The Insane 5-Day BMW E30 Swap You’ve Gotta See to Believe

Q: How do I even start something like this

Honestly Do a ton of research first Know what parts you need what fits what doesnt And if youve never done a swap beforetalk to people who have Forums and YouTube are goldmines

Q: Is the S54 swap super hard

It aint exactly easy That engines complex and the wiring especially is a big challenge But if youve got patience and tools its doable Just be ready for surprises

Q: Can I do this at home

Yup as long as youve got a decent garage and the right gear A lift helps but not 100 necessary Its mostly about having space time and not giving up when stuff goes sideways

Q: Whats the cost of a build like this

Totally depends If youre doing it all yourself youll save on laborbut youll still need cash for the engine trans mounts brakes and little parts that add up fast

Q: Why use the SMG instead of a manual

Some folks just like the SMG experienceits kind of a lovehate thing Plus if its already paired with the engine might as well try to make it work right

Q: Do I need to upgrade brakes too

Oh yeah Bigger engine means more speed which means better stopping power is a must Dont skimp hereyour life kinda depends on it

Q: What suspension upgrades should I do

At the very least get stiffer springs or coilovers The stock E30 setup isnt made for that kind of power You want the car to handle it not just go fast in a straight line

Q: Can I daily drive a build like this

You could Some do But expect quirksits still an old car with a modern heart so stuff might need tweaking now and then

Q: Will this be legal on the street

Depends where you live Some places are chill others need inspections or emissions checks Always check local laws before swapping stuff in

Q: Where do I learn more about swaps

Online forums are your best friendlook for ones dedicated to BMWs or engine swaps Youll find build threads tips even wiring diagrams Just be ready to do some digging

So here’s the deal—guy finds this dusty old BMW E30. Not the kind that turns heads. We’re talking faded paint, beat-up seats, and some real “yard art” energy. Most folks would’ve just parked it and forgot about it.

But this guy? Nah. He looked at it and thought, “Y’know what? I can do something cool with this.”

Five Days. That’s It.

And when I say he made it cool—I mean seriously cool. He didn’t take months. Didn’t stretch it out over years.

He built it in five freaking days.

Yep, five. I still can’t believe it.

S54 Power? Yes Please.

So what’s under the hood now? He dropped in a full-blown M3 engine. The legendary S54 from the E46 M3, to be exact. Straight-six, 3.2L—this thing’s no joke.

And he didn’t stop at the engine either. He brought over the SMG gearbox too. That semi-auto transmission most people love to hate? Yeah, that one.

Wiring Woes (And Genius Fixes)

He tried mixing the E30’s original wiring with bits from the newer car. Didn’t go so well. So what did he do?

Ripped it all out and just swapped the entire M3 wiring harness into the E30.

Risky? Totally. But it worked. And honestly, kinda brilliant.

Not Just Fast—It’s Built Right

He didn’t stop at power either. Suspension, brakes, chassis—all upgraded. He wanted the car to actually handle that new engine, not just spin tires and pray.

It wasn’t about slapping parts on. It was about building something solid.

Clean, Not Flashy

What I really love? The car’s not trying too hard. It’s not some over-the-top show car with LEDs and chrome everything. It’s clean. Understated.

Looks stock to the untrained eye. But under the hood? A total monster.

E30 Body, M3 Soul

That’s what makes this build hit different. It still feels like an E30, but it drives like something way more serious. You get in, hit the gas, and boom—instant grin.

Respect Where It’s Due

I gotta say—stuff like this really gets me hyped. It shows how far you can go with some passion, know-how, and a couple nights of lost sleep.

Makes me wanna wrench on something myself.

FAQ

How do I even start something like this?

Honestly? Do a ton of research first. Know what parts you need, what fits, what doesn’t. And if you’ve never done a swap before—talk to people who have. Forums and YouTube are goldmines.

Is the S54 swap super hard?

It ain’t exactly easy. That engine’s complex, and the wiring especially is a big challenge. But if you’ve got patience and tools, it’s doable. Just be ready for surprises.

Can I do this at home?

Yup, as long as you’ve got a decent garage and the right gear. A lift helps, but not 100% necessary. It’s mostly about having space, time, and not giving up when stuff goes sideways.

What’s the cost of a build like this?

Totally depends. If you’re doing it all yourself, you’ll save on labor—but you’ll still need cash for the engine, trans, mounts, brakes, and little parts that add up fast.

Why use the SMG instead of a manual?

Some folks just like the SMG experience—it’s kind of a love/hate thing. Plus, if it’s already paired with the engine, might as well try to make it work, right?

Do I need to upgrade brakes too?

Oh yeah. Bigger engine means more speed, which means better stopping power is a must. Don’t skimp here—your life kinda depends on it.

What suspension upgrades should I do?

At the very least, get stiffer springs or coilovers. The stock E30 setup isn’t made for that kind of power. You want the car to handle it, not just go fast in a straight line.

Can I daily drive a build like this?

You could. Some do. But expect quirks—it’s still an old car with a modern heart, so stuff might need tweaking now and then.

Will this be legal on the street?

Depends where you live. Some places are chill, others need inspections or emissions checks. Always check local laws before swapping stuff in.

Where do I learn more about swaps?

Online forums are your best friend—look for ones dedicated to BMWs or engine swaps. You’ll find build threads, tips, even wiring diagrams. Just be ready to do some digging.