Need help with power-on oversteer and Camaro ZL1

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1

Bear with me, this will be a bit long, but hopefully I will provide enough detail for you guys to help me.

I’m trying to dial in a 2012 Camaro Zl1 set up to run Class A. I have it at 51% weight dist, and running 3,300 pounds total weight. I got the race weight reduction, larger sized tires front and back, and fully adjustable suspension + roll bars, and diff, race brakes. I put race compounds on it, then I added a twin turbo conversion and racing exhaust to bring the power up. That has me sitting at PI 699 before I add wings, which I want to tune for once I get it to behave at lower speeds and tighter corners.

I started off with the car it was an undrivable pig…after a couple hours of tuning its better…but still frustrating me. Best I’ve managed so far is ~1:33 around the track.

I’m trying to dial it in at the moment on The Indy Grand Prix track for the flat track and seem to be having a great deal of trouble. I seem to have it turning in acceptably, though it still oversteer/pushes into the corners more than I would like. But coming out them is always a nightmare. Sometimes it will set just after apex start to take off, and then kick the rear out with a terrible throttle-on oversteer that can easily snap the car all the way around or into the nearest wall. Also anything with an S turns will see the first turn successful and then the next turn with the rear throwing out like somebody pulled at Pittman maneuver on me. I find setting the Diff Acceleration below 20% seems to leave the inside rear tire to spin freely, and can make the oversteer worse.

I found that it seems to like the springs softer to keep from sliding though corners in a 4-skid, it also seems to not really want to grab while breaking and loves to oversteer on the first half the turn. In fact if were not the car’s refusal to hook up and keep the rear wheels from burning out, I would say its oversteering into and out of the corners.

Corner Exit oversteer in Class A and better FR cars has been something I’ve been struggling with pretty much forever. It would seem like turn-exits are the bane of my tuning existence. I know you pretty much have to feather the throttle always with a car like this, but it never seems consistent, quite unlike class B’s that I have been able to dial in nicely so a gentle application of throttle easily helps rotate the car without snapping it around. It also seems to accelerate poorly given how much torque it has, I really would expect better.

I see the note that the car rolls over the outside wheel" a lot in tuning guides, but I don’t know how I can tell if this is happening while driving or looking at telemetry.

I have the car set up as follows F/R

Tires 28/28
Camber" -2.1/-2.1
Toe 0.1/-0.3
Caster: 5.5

ARB: 13.9/14.9
Springs: 575/423
RH: 6.1/6.1

Rebound: 8.5/8.1
Bump: 4.8/3.5

Brake: 50%
press: 100%

Accel 23%
Decl: 21%

If anybody could give me any help, especially with some explanation of why you made that choice I would be very grateful. I’m always trying to learn a bit more about tuning works.

Also, I’m rather confused about how to tune for camber. I watched a video by StellaSig that said use to the telemetry one should tune until a tire at 0.0 or less camber in a turn using telemetry, and with this car I’m arriving at -0.0 at like camber: -1.2/-0.7 or but then see Worm and others suggesting that camber should be set at -2.0 or even less. I’m not sure I understand how I can know when I have camber set right and proper camber settings seem to be important to keep the rear from jumping out on turn exit.

2

Hello,

Try lowering your deccel between 8-10

You might want to try reversing your arb’, softer arb’s at the rear will reduce oversteer.

One thing i might suggest is that all of your suspension settings including the Arb’s are way too soft for the weight of the car. This might be one of the cause.

Are you driving with steering assist at simulation? Switch to normal. Simulation is more sensible to snap oversteer.

Don t take this on the wrong side, you may lack the driving experience to control high powered cars with throttle control. Gently feather the trigger in order to control your acceleration coming out of a turn. The rumbles in the trigger will tell you when you are loosing grip.

Hope this can help.

Cheers

Rosny

3

I don’t race a class but I tuned one…before I give any advice my tune is there under my gamer tag…give it a shot if you like it I’ll tell you exactly what it is and maybe figure out what works for you

4

Unless you are friend with the OP, thank you for your feedback and help. You absolutely nailed it with your advice.

