So my first two tunes were somewhat pretty straight forward since I focused on the Indy Oval (for the BRZ and Eclipse D-class cars) and these both turned out to be pretty good with one landing in the Top 35 and the other Top 25. Now, I am venturing into a challenge with a more complex track, Catalunya National. I built a 1981 BMW M1 targeting the A-class and it seems to be in reasonably shape with the exception of this problem for which I’ve tried many things. I am actually getting a little confused with many of the posts I read whereas so folks suggest performing a setting change in the opposite direction to what others describe for the same problem described by the OP’s.
So, on to my problem…the car basically oversteers at corner-exit as soon as I start applying additional throttle. In some of the turns I have also experienced this mid way through the turn (last turn prior to straight / home stretch). I have ensured the throttle control is on check - even at relatively low speeds the issue surfaces. I have played around with the ARBs, Springs, Aero (min front/max rear, and, max front/min rear), and Accel/Decel (Accel range 10-60, Decel range 10-40) per many of the suggestions in the Forum’s threads w/o any luck. Any ideas/thoughts would be appreciated! Thank you!
A700, 5.2L V10 with Centrifugal Supercharger, HP 611, Torque 418, 2617 lbs (46%), 7.3/5.7/9.0/8.9/6.1
What are these numbers? What’s your spring rate and ride height.
It’s possible that with that amount of torque the rear is squatting heavily for RWD on application of the throttle skewing your camber and all sorts so offer some resistance. Try a front bump of between 2-3 and a rear between 4-5. Try rebound front between 11-13 and a rear rebound between 8-10. One click up on rear ride height from min and 2 clicks up for front. Rear camber slightly higher than front and decel slightly higher than accel on diff. Max aero f/r with rear tyre pressure slightly lower than front.
That’s a random setup based on not a lot of info but may work.
The build is currently looking like this…
Tp 29/28.5
C/T/C -3.3 / -2.8, 0/0, 6.5
ARBs 28.00 / 8.00
S 400.1 / 490.1
R/B 10.3 / 12.1, 2.2 / 3.4
Aero 50 / 200
Braking 65 / 160
Diff 30 / 15
ToOSk3tChY – Thanks for the fdbk! As you can see the Bump numbers are in the range as you suggest, except maybe the rear. The rebound is backward in my case for the range. I have not played at all with the ride height. By the way, I did try the Diff Decel higher than the Accel setting yet similar results. It could have been the combination of settings I had at that time. I’ll give these ideas a try again in a different combo/setup.
People offer what sometimes seems conflicting advice because there’s often more than one way to arrive at the same nett result. Post your setup. If there’s a howler there someone will spot it, otherwise I’m sure someone will build one up to help suss out the problem.
Yeah the ride height will shift some more weight rearward but with a stiffer rear spring and bump it should offer some balance and also promotes understeer, which is good if you’re oversteering with added benefit of taking those curbs better. It’s not common to use a high accel on RWD but a higher accel than what you have may offer more grip capabilities on throttle so long as you balance the decel with it so it’s not terrifying when your controlling throttle off and on through the corners.
Max out the downforce on the front, you will need full downforce a class and especially with that car/track choice.
Your tune seems good, I see a couple of your issues however. Your rear end is to stiff and your front is way to soft. Flip your springs around 490-550 range on the front 400-450 on the rear.
Drop the caster back to default, it’s not worth it, has little to no effect.
Diff is fine, maybe drop the rear to 10%
Rebound ( whatever the top option is ) the gap is slightly to big I would go around 11.5/11.0 F/R
Not sure if 65 is the brake bias because I don’t think I’ve seen that before.
I have basically no idea on the technical side I just work by the numbers. Looking at your tune your is to soft in the front and to me a soft front and a stiff rear will give you more front end grip, which is exactly what you have. Stiffen the front and soften the rear you’ll get rear grip. Your arbs seem to be in the right place if you’re having over steer issues. Give it a go it might work or it might not!
