FH6 Engine Swaps Guide — Which Swaps Are Worth It
Engine swaps can transform a car from uncompetitive to meta-defining — or they can waste 100K credits and 50 PI points on a worse engine than the stock one. I've done both more times than I care to admit, which is pretty much why this guide exists. The swap menu shows you power numbers but not PI cost until you select it, so it's easy to commit to a swap that looks good on paper and then discover you've blown your class PI budget on the wrong engine. Been there, have the empty credit balance to prove it. Honestly the swap menu UI is kind of mean — hiding the PI cost until after you commit is just bad design and I don't know why Playground Games thought that was okay.
I've been burned by this enough times that I started tracking PI efficiency for every swap I tried, writing it all down in a spreadsheet like a complete nerd. My friends make fun of me for it but hey, at least now I know which swaps are actually worth it and which ones are just credit traps. And honestly? Most of them are traps. Here's what I've learned — which swaps are actually OP, which ones are noob traps, and when you should just leave the stock engine alone. Stuff I wish someone had told me 200 hours ago.
Quick disclaimer: some of this is subjective. What works on my tune might not work on yours. But the PI efficiency stuff? That's measured. I didn't guess these numbers.
S-Tier Swaps — The Meta Picks
These are the ones you actually want. The rest are niche at best. Game changer territory.
2JZ-GTE (Toyota Supra)
Honestly this swap is broken. I'm not exaggerating — the 2JZ fits into way too many cars and the power-per-PI ratio is straight up better than almost everything else. With full bolt-ons you're pushing past 1,000 hp while still in S1 if the chassis is light enough. I've crammed this into 2000GTs, old Skylines, the S15, even an AE86 once for the memes and it actually worked. The power band is smooth too — no weird torque spikes mid-corner that make you understeer into a wall. Just predictable pull all the way through. I mean, for a 30-year-old engine design this thing is absurd.
PI efficiency: Genuinely OP. You get disgusting power for the PI it costs, especially keeping the stock twin turbos. Single turbo conversion can add like 150+ hp for 20-30 PI which is insane value. If you only remember one swap from this whole page, make it this one. I've won more races with 2JZ-swapped cars than any other build and I don't even feel bad about it. It almost feels like cheating and I keep waiting for Playground Games to nerf it but they never do.
Racing V12 (Ferrari-derived)
Look, this thing revs to the moon. Past 10k rpm and it's still pulling, which feels absolutely unhinged in a lightweight chassis. NA motor so there's zero lag — you breathe on the throttle and it responds. The numbers on paper aren't as big as a maxed 2JZ or LS, but the feel is completely different. For S1-S2 road racing where you're on and off throttle constantly, the instant response matters way more than 50 extra peak hp. Trust me on this one.
PI efficiency: Solid. Yeah it costs more PI than you'd like, but the NA character means what you lose in peak numbers you get back in driveability. I've won more races with this swap than any other in S2, and half the time I'm not even the highest PI car on the grid. There's something about that instant throttle response that just lets you carry more speed through corners. Once you go NA V12 it's genuinely hard to go back to turbo lag. You start noticing every millisecond of delay in every other engine and it kind of ruins other builds for you.
LS V8 (Chevrolet)
The classic "LS swap everything" meme is actually not wrong. Displacement for days, torque that pulls from 2k rpm like an actual freight train, and you can tune it in a hundred different directions. This is the go-to for muscle cars, off-road builds, anything heavy that needs grunt down low. Slap it in a Chevelle or a Bronco and suddenly the car just works. No drama, just torque everywhere. I put one in a '69 Charger and it was genuinely terrifying, in the best way possible. I remember the first time I floored it after the swap — I literally laughed out loud because the acceleration was so absurd. My friend was on discord and thought something was wrong with me because I was just giggling like an idiot for like 10 seconds straight.
PI efficiency: Depends on the chassis. In heavy platforms it's straight up meta — the PI cost is worth every point. In light cars the torque can overwhelm the chassis and the PI bill gets steep. Test before committing. I've wasted credits putting LS engines in Miatas and it was a learning experience. Undriveable levels of wheelspin in the first three gears. Kind of hilarious but also a complete waste of credits.
A-Tier Swaps — Niche But Nasty
Not meta-defining but in the right build they absolutely slap.
V10 (Lamborghini/Audi)
Less peak power than the V12 but also cheaper on PI, which matters in A-S1 where every point counts. The real reason to use this though? The sound. Best sounding engine in FH6, I will die on this hill. High revving scream that makes even slow laps feel cinematic. For street builds where you're not chasing leaderboard times, this is the one I keep coming back to. Put headphones on, crank the volume, just chef's kiss.
