Hi all,
I really like the smaller formula cars like the indy lights and the renault 3.5 world series.
So as I am trying to get the car set up for Spa, I can’t seem to get rid of the high speed oversteer.
The back an keeps stepping out of line way to easy and i really tried a lot of settings with
soft rear roll bars or very little acceleration diff but nothing seems to get it.
Any help, thoughts or tips to get is sorted out.
Thanks!
What part of the track do you face the oversteer? Is it too twitchy all of the time?
Downforce in the rear is important, even in high speed circuits like Spa, but a rear bias will cause some major understeer, especially in the second half of the course.
First off, adjust your brake bias. Single seaters like that will have some serious lift off oversteer if you have low downforce with a front bias.
Remember, even in road cars, the rear brakes eases the braking before the front takes over, in order to prevent the car from nose diving. If your back end goes light under braking, you’ll face oversteer.
Of course, there are lots of other things to keep in mind, but that’s one factor a lot of people overlook, so I thought I’d pitch in.
I softened the springs all around then dropped the rear ARB 1.4. Try running the higher bump settings on the car and lower rebound. That really worked for me and get the decel on the diff a bit higher.
Camber F= -3.2 R= -2.4
Rebound F= 2.5 R= 2.1
Bump F/R= 12
Aero F= 750 R= 1025
Diff decel= 35%
Give that a try and see if it works for you.
Seems that the caster was the problem, I was way to carful with that.
Also braking wasn’t the problem, brake bias is very easy to detect by
hard braking form high speed in to a slow corner. But that was fine.
Also still seems strange to run so much downforce on a high speed
track I’m running a combined downforce of over 900kg.
The big problem still however is the 190 degree turn in 5th gear it
starts fine but half way trough it seems to lose grip. And oversteers.
It is easily recoverable but as you can guess I lose about 150 KPH.
So do I go more downforce, more understeer options or just chicken
out and slow down?
If you want to stop the backend stepping out at high speed just lower the front downforce to the minimum and increase the rear until it stops. You’ll have to play around with the rest of the car to compensate but that’s the simplest solution.
This is THE solution.
I was running this very car at Spa for few days (just happen to be there) and the car is EXCELLENT for this track once the downforce has been sorted out.
The problem with this car is that the rear downforce is very high compared to the front. A short run at Indy Oval would confirm this; the default set-up oversteers horribly there.
The front downforce should be 50% or less than the rear but rear has to be fairly high, 1150 lbs or more. At 1100 lbs, the rear end starts to slip through high speed corners.
2:05.6 at Spa. My tune is shared: full throttle through Eau Rouge and a short lift before double left hander Pouhon. It feels like this car was designed for Spa.
edit
I have found using more negative chamber in the rear than front helps!
It’s not that much downforce the car still has a top speed of 186 mph and runs in to the chicane at 174 mph. The car has a ton of front grip and the nose likes to dive when you lift off or touch the brakes witch unloads the back of the car. I also don’t like a sketchy loose car so that’s just what works for me, sorry if it didn’t help.
I have a setup that seems pretty planted in the back end, I shared it if anyone is interested in trying it.
I did notice that cars with a more rearwad weight % need more rear downforce. I am still testing it.
Makes total sense if you think of it as a pendulum trying to carry its inertia around.
For this car all i did was rear wing full and front was left untocuhed at halfway.
I fiddled a bit more to get a touch more top end.