FH6 Gearing & Differential Setup , Tuning Guide
Look, gearing and the diff are the stuff 90% of players ignore and I'll die on this hill, like I will take this opinion to my grave and I've argued with people about it and I'm always right in the end because the proof is literally in the lap times y'know? Everyone tweaks springs and camber and calls it a tune, then complains their car handles weird or tops out halfway down the straight and they're like why am I so slow and the answer is always the gears, it's literally always the gears and nobody wants to hear it. I did this too. First hundred hours of FH4 and FH5 combined, I didn't touch gears once, just slapped on the default tune and hoped for the best which is basically the worst approach possible tbh. These two settings are literally how your engine's power meets the road. Nail em and a mid car becomes a weapon. Get em wrong and even meta picks feel like absolute garbage, like driving through quicksand bad, and you'll be wondering why everyone else is pulling away from you on the straight when you have the same car with the same upgrades and stuff like that. Not exaggerating. I once spent 4 hours trying to figure out why my Ferrari 488 was getting smoked on the final straight at the Guanajuato circuit, turns out my final drive was like 15% too short and I was bouncing the limiter a full 3 seconds before the braking zone, I felt like the dumbest person alive when I finally figured it out and my friend who actually knows how to tune cars was just laughing at me the entire time, deserved honestly.
Final Drive Ratio - The One Number That Changes Everything
Acceleration vs top speed. That's the whole tradeoff and honestly once you understand this one concept everything else falls into place, at least for the final drive part of things. Higher number = shorter gearing = harder launch but lower top end. Lower number = longer gearing = bigger top speed but you're sluggish coming out of corners and it feels like the car is asleep for the first 3 seconds after every turn. On paper it looks simple. In the car it's night and day, like you'll know immediately if you messed it up because the car will either be screaming at the limiter way too early or just refusing to accelerate past a certain speed like it hit an invisible wall. One click too far either direction and the whole build falls apart. No joke. I've spent entire evenings just tweaking one number back and forth, one click at a time, and my roommate thinks I've completely lost it and maybe I have but the lap times don't lie so who's really the crazy one here. Honestly at this point I've accepted that tuning is basically just a socially acceptable form of OCD and I'm fine with that y'know, like sure I could be doing something productive with my evening but instead I'm adjusting a single gear ratio by 0.01 increments and pretending that's a normal way to spend your free time which it absolutely is not but whatever the cars are fast and that's all that matters in the end I guess.
My rule after messing this up a hundred times: your final drive needs to put you at the top of the power band, redline or just before it, right at the end of the longest straight on whatever track you're tuning for. If you're bouncing the limiter before the braking zone, gearing's too short and you're bleeding time and it's the most frustrating thing because you can literally feel the car wanting to go faster but the gearing won't let it. If you coast across the line with RPM still climbing, gearing's too long and you left acceleration on the table which is just as bad honestly. Both are wasted potential. Both cost tenths that add up fast and I've lost races by like 0.05 seconds because of this, which is the most tilting thing in the world when you realize you could've just adjusted one number and won. But that's tuning I guess. Worth it though, when you finally nail it and the car just... works, like everything clicks into place and suddenly you're setting personal bests every lap and your friends are messaging you asking what tune you're running and you get to be all smug about it which is honestly half the fun of tuning in the first place.
Gearing by Race Type
- Technical circuits (short straights): Go shorter. You'll never hit terminal velocity anyway so you might as well maximize corner exit punch because what's the point of having 200mph gearing on a track where you never break 120, it's just wasted potential sitting there unused and your car is slower off every single corner exit and you're losing tenths on every turn while the guy next to you with properly short gearing just walks away like it's nothing. I run these pretty aggressive and it's never let me down. Not once.
- Speed circuits (long straights): Longer gearing. Top speed actually matters here and you'll use every bit of it. Don't go so long that 1st and 2nd feel dead tho. There's a balance and it takes some trial and error.
- Drag (quarter mile): Set it so 4th gear redlines right at the finish. If you're grabbing 5th, your gearing is too short and you're losing time on every single shift. Every shift is time you're not accelerating.
- Drag (half mile): 5th or 6th gear reaching redline at the stripe. Depends on the car and power level honestly.
- Off-road: Shorter gearing, no question. Off-road speeds rarely break 130 mph and you need acceleration out of slow messy corners where you're basically crawling through mud and rocks and praying the car goes where you point it. I've tested longer gearing on rally stages and it's a total noob trap, like it feels faster on paper because big number go brrr but in practice you lose seconds every single time and I had to learn this the embarrassing way by losing like 15 races in a row before I finally admitted my gearing was the problem and not my driving or whatever other excuse I was making up to protect my ego. Feels faster on paper but loses seconds in practice every single time.
Individual Gear Tuning
Final drive gets you in the ballpark. Then you go gear by gear. The goal is even spacing, you do NOT want a huge gap between 2nd and 3rd where the engine drops out of its power band and the car just... dies and you sit there watching your lap time evaporate while helplessly waiting for RPMs to climb back up, which is honestly one of the most frustrating things in this entire game and I'm not even exaggerating. Like it falls flat for half a second mid-corner and you can literally feel the momentum just evaporate. Absolutely infuriating and it happens constantly with stock gearing on certain cars. No joke. I swear some of these stock gear ratios were designed by someone who's never actually driven a car in their life, like what were they thinking honestly. Whatever, we're stuck with these ratios so might as well learn to fix em ourselves instead of complaining about it... or complain AND fix them, that's basically what this entire guide is if I'm being honest with myself and stuff.