Rotary (Mazda 13B/20B)
Stupid good power-to-weight. A built rotary can hit 600+ hp while weighing like half what a V8 weighs, which in a sub-2000 lb chassis is absolutely filthy. The catch? PI cost is pretty high for the raw power number, and the power band is peaky as hell. You'll be shifting constantly — 2nd, 3rd, 2nd, 3rd — just to stay in the sweet spot. Exhausting to drive for long sessions but in the right car it's untouchable. Lightweight builds only, anything over 2500 lbs and the rotary doesn't have the torque to move it properly. Oh and brap brap brap sounds. If you know you know. The rotary sound alone is worth the PI cost for some builds — I'll sacrifice a few tenths for audio that makes my brain release chemicals.
When NOT to Swap
This section would've saved me hundreds of thousands of credits if I'd known this stuff earlier.
Look, I've wasted so many credits on swaps that ended up being downgrades. Genuinely embarrassing amounts. Here's when you should keep the stock engine:
- The stock engine has good upgrade potential. Some cars (GT-R, Supra, 911 GT3 RS) have stock engines that can reach 800+ hp with bolt-ons. Swapping would cost more PI for the same or less power. Kind of defeats the purpose.
- You're near the PI cap. If you're at 895 PI in S1 and a swap would cost 40 PI, you'd need to remove upgrades worth 35 PI elsewhere. The net gain might be negative. I've done this and watched my lap times go up instead of down.
- The car's character matters. Swapping a Ferrari V12 into a car that was designed around a flat-six destroys its personality. For competitive builds, go ahead. For cars you drive for enjoyment, keep the original engine. I swapped a 911 GT3 once and immediately regretted it — turned a precision scalpel into a sledgehammer. Reverted within 10 minutes. Some cars are just meant to keep their original engine and forcing a V12 into everything is how you end up with a garage full of cars that all feel exactly the same, which is honestly the most boring possible outcome.
Swap Strategy by Class
Here's the TL;DR. Screenshot this table, seriously.
| Class | Best Swap | Why |
|---|---|---|
| D-C | None - keep stock | Swaps cost too much PI at low classes. Upgrade tires + suspension instead. You'd be surprised how far tires and suspension take you without touching the engine at all. |
| B | Rotary or mild V8 | Power-to-weight matters most. Light swaps with moderate power. |
| A | 2JZ or V10 | Best PI efficiency in this range. 2JZ can hit 500-600 hp at A800. This is basically where the 2JZ truly shines, you can build an A-class monster that punches way above its class. |
| S1 | 2JZ, LS V8, Racing V12 | Peak swap territory. Pick based on car weight and target power. |
| S2 | Racing V12, maxed LS V8 | Only cars with top-tier swap options are S2-competitive. |
| Drag (any) | LS V8 or max-displacement | Torque is king. Displacement over revs. I use LS for all my drag builds, nothing else comes close. |
Related Guides
Bottom line: the 2JZ and LS are the safest bets for 90% of builds. Racing V12 if you've got the PI budget and want the best feel. Keep the stock engine if it already has good upgrade potential. And for the love of everything, test before you commit the credits. Most engine swaps in FH6 are bait — honestly, probably 70% of them are either worse than stock or cost so much PI that you can't build a competitive car around them. I learned that through an absolutely painful amount of trial and error. I once spent 150K swapping a V12 into an RX-7 thinking it would be insane, and it ended up being literally undriveable — could not keep the rear tires from spinning through fourth gear. Then I had to spend another 150K swapping it back to the rotary. My friends still make fun of me for that one. Don't blindly swap everything like I did. That's the whole point of this guide. Save yourself the credits and the headache.
Also — one thing I totally forgot about: the PI cost of an engine swap changes depending on what other upgrades you have on the car. The game absolutely does not tell you this anywhere in the UI. I only figured it out after wondering why the same 2JZ swap cost different amounts of PI on two different builds of the same car. Made me think I was going crazy, so I spent an entire evening testing every combination of upgrades. Short version: always apply the engine swap FIRST before any other upgrades, because the PI cost is calculated based on the car's current stats. A stock car gets a lower PI penalty for the same swap than a car with full bolt-ons. Saves you like 5-15 PI points which is genuinely huge in competitive builds where every single point matters. Figured that out the hard way.