Ride height

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Venom
Venom
0
Joined: 01 Feb 2006, 15:20
Location: Serbia

Ride height

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I hope not to be n00b by asking this :oops:

1. What effect has ride height have on;

a) drag - reduces/increases drug
b) cornering - should increase cornering speed and handling?

2. Why is the ride height different at front and rear? Rear is a bit higher...?

It's normal that by lowering your car improves handling, that's why my car is lowered, but thats by like 30mm. To an F1 car, every mm matters, so I ask :D
The trouble with the rat-race is that even if you win, you're still a rat.

bhall
bhall
244
Joined: 28 Feb 2006, 21:26

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Two things happen when you lower a car's ride height: you lower its center of gravity and create more downforce (ground effect). Both of those mean faster cornering speeds and better handling. But the additional downforce also increases drag.

Adjusting the rear ride height of a car, making it higher than the front, is also a way of creating more downforce.

scarbs
scarbs
393
Joined: 08 Oct 2003, 09:47
Location: Hertfordshire, UK

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a) drag - reduces/increases drag
In theory lowering the car should increase drag, due the shear effect of the floor interacting with the ground, but I don’t think this is a tangible problem.
b) cornering - should increase cornering speed and handling?
Lowering an F1 car improves handling largely due to the floor\diffuser working better in ground effect. There is also a CofG advantage but again this is so tiny as not to be relevant. The ride height of an f1 car is not regulated directly, The teams could drag the plank along the ground all race, but the metal inserts in the plank would wear and these are measured after the race. Therefore smoother circuits can allow lower ride heights. But drivers and their engineers don’t like dragging the floor too much any way as this is actual contact with the ground and will slow the car. Ride height is controlled by two elements, firstly the static ride height set with the pushrods\torsion bars and then the third spring stops the car at a specified ride height at speed, this prevents the car being too low when the downforce is pressing the car down.
2. Why is the ride height different at front and rear? Rear is a bit higher...?
The rear of the car tend to have more ride height due to having more wheel travel to improve traction, plus there's the aerodynamic benefit of a floor being raked,

BTW on road cars it’s a generalization to say lowering improves the handling. On road car lowering reduces the CofG which is good, but it also required shorter and thus often harder springs, reduced wheel travel and compromised dampers (again with a shorter travel) plus the suspension geometry all goes to pot. Often with lowered road cars, the car feels quicker due to the harsher racier feeling suspension, but often are no better if not worse than standard car.

It's normal that by lowering your car improves handling, that's why my car is lowered, but that's by like 30mm. To an F1 car, every mm matters, so I ask

Lukin
Lukin
0
Joined: 21 Oct 2004, 17:34

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Yeah street racers always confuse response with handling. What you touched on is true in regard to ride height v stiffness. For anything other than a top end (ie high aero car) open wheeler the basic tuning method is lower the car until the point where the spring you need (based on the available grip level) makes the car bottom out.

As Scarbs said, in regard to mechanical grip, lowering the ride height reduces the load transfer, which maintains a smaller split between the loaded and unloaded tyres, giving a gain in overall COF. The load sensitivity of tyres dictates that what you lose in grip in the unloaded tyres, you never fully regain on the loaded tyre.

modbaraban
modbaraban
0
Joined: 05 Apr 2007, 17:44
Location: Kyiv, Ukraine

ride height - exactly...

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Can anyone tell me the absolute numbers (in cm) of F1 ride height. That's the plank-ground distance (correct me if I'm wrong). I know it's not the same for all tracks so maybe you can name the approximate highest, lowest and average front and rear ride heights used in F1 nowdays. Thanx!

scarbs
scarbs
393
Joined: 08 Oct 2003, 09:47
Location: Hertfordshire, UK

Re: ride height

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I cant find actual ride heights in my notes, I will try to dig them out.

