Cars F1 1975 HE V1.1 2017-01-25

[PLAYLIFE]

Very cool work on this mod, great fun.

Just to add to some more information in the quest to further improve this great mod, I have the following engine data:

Maximum power and rpm
Ferrari 312 Boxer ~500bhp @ 12,200 rpm
Cosworth-Ford DFV ~465bhp @ 10,500rpm

The 312T fuel tank was approximately 5 gallons larger than that of the BT44B.

In the '75 season there were a few gearboxes in play, the Ferrari 015 TV, Hewland FG400, FGA400 and TL200.

 

[CMGARAGE]

I'd highly recommemend reading through the rfactor 2 dev posts for some useful tidbits. A lot of it is explaining the changes from 1 to 2 but there's info on the Hewland FG400 ratios and interesting figures like the weight of the front and rear tyres.

This one has the info on gears and a torque and power curve
https://www.studio-397.com/2016/06/engine-model-and-gear-ratio-restrictions/

In the second paragraph of this we get the cars mass (650kg, which matches Reiza's F Retro) and the fuel tank size (41 gallons/~186 litres). As well as some values used in the .hdv
https://www.studio-397.com/2016/05/updating-hdv-and-tbc-files/

Tyres
https://www.studio-397.com/2016/07/tyres-the-big-one-part-i/

Blueprints here might be of particular use
https://www.studio-397.com/2016/07/steering-system-forcetorque-distributions-and-some-little-bits/

 

[CMGARAGE]

Here are the numbers for the Hewland FG400 gearbox:

[GEAR_RATIOS]
Ratio=(13,46)
Ratio=(12,38)
Ratio=(12,35)
Ratio=(13,35)
Ratio=(14,34)
Ratio=(17,41)
Ratio=(14,33)
Ratio=(14,32)
Ratio=(15,33)
Ratio=(15,32)
Ratio=(15,31)
Ratio=(16,32)
Ratio=(20,39)
Ratio=(16,31)
Ratio=(14,27)
Ratio=(20,38)
Ratio=(16,30)
Ratio=(17,31)
Ratio=(17,30)
Ratio=(17,29)
Ratio=(18,30)
Ratio=(18,29)
Ratio=(17,27)
Ratio=(16,25)
Ratio=(18,28)
Ratio=(19,29)
Ratio=(20,30)
Ratio=(19,28)
Ratio=(18,26)
Ratio=(19,27)
Ratio=(24,34)
Ratio=(20,28)
Ratio=(18,25)
Ratio=(24,33)
Ratio=(25,34)
Ratio=(20,27)
Ratio=(19,25)
Ratio=(21,27)
Ratio=(19,24)
Ratio=(21,26)
Ratio=(19,23)
Ratio=(20,24)
Ratio=(21,25)
Ratio=(19,22)
Ratio=(27,31)
Ratio=(22,25)
Ratio=(25,28)
Ratio=(27,30)
Ratio=(28,31)
Ratio=(29,32)
Ratio=(22,24)
Ratio=(25,27)
Ratio=(28,30)
Ratio=(30,32)
Ratio=(23,24)
Ratio=(24,24)
Ratio=(25,24)

[FINAL_DRIVE]
bevel=(1,1)
ratio=(7,31)
ratio=(8,31)
ratio=(9,31)
ratio=(10,31)

It was used by Brabham, Copersucar, Hesketh, Embassey Hill, Lotus, Maki, March (possible 6 gear?), McLaren (again cited as 6 gear but M23 ran for many years, need cross reference), Parnelli, Penske, Surtees, Tyrell and Williams.

I'd recommend changing the gear setting values in each team aboves .hdv to:

Gear1Setting=3
Gear2Setting=13
Gear3Setting=23
Gear4Setting=36
Gear5Setting=45

FinalDriveSetting=1

 

[Bill Thayer]

I really want this mod to work for me..I am still getting a severe snap around during gear downshifts un-like the Retro.
This takes my joy...is there a fix anywhere? I have asked about this before and it is still the same

 

[Dethrone1427]

Increase the engine brake to the highest setting. Lower rear tyre pressures, lower rear fast and slow rebound as well as rear bump. More front braking percentage, and bring the first and second gears towards third, about five clicks. Plus if the car is nervous lower the steering range to like 16.0.

