Is there anyway to make good competitive tune for muscle cars like Corvettes, Vipers and any other muscle cars? I tried to make good C6 Corvette ZR1, 1996 Viper ACR and Corvette C5 but I failed hard. I know Viper ACR from 2006 is good but what about other vipers? I play with difficulty level 105% ( I only turn of mechanical damage) and I cannot make musle cars from 80’s,90’s or newer to win street races. Any advices? I don’t like AWD swaps, like to drive RWD.
With RWD, first major tip is avoiding turbochargers. They can kick the tires out. NA power first, avoid heavy swaps.
Other avoids, dont be tempted to put in the lightest flywheel. Slight traction lost will rapidly redline you with no flywheel to keep it in check.
After that, tuning… A lower lock setting on accel can actually help, try and keep them similar. A hard lock from an open decel setting can kick it out too.
Focus on handling over power. Higher pressure, softer suspension in rear also can keep it more planted. The key to rwd is a smooth line and to maximize the handling advantage.
I will peek at those specific cars and play with them this evening to give more detailed advice. Any particular PI?
Gonna try your advice.
S1 class is enough for me. My faouvorite class is A800. Going over S1 and handlind starts to look like NFS because there is so much grip.
I just tried the Edinburgh city sprint street race in the 2018 Camaro tuned to S1 and managed to pull out a win on the last turn against unbeatable track toys with only the braking line on. The upgrades I did to that car were the following: max out front and rear tire width, widest tires, brakes, weight reduction, race transmission, clutch, sport camshaft, and some rims. Tuning was just just bringing out more speed and better 0-60 and 0-100 times on the transmission final drive and dropping the ride height. I usually don’t fiddle with individual gears and I find myself going faster with nearly stock spring setups as opposed to tuning calculator ones.
I think the general upgrade path if I remember correctly was centrifugal supercharger (if possible), race tires, tire width and spacing, weight reduction, transmission, springs, and power at the end. That might be outdated now. You could throw aero on too, but I can’t stand ruining the look of a car.
Comment on above. Supercharger… First? Forced induction should be last power adder unless you just want front weight ballast. Makes torque curve more peaky and is heavy. What am I missing?
Well, Did a C4 ZR1, 95 to A class. I sort of focused on what I invested in. With A class, there are many traps one can fall into. In older racing games, you rarely could easily max out something, just too expensive. Money though for Horizons? One wheelspin will cover a full upgrading. Even races pay out well.
I am no minmaxer, I just like to race what is fun and I am in the mood for but do so on the high difficulties. So while may not be optimal, they tend to be versatile and effective all the same. Reason I think many recommend centrifugal superchargers is that it can shift your torque curve to a higher RPM, some cars affected more than others, but it does have a significant PI cost to balance with other potential upgrades.
(sorry if used to hp, going to speak metric here, but relatively they are the same at least for example purposes)
Right now am looking at the 99 ACR Viper. You pick up 54kw, but also 36 kg on the install. It also doesn’t affect your bottom end of the shift point, only peak. Lets compare to other upgrades. For that same 10 PI, 16kw, but across the whole power curve with a weight reduction of 17kg for exhaust, 3kg and 10kw for the the intake, and 6kw for a displacement at the same 10 PI. So it is a total of 32kw, but a difference between the two of 56kg, almost a hundred pounds. In terms of this tune, that is a 5% weight difference. So it does come into the what you need more of. If power? Maybe the supercharger. If handling? Perhaps not.
The biggest PI trap is the tires. For A class, racing tires are an overkill. With RWD, you can perform fine in wet with just the sport tire compound. I call it wasted PI because you really cannot make the most of the PI gain. So with the Viper, by default, race tires put you into the S1. So keep in mind about the gains and if you will need somewhere else. Example is the ZR1 build. It won an unbeatable RWD, no aides on wet street scene, but barely. It doesnt have enough power. I need to tune down the gearing more, perhaps take off one stage of weight reduction for more power.