I know suspension travel at the wheel is 25mm front and 75mm at the back. then there the tyre squash to account for. Bearing in mind these figures were gained before the front floor was stiffened, ride height could actually be less than these travel figures. The front splitter bends as ride height reaches zero and can even go into minus figures.

icef1mkd
icef1mkd
0
Joined: 25 Mar 2003, 10:07
Location: Republic of Macedonia

Re: ride height

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:lol: , modbaraban, you reminded me on one situation at Uni, -
where as (future) mechanical engineers we were teached to
operate in milimeters in (alomost) every case. When we asked why,
we were told to leave the centimeters to the civil engineers :wink:

Поздрав до Киев :wink:
"You will never know the feeling of a driver
when winning a race. The helmet hides feelings
that cannot be understood."
Ayrton Senna, November 1988

modbaraban
modbaraban
0
Joined: 05 Apr 2007, 17:44
Location: Kyiv, Ukraine

Re: ride height

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Thanx Craig. Looking forward to it.
I expected less difference in front and rear ride height :-k
icef1mkd wrote::lol: , modbaraban, you reminded me on one situation at Uni, -
where as (future) mechanical engineers we were teached to
operate in milimeters in (alomost) every case. When we asked why,
we were told to leave the centimeters to the civil engineers :wink:

Поздрав до Киев :wink:
lol I don't really care as long as it's METRIC! :lol:

Alo! :wink:

Belatti
Belatti
33
Joined: 10 Jul 2007, 21:48
Location: Argentina

Re: ride height

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F1 racing simulators do well with these ride heights:
Front: 20 to 30 mm
Rear: 35 to 55mm

Statical ride height depends too much on the type of circuit (smooth or not), height of kerbs, aero downforce, packers (which prevent car bottoming but makes suspension very very stiff when reached) and, of course, spirals and torsion bars stiffness.
"You need great passion, because everything you do with great pleasure, you do well." -Juan Manuel Fangio

"I have no idols. I admire work, dedication and competence." -Ayrton Senna

modbaraban
modbaraban
0
Joined: 05 Apr 2007, 17:44
Location: Kyiv, Ukraine

Re: ride height

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That was the reason of my question. Now that I moved from F1C to rFactor I find my the floor scraping the road at the end of the straights. And that's with the 50-70mm ride height! Same on the curbs when I happen to go too wide.

Belatti
Belatti
33
Joined: 10 Jul 2007, 21:48
Location: Argentina

Re: ride height

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Only one of the reasons ride height is bigger at rear is that Aero downforce is bigger at rear.

Mod: just increase the packers and you´ll se that your car wont scrap the road at the end of the straights. Just try to setup the car in order that packers don´t work in the highest lateral acceleration curve.
"You need great passion, because everything you do with great pleasure, you do well." -Juan Manuel Fangio

"I have no idols. I admire work, dedication and competence." -Ayrton Senna

bizadfar
bizadfar
0
Joined: 03 Jan 2007, 15:51

Re: ride height

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thats a graphical glitch in rfactor sometimes.

wack up ur 3rd springs/3rd packers and use motec plugin.

ralt12
ralt12
0
Joined: 22 Jan 2005, 06:06
Location: SoCal, USA

Re: ride height

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On our older F1 car (1988 Tyrrell 017) we use 1 1/16" front , 1 3/16" rear.

scarbs
scarbs
393
Joined: 08 Oct 2003, 09:47
Location: Hertfordshire, UK

Re: ride height

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I found some of my old info….


Static ride heights are around 30mm and 70mm, However this rake at low speeds flattens out at high speed to create something like 15mm 25mm at 150mph.

Jersey Tom
Jersey Tom
166
Joined: 29 May 2006, 20:49
Location: Huntersville, NC

Re: ride height

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Ahh, rFactor. Gotta up those springs. I get away with about 25-30mm ride height at Monaco. No bottoming, or maybe at one point just barely kisses the ground. Handles the track and curbs real well too.
Grip is a four letter word. All opinions are my own and not those of current or previous employers.