 

[Bill Thayer]

Increase the engine brake to the highest setting. Lower rear tyre pressures, lower rear fast and slow rebound as well as rear bump. More front braking percentage, and bring the first and second gears towards third, about five clicks. Plus if the car is nervous lower the steering range to like 16.0.

No Joy... If only the retro had the car models of this mod. i'm going back to the Retro and stop my frustration.

 

[CMGARAGE]

Default values from the F Retro and the ISI Brabham suggest a 52:48 brake bias and tyre pressures at around 127.

Default diff settings may help too:

Power: 20
Coast 35
Preload : 7

It's worth mentioning the tyres take a wee while to warm up before you can push and the cars are more sensitive to direction changes under braking which is exaggerated by a downshift. Shift later/ at lower revs and make sure the car is as balanced as possible before committing to the brakes.

 

[Dethrone1427]

Bizarrely I take a different approach, I shift down using a reasonably high amount of revs BUT I absolutely make sure I rev match so it doesn't disturb the car and unsettle it. @Bill Thayer I'll PM you something tomo, it means you wont be able to race online with others but you'll be satisfied

 

[Bill Thayer]

Dethrone.. If you can make a fix I'll be a happy camper, I stopped my online racing long ago. Too real for me, I got so mad at other drivers, it just wasn't worth it for me. It should always be fun.

 

[Dethrone1427]

Dethrone.. If you can make a fix I'll be a happy camper, I stopped my online racing long ago. Too real for me, I got so mad at other drivers, it just wasn't worth it for me. It should always be fun.

Yeah no worries mate, it'll be a simple little fix and you'll be well on your way to being one happy camper again

 

[CMGARAGE]

btw @Dethrone1427, I'm in the process of compiling some new suggested mass for each car.

As far as I can understand the mass value is a little low in your estimates. The regulation minimum weight was 575kg for that era from what I gather and it looks like Reiza and ISI have used a driver weight of approx 72kg taking the Brabham to 650kg when added to it's kerb weight. It looks like some of the weights are possibly 50-70kg out at times which could be as much as a third of a grand prixs worth less of fuel.


Also, have you had chance to try the Hewland ratios yet?

 

[Dethrone1427]

If I'm honest not yet, I will make the adjustments to the kerb weight, but what you then run the risk of is hurting performance. Something you mentioned prior about the DFR being sluggish, extra kerb weight is not going to aid that, but a couple of evenings this week I'll try and fine tune. The only way to get round this is to add more power but currently in menu the fords are pretty much bang on correct engine power values.

 

[Russ Craven]

Thanks to all the guys trying to tweak this gem to maximize its accuracy.

 

[CMGARAGE]

If I'm honest not yet, I will make the adjustments to the kerb weight, but what you then run the risk of is hurting performance. Something you mentioned prior about the DFR being sluggish, extra kerb weight is not going to aid that, but a couple of evenings this week I'll try and fine tune. The only way to get round this is to add more power but currently in menu the fords are pretty much bang on correct engine power values.

I'd avoid getting fixated on the menu numbers in this instance.

Again, at risk of repeating myself; if you haven't already, drop Reiza's engine.ini from the Retro in after setting some laps with your stock engine file. On the menu Reiza's engine is rated at a measly 418bhp @10,500rpm with 310NM @8,600rpm. Yours looks much closer to quoted figures at 448@11,000 and 303@8,500 and on paper I'd bet it'd be faster/more powerful.

Despite this, in the same car (mclaren) at the same track/conditions (test day, vintage speilberg, max track, 30l fuel and shared setup) I was 3.5 tenths faster and about 5-10kph faster on the straights in Reiza's engine!

It's not just the margainal gains though, seriously when you've got time, try it side by side, and you'll notice the back end stepping out much more.

All this is in vain because the Reiza numbers just don't add up though, right? Well actually they do with a bit of context. I remember Renato explaining on the official forums that the power figures don't correlate to real world figures because:

"the power / torque figures from the UI are "at the wheel" measures, so already factoring drivetrain losses (anywhere between 10-20% depending on the car)."

So assuming a 10% loss resulting of 418bhp we get a power reading of *drumroll* 465 bhp, which is the quoted typical output of the Cosworth from that time.