Cheers

Rosny

5

Rear bump looks too low. Raise it to at least 4.5/4.6. I would also stiffen the rebound by two full digits. ARBs are very effective tuning elements in FM5. Try starting with them in the high teens/early twenties set to reflect the nominal weight distribution of the car and adjust in small increments from there. The spring rates may be generally a little low also as Rosny has said. Try raising them a little, not so much that the car starts resisting a set into a corner, but enough that you aren’t getting excessive weight transfer. I haven’t tuned one of these but at 3300 pounds it may be that slightly stiff is the best way to go. Like I said , let your ARBs do most of the balance work. That’s whats always worked with muscle for me.

6

+1 on what Mick says

7

I actually built one of these last night but i forgot to tune it. I would say like the others though to try raising your ARB and spring rate. I personally run quite low damping and high rebound so that could be something to try. i usually run in the 2’ for bump and in the 9’ for rebound as a starting point and adjust from there. Also the reason a lot of people run high camber (like myself) is just simply for grip. The telemetry doesnt show it but when you raise your camber you will feel the grip in most cases. Most of my new tunes are running around 3 on the front and 2.5 on the rear for camber.

I used to use the telemetry but i found myself to worried about numbers to much compared to how the car felt. I would also stare at all the moving lines and colors on the screen and found myself in a catatonic state lol.

One more thing. I would recommend putting the CS on it instead of the turbo. The reason being all that torque is hitting at the same time instead of the gradual build up so that could help you with you throttle on oversteer as well.

8

Could you explain a bit more what you mean by the fact ARB’s being very effective in F5? Do you mean they make changes to the balance more effectively, or just have a greater effect on the car? Also I heard the advice of running a soft rear spring so it sets on accel, and hard R ARB so it doesn’t understeer on a FR car, what would you say to that thinking?

When I tried to raise my bump I was getting transition oversteer. Should I try raising bump still it starts to get loose and and then start dropping R ARB to tighten up the rear? Also with a higher bump I was losing the rear any time it touched a kerb, dropping that rear bump seemed to make it more compliant. Is there any a way to up rear bump and keep a kurb from throwing rear end around? I don’t mean to neg on your advice, just curious why you say to up bump to 4.5ish.

Also when I added 50 pounds to both F and R springs I started to slide around a lot. Is there something I should be doing to help counter the sliding? I’m thinking that perhaps I should raise ARB and springs at the same time so they work together? I could see raising ARB’s first lifting the insides wheels as the softer springs would transfer weight and then the ARB’s would resist letting the inside wheels rebound.

I’m running normal steering, I’m not gonna try sim steering without a wheel controller. At the very least I want to learn sim steering with a much more stable car. As for driving technique, no doubt I could always use improvements there, but hopefully I know at least as much as a mildly experienced racer? Not to say I’m right but I have been playing these kinda games for 10 years. I would like to focus on tuning so I can be feathering the throttle out of a turn, not just maintaining my speed all the way until the car is completely straight again and then accelerating, which is about all my tuning attempts have managed. Its not that I’m mashing the trigger every exit, but rather I can’t get the car to behave predictably so I can manage it. Not to mention what always kill me is when I get mid-exit snap oversteer. It will set fine at the apex and start accelerating, and about half way to the end of turn it will shoot out on me, I really want to learn what steps master that little misbehavior.

Also it really didn’t seem to be planting because I would be getting terrible accel out of the corner when it was rumbling. I also mentioned I already tried lowering my Accel settings. Below about 18% or so I was getting the inside rear completely breaking loose and jumping to “orange” temperatures exiting a turn.

This sounds really interesting. What are the signs you notice when you have increased grip from a camber adjustment? You say I will feel the grip but I unsure what that means and I would love to know what I’m looking for. Does the car simply take better in the corners or is my corner exit speed going to be higher? Also I will give the supercharger a try, because if the engine curves are to believed, the turbo does seem to slam 150 HP in there in about 300 RP’s range.

