HELP: Audi TT Cup understeer

[RasmusP]

Hi,
as you all can see we had some good discussions going on in the last days and the consensus was something like "Let's have a place to talk about the driving".

So here I am, creating the first of that threads:
I need some advice on fighting the understeer in the Audi TT cup
When I watch the replays I see that "the fast guys" are having a better line and when I compare it to me in detail I see they are faster while cornering, turning in point + braking is almost the same and I see no clear difference.
It's like some "magic" that pushes them tighter around.
But then sometimes I get that too... Just don't know how to do it consistently

My thoughts: when you brake you will gain grip on the front wheels. So touching the brakes slightly while cornering will give you a tighter turning radius but will also slow you down. If you brake too hard you will transfer too much weight to the front and you will get understeer.
If you accelerate you will get understeer because the front wheels lose weight and therefore grip.
If you accelerate too much you will get HEAVY understeer, because FWD...

So somewhere in between there seems to be a "trick" that lets you do the "tighter turning radius" you get when touching the brakes, but without braking and without slowing down.

Can you help out? Do I have to turn the wheel more aggressively or trail brake deeper into the corner? I don't know and before I'm spending a few hours on doing a splitscreen slow motion video, studying the details etc. (maybe I will do that either way) I just thought about asking you all and start a nice discussion about the handling of our beloved (and sometimes hated) friendly event car

 

[Kek700]

Another interesting point ( or maybe not) I have noticed this last year is that on a couple occasions racing drivers who have now got into sim racing, during a long interview have indicated during the conversation in a way that you
would easily miss the comment

" these are my words"

( once you understand how to drive in a sims)

I cannot quote who and we're this was said
and never got round to re-running the videos
or noting were these videos seen.

I just stored the statement in the back of my mind for future use.

This is probably incorrect, but it is worth stating.

 

[BhZ]

What? Where?? I thought he took up permanent residence in Simberia?

For a moment i thought the exact same thing...

 

[Kek700]

Quote

One more remark, having watched more of the split-screen footage (omfg, 40GB per lap! ):
@Kek700 is shifting too late. This is most important in 4th and 5th gears. Optimum shift speeds in 3/4/5 are about 114/154/195, but you can just download Sidekick which will get it pretty near perfect for you.
If you wait until the redline in most cars you won't feel the hit, but in this car it's a bit of a disaster cos the power curve falls soooo fast after the peak. I'd say this is worth at least 5 tenths over the whole lap, but it could be quite a bit more (hard to guess).




On lower powered cars like the TT with fixed gearing I usually do a standing 1000m drag race, first changing gear just past peak power then to red line
If there is hardly any difference in time, then I usually go for the red line.
in the case of the TT there was virtually no difference. I concluded that the drop off in torque is countered by a lower gear amplifying that torque. ( wide spread gear ratio's )

Remember changing gear should always lose some forward motion

I do not know how they treat a sequential shift
In a TT gearbox the same as a F1 box or an
TT box ?

In the real world I would take the dyno results
And compare that to each gear ratio to find
The optimum point and all the associated if's and but's of that.

But and this is a big but I do not know we're the software physics start and stop.

As I cannot be bothered with it all , i just do the 1000m drag race.

Although after Neil's comment I will look
more into this when I get back home.

See Neil's post about this from Saturday: http://www.racedepartment.com/threa...-gp-wed-12-07-17ed.137953/page-2#post-2521055

 

[Neilski]

Well, in your test you may have shifted too early if you went "just past peak power", and that could be nearly as bad as taking it to the redline. Would be interesting to see how your drag results compare if you shift at the optimum points, either by using Sidekick or just watching for the speeds I quoted above

 

[Kek700]

I'll do that

 

[Neilski]

I reported the issue on the AC forum (as you might have spotted) and it seems not to be a known problem.

@Kek700 and @RasmusP - do you know if your replays were both saved on "medium" quality, like mine? (I know it wasn't your own replay Rasmus.)
I will also change my replay quality and see if I can see the same effect in another session.

 

[RasmusP]

Yeah we should investigate that... I honestly didn't check the second replay I got sent. Simply forgot it over creating the video
Maybe you could send me your replay of yesterday? I will then check MY replay of YOUR driving against YOUR replay of YOUR driving. And the same with my driving

 

[RainhamIron]

Wa

Yeah we should investigate that... I honestly didn't check the second replay I got sent. Simply forgot it over creating the video
Maybe you could send me your replay of yesterday? I will then check MY replay of YOUR driving against YOUR replay of YOUR driving. And the same with my driving

Are you still looking for more replays? Happy to upload mine if you like. Not something I've done before, but I see in Content Manager there's a share and upload option (or something along those lines)

 

[RasmusP]

Wa

Are you still looking for more replays? Happy to upload mine if you like. Not something I've done before, but I see in Content Manager there's a share and upload option (or something along those lines)

As I didn't get 10 replays in the last 20 minutes:
yes
I have no idea what that content manager options does but you will find your replays in the documents\Assetto Corsa folder

 

[Neilski]

Yeah we should investigate that... I honestly didn't check the second replay I got sent. Simply forgot it over creating the video
Maybe you could send me your replay of yesterday? I will then check MY replay of YOUR driving against YOUR replay of YOUR driving. And the same with my driving

Sure - here are the last three laps of my replay. (I just discovered how to crop replays )
I already compared my speed with Scott's as we came out of the last bend and so I'm already sure that his speed and mine are showing up as hugely different even though we were going at the same speed (the revs match but the speeds don't).
I've set quality to "high" but won't know until after my next MP race...
If your own replay of last night is at "high" or better it'll be interesting to see how your car shows up in your own replay vs. mine.

 

[RasmusP]

Sure - here are the last three laps of my replay. (I just discovered how to crop replays )
I already compared my speed with Scott's as we came out of the last bend and so I'm already sure that his speed and mine are showing up as hugely different even though we were going at the same speed (the revs match but the speeds don't).
I've set quality to "high" but won't know until after my next MP race...
If your own replay of last night is at "high" or better it'll be interesting to see how your car shows up in your own replay vs. mine.

Have them at high! Will look into it tomorrow

 

[Nico Major]

Very interesting thread. Thx for all efforts that have been put in here!
I'd like to play around with this combo and see how it feels to me and how quickly I can get the TT around. Does someone roughly remember (or guess) the grip level when the lap in the video was done?
And, how is the grip level usually set up for club races?
Thx!

 

[Brandon Wright]

And, how is the grip level usually set up for club races?
Thx!

If you set it to Fast, 23º, and around noon that should be pretty close to what the club races usually run at.

 

[Nico Major]

I stumbled across a very nice video on YouTube that (IMO) adds verry nicely to the things that have been discussed here. (Google is so good at spying me and suggesting what to watch next ... )
It vividly presents things like "use whole track", "late appex", "setting up for accelleration out of a turn" and "preparing for last turn in combinations".