Group C cars grip under acceleration

Any group C race I don’t see anyone running a 962. Since this is an 87 per Gabriel, would/
the 89 962 have more HP, more competitive

 

I don't think it's just the differential. In a straight line, the cars don't break traction even in 1st gear, on cold tires and green track. Normally we should see some serious wheelspin in these conditions. Please see first post in this thread for videos.

 

are you talking about the 962. If so, yes it’s like a gt4

 

Sure, but you can't just model anything you want. The '87 car is the one Porsche seems to be giving away most easily for licensing because it was the last 962 that won Le Mans, they also fully stopped competing in the World Sports Prototype as a factory team mid-1987.

 

The Group C experts FB page says they did run 1.2-1.4 bar during race

 

So ams2 default is 85, how’s that related to “bar

 

The in game setting AFAIK changes how much boost pressure in percentage and not in actual pressure. So 85% is 85% of available boost pressure

 

The Porsche 962 has a big gauge right in your line of sight showing boost pressure in bar. At 85% boost it reaches just over 1 bar, and at 100% boost it reaches around 1.15 bar.

 

So the cars need more boost pressure?

 

The 962 has a visible boost gauge, which the C9 for example does not. Both have the same physics parameters for the turbo, and both reach 1.2 bar. Which is correct for the Sauber, but not for the Porsche. Maybe if it had a less effective base engine but a bigger turbo, it would have the same power but a more laggy/kicky behaviour that perhaps would appeal our userbase more?

 

So 90 in game would be about 1.4 bar

 

And now that you mention it...

The C9 bodywork that we have, is from 88 or 89? Cannot recall.

 

AFAIK 89

 

I just did a quick test with default setups and with the power ramp adjustments at Spa 2022. With the default I can understand your complaints, its a little too stable as I already mentioned as well, but I could not floor it out of the last chicane, La Source(1st gear) or Bruxelles without corrections, so it's possible to make mistakes. Reducing the power ramp did make the car a little more tricky, nothing major but a noticeable difference.

Also regarding the video I posted, as I thought Les Combes was much tighter in the 80's, it has a wider and straighter approach now, you can floor it quicker without losing traction or running out of road, so you can't compare the throttle inputs 1-1 on that corner. In the game on the 1993 version, I can floor it out of the corner but I will always run wide, so you have to control the throttle to make the corner properly.

But overall like I wrote before, I do agree that they need to lower the grip while accelerating on lower gears a tiny bit. What I don't agree is that it's impossible to make mistakes or that they feel like a GT4. Also the Porsche wanders on a straight line, dunno if it's a FFB or car problem, but it's noticeable.

 

Spot on! Day and night difference, lowered the power ramp to the minimum and now I can feel how the rear wants to step out if I give it too much throtle!

 

Kept on testing the C9. I moved to a more conventional and grippy scenario: left the date at 17/9/89, changed weather to a fixed slot of medium cloud, and set track state at medium grip.

Laptimes were faster but the grip did not change a lot. It seemed like the biggest factor was lack of wind instead of track state! Trickiest sectors with the rear end were La Source, where I could never floor it on the apex (as it should be), and if I was a bit brute when shifting up to 2nd, the car would snake tail downhill and lose time; and Les Combes, where you need to be precise with feeding enough throttle to load the rear tyres, but too much and you loop it. Rear tyres wear down faster than the fronts now, and that punctuates a tail happy car as you pound out the laps. It's good in my books, and it's more noticeable on a scenario like the one that follows...

I switched to a race oriented approach: topped the tank, fitted hard tyres, turned down boost to 60%, and did some laps to gather data. From those results, I turned boost down again to 40% (at 60 it was swallowing 4.65L per lap, producing around 750 HP), set cambers at -2.5 front and -1.0 rear, tweaked dampers, kept ride heights at minimum, set spring rates at 220 front and 250 rear, reduced one click of toe in at the rear, brought power ramp down to 45 degrees and coast ramp up to 50, and off I went for a longer run.

Power output was now down to about 685 HP, and fuel consumption was down to 4.25L. Considering Heinz Harald Frentzen's details on driving those cars in that era, when he would be instructed to save up to 20% from a given baseline, this is the right boost number for this iteration of the C9: with a 20% save the fuel per lap goes down to 3.4L, and you need to hit a 3.53L per lap number at Spa 93 to get inside the actual 1989 fuel quota rule of 51 liters per 100 km, which would be a saving of 16%.

I did not try to hit those numbers, and my kids interrupted when I was beginning to test what happened with the fuel lowering the mapping. Lapping at max pace with the described setup, best laps were on the mid 07s, when the 1989 race had a best lap from the Saubers of 07.8, presumably at an instance of no conservation taking place. Seems quite close, right?

On the surface, yes. Looking closely, not quite. We are talking about an engine baseline of 40% boost, which would be roughly 0.5 bar. The actual race baseline for this engine was 0.8 bar (should be 65% boost in game) and 770 HP. And I'm definitely no Mauro Baldi. This points out to what has been a flaw across all high performance cars in AMS2: too good aero efficiency, too much downforce for too little drag. I don't know if it's the bodywork lacking drag, the elements not generating enough, the tyres having too little rolling resistance or what. But the end result is a too effective chassis with a too ineffective engine, which yields similar laptimes in the end, but it's perhaps a tad easier than it should. For validating this, I need to repeat these tests at another, twistier track of 1989 WSPC season. Suzuka and Donington would be the best places for this.

 

Very informative post, it could indeed be a case of aero and not tires only, were all the focus is right now. But still comparing laptimes to real life should not really be a focus, there are too many variables for it to be an accurate comparison. Looking forward to what you find on less power focused circuits.

 

Agreed, I'm happy with laptimes in a ballpark of 2s more or less, personally

At one point we should all get together and have a blast with a race