Various tips & tweaks to improve Papyrus Nascar 2003 Racing performance

[Info needs to be organized. It is here for my easy access.]

This information was gathered from various Sim Racing sites.

1. How to tweak graphic settings to increase FPS:

These tweaks and suggestions are to help improve your frame rates and game playability.

The idea is to free up as much system resources as possible to get the most performance out of your racing experience.

Second, You should take a look into your video card drivers. The latest isn’t always the greatest and performance can vary with different adjustments made from within them. The main trouble from them is caused when you have V-sync and FSAA turned on. So be sure to turn those two things off. They can be found under Start/settings/control panel, then under display/settings/advanced, Select your video card and click on Additional Properties. Most people claim you’ll get better performance in openGL rather then D3D,and I agree. You’ll want to make sure these two things get turned off as they will have a serious affect on your systems performance and will cause a major frame loss.

Unless your running a G4 4400/ti4600/The new FX or a ATI 9700pro you’ll want to consider this.

Next, we’ll take an in-depth look into those ini.files and slam every last drop of performance out of your system.

Open up your “C:/Papyrus/NASCAR Racing 2003 Season” directory.

Look for your core.ini and open it with notepad or just by double clicking it. Look for the line that reads,


Just put a 1 in front of the number, So it’ll read


Next, look for the


You’ll have to calculate the amount of RAM you have. Just multiply your ram by 1024
Example: 512×1024=524288

Then insert that number so it reads,


***On some computers Nascar 2003 will lockup and/or crash to the desktop when using values above 512 on your ram to configure your [Memory] Maxblocksize .

Save the core.ini file and close it.

Next, open the rend_ogl or the rend_d3d file, Whichever your running the game in, OpenGL or D3D.
look for the line that reads.

TextureSetSize= “????????”

The “number” is what you want to replace. There is a formula for this…
( Mb of video ram) x (1048576) – ( 4 x Screen Width) x ( Screen Height) x (BPP) Bits Per Pixel, use (2) for 16bit or (4) for 32bit color.
NOTE: 16bit color will be less of a performance hog then 32bit color

Just look and match up your resolution with your color depth and you’ll find the answer to the formula for your TextureSetSize.

32mb video card running in 16bit “Don’t even try 32bit, it’ll be a waste of your time”
640×480= 31096832
800×600= 29714432
1024×768= 27262974
1152×864= 25591801
1280×960= 23724032
1600×1200= 18194432

64mb video card running in 16bit
1024×768= 60817408
1152×864= 59146240
1280×960= 57278464
1600×1200= 51748864

64mb video card running in 32bit
1024×768= 54525952
1152×864= 51183616
1280×960= 47448064
1600×1200= 56388864

128mb video card running in 16bit “Crank it up”
1024×768= 127926272
1152×864= 126255104
1280×960= 1246387328
1600×1200= 118857728

128mb video card running in 32bit “Crank it up”
1024×768= 121634816
1152×864= 118292480
1280×960= 114556928
1600×1200= 103497728

256mb video card running in 16bit “It’ll happen”
1024×768= 262144000
1152×864= 260472832
1280×960= 258605056
1600×1200= 253075456

256mb video card running in 32bit “It’ll happen”
1024×768= 255852544
1152×864= 252510208
1280×960= 248774656
1600×1200= 237715456

Then look for the,


Change the 8 to a 0


Save these changes and close the file.

In your players directory: “C:\Papyrus\NASCAR Racing 2003 Season\players” open the Player file (player.ini) and look for the line that reads”

[Graphic Opitions]
texture_quality= -1

Change this number to a value between -1 and 100 for a increase in picture quality. This will give some performance hit, but the increase in eyecandy is well worth streaming film The Lego Batman Movie online

[Graphic Opitions]
texture_quality= 100

There’s a few more general things to keep in mind. The number of cars you draw ahead and behind will affect your FPS. The draw distance and mirror detail will affect FPS along with anisotropic filtering, lightmaps, reflections and shadows from cars or sturctures. Last but not least, Maximum Sounds Played has an effect on FPS. Lowering this to 8 seems to really help on many machines. These changes can be made under your options menu in the sims main menu screen. To tweak the most out of your system you will want to play around with these settings until your happy with your FPS.

You can also take control of your Virtual memory settings. Under Settings/Controlpanel/System/Performance/Virtual memory Select “let me Specify” Ignore the Windows warning. Then set your minimum and maximum to the same setting. Let’s say, at least 500mb each or if you can spare it 1000mb minimum and maximum. This will prevent your HD from resizing it’s memory Swap file during racing and eliminate some stuttering that occurs during game play. It is best to defrag often or even partition your HD with a 1gig partition and assign your virtual memory to that.