And such a crying shame Turn 10 refuses to have replays with telemetry in the test track… All that data changing per millisecond, its damn near worthless to try and read and drive.

Everybody thank you for the replies. This was quite a bit more response than I was hopeful for, and I’m happy to see people who wanta help a fellow player out. When i get a chance to play again, I’ll have to test out Fury’s tune too.

9

ARBs just seem more effective at trimming handling and balance than they did in FM4 and earlier.

Using spring bias F/R can also be effective, but you really need to know what you are doing if you don’t want to run the risk of introducing new problems elsewhere.

Having your rear bump notably lower than your front is going to magnfiy your problem with squat and will make keeping the car stable in entry and transitions all the harder. I suggested 4.5/4/6 because that is technically (orthodox view) where your rear bump should be given the front setting you currently have. Setting your bump lower overall - say in the 2-3 range - can be effective with many cars, but with softly sprung and heavier cars that like to belly around and pogo, raising it into the 4-5 range can help with control of unwanted movement. If you are having a problem with kerbs, then lowering the bump overall can help, but you will need to strike a balance so that you aren’t compromising overall handling for the sake of skimming the kerbs. Having said that, if your suspension is set up well you should be able to handle most kerbs at part throttle.

If raising the spring rates 50 pounds is causing sliding, given where you started then I would say you have probably reached your grip limit - unless of course it is just one end of the car coming unhooked. If you look at the friction telemetry, this will be obvious. You can either work with the drift, or add rubber or downforce.

As for the ARB part, you need to look at the front/rear behaviour of the car. The ARBs can play a big role in the way weight transfer plays out. If your front is stiff, as well as affecting the way the two front wheels are handling lateral loads, it will transfer energy to the rear of the car. If you have your rear ARB too soft it will accentuate the problem you seem to be having with squat. If you have your rear ARB too high, it will make the rear stiff and prone to sliding and wheelspin. There’s usually quite a bit of room to move in between. Like I suggested, try setting the ARBs more or less in line with the standing weight distribution of the car, drive it, and tweak from there. If you are getting good power down without either excessive spin or squat then your rear ARB is probably in the zone. If you are getting good turn in for both slow and fast curves, and keeping shape on track out, then your front is probably OK. It really is just a feel thing unfortunately, like just about everything else. Sometimes just one click can make a tangible difference.

With regard setting camber by feel, yes, you can tell by the set and flow through corners. The car will, literally, just feel quicker and smoother.

10

This will create more stiffness in the vehicle. It will also add grip to the front and not the rear, he needs rear grip but that is beside the point because it’s simply too high. The shocks cannot absorb at an optimum level when they are this stiff and they need to absorb everything they can.

This is correct but since you have the bump so stiff it is going to increase the stiffness of the vehicle making it even harder to drive.

Lower ARB’s allow the car to set into a turn more. Running them close to 10.0 at the start is generally the way to go. They do play an important role in tuning the car.

Again, stiffening a car that is unstable is just going to make it more unstable and unpredictable. If it is too soft it will roll and lift, this will be a gradual loss of grip until it breaks. Not something that happens suddenly or with “power-on”. In theory based upon real life stiffening the springs would increase mechanical grip but this isn’t real life. The physics and lack of damage in Forza allow you to run cars that acquire damage and running soft cars has always been faster than stiff. The softer the spring the harder the set it can take and the more it can absorb.

