Need help on the Porsche 718 Boxster S w/ PDK

When I did a quick test of his track/car combo and posted in one of the other threads I did 1:54 on street tyres at 98% grip. I don't really know the track well though so there maybe 1 or 2 seconds left on the table. I think slow is 95-97% so probably 1:54-1:56...ish.

 

I don't know what RSR is. However, my goal has been to get the sim as close as I could to the actual and use that as a training aid to improve. So, my initial goal is to match my real times and to know why I match so I can then begin to use the sim to improve my lap times. Therefore, I do want to go fast(er).

I'm doing this by adjusting settings that can actually slow the car down. Two obvious ones are adjusting the camber to match my car and using slow to match my track. I also adjust ambient temperatures and so on. With everything set to optimum I have lapped PIRC under two minutes, which is not realistic for my car. As things stand now I am doing around 2:07-2:09, which is about what I actually do. Once I get comfortable with that and understand what is going on I can start to improve. I once did 2:04.5 but don't really know how I accomplished that. I'd like to find out!

My problem, and the reason I started to use AC, is I may get only 10 days at the track in a year but I can get the equivalent of one day every day in less than 90 minutes in the sim. Trying to learn how to improve on the track is difficult, tedious and may not even be possibles in the long run. Noticeable improvement is possible in the sim in a few days.

 

Hate to say it but your goal is pointless. AC doesn't have your car. You keep saying "All goodsies, it feels very close to my car" but you could possibly do that to ACs Lotus Elise or the 458 Italia by adjusting all factors available.

If the 718 is the closest car in AC to your RL car, take it and go as fast as you can with it. Use the fastest setup. Tweaking all available factors to make it match the feel of your car and then taking the lap times (not even compared to AC's fast guys) is an absolutely non-systematic approach.

The majority of thread participants tells you that your approach is misleading and wrong - why don't you accept it?

 

Because what I am trying to do probably isn't what others are trying to do. As I said, the ONLY reason I decided to go with simulators at all was because AC had a car that was similar to mine and a mod of my local track. My goals don't have to match everybody else. They just have to meet my needs. If I can't do that I will abandon AC but right now I am pretty happy with the results I am getting. Just considering some of the ideas from this thread is getting me closer.

I suppose, as you say, I could tweak any car to try to match mine but starting with the 718 is a heck of a lot easier and may actually be achievable.

I know some folks just want to try all the cars they can on all the tracks they can and that's okay, but it's not me. Ditto tweaking the 718 to get the best possible results. I've had the same discussion with folks who think I should modify my car to get faster lap times. That's not what I'm after. I want to learn to get the best results I can with the car I have. This may be equally weird for all drivers but it makes sense to me.

 

There's nothing to match, just go fast. If you manage going faster and faster with the same car/conditions it means you're actually improving. Set the thing so it drives alright and just do laps.

 

You can try then to mod the car , for personal use of course since it will fail to enter a server and also because it is forbidden by kunos to alter official car.
You can try to ask for someone by pm to give him your dyno from your engine or similar and make the 718 with less torque on higher revs.
In that way you will get an even closer car to yours.

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Hi bob

I too have a cayman 981, mine is a Gts, I too have been using ac as a training tool
Now I also use it to understand more about the car dynamic

The reason why the car is so loose under hard braking is that the rear toes out a lot under braking (rear goes in droop)

Try setting rear toe to 0.16-0.17deg toe in per wheel




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Thanks, but I think I finally have that under control. I've got the alignment set as close to my R as I can get. I now find if set the track to "slow" I get very comparable lap times. When it was "optimum" I was getting times I would never see in real life.

I still have an oversteer problem but I am working on that as well. Although the R uses the same pressure all around, I find dropping the front of the 718 by 2-4# (still experimenting) really helps.

There are two schools of opposite thought on this and both seem to have pretty sound arguments, but my own experience over 60 years is to raise the pressure at the end losing traction relative to the other end. In this case, since the rear is as high as I want to go, I am lowering the front. Yes, I know many would council the opposite but this works for me.

 

I guess there's three schools then, cause I just dont use pressures to control the balance period.