Thanks buddy! Will check this out for sure. I have a couple of hrs to play with it in a little bit. On the Diff, on one of Worm’s threads he suggests (for Mid-Engine, RWD) settings for Accel between 20-50% and Decel 10-50% which are pretty wide ranges. I also read, and as you suggested, to set the Accel lower than the Decel.
Thanks Crav! I’ll check these out. I have played with full downforce on the front, yet, it seems I need to do a little “combo” change to hit the right range, then, tweaks from there. I’ll do some testing and report back for further advice/insights.
Caster - yeah, I have not noticed any impact so I’ll take to default.
When you say drop the “rear” to 10% on the Diff, are you referring to Accel or Decel?
I’ll test the Reb closer together.
The 65% is the brake bias. For some reason, I tested to ensure the brakes/tires were getting red (about same temp) and arrived at this setting. How do you best test for this setting? I want to make sure I can turn the car effectively. Sometimes I have noticed if it is too low, the car keeps going straight an not turn on me. Thoughts?
Well I just typed out a big response to help you and the forum malfunctioned.
So I’ll do the short version
Camber increase Front 2.5-3.0 Rear 2.0-2.5
Accel decrease: 30-40%
ARBs: 20F/10R
Brake bias: 48% (2 clicks to the right)
No Toe. It is forbidden unless its a AWD or FWD… or a hummer
Now I’ve already wrote this once so here it goes again! Note: I’m a terrible teacher/explainer.
First Issue: Your car was oversteering exiting corner.
Problem: The front was to good for the rear - > Cars front end was too soft and the rear was to stiff
Solution: Stiffen the Front and soften the Rear of everything → Decreases Front grip and increases Rear grip
Now since you said that has helped a lot, your new issue that it is understeering through the S’s But it is still good through exiting corners.
This is going to be because your ARBs and springs are now outrageously crazy on the Front.
Second issue: Understeers through quick correctional corners
Problem: The Rear is now to good for the Front - > Cars Front end is to stiff and has less Flex creating the car to not be able to turn more. Rear is to soft and is flexing to much causing contact with ground more easily. More contact = more grip. → More rear grip causing the front end to push. → More understeer.
Solution: Decrease the stiffness of your Front springs less and less to you find a good point. (DO not go less on the front springs because Issue 1 will happen again)
Decrease the Stiffness of your Front ARBS a lot (18-20 range) and increase your Rear ARBs to (10-14 range) It will help with the turn-in speed.
You need to sacrifice a little of the rear grip you have to the front and just find the sweet spot. I hope this helps!
Crav – I forgot to ask…are these setting relative to the initial settings I posted, OR, the build/tune that was developed with reaper mech? Just to make sure I test the right build & tune combo. Thanks!
Thanks for the follow-up Crav! I am currently testing 2 setup versions, and, will modify my first version (the one in which I was able to get rid of the oversteer at corner-exit) with your recommendations. It’s been along day, yet, I’ll keep at it for a little longer tonight. These fun things get me excited and it’s hard to take a break, yet, I need it! The springs change was a key factor. Now, it requires getting rid of these other little annoying items, and to your point, tweak until a “happy” medium is found. Again, thanks!
I would say soften rear springs, soften the rear rebound or raise the front.
Also, could be to do with the build, the car is fairly light, and you have over 600 hp. no matter what you are going to require a lot of patience and good throttle control.
Thanks Torrider! I am checking these out as I multi-task wight he Forum as well.
As far as the build/HP, you are correct…however, I sort of did this somewhat intentional to see how much I can push this vector. I actually had more HP in an initial build and had to back off. This one seems a lot better and I think I can get a tune, along with throttle control to meet it’s driving/performance needs.
bump settings are too low anyway (I do not care for the ridiculous 1-13 settings others suggest) but increase front bump by 0.3 increments and see if the issue starts to go away. Don’t get carried away with massively over damped settings though so if you’re getting into the 8+ region I’ll suggest something else.
oh and careful with the diff setting, too high is better than too low, at least when it’s high the oversteer is predictable, when it’s too low the car handling is very unpredictable and in some long corners downright horrible.