I've not tested it recently but it's also worth noting that if you take the F Retro or Copasucar by Reiza out on the same track that'll probably be faster still despite being 30kg heavier with an enginee rated 30bhp less. So it is possible strike a balance hopefully.

I'm off to test them now along with reverting the changes I made to the mclaren (Your original mass figure, engine; I'd made a seperate test suspension with more realistic mass data, inertia be damned!) to see what time is lost/gained by changing different compenents, adding that extra mass etc.

Please don't see this as trying to diminish you're great work. I'm having a lot of fun with the mod as is and am only offering up suggestions to hopefully make it a little more accurate. I can always just tinker with it offline.

 

[maxspeed3]

If I'm honest not yet, I will make the adjustments to the kerb weight, but what you then run the risk of is hurting performance. Something you mentioned prior about the DFR being sluggish, extra kerb weight is not going to aid that, but a couple of evenings this week I'll try and fine tune. The only way to get round this is to add more power but currently in menu the fords are pretty much bang on correct engine power values.

I really like this mod but the cars are very unpredictable you don't know what you're going to get
from corner to corner ...massive understeer to back end coming around .....very hard to string a lot of consistent laps together with racing offline... tried the setup adjustments you posted ...it does help
the car should not come around on you in 3rd gear (turn 2 Johannesburg Historic ) under power

 

[maxspeed3]

Yeah no worries mate, it'll be a simple little fix and you'll be well on your way to being one happy camper again

any help would be great

 

[Dethrone1427]

any help would be great

The only recommendations I can make is rev matching on the downshift, and controlling the rear of the car with the throttle using tiny increments of throttle.

You cant stab at the throttle or use on ON/OFF style, id recommend braking early and in a straight line, get ALL the speed off then get back on the throttle a small amount before the rear comes round on you and keep the car pointing front end first by using 1/8 to 1/4 throttle. But like I said don't come off or on with the throttle, abruptness won't be rewarded.

Plus, and this may just be me being a dumbass, but you are looking where your going yes? I realised when developing this mod I was (for some unknown reason) staring at both the steering wheel and the road. Once I actually looked where I was going (the apex!!) at all times I was a lot more consistent and accurate. But I'm practically a village idiot so that could explain that one!!

 

[Dethrone1427]

...huh, funny thing. Remember we were all complaining about the physics before and how critical they were on the downshift etc. Well I've implemented the new gear ratios, mass and updates to the HDV file, and a totally rebuilt engine to go hand in hand with the figures that were supplied, annnd it handles just as it was at the start. **head in hands**

 

[Russ Craven]

I guess there is no happy medium, if its to hard to drive,it unrealistic, if its to easy its unrealistic.I guess the answer lies in the drivers talent., or lack thereof.But thanks anyway. Looking forward to doing my best to drive these little beast.

 

[CMGARAGE]

...huh, funny thing. Remember we were all complaining about the physics before and how critical they were on the downshift etc. Well I've implemented the new gear ratios, mass and updates to the HDV file, and a totally rebuilt engine to go hand in hand with the figures that were supplied, annnd it handles just as it was at the start. **head in hands**

Hang in there, mate!

I've done some more tinkering. I think a lot of it may lay in the tyres. Fiddled with inertia values and made some alterations to the suspension file and whilst the car handling become more responsive/snappier there was virtually no difference in times.

Compared the brabham tyres to some of the data from ISI's. I did a 54 lap race of Johannesburg and I felt the tyres were a bit off. Everything but the front left was struggling for heat and even that was often 10C under what I was seeing with Reiza's car. Wear was also a bit high, imo, down to < 30% after 50 laps when the tyre blog suggested they'd last a race and drivers only pitted if they were damaged.

I've left all the slip curves alone but tweaked the tyre dimensions, spring/dampening rates, rolling resistance and tinkered with the wear.

All else as before, I gained 2 seconds on my pervious laps. Temps were higher and more consistent across tyres and loss of grip felt more progressive. It also felt better under braking but personally I haven't struggled with the backend since you toned it down from the original.

I'm gonna grab a bite to eat but get back to it later. Will need to test it with your base settings as my test car is a frankenstein of different physics files If it makes a postive difference to your 1.1 physics I'll look at sending you my tyre file and what I've changed so you can have a look.