In this respect, I love A and S1 not just for the feel of racing, but for the tuning considerations. Most cars are a give and take so consideration of the other effects of tuning are essential. Most components have effects outside of the number value. Tires for example do have sidewall deformation. The simulation works on contact patch. Going really wide can be detrimental due to the change in contact patch. Too wide can hurt handling. Wider tires have more scrub and more resistance to turning. You gain in grip, but harder to turn, like with differential. So sometimes stuff that shows a detriment to PI, can actually help such as larger wheel diameters. Worse over bumps, but are less affected by high G turns.
With this in mind, some of what I consider essentials:
Adjustable sway bars, Sport Transmission, Race diff., race suspension.
These tend to be of no, or very insignificant PI cost but open up a ton of tuning options as you see fit, sometimes essential tuning.
Depending on the car, at A class you can get away easily with the street or sport tires. All upgrades after the initial start becoming situational. A wing for example, weight reduction, etc. Some cars will lose pace in different places than others. If you are not able to corner, take some power put to handling. If beating in acceleration, but not top speed, then maybe the supercharger instead for more top end acceleration. Traction problems, go from the street to sport, racing only if serious holding problems which usually is only S1. The ZR1 tune for example, I have a bit too much in handling, but wasn’t able to take advantage of power in straights or corners, so I will probably go from sport to street and then put some more into power.
The viper tune I just finished up, it was a bit trickier. I did my normal with the standard handling modifications, then put some power upgrades. Boy is that thing a picky beast. It definitely needed sport tires. The rear differential, I also turned it down to about 30%, letting off the throttle/brakes at all into turn did some destabilization. Had to pull off most of the engine upgrades. This thing is a pig to tune! It sort of threw off all my old concepts, but then through trial and error, I improved each section. Really this car has enough power for A class right out of the basket. I tried a gamble by not putting rear wing on, but it really needs it.
Did testing on coastal charge.
Sorry if this seemed rambling. Was posting as I wrote. With these cars and A class, it really is less about upgrading stuff, more about tuning out their weaknesses. The vettes are fairly balanced already. An A class 99 Viper though was a fun treat and challenge for me. But it really has too much top speed power for A class I feel. Plus it had wierd gearing but the PI doesn’t really leave much for improving that. It cannot really take advantage in corner, but is much faster in the straights. I feel it would probably make a better S1. TBH, this track was almost cheaty feeling. The first place drivertar just always disappears at the start but was able to get it consistently to second on unbeatable. That really is the least enjoyable street scene… well, most lazy speed runs arex… so I went somewhere else after finally managing to eek in a win, but it did require dirty racing. Lead car was just gone right from start on that one. So I quit and re-entered to generate a new field. A 1m45 race length is just pathetically impractical.
-----TLDR LINE BREAK-----
BUILD
A bit of breathing room, following worked really well to get to A800
Engine stock, only following modified.
Race brakes, suspension, adjustable roll bars, sport reinforcement, sport weight reduction.
Sport clutch, transmission and driveline, race diff.
Sport tire compound
Rear wing.
TUNING
After this, it was lots and lots of tuning and adjustment to feel. This is what is required to bring these to perform. Cause it also factors in what controller and playstyle, keep in mind these generalizations for for me on a wheel. The test track is also wet.
Increased rear tire pressure to help road hold
A much higher gear ratio, will run out of gear before power. Default tune has a real long legged 5th and 6th, but need more gears for handling section else cars will walk away. More than enough HP, so more acceleration in 4/5 very useful, specially 5th.
Alignment had some strangeness. The steering on this car felt very sluggish and lazy. I put 2.5 degrees front toe out, 0.0 in rear until it felt responsive.
Suspension not much was changed. Slightly stiffer front, softer rear to balance out the oversteer, not too much though to keep it from getting waggy.
Aero, upped the rear downforce
Brakes and diffie. this is where feel is very important. For me, I usually habit late off the brakes, but find with my tunes a 40% works nice to give it a little bit of extra flick into rear, but brakes are entirely to how you drive.
Diffie though, I even set this more different than normal, something you can do to flavour. I found an accel of 70 and decel of 35 gave me a smooth into and out of the corners despite what I said earlier.
