E46 330i M73 V12 Manual Swap

[driftfinatic 2]

Hi guys long time no post.

Ive been missing from the bmw world for a bit but Im back with a friend thats building the sedan. Here is the basic gst of whats going on and what we have going so far.

BMW 330i sedan (looking to buy in next few weeks if any ones selling one hit me up)

- M73 5.4 V12

- The super rare Getrag 560 6 speed, with the flywheel, clutch, and drive shaft (imported from the UK)

- Link G4+ fury

So now the fun begins. Basically its gotta be mounted up and thats going to take some work. 

My first question is, Does the 7 series cross member even pretend to fit the 3 series chassis?

Any help and recommendations would be gladly accepted

Cheers, Conrad

[Olaf 3317]

Hi Conrad, interesting project!

are you looking for an e46 or e90 330i?

[driftfinatic 2]

Looking at e46 sedan 330i. Definitely wants a 3 series with the msport interior etc

[kulgan 1042]

I have a  M73B54 still sitting in a 97 e38 with all modules there if you want it. Cheap..lol

 

Edited March 22, 2017 by kulgan

[E30-323ti 66]

Have a look at Rays (HellBM) E46 M3 Convertable with the E39 M5 engine.

He used the complete E39 cross-member steering and suspension in the E46 (with a lot of fabrication work).

Given E38's and E39's are very similar, this would be you best guide to what to expect.

Someone else on here recently put an M60 into an E46 wagon, and made a neat dry-sump setup to drop into the E46.

Edited March 22, 2017 by E30-323ti

[Michael. 2313]

Would be a cool project. A big job however. Have you done an engine swap before?

Must consider these parameters:

 

• Custom engine/gearbox mounts - how to design them, what they will be made from etc
• Positioning the engine as far back and low as possible while keeping the driveshaft angle within the fine tolerance the joints require. Setting the position to dictate where the manual shifter will sit is also something to consider. 
• Custom driveshaft modification to adapt to the 560 trans prop. 
• Engine oil sump, M73s are a front type so would clash with the subframe / steering rack.
• Custom engine headers, stock ones might work, but often don't without modification. Need to also factor in the steering shafts proximity on the drivers side. Might be reasonable space given its a 60 deg block. 
• Wiring wiring wring
• Fuel lines, power steering and coolant lines, fairly simple but depending on fittings you'd have to have some custom made to suit (namely power steering lines. 

A 330i is a good option in M spec trim as you already have the bigger axles, 188mm diff, larger hub bearings and brakes than the smaller engine models. That said I think the 325i, 328i get similar specs afaik.

Budget and cost is the other factor, doing this properly wouldn't give you much change left out of $20,000.

My own personal thoughts say that for the amount of work required there are better options than an M73B54 engine, while the V12 aspect is unique and interesting, it's fairly low on power for a 5L engine, 320hp isn't a lot in a heavy E46 body, that said, the torque is pretty good at close to 500nm, so it will shift but to what degree of excitement? Keep in mind they only rev out to 6000rpm so aren't a screaming V12, more so a lazy big 6 cylinder given their signature exhaust note. Wish they were more like the Ford/Aston 5.9 V12! 

For more performance gains, at a lesser cost and with bolt in options you could use:

S54B30 M3 engine. Would bolt in. 

Supercharging (twin screw) M54B30 would yield excellent cost effective results. 

V8 LS swap using parts from Vorshlag USA header and mounting kit.

Supra 2JZGTE, an easy 400hp / 500nm powerhouse without really doing a lot. 

 

 

[Olaf 3317]

On 3/20/2017 at 8:17 PM, driftfinatic said:

Looking at e46 sedan 330i. Definitely wants a 3 series with the msport interior etc

yeah there was a chap in the For Sale section looking to sell/wreck an e46 330i sedan, but it wasn't a Motorsport.  Take a look...

Edited March 23, 2017 by Olaf
/wreck