- 1st gear: Make it tall enough to not roast the tires from a dig. Too short and you're smoking rubber before you've moved 10 feet and your launch is completely ruined and you might as well just restart because you already lost the race in the first 5 seconds which is the worst feeling honestly. Might as well restart. For AWD you can go shorter since grip isn't the problem, basically you have more room to play with because all four wheels are putting the power down instead of just two and that changes the math completely.
- 2nd and 3rd gear: These are your corner exit gears and honestly they matter more than anything, like I cannot stress this enough, if you only tune two things in the entire car make it these two gears because everything else is secondary compared to how your 2nd to 3rd transition feels. Space em tight. You need to be in the power band the whole time coming out of slow to medium corners , that's where races are won or lost and a tiny dead zone between 2nd and 3rd will cost you like multiple tenths per corner which stacks up to full seconds per lap and you WILL lose because of it. I spend like 60% of my tuning time on just these two gears and my friends think I'm insane sitting there for 20 minutes adjusting by tiny increments but my lap times don't lie and theirs do so I'm gonna keep doing it my way.
- 4th gear and above: Let the spacing stretch out. At speed aero drag means you accelerate slower anyway, wider gaps are fine. Nobody notices the 4-5 shift feel at 140 mph and anyone who says they do is lying.
Differential , Accel and Decel Settings
The diff controls how locked together your left and right drive wheels are. 0% = open diff, wheels spin independently. 100% = fully locked, both wheels turn as one. Most cars want something in between and finding that sweet spot is what turns a frustrating car into one that actually does what you tell it to, it's kinda like seasoning food where too little is bland and too much ruins the whole dish and you just gotta develop a feel for it through trial and error and a lot of failed test laps and wasted evenings and stuff like that. No joke, diff tuning took me longer to figure out than literally every other setting combined, I was convinced my car was just broken for like a month before I realized I had the accel lock set to 100% on a RWD road car like an actual psychopath, the thing was basically undriveable and I just thought I was bad at the game which in fairness I kinda was but still.
Rear Differential (RWD and AWD)
| >Race Type | >Accel % | >Decel % | >Why |
|---|---|---|---|
| >Road (RWD) | >70-80 | >10-15 | >High accel = traction on exit. Low decel = the car actually rotates on entry instead of plowing straight |
| >Road (AWD) | >60-70 | >5-10 | >AWD already has grip for days, lower lock keeps it from feeling twitchy and unpredictable |
| >Dirt/Off-road | >80-90 | >5-10 | >Loose surface eats power. You need high lock to actually put it down or you're just spinning one wheel |
| >Drift | >100 | >100 | >Full lock, both wheels spinning, no questions asked. Anything less and you'll one tire fire, it's embarassing |
| >Drag | >100 | >0 | >Locked on throttle for max launch, open on decel so it stays stable at the top end |
| >FWD | >60-70 | >0-5 | >A proper LSD transforms FWD corner exit from misery to actually usable. Nearly zero decel lock to avoid understeer death |
Center Differential (AWD Only)
Center diff splits torque front to rear. The percentage shown = how much goes to the rear. So 70% means 70 rear, 30 front. More rear bias = more RWD-like feel, which is what you usually want unless you're in dirt or snow.
- Road racing: 65 to 75 percent rear. Gets you that RWD rotation feel but with AWD grip. Sweet spot for most meta AWD builds and what I run on basically everything.
- Dirt: 60 to 70 percent rear. A little more front power helps on loose stuff where the rear alone can't find consistent traction. You'll feel the difference immediately.
- Drift: 85 to 95 percent rear. Basically RWD at this point. You want the back end to step out and stay out. Front is just there to pull you thru transitions and keep you from spinning.
- Drag: 80 to 85 percent rear. Maximum rear bias for launch grip. Front axle is just along for the ride at this point, which is fine for drag racing.
Diagnosing Diff Problems
When something feels off I run thru this checklist and I've probably done this literal hundreds of times across different cars and race types so I'm pretty confident about these by now, like I'd bet my entire garage on them at this point. Four symptoms cover like 90% of diff issues and if it's not one of these then honestly you've got bigger problems and should probably just start over from scratch or download someone else's tune and call it a day.
- Inside wheel spins on corner exit: Accel lock too low. The diff is opening up and dumping all the power to the unloaded inside wheel while the outside wheel does nothing. Bump it 5-10% and try again.
- Car won't rotate on corner entry: Decel lock too high. The diff stays locked off throttle and fights your steering. Drop it down and suddenly the car turns in like a normal vehicle.
- Car snaps sideways when you get on throttle: Accel lock too high. Both wheels spinning at exactly the same speed on exit = instant traction loss. Back off 5% at a time til it settles.
- Car pushes wide (understeer) constantly: Center diff too front biased on AWD. Or front accel too high on FWD. Shift power rearward, understeer magically goes away. It's almost always this. I remember one time I spent like 2 hours trying to fix understeer with camber and toe and spring rates and literally every other setting in the menu before I realized it was just the diff the whole time, I felt so stupid afterwards like genuinely embarrassed that I wasted an entire evening on the wrong settings while my wife was asking if I was ever coming to bed and I was like JUST ONE MORE LAP I swear I almost have it figured out. Didn't have it figured out. But hey, that's how you learn I guess, you make the dumb mistakes first and then you hopefully never make them again. Or you do make them again and catch it faster the second time, which is progress I suppose. ...things like that.