More info found:

Track types:
0 = short track
1 = mile oval
2 = medium oval (>1 <2)
3 = long oval (think this is the 2 mile)
4 = super speedway
5 = road course

Chassis types:
0 = ?
1 = super speedway
2 = speedway
3 = short track
4 = road course
5 – unrestricted SS

The AI is just all around too Fast. What do I do?

‘ai_grip_modifier = xxx’ Decrease this for them to go slower, pretty much all around. Increase for them to go faster all around. Only Decrease/Increase in small incriments.

I slam into the AI going into the turns, what do I do?

The line that says ‘ai_decel_modifier = xxx’
— INCREASE THIS NUMBER. Play around with it a bit. The more you increase this number, the faster they’ll enter the turn.

-If the AI slams into you going into the turns, Decrease this number to slow them down.

I Slam into the AI coming out of the turns, what do I do?

The line that says ‘ai_accel_modifier = xxx’
— INCREASE THIS NUMBER. Just like above, play with it. The more you increase the faster they’ll exit the turns.

-If the AI Pulls you bad coming out of the turns, Decrease this number to slow them down.

The AI Pulls away from me on the Straitaway, what do I do?

The line that says ‘ai_drag_modifier = xxx’
INCREASE THIS NUMBER. The more you increase it, the slower they’ll go, mainly on the straitaways.

If you are riding the brakes to keep from slamming into thier BUMS on the straits, Decrease this number to speed them up.
The AI is too fast in Qualifying, but they’re good while racing, what do I do?

‘ai_qual_modifier = xxx’ INCREASE this number for them to go FASTER. DECREASE for them to go SLOWER. Use disgression and don’t edit the parameters TOO FAR or you’ll either have an IRL race or a dinky derby race on your hands.

The AI wrecks Way too much. What do I do?

It could be 1 of 2 things:

‘ai_wall_offset = xxx’ Turn this down first. This tells N02 how many times out of 100 the AI will actually make contact with each other when they touch. If set to 1, the AI may merge into each other.


‘ai_drafting_distance = xxx’ This is how close (in carlengths) the AI get on each others back bumper. IF you turn this down too much, the AI will get confused and they’ll go 4, 5 or even 6 wide and wreck alot. A good setting for this setting is anywhere from 1.00 to 1.50, depending on the track. (See Below for more Info)
My races are Boring. (Much like Real Nascar right now…. ) The AI only goes single file and dont usually pass. What do I do?

There are a Few parameters you can edit.

‘ai_line_modifier = 1.00’ This line tells the AI how to enter the turn, based on the *.lp file. DO NOT EVER EDIT THIS LINE!
If you want the AI to run more random lines, like up near the wall, down on the bottom and take more chances of passing, TOTALLY DELETE THIS LINE, DO NOT EDIT IT Thats right, just take it out. This is good for tracks with multiple lines like Rockingham and Other tracks.


‘ai_drafting_distance = xxx’ This line tells the AI how far to follow the next AI car (in carlengths). DECREASE this number for Closer races and the ability for the AI to pass more often. CAUTION Do not edit this too much, or else you’ll end up in a Demo Derby. Only Decrease this number by 2.5 MAX at each track. Even then, you’ll have some trouble on your hands. Some tracks are different than others. At Daytona and Tally, you want to Decrease by like 3. But at Bristol only by 1. Use your disgression and play with these numbers.


‘ai_squeeze_pcnt = xxx’ I’m still figuring this one out. I believe it shows how long it takes the race before the field spreads out. I’ve done alot of playing with this one, and if you go too low, they spread out fast. Go too high and they spread out fast. There must be a ‘perfect sweet spot’ number to get the AI just right. I dont believe I’ve found it yet. If you find some good settings, Email or IM me.

Well, thats about it. I’m still researching these:

‘ai_panic_decel = xxx’

I hope this helps a lot of you guys and Happy Racing.

