24 Hours of ATT: 1985 (DEADLINE: 24/2/2017)

The Contest

This is a competition of endurance, as you’ve probably guessed, set on the pantheon of Killrob, The Automation Test Track!

anyway, the cars will be split in to 2 seperat catergories; GT-R, and GT-P.

GT-R is the premier category for one off racers built to vie for top honors.

GT-P is the lower, more restrictive category for road based cars.

##The Rules for GT-R:

Car and engine: 1985

Up to 4000cc N/A or 2800cc Turbocharged engines

Premium Unleaded Fuel only

Min. weight of 900kg

Semi Slicks with 295 max. width

20 quality points for both engine and car, with no more than 5 per slider

Standard safety at 0 quality minimum

no negative sliders.

Rules for GT-P

Car and Engine: 1985

Up to 4000cc N/A or 2800cc Turbocharged

Standard Unleaded Fuel only

Min. Weight of 800kg

Sports Tyers with 235 max width

no racing components

cat. required

10 quality points for both engine and car with no more than 4 per slider.

no negative quality sliders

standard safety at 0 quality minimum.

no wings/lips

no downforce generating undertrays

fuel economy of 8.00L/100km or better.


i will determine laps completed by the lap times in 24 hours, with a 5 minute minimum pit stop to simulate the need for fuel, tires, driver changes and the like.

each car will provided with a 90L racing fuel tank for the race, so that will determine the stint length between pitstops.

as for retirements, i will take into account both reliability and driveability in a combined score, and roll a number generator out of 150. if the roll is lower than the combined score, you finish the race, if it’s higher, you retire.

Car Name: ATT85-forum name

Trim name is free

Engine Name: ATT85-forum name

Trim is again fee

if you have any suggestions, feel free to leave them as i would really like this to be workable.


I’m always for racing competitions, so I’ll be glad if this really happens.
Now few suggestions:

  • if it’s endurance, fuel economy and tyre wear should be a thing, otherwise there is no point in not doing just best laps
  • as for retiremets, maybe include small bumps and big bumps that add some penalty in pits so it’s not so binary
  • if you haven’t, check AMWEC '15 [Finished] because endurance has been calculated before and maybe you get there some good tips

And what stops us from making a car in year 2020?


i mean, it says 1985 in the title, but i glossed over the description


I am stupid, forgive me master


Oh hello, this looks interesting :smile:

Could be interesting. Would probably join in.

There is a big gap between NA and Turbo displacement. And it’s 1985. There is no way Turbo is going to be competitive to NA. Go for a factor between 1.2 to 1.4

EDIT: Or give the NA some penalties, like a much smaller fuel tank. And I think a fixed budget/production time would suit better.

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Really hyped for this, I’ve been waiting for such a challenge. But, I would like to echo @matti’s comments about the Turbo’s, there needs to be higher displacements to keep up.

Also, how many cars are we allowed to enter? One per class or just one overall?


hmm, i thought the disparity wouldn’t be too bad, blame F1.

but one per catergory is ok, but you can enter either or, if you so chose.

i’ll bump up the turbo cap to 2.5L and 4L rispectivly

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Is there a HP cap as well? Or can we have super high HP cars?

no hp limit, the slider limit and capacity limit should keep power figures on the more sane side, and the economy limit for the second class even more so.

How about you build some test engines and see where is the balance? Because if you don’t do that correctly, one aspiration will dominate for sure.
Also if you want to do it simple than ok, but if you want to do it big you might ask Sillyworld for his calculations. That could save you a ton of trouble.
Also before this starts, calculations/scoring needs to be defined. We need to see the math behind it :wink:


you’r right. i tested and they need to be like 3.2L and 4.5L to work

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The turbo vs n/a balancing really depends on how important fuel economy is to the challenge. 3.2L and 4.5L is pretty much similar to the brc 1976 cars for turbo and n/a, where the turbo engines had slightly more power but abysmal fuel economy.

With the better turbo tech of 1985 that fuel economy gap might close a bit.


the turbo’s have alot more tourque, but a little less power, so it should even out nicely. as for the economy, it’ll probably depend on the tune, i guess.

n/a you can probably get 120hp/l with a high revving engine, turbo should be easily past 200hp/l if fuel economy isn’t a concern.

edit: actually, trying it out, the trollercoaster-style approach gets me 780bhp from a 3.2L turbo v8, while a 4.5L n/a does 530hp.

Of course you’d have to deal with wheelspin and stuff on the turbo engine.

i’ll add an econ rating to curtail that. 12L/100km sound good?

Why not have the fuel guzzlers spend more time in the pits?


this is a little more tricky than i thought in regards to fueling.

also, to stop the boost cars going mad in GT-R, how about a 6 cylinder limit? i want this to be a fair fight.