make it bolt-in friendly.

We've seen yours and we like it.

[Thaniel]

One of the things that has put me off is the rear diff is not LSD except in m3 which is more rare and mor expensive. It can all be over come but is the added cost worth it? Other than the newer body style going e46 gains what? That said I'd probably be swapping an e46 right now if I wasn't in Sweden and my garage and cars in Virginia.

[MPD47]

One of the things that has put me off is the rear diff is not LSD except in m3 which is more rare and mor expensive. It can all be over come but is the added cost worth it? Other than the newer body style going e46 gains what? That said I'd probably be swapping an e46 right now if I wasn't in Sweden and my garage and cars in Virginia.

The subframe is $100, the diff is $600 (used of course), I can't recall if you can swap the stubs from your standard diff or if you need to swap the axles too.

[KarlSpackler]

Awesome info guys. Thanks for the 2 links.

3 things -

1. I already am getting a motor
2. I dont really care about A/C but it would be nice
3. The car will be a M3

[Schitzo]

There is nothing difficult about doing a LSx swap in the E46.
When you see swaps like this one (see link below) you quickly realize the E46 swap would be child's play.

http://www.motorgeek.com/viewtopic.p...9901&start=375

[modular93fox]

I bought an e46 just for the swap, and laid out all of the wires in excell to get the cluster and everthing to work properly. Im still waiting for the motor and trans though. cant wait... might pick up a 2000 E39 and do a swap in that first, sell that to fund the E46
clint

[Fair]

There is nothing difficult about doing a LSx swap in the E46.
When you see swaps like this one (see link below) you quickly realize the E46 swap would be child's play.

http://www.motorgeek.com/viewtopic.p...9901&start=375

Child's play? Well I wouldn't oversimplify it quite that much.



The E46 LSx swap "hard parts" are relatively similar (but shares zero parts with the E36 - mounts, headers, etc; the header routing for full lengths are actually more difficult to make fit this chassis) the E36 LSx swaps, its these CAN-BUS / DME controlled systems that gives E46 swappers the most headaches.

There is a good bit more bit more work to make the gauges, HVAC, ABS and such work vs an E36. The E46 has all of these systems controlled by and a fully integrated through the factory DME.

Good luck,

[BikealarmBlair]

It's easy enough for us to do a one-off. But we have to be able to sell the parts and the instructions to make it work with an E46 that will face US style 49-state inspections. And make it bolt-in friendly.

We've seen yours and we like it.

Thanks & good luck with the plug in loom

[barkerpa3466]

Ok Don't flame me Just thinking out loud.

For the A/C compressor couldn't a bracket be fabed up to put it on the LSx belt system?
you would probably still have to modify the A/C lines and extend any wire harness connected to it because the Compressor would probably still be in a different location.

[M5Hunter]

No reason to flame.

I dont think compressor engagement is the problem... I think its the entire climate control system in the car. sure you could put a button on the dash to cut the compressor on and a 4 way dial switch to control the fan speed but most people want to keep the factory stuff working.

[barkerpa3466]

That's why I thought using the BMW compressor would be beneficial to using the GM one......that way the BMW compressor could "talk" to the BMW climate control.....

unless the BMW compressor has to "talk" to the DME then the DME to the climate control. If this is the case then it wouldnt matter because in all the swaps I have seen the DME is removed and the GM ECU is installed.

Another Thought: What about using BMW sensors on a LSX motor there are a lot of "ifs" in this first would be how tune-able is the BMW computer because there are some sensors that are going to have to be removed from the system entirely and you don't want a fault code for something your not using. Can the sensors that are being retained be modified to fit or can the LSx be modified to mount the sensors....This is probably a stupid question because if it was that easy someone would have done it already.....if it is possible it would most likely only work for the 540 crowd because they have a DME expecting a V8