If you have any questions, comments or additions, you know where to put them, Right down there.

track_tire_heat = 0.89 Tire heat number with 1.0 being the base number. Seems that the higher the banking and the faster the speeds, the lower this number needs to be and the lower the banking and shorter the track, the higher this number is. This is actually important because if the tires do not heat up enough, or heat up too much, setting up a car for your track is going to be next to impossible. This was the last hold up on Jennerstown, as I had to run many laps in each series to get this correct, then I had to be sure that the temps were a result of this number being right and not just a poor setup.

track_tire_wear = 1.02 Tire wear exponent with 1.0 being the base and a number higher that 1.0 meaning more wear and a number less than 1 meaning less wear. Obviously this number has to be in conjunction with the number above because the tire model needs to caculate both tire scrub and tire heat to produce tire wear. You can dirt track all you want and never experience tire wear if the tires don’t heat up enough, so initially you may crank this number way up, but everytime you touch the number above, you have to worry about affecting this number. If not, your track may make Darlington look like a tire lover.

track_tire_wear_loss = 0.38 This means that if a tire is red and ready to explode, what is going to be the percentage of grip lost? At some tracks, tire wear does not mean much, so this number will be low, a track like Rockingham and this number is going to be super high. Remember that this is a percentage so 0.38 is 38% grip loss and that is pretty significant.

track_tire_wear_exp = 0.94 Determines during what part of the run that times fall off due to tire wear. A number greater than 1 means later in the run, such that 1.0 means that 1/2 way through the run the times drop significantly and if the number is greater than 1.0, the drop off will begin after the half way point and the opposite for a number less than 1.0.

track_asphalt_grip = 0.94 Grip value for the parts of the track designated as asphalt for their surface type. This value affects both the human player and the AI cars, so keep that in mind. Fine tuning this number by values of .01 at a time will allow you to adjust both yours and the AI’s speed to the real life speeds once you get the AI running lap times comparable to yours. What I am saying in my opinion, you should adjust the AI parameters so that the AI run close to you, then change this value so you get the speeds that you expect on your track.

track_concrete_grip = 1.00 Same as the asphalt value above.

track_north_angle = 110 Angle in degrees around the 0,0 point of the track where true north is. This sets up which way the winds blow across your track when it says winds are 5 mph from the north. Don’t forget to coordinate this with the angle of the sun in the ptf file or people will get confused why the sun is showing from the south

This is the meat of the AI behavior, although remember what Steam always preaches that no matter what you do here, if you have bad lp lines, the AI will never do what you want them to.

[ ai_track ]
pace_merge_from_pit_line_dlong = 300.000 this variables name says it all. It is where the pace car will merge to the track from the pit.lp file based on dlong distance in meters.

pace_merge_to_pit_line_dlong = 2000.0000 same as the line above, but this is where the pace car will merge to from the racing surface to the pit.lp line. Just remember that this is the point that the spotter will say the pacecar is in, so you probably want it to be around the point of where the pit.lp line cuts away from the racing surface.
pace_speed_limit_mph = 60 pace car speed.

ai_accel_modifier = 1.00 the acceleration of the AI with 1.00 being what is calculated from the lp files. A number higher than 1.00 means the car will accelerate faster than the person who made the lp file did, and a number less than 1.00 means the opposite. This number is just for adjustment so you can run the lp file at any speed, then fine tune the AI’s acceleration with this value.

ai_decel_modifier = 0.95 braking adjustment number that works for the AI’s brakes just as with the acceleration value directly above.

ai_fuel_use = 0.96 base value is 1.0 and it determines the amount of distance the AI can go on fuel. A number higher than 1.0 means they can go further than normal on fuel and less than 1.0 means they go less distance.

ai_grip_modifier = 1.08 This number works in conjunction with the asphalt and concrete grip values above. Also helps if you are having problems with the AI sliding off of the track on a tight turn.

EDIT: Further explanation of AI grip mod – Jan
jay taylor wrote:
The AI line modifier changes the AI’s perception of their grip limit. at 1.0 they see 100% of the actually grip they have available to them ( as set by their grip value in the track.ini). Decreasing its value will make them drive like they have less grip and run easier into and out of the corners, and will also slow their speeds slightly. Raising the value above 1.0 will make them think they have more grip then they actually do, and they will charge the corners harder. In some cases going slightly higher then 1.0 can help make them race better, however going to high may cause them to over drive, and wash up the track or check up as they slip beyond their grip threshold.

ai_drag_modifier = 1.03 base value as with most is 1.00 and a higher value means more drag and a lower value means less drag. This is useful if the AI are getting off of the turn correctly (see ai accel modifier above) but seem to be outrunning you at the end of the straight.

ai_line_modifier = 1.00 I would follow papy’s advice and not change this line, although at a high banked short track such as bristol, if you change this to 1.01, it can sometimes get the slower AI to run the high line more but that can cause a ton more wrecks sometimes as well.

ai_qual_modifier = 1.038 values higher than 1.000 will speed up the AI during qual and a value below 1.000 will slow the AI down in qual to get them around human speeds.
ai_wall_offset = 100 this is a AI collision detection value. It can be anything from 1 to 100 with 100 being 100% of the time the game is looking for AI collisions. This can be reduced from 100 if you are having major problems with constant wrecks. The problem with reducing it, is AI cars will morph into each other and the walls, creating wierd wrecks and flips, or no wrecks even though they touch. You can also get away without having this value in here at all, as it will default to 100 anyways.

