Ride Height Setup Tips

Recently I've been playing around with car setups again, and my brain struggles a bit with some aspects of the ride height setup.

I know that lower ride height is generally preferable, as it lowers the center of gravity and helps the aerodynamics of the car produce downforce. I know that if I set the car too low and it touches the ground, I get in trouble, especially in corners, and that I think I can check that in the dev apps in the telemetry app for ride height and the wings app for aero stalling.

Now I've been playing around with the BMW M235i, and taking this car as an example I'm not sure how low I should set it. There seems to be no problem with ground clearance, but afaik setting the car lower also changes my suspension geometry, but I don't know what that means for the handling.

Regarding rake angles, I know what rake is and what the effects are, but how can I discern if the car even has rake, or how much rake it has? The ride height values on the setup live screen often times show vastly different values for front and rear. Can I expect each car to start with a level rake, or is there something in the dev apps that can help me with that?

 

I'm a noob when it comes to car setup, but with suspension setup I follow the tips provided by Aris in the video linked below.

Making the ride stiff or soft seems to be the primary concern - to improve weight transfer and mechanical grip. However making the suspension stiffer for example will push the suspension geometry out of balance as a result of the car sitting higher. So in this case it is necessary to reduce the ride height to maintain optimal suspension geometry.

Also, I'm not sure if this is the right approach or not, but for cars that suffer from lift off oversteer, I stiffen the front springs (then lower to maintain geometry) to alleviate the effects of weight transfer and thus the oversteer.

Like I said, I could be wrong, but hope this helps somewhat.




Sent from my Nexus 5X using Tapatalk

 

A video on the subject made by @Nahkamarakatti

 

Not an expert of M235i but if I remember correctly that's the car that have "no dampers". Lowering the car shouldn't give you much aerodynamic benefits but you may want to do it to get the car to behave.

In general I believe the aerodynamics and suspension on race cars has been designed to work best on similar ride heights. At least it would make sense to me.

 

In the real world you always want the back end to be just slightly higher than the front end. The reason: air flow under the car.

If air escapes faster than it enters it creates a vacuum and aides in downforce. The way you do that is by making air get out the back of the car faster than it comes in the front. The way that is done most effectively is raising the back up slightly higher than the front.

People that drop the car to a perfect level normally do far more harm than good as the air can actually compress under the car and actually lift it off the ground fighting the downforce from the spoilers and making it less effective.

It's lift. That's why aircraft wings are not perfectly straight. They work on the same exact principle, only going the other way.

 

Interesting thread with a good question. I usually try and get the car as low as I can without getting into trouble over curbs and stuff. That's usually the goal, right? You'll need to adapt the rest of the available settings - lower = stiffer spring + dampers/less suspension travel/stiffer ARBs.

Last night I racet the Audi R8 2016 GT3 around Nürburgring GP and even though it was fast out of the box, I shall increase ride height (+ resulting tweaks) next time I race here - car would get very nervous across shallow curbs like in Schumacher-S where riding curbs will gain you some tenths.

About rake angle I'm not so sure...I understand that higher rear = more oversteer. But since I don't really understand that aspect of suspension setup I try and keep the angle identical while lowering the car. With hopeless cases like the default Cobra setup however, I go maximum low right away.

 

Is it simulated in AC?

Kind of useless to know if it's not simulated.

 

Realtime airflow isn't simulated but the effects it would produce are, though like with anything there's always room for improvement.

 

Are we talking about the M235i or some proper race car?

Correct me if I'm wrong but floor alone is not an aerodynamic component in AC but splitter and diffuser do have its own operational range.

Also irl airflow alone is not the magic but you also need to have a clean, non-turbulent airflow so floor has to be built underbody aerodynamics in mind.

 

@kofotsjanne
Thank you for that video link, I have something to watch at work tonight.

@Nahkamarakatti
Thank you for making this video. I just thought to myself I should subscribe to your YT channel and guess what, I've already been subscribed for several months. I just didn't know it was you Good content.

@Parminio
Thank you (yes I'm starting all these with "thank you") for this info. The problem I have is that I'm not sure where in AC I can see if my car has rake or is level. The ride height values in the setup screen are (maybe) not always helpful as they can differ by a lot in some cases.

Posing this question generally, maybe somone knows. Looking at the video by @Nahkamarakatti at around 2mins you can see the ride heigts as 69 front and 75 rear. Can I assume that is already a few millimeters of rake, or could the car be level but different reference points were used to measure ride height? Going back to the BMW M235i, it shows the standard ride heights as 109mm front and 175mm rear, thats almost 7cm difference. I understand rake is not as relevant to the BMW speceifically, I'm just trying to correctly read the values AC gives me.

 

My internet exploit using google at finding what every acronym mean on the wing app:
https://catsonslicks.wordpress.com/2017/02/25/ac-wings-dev-app/

AOA - Angle of Attack

GH – Ground Height

CL – Coefficient of Lift.

CD – Coefficient of Drag

YAW

TOT CL – Total Coefficient of Lift

@X% front – Aero Balance

TOT CD – Total Coefficient of Drag

EFF – Aero Efficiency

TOT(KG) DOWNF – Total amount of downforce in KG

TOT(KG) DRAG – Total amount of drag in KG

 

OK, now having watched the video by @Nahkamarakatti I saw that as soon as the suspension parts were stiffened completely, the ride height for front and rear were actually the same. To my understanding, the car was level at that point, so the default suspension settings actually gave the car a few millimeters of positive rake. So it seems like one could test for this in other cars, using a flat surface like the drag strip and stiffening up the suspension to get the car leveled.

 

In the wing/aero/whatever it's called app you can almost always look at the "Body" wing's AoA (which is usually measured from a 0 degree reference - unlike other wings in the app) and that will be the rake angle of the car.

 

Rake effects are "kind of" simulated on some cars. This can be seen from higher downforce multiplier when the certain aero element (splitter, front/rear diffuser) is at certain angle. However for every aero element there's height sensitivity multiplier as well, which is usually way more remarkable to get right. That's why you shouldn't think about rake effects importance at all in-game. There's clearly been intention to get rake work like IRL but it just doesn't correctly with the height sensitivity at least on cars that I've driven.

TL'DR: undertray AOA doesn't matter, height matters.

 

I don't know about Kunos cars, but on most of the stuff I've done I've been able to get within 3% of the real car over the entire aeromap (and rake is typically less important than ride height in any case)...