 

You may want to consider it. It doesn't make a major difference but it helps, at least on actual cars. The sims seem to be pretty good out of the box, and pressure changes don't seem to have as much impact. BTW, does anybody know why the beginning pressures on most cars are so low compared to the pressures from tire pressure engineer? I haven't noticed a lot of difference between the two which got me wondering.

 

On my track car I can raise or lower the car, in this case I'd do the rear since it wont mess the alignment as much. Can also do swaybars, but thats too extreme.

Pressures for me are meant to make the tyres work properly and get the laptimes. Not band-aid the balance, which frankly most of the time people do it to compensate bad driving. I know my setup wont change from track to track.

One exception being a FWD car, but for more reasons than that.

 

I think we're probably saying the same thing. I don't use a pyrometer at the track but in my experience when the tires are working properly the car grips and feels balanced. I haven't had to jiggle the front/rear but I've frequently added or removed a pound or two all around depending on ambient temperature.

I was speaking more of street cars where my experience, especially with American cars (older ones actually), is that the manufacturers seem to be aiming at something other than balance and 2-3# in the front of a front engine car compared to the rear produced a much more balanced feel. European cars, at least Porsches and Audis, recommend pressures that are pretty much ideal. My R is 32# all around and the A7 is 35#/32# and I've never seen a reason to change that relationship, although as I said, I will almost always have to add or deduct some pressure at the track.

 

32# hot or cold ? Seems like a lot if that's cold, at least on performance tyres and with the fitment it has. On the street sure.

 

That is the recommended cold pressure. On the track I used to try to run at about 36# hot but last week I discovered 35# is a little better. In hot weather that means dropping about 5#. Starting at 27# seems a bit low so I usually drop a couple of pounds to start and then bleed off more after the first session if that is warranted. If ambient is around 55° I may end up not having to do anything.

BTW, "slow" track is the closest I have come to actually duplicating the track I run on in AC. Th 718, GT4 and GT4 ClubSport are all within a second or two of what I do or have seen others do. The differences are probably mostly due to talent, less in my case, more in others.

 

35# hot seems a little more realistic haha.

 

Not sure why the haha! Most folks have said 36-37#. I just tried 35# to see what would happen. 35-36# is about where I get on the street if I start at 32# cold.

 

I may have been wrong about this. Slicks and semi-slicks seem to be very close. Street tires, at least for the 718, are about 8# low. That, BTW, is around 32/33, pretty close to actual cold pressures. Also, they seem to work better at the lower pressure which makes me wonder how useful the app is for street tires. Any opinions?

 

Well, obviously it depends on tyres a bit but most of the time Cup 2s and the like are ran at 30-32psi hot. But then as I said it depends, and also on wheel width, profile, alignment, etc. And then also if you're going for laptimes or "best wear" possible.

 

I will keep that in mind if I ever get a GT4 . My tires start at 32# cold but even on the street on a warm day they can get up to 37#. I always tried to keep them under 37# on the track, but I'm finding a little lower is better and 35# is noticeably better than 36#. I couldn't believe I could actually feel that!

 

This is for the newbies like me. Old timers have already figured this out but aren't on our plain anymore.

I've discovered the problem seems to be related to tire pressure and track specs.

First, if like me, you are trying to duplicate an actual track experience, at least as much as possible given the differences in sims vs. actual track driving, then a "slow" track will be much closer than an "optimum" track.

Second, for some reason, AC thinks street tires on a Porsche 718 ought to be 40# in front and 41# in the rear, hot. I tried it because that was what was suggested in tire pressure engineer, but it is way too high. I usually run 35/35 hot on track and that actually works very well in AC. It may not be perfect but it is a better place to start. Tire pressure engineer can change the recommended pressures using the +/- buttons and it remembers. I set it to 35/35.

Finally, given the lack of g-forces and other inputs you get on the track, it is easy to overdrive a corner leading to pushing off or spinning. Getting this right is as much a learning experience as getting it right on track.

In the end, if I set the alignment to match my R, set the track to slow and run 35/35 hot, my lap times, on tracks I know, are comparable to actual lap times and the car is just as controllable as my actual car. That, rather than going as fast as I can, was my goal. I now have a base for experimenting and improving.