ai_tire_wear_left = 0.40 as papy says, ; left tire wear adjuster for ai This number affects whether the AI change left side tires during pit stops and how many laps they will go before changing left side tires. I mean, if this number is like .8, then the AI will slow down quickly into the run and need to change left side tires after like 10 laps, but if the value is .2, then the AI may be able to run 100 miles without changing left side tires or having their times drop too much.

ai_tire_wear_right = 0.48 as papy says, ; right tire wear adjuster for ai This number affects whether the AI change right side tires during pit stops and how many laps they will go before changing right side tires. I mean, if this number is like .8, then the AI will slow down quickly into the run and need to change right side tires after like 10 laps, but if the value is .2, then the AI may be able to run 100 miles without changing right side tires or having their times drop too much.

ai_arcade_tire_wear = 0.01 The lower this number, the less tire wear experienced. I do not test my tracks in arcade mode, so I make the AI unbeatable Very Happy

ai_arcade_fuel_use = 1.00 see papy explaination here ; > 1.0 = even more fuel consumed (in addition to fuel_use above)

ai_arcade_grip_modifier = 1.01 see papy explaination here for AI arcade grip modifier, works like grip modifier above ; > 1.0 = more grip

ai_arcade_drag_modifier = 1.22 see papy explaination here for AI arcade drag modifier, works like drag modifier above ; > 1.0 = more drag, which is slower

strategy_lap_time_wear_loss = 2.163 see papy explaination ; lap time loss from totally worn tires this would be if all 4 tires were red and ready to explode. You have to adjust this to what happens to the human driver or else the AI will be too fast or too slow on the long run.

strategy_lap_time_fuel_use_gain = 0.140 time gain due to less fuel (reduced weight in car).

strategy_base_pitting_cost = 29.792 Time lost doing a stop and go penalty. It affects whether the AI will stop and pit or not. Don’t know why papy calculated it based off of a stop and go, but basically do some stop and go stops and see how much time you lose to the AI in a race to properly calculate this.

ai_pacing_distance = 1.8 how many car lengths between AI cars during a pace (yellow) lap. 1.0 would mean that the second cars front bumper is touching the lead cars rear bumper

ai_bunching_distance = 1.65 how many car lenghts between the AI cars when they start to bunch up for a restart. 1.0 would mean that the second cars front bumper is touching the lead cars rear bumper

ai_drafting_distance = 1.25 distance that they AI cars try to keep between themselves while races before switching to another lp line. Remember that 1.0 would mean that the second cars front bumper is touching the lead cars rear bumper. Too small of a value means that the AI will touch a lot in the turns, especially tight ones causing wrecks or the AI will jump to the min, max race lines way too much. Too large of a value and the AI will not be able to pass properly.

ai_panic_decel = 7.0 This is the number of G forces of extra deceleration a AI car must be enduring before it will use the panic lp line. If this value is too high, the AI will not avoid each other well during a wreck, but if it is too small, even a minor bobble will cause them to use the panic lines.

ai_dlongpad_scale = 5.0 This pads the braking of the AI so that they don’t suddenly stop when going into a turn or trying to pit. The smaller the number, the more scaling that takes place.

ai_dlat_pad = 0.85 This number has to do with how close the AI like to race to each other when side by side. If this number is too low the AI will wreck each other alot, if it is too high, the AI will be sluggish getting off of the turn when side by side, causing major problems. Papy’s AI guru says to get this number as low as possible without causing side swiping wrecks, usually around .75 or so.

ai_squeeze_pcnt = 0.0 This seems to be set at 0.0 in most default tracks, and has not been difinitively defined by anyone that I have talked to including Steam, Jay Taylor, steveb73, or JJ. There are many theories on this, in fact too many to list, so if someone can truely answer this for me, I would like to know Very Happy

I’ve been racing a little more lately, and noted how bad the AI was at certain tracks. Not bad in a they react weird or something, but bad in the fact that it isn’t like the real thing at all. So I started messing with the Track.ini files again (I’m pretty acquainted with everything and what it does). I was reading up on Butters_ Tutorial just to freshen up a bit, and read about the dlat_pad line, which determines how closely the AI runs apart side-by-side. When set at like 1.5 they will stay pretty far away from each other side by side, but when set to 0.2 to 0.6 depending on the track, they will run closer. Then I started messing with the ai_squeeze_pcnt line. Too much, and the AI acts like they’re blind, they swerve and veer and wreck all over.

