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Re: BRC QuER - Hockenheim 1000 km 1976 [OPEN]

PostPosted: Mon Mar 21, 2016 6:49 am
by KLinardo
Do I go small and high specific output with lightweight or throw a Ford 427 Cammer into a car?

Hmmmmmmmmm? There's much private testing to be done!

Re: BRC QuER - Hockenheim 1000 km 1976 [OPEN]

PostPosted: Mon Mar 21, 2016 6:52 am
by squidhead
Absurdist wrote:Wheelspin at 180 is now my goal.


... you mean at 225

Re: BRC QuER - Hockenheim 1000 km 1976 [OPEN]

PostPosted: Mon Mar 21, 2016 7:13 am
by Packbat
AirJordan wrote:If someone has forgot how to do consumption calculations: Packbat's info ;)

Thanks, AirJordan!

Copy+pasting from my several posts in that thread on the subject for ready convenience:

  Code:
    Estimated Race Fuel Consumption [in kg/hr] =
                 (Engine Economy @ Max Power RPMs [in g/kWh])
                 * (Engine Power @ Max Power RPMs [in kW])
                 * 1 kg/1000 g
                 * r

"r" is the fudge factor, which varies based on a lot of vehicle design parameters I haven't figured out and based on track. As others have said before, Hockenheimring is probably a high-consumption track; a car which is on the high end relative to my formula would use something like r = 0.75, a median car about 0.64, and a low-fuel car about 0.53.

You can eyeball the numbers from the in-game graphs or read off the exact numbers for engine economy and power from the Results/Curves section of the engine variant .lua file.

For the graph method:

Image
  • Convert peak power to kW at 1 hp = 0.7457 kW if necessary. (In this case, 158 hp = 117.8 kW.)
  • At peak power RPMs (i.e. the same position on the horizontal axis), estimate the position of the fuel economy line between the gridlines of the economy graph. (In this case, about two-thirds of the way up.)
  • Interpolate using the numbers on the left side of the chart. These numbers are always measured in g/kWh, even when the number on the chart is lb/(hph), as here. (In this case: 650-350=300, 2/3*300=200, 350+200=550 g/kWh.)
  • Multiply the numbers together to get kilograms. (In this case: 117.8 kW * (550 g/kWh / 1000 g/kg) * 0.75 = 48.6 kg/hr.)

For the engine variant .lua file method, you interpret the data like this:
  Code:
       Results={
          AdjustedAFR=12.75,
          AverageCruiseEcon=453.43594397352001,
          BaseEcon=338.99330784286002,
          BaseTorque=293.31209796106998,
          BaseVE=0.93100000000000005,
          CoolingRequired=88.864391049931996,
          Curves={
    [...]
             {
                6500, -- <-- this is the engine RPMs
                199.28471402951001,
                135.65301510020001, -- <-- this is the power in kW
                523.85505501344005, -- <-- this is the economy in g/kWh
                23.536122865397001,
                RPM=6500
             } --[[table: 0x0f26e668]],
    [...]
          PeakPower=135.65301510020001,
          PeakPowerRPM=6500, -- <-- this is the RPMs for peak power (i.e. the RPMs to check in the Curves, above)
    [...]


Either way, to get fuel tank size, you can either note the first and third numbers in the body dimensions when you first select a body to get a rough estimate, or you can open the Trim .lua file and search for "Footprint" to get the exact figure. The in-game numbers are meters, so just multiply them together and take the product times 10; the numbers in the .lua file are centimeters, so multiply the dimensions, divide by 10000 (m^2/cm^2), and multiply by 10.

Edit: Correcting fuel tank size - thanks, Der Bayer!

Re: BRC QuER - Hockenheim 1000 km 1976 [OPEN]

PostPosted: Mon Mar 21, 2016 7:15 am
by AirJordan
squidhead wrote:
Absurdist wrote:Wheelspin at 180 is now my goal.


... you mean at 225

What are you doing man :lol: do you run like 400hp FR with 165 tyres?

