Rank: D-Class Racing License
#1 Posted : Saturday, November 4, 2017 9:24:21 PM(UTC)
Hey y’all. I love driving old light cars in forza such as the Meyers manx and the fiat esse-esse. The problem I’m having is that these cars love to body roll and lift the inside tires. Does anyone know how to tune suspension to reduce this?
Rank: B-Class Racing License
#2 Posted : Sunday, November 5, 2017 8:05:42 AM(UTC)
Full race suspension, anti roll bars, cage installed?
Rank: D-Class Racing License
#3 Posted : Sunday, November 5, 2017 8:49:44 AM(UTC)
Yes to all of those. I’ve tried adjusting ride height, roll bar settings, damping. Only lowering the ride height seemed to make a difference.
Rank: C-Class Racing License
#4 Posted : Sunday, November 5, 2017 6:16:24 PM(UTC)
Could you describe a specific situation where it's happening? With or without curbing?

When I've had this problem in the past the car would want to go up on two wheels after hitting curbing on the inside. I'd check the suspension travel telemetry screen and the inside wouldn't bottom out, as the bump was absorbed, but it would still launch up on two wheels. If this is what's happening to you, reduce antirollbar stiffness until the wheels stop lifting. Then play with spring and damper stiffness to ensure that the bumps are absorbed without letting the car bottom out.

Another situation where this can happen is if you check the telemetry screen and it completely bottoms out before the tires leave the ground. In this case it's probably some mix of not enough spring rate, not enough bump dampening, too much rebound dampening, and ride height set too low. If the car is soaked to the ground, raise it and see what happens. Then start increasing the spring rate a bit at a time, and then move on to increasing bump dampening stiffness to prevent it from bottoming out or reduce rebound stiffness so the wheel can rebound faster and keep contact with the road.
Rank: D-Class Racing License
#5 Posted : Monday, November 6, 2017 2:58:16 AM(UTC)
Each of the cars (fiat 500 esse-esse, Meyers Manx, mercury coupe) lift the inside wheels without any curbing. I’ll try your methods and report back. After that I’ll put the street and sport suspensions on and watch the telemetry. Thanks for the help everyone.

Edited by user Monday, November 6, 2017 3:00:41 AM(UTC)  | Reason: Not specified

Rank: D-Class Racing License
#6 Posted : Wednesday, November 8, 2017 4:13:55 AM(UTC)
Okay so I didn’t find a fix for the wheel lifting but after much testing and tuning, stiffening the suspension and lower the ride height to the minimum helped a lot. I believe the older cars have too flexible of a chassis and / or too much grip for their chassis. The Mercury now lifts only on high speed turns, chicanes, or turn exit.....so still all the time but the severity is lessened. Previously the car would lift and slam the ground multiple times in one turn. Now it only does it once.
Rank: B-Class Racing License
#7 Posted : Wednesday, November 8, 2017 7:18:22 AM(UTC)
Out of interest: can you provide following data for the mercury:
- weight & weight distribution
- tire compound and tire widths front & rear
- installed chassis reinforcement upgrade
- installed aero kits and aero levels front & rear

Or better yet provide the whole build. I'd like to give it a shot.

Any particular track?

Edited by user Wednesday, November 8, 2017 10:15:58 AM(UTC)  | Reason: Not specified

Rank: D-Class Racing License
#8 Posted : Wednesday, November 8, 2017 3:58:37 PM(UTC)
Upgrades:

Engine 6.2L w/ supercharger
Intake- race
Intake manifold - Race
Fuel - stock
Ignition- stock
Exhaust - race
Camshaft- stock
Valves- Street
Engine block- race
Pistons- stock
Supercharger -race
Oil / cooling - race
Flywheel -race

Suspension category
All race

Transmission category
All race

Tires
Race tire
Widest possible front and back
Wheels - Speedline F1
Wheel size -stock

Aero
Front-adjustable wing
Rear wing-adjustable wing
Rear bumper - removed
Side skirts- Street
Hood- stock

Gearing
Tire Pressure
Alignment
ARBs
Springs
Dampers
Rebound
Front 6.3
Rear 6.3
Bound
Front 4.2
Rear 4.2
Aero
Brakes
Differential

Edited by user Wednesday, November 8, 2017 4:23:10 PM(UTC)  | Reason: Not specified

Rank: B-Class Racing License
#9 Posted : Wednesday, November 8, 2017 9:18:51 PM(UTC)
Thankss will check it out and report back.

Not sure what’s on the pictures but it gives a „please update your account to enable 3rd party hosting“ error for me.

Edited by user Wednesday, November 8, 2017 9:20:52 PM(UTC)  | Reason: Not specified

Rank: On the Podium
#10 Posted : Thursday, November 9, 2017 10:34:18 AM(UTC)
Originally Posted by: fifty inch Go to Quoted Post
Thankss will check it out and report back.

Not sure what’s on the pictures but it gives a „please update your account to enable 3rd party hosting“ error for me.


It's not you, it's photobucket. This is an issue on another forum I frequent. If I recall you basically have to pay in order to have the right to share pictures saved on that site.
Rank: On the Podium
#11 Posted : Thursday, November 9, 2017 10:41:27 AM(UTC)
Increase front spring stiffness by a lot. Try something extreme. Maybe not max but maybe 75% of what the game allows.

