Car setups: Tyres

ScumLord

I'm trying to get my head around car setups and from what I've read you start with tyre pressures and go from there.

I've been working off this guide for NetKar pro http://www.scribd.com/doc/49703556/MaiDireSetup-Ver-1-1-2-English and trying to apply it in rFactor2.

According to this guide if the middle of the tyre is hotter than the outsides the tyre is over inflated and it seems all the cars in rFactor have over inflated tyres in the standard setup. Although rFactor seems to have a different way of telling the temperatures it doesn't seem to be celcius.

Is there an rFactor equivalent of this guide or some where that would tell me what kind of temps I should be aiming for?

SouperComputer

Tire pressures are a can of worms and I don't have a direct answer for you, but in my experience a lot of the setup and theory with sims have been more about exploiting loopholes in the physics code than anything else. Ie what you do in real life may well be different. Example, fully locked front diff in the FWD cars LFS is the hot ticket.

Ideally you want to see near-even temps across the tread, but there are exceptions. Remember that camber will cause the inside of the tire to get hot too. Overall I would say the inside getting a "little" hot isnt too bad, but you want to keep the middle a little lower in which case you would adjust your pressure to suit.

But, you also change the spring rate of the tire when you change the pressure. Depending on the mass of the vehicle and its suspension setup, the affect of this can be large or small. This is where setup becomes less science and more art. It's cool stuff but you can get lost in it..
The other thing to consider is that the absolute fastest setup may not always feel fast, it may be effortless and actually feel slower. Or quite the opposite, it might be an absolute handful and feel impossibly undriveable.

Anyway, im going off track, but if you can get your temps near even across the tread or even a teeny bit hotter on the inside, I would call it good enough for now. I believe RFactor uses F for temps as default. You can probably change it, I'm not sure.

Have fun!

ScumLord

SouperComputer wrote: »

Ideally you want to see near-even temps across the tread, but there are exceptions. Remember that camber will cause the inside of the tire to get hot too. Overall I would say the inside getting a "little" hot isnt too bad, but you want to keep the middle a little lower in which case you would adjust your pressure to suit.

I've read that the temps should be within 10 degrees outside to inside, I'm wondering how I should deal with camber and were the cut off point is between effective camber and effective tyre pressure.

The other thing to consider is that the absolute fastest setup may not always feel fast, it may be effortless and actually feel slower. Or quite the opposite, it might be an absolute handful and feel impossibly undriveable.

I've often been surprised when fastest laps come in, it's usually after I tell myself to calm down and just get around the track without pushing too hard.

I believe RFactor uses F for temps as default. You can probably change it, I'm not sure.

The problem seems to be my mixed Irish use of measurements, we seem to use half imperial, half metric. So I understand celsius but then have to deal in inches or the other way have to deal with pressure readings that make no sense to me.

I suppose I should really concentrate more on getting consistent laps before I get too into setups, I just can't help messing with them.

SouperComputer

10degrees would be nice, of course 10degF is less than 10DegC. Stopwatch has final say of source. Sometimes the fastest laps will be done by burning off the inside of the tire, but thats useless for a race. Basically use camber to tweak the in/outer temp relationship and use pressure for the middle.

Say you had something like this on the RF
220 200 190

Then take some neg camber out
205 210 200

Then you could drop pressures a little
205 200 205

That wouldn't be bad.
The other thing to consider is that you are typically looking at your temps statically, whereas during actual cornering they may be closer to where they should be. Camber and bumps on the turns, the actual surface itself, length of straights all will sqew those readings some too.

Like I say, its a dark world that you can end up disappearing into. Get em in ballpark so that you aren't obviously overworking one part of the tyre and move onto something else.

ScumLord

Should the temps be symmetrical, or would having different pressure on each tyre only be for absolute fastest times and not worth it outside of trying to set a very fast lap?

There can be a big difference left and right on some tracks.

SouperComputer

Work towards getting them close, look at the times. Theres your answer. Sometimes its worth it... sometimes not..