The viper and it’s default tire sizes really doesn’t like lots of decel lock, that seemed to be one of the major causes of it getting bad in the corners. With the wet, it would too much lock and slide out. If you get squirelly when you let off gas going into corners, consider your brakes and diff settings for sure with the viper.
I probably could improve it more, but that is part of the fun for tuning. This car took a fair bit of time, but am liking it for A class now. Going through S1 would for sure go to the race tires, weight reduction and front diffuser before adding more power. Race transmission to get it a better gear layout. It has more than enough power.
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Your rambling actually provides a lot of insight into tuning practices. Thank you.
The only tuning I use is gearing and aero. Haven’t ventured into other areas as I am happy now finishing podium on Expert in nearly every car or class I attempt to tune. It is good enough for now but in many cases, the expert drivatars are not a challenge. Hope to be able to drive RWD cars above Class C someday. For now…all tunes start with AWD. Thx again for all the little tips!
Tire compound gives better mechanical grip than width for the same handling stat. However, the impact on PI is more severe.
I like Sport tires for A class, but some cars will need Race tires because they already have enough power but the chassis is either old or bad.
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I like Vintage Race Tires when I’m building up an older car for racing on roads. I think they have similar stats to Sport…
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On most cars that have access to Vintage Race Tires they are more or less equal to Street Tires. Sport always provides more grip and costs more PI.
On topic:
The Viper GTS and Corvette C5 can be tuned to A800 as RWD without the need of Race Tires or Forza aero. The C6 ZR1 can be tuned to S900 as RWD without the need of Forza aero. They are not on the pace of the fastest class-cars but can handle all AI difficulties on all road/street tracks. Thanks to theirs rear tire widths they can easily handle the power with the correct diff setting and a little bit of throttle control.
If you want I can post my shopping list + my tune in metrical units here. So you could alter settings that don’t fit your liking.
Thank God!
(not the fastest as you said but… only a few cars are fastest)
Saw it again, tire width is a red herring stat. There is more complexity to its handling capabilities than that. It has higher “handling” because of less tire roll under high G, but too much width can cause poor or negative sideloading mechanical traction and predictability. More noticable offroad, but still there onroad. All tire size changes are more for how it affects the car outside the raw numerical stats. All about that contact patch shape.
And yeah, viper stock has pretty good rear aero. Not sure if it simulates, but rear aero like that isnt just downforce but also has a stabilization effect.
Tire width (especially on the powered wheels) is way more effective in Forza than irl. Irl extreme wide tires can hurt the car’s performance but I’ve never seen a car in Horizon which suffered from wide rear tires. On RWD cars (especially from A-class upwards and without Forza aero) selecting the widest tires is a must. The Tuscan on A-class for example can only fit 285’s on the rear and although it weighs less than 1.000kg and can fit Sport tires it suffers when accelerating out of corners. It rolls too much over the wheels and the diff can’t compensate it.
On the other hand in favour of this thread I built the C4 ZR1 yesterday (1.37xkg and stock tires which are below Street) and it immediatly stopped rolling over the wheels when I fitted the 345’s on the rear.
Even highly unbalanced AWD cars like the Nova FE (125’s/385’s) or the Bone Shaker profit from wider rear tires because it decreases PI (for no reason) and adds grip. With a fitting suspension & diff setting they handle perfectly fine. Both would be undrivable trashcans irl with basically no turn-in capability.
If one knows how to “play” Forza’s tuning system wider rear tires are always a performance gain. Wider front tires are only a necessity on FWD cars.
OT: I built the C4 ZR1, C5 & Viper GTS on A-class and the C6 ZR1 on S-class. All come with RWD and without ugly Forza aero. Lap times:
C4 ZR1 (stock engine, centrifugal supercharged, stock tires): 6:41.304
C4 ZR1 (V8 swap, Street tires): 6:41.938
C5 (V8 swap, stock tires): 6:41.111
Viper GTS (stock engine, stock tires): 6:41.038
As shown they all have pretty much identical performance which shouldn’t surprise because they have similiar stats and traits. Those times put them in the 2nd tier of RWD cars at A-class (with cars like the NSX’es, Aston DBS, Ferrari 360CS, Lotus Esprit V8). Only the Retro Supercars with the special “Retro Supercar” tire compound are quicker as RWD (Lambo Diablo SV, Lambo Countach, Ferrari 288 GT0, Ferrari F355, Ferrari 512 TR).