Re: BRC QuER - Hockenheim 1000 km 1976 [OPEN]

PostPosted: Mon Mar 21, 2016 7:20 am
by Der Bayer
Two additions to Packbat's post:

The race time now is not 1,5h but 1000km which is ~ 6 hours. The factor for tanksize (footprint * x) is not 7 anymore but 10. I don't know how good the estimation is for turbos because of a totally different torque curve and thus BSFC graph.

Re: BRC QuER - Hockenheim 1000 km 1976 [OPEN]

PostPosted: Mon Mar 21, 2016 7:24 am
by squidhead
AirJordan wrote:
squidhead wrote:
Absurdist wrote:Wheelspin at 180 is now my goal.


... you mean at 225

What are you doing man :lol: do you run like 400hp FR with 165 tyres?


I might have an engine output measured in 4 digits
I'm backing down now, since I noticed that at 250kph the driver uses about 30% throttle.

Re: BRC QuER - Hockenheim 1000 km 1976 [OPEN]

PostPosted: Mon Mar 21, 2016 7:30 am
by DeusExMackia
Just as a rough ball-park, what sort of HP does everyone's engines have? I'm currently in the 250bhp range but not sure if that's enough or too much.

Re: BRC QuER - Hockenheim 1000 km 1976 [OPEN]

PostPosted: Mon Mar 21, 2016 7:33 am
by Denta
DeusExMackia wrote:Just as a rough ball-park, what sort of HP does everyone's engines have? I'm currently in the 250bhp range but not sure if that's enough or too much.


340HP with horrible fuel economy but still cant pass below 2:24

Re: BRC QuER - Hockenheim 1000 km 1976 [OPEN]

PostPosted: Mon Mar 21, 2016 7:36 am
by AirJordan
Der Bayer, for test session, what to do with strategy in brctool? R1? sprint or endurance? Q yes no?

squidhead wrote:I might have an engine output measured in 4 digits
I'm backing down now, since I noticed that at 250kph the driver uses about 30% throttle.

4 digits?!?!? shit... and your consumption? :lol:

EDIT: I am at 440 and 2.22

Re: BRC QuER - Hockenheim 1000 km 1976 [OPEN]

PostPosted: Mon Mar 21, 2016 7:37 am
by GenJeFT
A little south of 700 And somehow got 31 drivability.

Also a insane top speed.

I still dont break 2.21 recommended time with Turbos on this track (smash it in the automation test track).

Re: BRC QuER - Hockenheim 1000 km 1976 [OPEN]

PostPosted: Mon Mar 21, 2016 7:50 am
by BobLoblaw
Vri404 wrote:Just wondering, would it be possible to enter a van?

I have plans, is all...

I was debating doing that as a novelty, but you beat me to it.


Also a question, is there any restriction on fuel type?

Re: BRC QuER - Hockenheim 1000 km 1976 [OPEN]

PostPosted: Mon Mar 21, 2016 7:56 am
by TheBobWiley
Pushed 288 from a turbo'd 1.8L I6...... I am now building something with a little more oomph.... Power is king on this track
EDIT: was getting 2:26 flat with this engine around Hockenheim... I thought I was doing good :cry:

Re: BRC QuER - Hockenheim 1000 km 1976 [OPEN]

PostPosted: Mon Mar 21, 2016 8:07 am
by DeusExMackia
Ok, so update from the ErinSport garage, they aren't using turbos because "they're too annoying to setup". N/A all the way now!

I'm onto ~470 bhp with no suspension tuning and I'm getting a 2:27 around Hockenheim.

Re: BRC QuER - Hockenheim 1000 km 1976 [OPEN]

PostPosted: Mon Mar 21, 2016 8:17 am
by squidhead
AirJordan wrote:4 digits?!?!? shit... and your consumption? :lol:


.... ehm... reasonable? About 39l/100km

Re: BRC QuER - Hockenheim 1000 km 1976 [OPEN]

PostPosted: Mon Mar 21, 2016 8:24 am
by Der Bayer
Because of the expected surprises in the practise session I will open up the challenge for 2 cars per player. Use that possibility to directly compare your cars.

If the two cars of each player will be entered into the race, too, still must be determined. This will depend on the total number of cars.