Thanks Christian! Yes, the front bump does appear to be too low. Currently testing somewhat higher setting.
When you say “massively over damped settings”, are you referring to the Rebound? It seems, the majority of threads suggest 10 and above for Forza 5 (the least I have seen posted is in the 8-9 range)!
On the Diff “too high is better than too low”, are you referring to such in a relative measure? Or meaning to actually (absolute) have higher numbers? And, if so, for both Accel & Decel?
For Accel, it seems it is easier to feel the impact upon throttle on corner-exit, yet, I am not sure how to really feel the Decel number. Thoughts by you (or others)?
First of all, thank for all the inputs so far, it’s certainly appreciated! OK, so I have tested many of your inputs and the car results are much better as it relates to the mid-turn and corner-exit oversteer. Actually, looking great in that area. Now, I did encounter turning to be somewhat harder in the sense of the wide turns (which before was much better, easier to turn), thus, hard to stay on track at medium speeds.
So, here is what I did get “rid” of the oversteer (rear end going off) during the turns…
Softened the Rear and Stiffened the Front (Springs Rate higher in the Front than Rear), yet, kept same total on overall springs.
Increased Rear Camber 2 clicks above the Front Camber.
Set the Caster to Forza default (5.0) versus my setting of 6.5
Increased Ride Height by ONE click in Front and 2 clicks in Rear (now are at even height)
Rebound F/R closer together, set at 11.7/11.1 (before at 10.3/12.1), Front now higher.
Increased Front Bump slightly higher and Front lower, basically swapping the settings. Front now higher.
Aero maxed at 100/200 for F/R
Changed Brake to 52% balance (this one still needs work) – any ideas on how to best set this would be great.
Increased Accel Diff to 40%, set Decel to 10%
Now I will try playing with the Springs and the ARBs to ensure I can turn somewhat better and reduce turning understeer. Additional thoughts? Again, thanks!
What I was meaning was that it is better to be under damped than over damped, if you run very stiff bump settings the balance might be better but you’re giving away grip. I normally run decently high settings (5-6ish) but something like 11-12 would be overkill and ruin the handling so usually I would try adjusting something else if by that point the handling issue was still present.
Diff setting I was meaning in absolute in the context of the scale, I usually run roughly in the middle, running below 20-30 brings strange handling I find, running above 70-80 and the second you apply throttle the diff locks and the back goes. But, I find that running slightly towards the higher end gives a more predictable car and tend towards that since it suits my style better. Decel number is mainly under braking, I’ve not fully got a handle on it yet but I try to keep accel/decel roughly similar otherwise the handling can get a little bit funny in corners where you’re only lifting. I tune my cars much more for consistency than outright laptime, it’s not impossible to have both but I don’t hotlap I race so consistency is more important to me.
Point 8, is this on the incorrect forza scale? or do you mean the ACTUAL 52% and 48% rear setting?
Christian, so, I get your point about not being over-damped…yet…getting a little confused since you are mentioning “BUMP” settings and not to have them high. I have the REBOUND high and low Bump settings. I think you really mean have the rebound in the 5-6 and not high like 11-12…correct (or not!)?
On my braking balance…YES, I know the issue with the Forza scale. I am basically trying to apply more braking power to the REAR, thus, the reason for the 55%. However, I am still trying to figure out what is best!!! This car is heavy rear, RWD, and mid-engine. I do not know if there is a guideline for FWD/AWD/RWD along with weight balance to properly set the braking power/balance to Front or Rear.
Your comment on ARBs, thus, I should not mess with them for the understeer (wide turns that I am taking)? I’d like to get better turning response and not take those wide turns.