The C6 ZR1 on S1 achieved a 5:56.660 which puts it in the 2nd tier of RWD cars on S1.
All of these cars should be usable against “unbeatable” AI on all street/road tracks.
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I was using my own test track (originally created for S-classes but it does work for A-class quite well too) “Forest Run” which starts at Astmoore Circuit.
Haven’t looked into the C2 yet but given its very old chassis I would assume that it needs at least Sport tires at A-class when running as RWD without aero. If this leaves enough PI to make it work I’ll have to see. Will look into it once I’m back from work.
I tune many RWD,FWD cars, i don’t like change drivetrain and use ugly forza aero in cars,if someone need some good RWD tunes look at my Creative Hub in FH4.
Hope it all helps! Been a racing gamer right back to the classics such as original test drive and F1 for the amiga. So I keep underestimating the complexity of horizons physics with the more extreme simulcade gameplay. So it does a fair bit of detailed stuff unmentioned I am finding like flywheel weight and unsprung weight.
So once in a while, I will just start adjusting a car to see just what all actually happens outside of the points table. The tire one I didnt think about until I started racing in muddy tracks the 959 rally. 959 street is a favorite of mine, but did the arcade play of big and wide tires. I hated it for rally and muddy rally especially. Swapped to the stock size again and much more controllable/predictable. Loss on launch but better at speed. A large tire is sort of counted by higher pressure, better grip, but less stable/predictable.
Many guys have tunes and times far better than mine, but like this post, sometimes want to keep a car a certain way. Then tuning is fun.
I should share that viper tune up.
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Ok I’ve tried your build and youre right. There is no need for tuning engine the power is already there. Gear tuning gave me difference about 0.3 s on that short drag strip at the festival. About tire pressure how much should I set? And toe is negative or positive +2.5?
Tire pressure can be tricky. A lower pressure can help in acceleration grip, but it has less handling grip. A higher pressure will help improve side loading Gs and with braking. Drawback is that when traction is lost, it tends to go more dramatically. Tires are also part of suspension, so it is able to be considered that higher pressure is like a stiffer suspension. It is the suspension for all your unsprung weight.
Overall, I dont play with it too much. Lower offroad for the bumps, higher on the road, but that is me. For AWD, usually kept similar. For RWD, I recommend experiment for self to find where you are comfortable. Drive around, adjust and see if you notice different.
Toe in/out is the biggest for feel and no really direct answer. If the back is squirrely, you can to in reat to keep it planted, toe out if it feels like not really responsive.
For front is where it gets interesting. But fortunately is more clear in how to adjust. If turning seems sluggish, add some toe out. If it seems as though is diving in when turning and fighting track smoothly straight, toe in. All about feel. Lambo Diablo SV for me seemed to almost drive like the front was being pulled inside the turn, over steering inwards. So I gave toe in. That viper was very lazy and boaty turning in, so I actually ended up giving a fair bit. Usually I might one degree, but 99 viper for me to like the feel was 2.5 out. All about feel. Effectively toe in makes it less sensitive, out makes it more to simplify.
I saw this as a challenge and buildt a James Bond AMC Hornet '74 and gave it a go at Coastal Charge against unbeatable. It wasn’t easy but I did manage to place first with a time of 2:01.021 in the wet, even though I’m a noob when it comes to driving. It’s an A800 build with the stock engine, RWD and no aero. You can download the tune “Street Scene RWD” and reverse engineer it to get the rest of the build.
Here are my tuning numbers in metric:
Tires:
1.8
1.7
Gearing:
Final drive: 2.71
Alignment:
-1.4
-0.7
0.0
0.0
4.8
ARBs:
28.07
20.13
Springs:
76.5
70.5
18.5
18.9
Damping:
6.2
5.6
3.1
2.8
Brake:
46%
103%
Diff:
78%
78%