I was already doing that as you can see. : (

A lot of experienced people are loathe to post into help threads because their knowledge and grasp of the game is dismissed based upon real world outcomes or because someone wants something to be different. Do you think I haven’t tried everything in this game and previous games? I was one of the first people to touch the tuning menu in FM5, I was running camber close to -4.0 a month before anyone had an Xbox ONE on a dev kit. It was pretty easy to feel the difference the second I got in the F1 car and moved it down. I’ve had 40/1, 40/40, 20/20, 1/1, 1/40 roll bars, I’ve had springs set at the minimum, maximum, on the “T” of “SOFT” and everywhere else, ran 0 and 100 accel on all drivetrains, same for decel, and a bunch of other things. There were cars in FM4 like the Lancia that were faster with max ride height, cars that did horrible in corners that did better with 2/2 rebound and 10/10 bump in FM3, cars tuned for drag racing that demolished conventional tunes, running max front ride height gives you more mph in longer straights like Sunset, Indy, etc…I could go on and on for hours about this stuff. There is a reason my CRX doesn’t do well on telemetry data, it’s a little twitchy but it flies. Same as the Mini I have and any other FWD car. It’s way, way faster to tune them that way even though they don’t feel great.

No one is intimidating you, I gave you an option to prove your theory and if that option isn’t laid out people argue to the death about it. How many times have you seen that happen and you saw it here before I even asked you the car, track, class.

11

I don’t know what everyone is talking about here but…

Zero out your toe. The .3 in the front is not good and the -.1 in the rear is going to mask issues when you do the rest of this:

Your ARB’s are likely fine or very close to it.

Leave your springs alone.

Lower your rebound to 2.0/2.0. It’s too high already

Raise your rebound to 10.5/10.5, it’s too low especially for such a big car.

I don’t say camber at -2.0 or less. I say -2.0 or more, I would go -3.0 on both for a base.

Decel is going to do nothing for your problem. Move the accel up to 30%

Now for your main mistake. Put the aero on the car and start tuning with the build you want. The aero will help in slow corners in this game. It’s pointless to change what could/will change the handling characteristics of the vehicle as much as anything right after you bust your butt tuning it.

12

Everybody tunes a little different so we are just giving ideas for him to try. I have tuned my camaro now (with aero) and its quite fast. I have higher spring rates front and rear, lower rebound setting now and roughly the same bump stiffness he currently is running. I dont have any toe on the car because like you said it can mask the real issue. I also have the accel sitting at 55%. Yes it is different from what you run but its a damn fast camaro.

13

Does everyone tune as well as I do?

I can go look at tunes I have from FM3, FM4, and FM5 from myself, EMW, TPR, etc and they all pretty much look like mine and moving things in small increments off of it is the difference. I gave him ballpark, not exact numbers.

You know what else all those tunes for LB to lobby cars have in common? They run faster times than anything anyone else can do.

Tune different all you want, it is your choice but this isn’t the NBA where you can have a jump shot that looks miles different than the next guy but still goes in. There is a way to do things contrary to popular belief.

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[Mod edit - removed]

15

Im not disagreeing with what you are saying but not everybody can drive the same car. I know you can tune great i have read all about them but his style might not let him drive your tunes. If im faster in my tunes im not going to drive somebody elses tune because they say its right. I am also not saying my tunes are faster but i am fairly new to this and my cars have improved quite drastically with trial and error.

16

You could take tunes I did, if they were open sourced, and change a little here and there to make it faster for you but you won’t move things as drastically as above and be optimal. It may be fast because you are driving it but it won’t be as fast as you could get it if you sat down and tuned it correctly. Does that make sense?

There are very, very few instances where you would run bump that high and be as fast as if it was low. Same for rebound being very low instead of high. 50 pounds of spring weight on a Camaro isn’t much, about like moving the diff 5%.

17

I do agree with you but for the act of learning its always good to have trial and error instead of this is the only way to do things.

18

Yes but he is asking for help presumably because he is stuck. We’ve all been there. If someone asks for directions from Dallas to Phoenix you could point them into traveling directly west. Why would you let them travel east across 50 countries, two oceans, and five war zones?

I’d be quite upset about the guy in Texas that told me east would work. Show them the direction, show them the road, let them trial and error it themselves from there.

19

Well with the way you just explained it all i can say is i would be pretty upset. Well played good sir well played.

20

Happens to all of us though. I ask for second opinions all the time.