Lower spring stiffness = more bouncy
Higher spring stiffness = less bouncy

I'm talking about in the extremes only.


Rank: On the Podium
#12 Posted : Thursday, November 9, 2017 3:01:12 PM(UTC)
.
What are you trying to get out of the Mercury Coupe? (Class & track?) Seems like a bullet that you are trying to build! When I try to put the build together I have several options per your writeup... Is it the Centrifugal SuperCharger that you are using??? Seems more of a Drag build.

Could try to replicate issue if you provide a couple of more details. Thank you!

PRKid
.


DJ Saoco
Rank: S-Class Racing License
#13 Posted : Thursday, November 9, 2017 6:20:05 PM(UTC)
1. go harder rear springs
2. go highter rear ride hight
3. go softer front springs
4. go lower front ride height
5. Go softer sway bars.

Edited by user Thursday, November 9, 2017 6:20:56 PM(UTC)  | Reason: Not specified

Rank: C-Class Racing License
 1 user liked this post.
#14 Posted : Thursday, November 9, 2017 7:14:52 PM(UTC)
Sounds to me like traction roll. Too much grip for the narrow wheel base and high center of gravity. You can't make the car wider so minimum ride height and less tire. Messing with springs, bars, and dampers will change which wheel lifts and how long it takes to lift but if the problem is traction roll the only solution is less grip at min ride height.

Maximum downforce may keep it from lifting but it might also increase the grip making the situation worse. More un-sprung weight that can't be transferred off the inside tires may help (big heavy wheels and stock brakes). You might also try low bump and high rebound to jack the center of gravity down but it is still going to be tipsy over curbs and when unloaded cresting hills.

In FM5 the trick was drag slicks to kill the lateral grip without loosing the better than race compound strait-line traction during acceleration and braking. Drag slicks never seemed to work as good in FM6 and I haven't experimented with them in FM7. Ditch the race compound and add more power.

Crash
Rank: R-Class Racing License
 1 user liked this post.
#15 Posted : Thursday, November 9, 2017 10:35:40 PM(UTC)
Only way to really mitigate that is to drop the ride height. Nothing you can do with springs will help you here because if the wheel's off the ground the spring isn't doing anything. It's a center of gravity and roll center height problem and since we can't change the roll center all we can do is drop the CofG as much as possible by lowering the ride height.

Also if it's the inside rear wheel with these cars then that's not an issue at all, if anything it's probably helping you to get the car to turn.

Something else that will help you during this scenario is to increase the accel/decel settings on your diff to give you more lock up during these scenarios.
Rank: S-Class Racing License
 1 user liked this post.
#16 Posted : Friday, November 10, 2017 11:24:31 AM(UTC)
Actually I have battled with what I would guess it the same issue with my offroad Buggies some SUV's Abarth 595 etc...
What you get is essentially a grip roll. If it is ONLY front axle where the wheels lift you can combat it with
1. Softening front rebound.
2. Softening front suspension
3. Softening front ARB & Stiffening rear ARB
4. Reducing front camber.
Lift the front if it's a must, as now the frond dips deeper while turning.
This does generate more understeer, but it should tame the car enough to make it stop

If all else fails, you might have to use skinnier front tire, or drop down on tire compound, as the issue you are having is essentially grip roll, therefore reducing grip reduces the roll.
Proud member of Hard Luck Racing.

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Rank: Driver's License
#17 Posted : Sunday, September 12, 2021 3:38:36 AM(UTC)
Originally Posted by: HLR Juggernaut Go to Quoted Post
Actually I have battled with what I would guess it the same issue with my offroad Buggies some SUV's Abarth 595 etc...
What you get is essentially a grip roll. If it is ONLY front axle where the wheels lift you can combat it with
1. Softening front rebound.
2. Softening front suspension
3. Softening front ARB & Stiffening rear ARB
4. Reducing front camber.
Lift the front if it's a must, as now the frond dips deeper while turning.
This does generate more understeer, but it should tame the car enough to make it stop

If all else fails, you might have to use skinnier front tire, or drop down on tire compound, as the issue you are having is essentially grip roll, therefore reducing grip reduces the roll.


yea ran in to the same issue with my 71 GT-R i had a awd build that just went on 3 wheels for almost no reason, but i also had a RWD that i recently took a interest in, bit tricky to drive so i started tweaking it, when i was most happy with the grip level's the accelerator turned in to a tripod mode activation switch though as i could suddenly put my power down (S class build with ~750hp, fun on the bun...unless it slams that power in to the ground lifting one of your front side's and sending you in to the wall :P)

i'll have to try your suggestions, my initial thought was stiffening up the rear so it wouldn't move down under power as much but this....eliminated the turning advantage i just manged to tweak in so back to tinkering :P (it went from pretty good low speed turning, to turning on a dime, to barely turning :P when i reduced but did not eliminate the grip roll?
Rank: Driver's License
#18 Posted : Wednesday, September 22, 2021 6:26:34 AM(UTC)
@OP:

I know it is a solution that you will not like but it is the one there is, that or dealing with the uprising.
Based on your setup your car is extra hard and is behaving like a "Go-Kart". To solve this you must raise the ride height and soften the suspension and ARBs at the end where it rises. go step by step on each change until reach your confort zone.

Edited by user Wednesday, September 22, 2021 6:29:34 AM(UTC)  | Reason: Not specified

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