Grand Prix 4 No Refueling Patch

Previously exclusive to the 2021 Mod... let me present you the No Refueling Patch:

Surprisingly enough to me, this patch works by changing only 2 bytes of code in GP4.exe. The first one is in regards to fuel at the start of a race. GP4 usually checks for the pit strategy of each car to determine how much fuel to start - if a car is on a 0-stop strategy (which normally happens in 50% distance races or below), then it fills the tank for the whole race. The patch changes a jump instruction to skip the pit strategy check, and go directly to the 0-stop case instead. This only affects starting fuel, and cars will make a stop on the laps specified by the track's magic data. This affects both player and AI.

The second patch is on refueling itself. During a pitstop, GP4 will again check the pit strategy and will determine how much fuel the car needs to leave the pits with. The patch changes a instruction from "update car fuel with calculated fuel" to "update car fuel with existing fuel". This works for AI only since the player can still choose to refuel in the cockpit commands. A side effect is that this makes pits faster - the fuel man will insert the fuel hose and immediately remove it, since there's nothing to be added. On a related note, please check 32BOBO32's No Refuel Animation patch.

What this patch doesn't change: 1) pit strategy, cars will still stop at whatever laps are specified in the magic data, and will change for new sets of tyres. 2) fuel consumption, if magic data for a certain track/mod combination is poorly calibrated, then cars will run out of fuel before the end of a race, and there's no way for the AI to save fuel. 3) tyre changes still take around 5 to 6 seconds.

This is the patch.ini code. You can use this in a CSM mod or with Duffer's Wad Controller, or even change the specified address with an hex editor, to patch your GP4.exe. In the download link here there is also a .cap file for use with CSM.

[Main]
Format=

[V1.00] 
Offset1=0x008806 ; Full tank start (GP4 v1.00)
Code1=0x31
Offset2=0x008BB9 ; Disable pit refuel (AI only) (GP4 v1.00)
Code2=0x56

[V1.02] 
Offset1=0x008833 ; Full tank start (GP4 v1.02)
Code1=0x31
Offset2=0x008BE6 ; Disable pit refuel (AI only) (GP4 v1.02)
Code2=0x56

My unfinished tracks: [www.grandprixgames.org]
Send bug reports and track editing questions to f1virtualblog@gmail.com



Edited 1 time(s). Last edit at 10/30/2021 08:10PM by Prblanco.

Thank you Paulo

another breakthrough from you! thank you!

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GP Files | GP Videos | Discord: Carl_gpgames#2350

Thank you Paulo!

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Superb Paulo! Long life elixir for GP4

Samuele
32BOBO32

Prblanco, I take my hat off. It´s FANTASTIC!!! Thank u!

I have a question related to pit stops:

Same as this solution to avoid refueling. Is there a solution to simulate the situation of the 2005 season, to refuel in the race without changing tires?

Thank you a lot for your works.

wow, thank you Paolo for solving another secret of GP4

Thank you, Paulo! It makes the mods more realistic. I will test it right now in 1991! Obrigadinho!!

Hats off to you once again Paulo! Absolutely mind-blowing, thank you!

Thanks Paulo!

Fantastic little tweak that makes a massive difference, for old and newer mods. Thanks Paulo!

Thank you Paulo!

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No words to thank. Great work!

Thanks Paulo, much appreciated

This would be very helpful with mods before 1994.

Awesome work, thank you for keeping this game alive.

This is a 'game changer' patch!
I updated the two bytes and the game suddenly had a behaviour like current F1.
Cars start with heavy fuel, full tank and running quite slow. In fact, just before the pit the cars are dramatically slower than after pitting, 3-4 seconds easily in my test at montmelo. Now it's time to fine tune tyre degradation and so on, but now cars are much faster after pit...
Great!

I must thank Prblanco and 32BOBO32 again.
After make some races(100%) in the not re-fueling 1986, I must say, its just magnificent. The cars act really different, I had to be careful at the beginning of the race: break earlier, not accelerate to much, be patient...
It tooks some races, now I love it. This feeling its only with race 100% possible. And it shows how Crammond was good! Still waiting for GP5
Thank you, Guys!

Thank you very much

landex Scritto:
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> I must thank Prblanco and 32BOBO32 again.
> After make some races(100%) in the not re-fueling
> 1986, I must say, its just magnificent. The cars
> act really different, I had to be careful at the
> beginning of the race: break earlier, not
> accelerate to much, be patient...
> It tooks some races, now I love it. This feeling
> its only with race 100% possible. And it shows how
> Crammond was good! Still waiting for GP5
> Thank you, Guys!

Thanks for your feedback mate! Really appreciated!

Samuele
32BOBO32

Hi, can someone explain how to use the .cap file with CSM?