Project GMW E46 Turbo: Part 1 - Introduction

by Mark Hutchison


When you think of a high-performance E46 3 Series BMW, you may automatically think of the ever popular M3.  It’s true that the E46 M3 produces great power with its fabled S54 inline six. It also looks amazing with its distinct fender vents and aggressive front fascia. While this 2001 325ci BMW may not be an M3, it will decimate all other cars with an affordable and reliable power plant from an American classic – the GM LS series engine.

The goal of this build is not to break records or make the most outrageous racecar possible. Our aim is to build a car with affordable parts and create something that is unique and will turn heads and ears at every turn. This build will not be 100% plug-and-play, but it will incorporate many off the shelf parts that work with the goal of the build.

The all-mighty LS series engine manufactured by GM has been placed in many different vehicles since 1999, including the sporty Corvette and the hefty Silverado truck. Many people are familiar with the popular LS1, but don't know that the LS comes in many different forms. There’s the 4.8L LR4, 5.3L LM7 and 6.0L LQ9 that has been included in most GM trucks as well as many other adaptations and variations with different intake manifolds, cylinder head designs, block materials, and engine technology. Additionally, GM has the style of LS that goes in the Corvette and Camaro. They started with the LS1 and it slowly evolved into many different versions throughout the 15 years of its passenger car production with the LS2, LS3, LS6, LS7, LS9 and LSA.


When it came to finding an engine for my build, I wanted to be a tad different and not just go get a full LS1 swap- with an engine harness, PCM, Transmission and accessories included. That would have been WAY too easy and I’m a fan of pain and frustration…  My engine was sourced from a salvage yard in Oklahoma City, OK. It’s a 5.3L LM7 with 100,000 miles. It ran great when it was in its donor Chevy Silverado. An unlucky accident ended its life with its original chassis and will be reborn like a phoenix in the E46.


This 2001 325ci came with 96k miles and was listed on the popular website, craigslist.com, not running and possibly needing a fuel pump.

This was no big deal to me since I just needed a straight chassis to swap a V8 in and with the local Fuel Systems Company, DeatschWerks, right down the street, we could throw a universal fuel pump in the tank to get it running, if needed, and the price was hard to pass up. Obviously, for a car that had been sitting, it wasn't in the best shape – which included a few dents and dings, a busted headlight, a busted taillight, paint a little faded, and a clear coat that was coming off in some spots. But not to worry, she will get the executive treatment throughout the series with new exterior, including a new front fascia and vinyl wrap.

The day after I got it home, we cleaned out all the animal nests from the engine bay and installed a DeatschWerks inline DW250iL, 255lph fuel pump (PN# 9-250) in the OEM fuel pump module. With slight modification and soldering the connectors provided, the E46 started up. For the final build, the plan is to use two OEM pump assemblies mounted on both sides of the saddle style fuel tank to take advantage of a more OEM fit fuel system. It didn’t leak a drop of oil and idled great.  I drove the car for about a month to really flush out any issues it may have had in the chassis or in the electronics of the car. Other than an old battery, everything worked well, even doing a couple autox events with the local BMWCCA.


The DW250iL Inline fuel pump uses rotary vane technology that allows for higher flow at higher pressures, which are essential for boosted applications.


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Monday, February 13, 2017 6:40 AM
It's nice that there is now an alternative to the T56 transmission. People must think those things are made of gold. Even a used unit fetches $3k! Excited to see more of this build. Hopefully there will be more details and pics than this intro article.

A quick note, the LS1 was first used in the Corvette in 1997, not 1999. (as far as my sources tell me at least)
Monday, February 13, 2017 11:29 AM
In Part 2, can you please go over how you are going to position the engine in the chassis, and why you chose that way?

I am planning my own engine swap and have been looking for some info on this.
Monday, February 13, 2017 12:32 PM
Awesome. I have been kicking around this same idea for about a year (or a W203 coupe). Can't wait to see how this one ends up!
Mike Kojima
Mike Kojimalink
Monday, February 13, 2017 4:10 PM
Interesting about the Z33 tranny right?
Monday, February 13, 2017 7:28 PM
What kind of torque can the Z33 manage? How much does it weigh compared to the T56? It is interesting to learn about a different option for high-power motors. How does the gearing compare? Soooo many questions.
Monday, February 13, 2017 9:48 PM
Very excited for this build!
Tuesday, February 14, 2017 4:10 PM
Nice to see a V8-swapped 3 series on this site; will be interesting to follow along. Why not point out the main advantage of the LM7 though - low price? By not buying an e-rod kit or a crate engine, you stand to save 80% by sourcing a takeout LM7 or LQ4 or similar from a wrecked truck or SUV.

