Hi,
I found out how it works, it's not complicated if you know what to do:
1) Install GP4Tweaker V1045_reloaded (date 6 sept 2005), you can get it here: [
gp4tweaker.vadertrophy.com]
2) Run GP4 tweaker, make sure that if you have multiple installs of GP4 it points to the right install (see also the readme file), make a change to one of the options and hit "apply" I changed option 22, headmovement because it's easy to check if it works
You HAVE to do this to "activate" GP4tweaker. It doesnt matter which option you pick, you will/van disable it again in step 5.
3) Run GP4 from within GP4tweaker (button "run gp4"
4) Quit GP4, check the GP4 main folder to see if there's a file called "gp4tweak.txt", this is a log file from gp4tweaker. Open it and check if GP4tweaker has run.
5) Run GP4 tweaker again and disable the option you have enabled in step 2, quit GP4 tweaker
6) Run GP4 from GPxPatch and check if the headmovement is gone, quit GP4 and check the "gp4tweak.txt" file again
7) Download GP4tweak_PE.zip (date 27 june 2004) from here [
gp4tweaker.vadertrophy.com]
8) Unzip the file and read the readme and follow the instruction to install it. You have to overwrite some files.
9) Open the "gp4tweak.ini" file which is stored in the main GP4 folder. In this file you can disable or enable some options including the slipstreameffect. I disabled the FFB, dirt and visor option because I dont like them. I enabled the slipstream effect!
10) Run GP4 from GPxpatch. Quit GP4 and once again check the "gp4tweak.txt" file. You should see these lines:
01-08-2007 14:21 [ ] Patching successfull [slipstream->SlipFrontWing()]
01-08-2007 14:21 [ ] Patching successfull [slipstream->SlipRearWing()]
01-08-2007 14:21 [ ] Patching successfull [slipstream->SlipGripInit()]
01-08-2007 14:21 [ ] Patching successfull [slipstream->SlipGripFinal()]
01-08-2007 14:21 [ ] Patching successfull [slipstream->SlipNoAccel()]
Then you know for sure that the slipstream effect works!
11) Do some testing to see if you like the slipstream values, I like the default which make it very difficult to overtake cars (which has to be difficult!). If you dont like it you can allways lower the effect by changing the values in the "gp4tweak_data.ini" file which is also in your main GP4 folder. You have to reduce the vaule 50 to something like 20-30.
Good luck!!
BTW I did some testing on Barcelona with the slipstream effect enabled and with it disabled.
I started at the back of the grid to test it. Without the slipstream effect disabled I could easiliy follow other car around the track and was within the top ten in a few (4) laps. With the effect enabled it took me 15(!) laps to just find the right opertunity to overtake the car who was in 15th place!