I did an LM7 into E36 swap for LeMons, and we ended up going with a Super T-10 4-speed trans out of a late '70s Firebird. For those that don't need overdrive (e.g. track oriented builds) it's a cheap and pretty strong and reliable option at stock V8 torque levels. Using a big block Chevy bellhousing and some parts bin engineering to select flywheel and clutch component, you're on your way for less than a grand.
Tuesday, February 14, 2017 11:57 PM
A turbo LM7 will be cool, but I think this chassis is crying out for a de-stroked LQ4. You just drop the short-stroke crank out of an LR4 into an LQ4 long-block, hit it with some decent rods/pistons, and away you go.

That setup wins you 500+ horsepower out of 327 cubic inches with a ridiculously fat power-band that will wind all the way out to 8000 RPM!

Hotrod Magazine built a similar de-stroker, but based around the more expensive LS3 block. The slightly larger bore size yielded 339 cubic inches and over 600 horsepower. Similar, less exotic builds have been done with various 6.0 liter truck blocks with impressive results.

Ah well, still really looking forward to this build!
floating doc
floating doclink
Wednesday, February 15, 2017 5:21 AM
Years-long reader here, just registered to comment on this project.

How is this swap going to work with the e46 canbus based electronics?
Wednesday, February 15, 2017 1:19 PM
It's amazing. I've been snooping around craigslist, trying to find an 346 wagon to turn into a "dad" car.
But as mentioned above, the price of a T56. Any T56 is ridiculous. But the Z33 trans puts thus back in the running.
Can't wait to see what you do for the suspension. Particularly the springs and dampers. And the differential.
Saturday, February 18, 2017 2:03 AM
Has anyone else noticed that the LM7's displacement just happens to be 325ci ? Spooky.......

Are there any relevant considerations you foresee on this project with the increase in weight bias?
(M54 375lbs dressed. LM7 580lbs dressed)

Hey don't forget about those 8mm hex head screws when removing the bumper.
Do USDM E46 headlight mountings differ from other markets ?
Curious as all the E46's I have worked with have 8mm hex head fasteners that retain them to the core support.
Sunday, February 19, 2017 10:14 AM
I saw the title and was about to point out just how pathetically weak engines m54 is. I like this a lot :D
Mark Hutchison
Mark Hutchisonlink
Friday, February 24, 2017 1:39 PM
czubaka, The trans, in what i have seen, the CD009 hasn't been officially test in most applications, but has seem to do well with 800+ hp. Ill let you know on torque when the car is done. The gearing is VERY short. 1 to 1 is 5th gear.

floating doc, I am using a Wiring Harness from Wiring Specialties. No OEM canbus integration.

Loagz, i don't see the weight being an issues since ill just be doing lots of burnouts in it. lol. But Definitely a focus down the road when i get everything how i like and to focus on weight and moving stuff around to make it more settled.

Wednesday, March 01, 2017 6:10 AM
@ Mark Hutchison

Allgood. Was curious on your thoughts. Thanks for the reply
Can't wait for this monster to be shredding some treads in anger !

@ czubaka

CD009 (Z33)
Ratios :
1st 3.794 2nd 2.324 3rd 1.624 4th 1.271 5th 1.00 6th 0.794 rev 3.446
Approximate weight :
130 lbs
Torque Capacity:
Sorry no reliable data

TUET11009 (T56 set a)
TUET11012 (T56 set b)
(set a)
1st 2.66 2nd 1.78 3rd 1.30 4th 1.00 5th 0.80 6th 0.63 rev 2.90
(set b)
1st 2.97 2nd 2.10 3rd 1.46 4th 1.00 5th 0.74 6th 0.50 rev 2.90
Approximate weight:
125 lbs
Torque Capacity
700lb-ft continuous
Wednesday, December 27, 2017 1:10 PM
Is part 2 to this project on the way?
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