There is a sweet spot, and at most tracks it’s about 2.0. Different tracks yield different results but from what I’ve found, this number makes all the difference in the world. This parameter makes the AI run more randomly around the track. When set to 0.0. the AI car will drive behind another car until it gets XXX away (depending on the AI_Drafting distance) and will pull out (usually to the inside) and pass, getting slightly ahead, and then pulling back in line. With this number at 2.0 or so, they will attempt to pass earlier, and run their own line. Also, cars will use up more space, the higher the number is. When it’s set to 5.0 or so, they will run up on the wall at full speed and wreck, but at 2.0 you will see the occasional car (at tracks where there is a competitive High Line, like Daytona or so) and they will brush the wall.

This is my theory:

When this number is set at 0.0 (Default) the AI knows exactly where their limits are (as to where the LP File lines are located) and will not deviate from them. As this number increases, the AI will take more of a risk at Passing and blocking, and to using as much of the track as possible. If I were to give this a textbook definition, I would say it is the Percentage of which, the AI deviates from the ususal Race.lp and other files. At 100% They don’t know where to go, so they just swerve and wreck about. At 2% they know that they have more room to work with.

I’ve gone and changed the following values at pretty much ALL of my tracks, and have seen much more competitive and realistic racing. Try it out, and let me know how it works for you.

With the Values below, the AI will run closer Side-by-Side, make more Human errors and decisions and race more realistically.

From what I’ve found with the Squeeze_Percentage, the smaller the track, the smaller the number. But make it as High as it can, before you see too many AI errors and risks.


ai_drafting_distance = 1.20
ai_panic_decel = 5.35
ai_dlat_pad = 0.40
ai_squeeze_pcnt = 2.0; 1.90; 1.75
ai_inverse_slipcurve_k = 0.35

ai_inverse_slipcurve_k = 0.63 papy defines this value as ; how much slip angle AI need to corner. smaller = more, more = increased drag It basically means how out of shape can the AI get before they lose grip and wreck. The higher this value, the more you can bump the AI without them losing grip and wrecking. Too high and everytime you get into them too much, you will wreck because they will be unmovable like a dump truck.

This next section is the hardest in my opinion to get correct, at least when doing a short track. The AI will wreck a lot on a tight pit road if these settings are not perfect. There is also a [ pit_lane_1 ] if you have 2 pit roads.

[ pit_lane_0 ]
; AI stuff
merge_from_pit_line_dlong = 1100.0 as papy says ; dlong at which cars leaving pits will merge to race line note that this is the point at which the spotters say that you can now merge safely from pit road and should be slightly after the last value in this section that determines the black flag point

merge_to_pit_line_dlong = 1400.0 this is the dlong at which cars entering pits will merge to race line. Just remember that your lp files for pit road should se out on the racing surface at this point so there are not some crazy things going on. If not, the AI will be very likely to stay to the right of the pit.lp line too long and hit the pit road wall.
merge_to_pit_line_length = 450.0 length of merge window in meters from the original dlong value given directly above. Once past this point, the AI will not pit.

pit_lane_end_dlong = 211.3 dlong where you can accelerate off of pit road and not get flagged for speeding. Must be set around the start of the first pit stall as that is where the spotter will give the signal at.

pit_lane_start_dlong = 2199.13 dlong where pit road starts at in terms of the black flag for speeding. Should match up with the track side detail line at the beginning of pit road. This would be right where the app pit entrance points are at that you must cross between.

slow_pit_line_dlat_offset = 4.0 dlat distance between the pit.lp and the maxpit.lp lines

stall_exit_goal_dlat_offset = -4.0 dlat value from the center of the pit stall the the AI will shoot for when leaving their stall. This works in conjuction with the value directly below to form a point upon which the AI will pass over.

stall_exit_goal_dlong_offset = 8.0 dlong offset defined in meters from the center of the pit stall that the AI is leaving to where the AI will go. Forms a point that the AI pass over with the dlat value defined directly above.

begin_stall_entry_offset = 15.0 dlong in meters before the target pit stall that the AI will begin to move from the pit.lp line to the maxpit.lp line to get ready to enter their pit stall. Too small of a value will cause the AI to back into their stall and too big of a value will cause the AI to clip other cars sitting in their pit stall already.

begin_stall_approach_offset = 80.0 dlong in meters before the target pit stall that the AI will begin to get ready to enter their pit stall. This is when they will move from the pit.lp line to the maxpit.lp line to get ready to enter their pit stall. Too small of a value will cause the AI to back into their stall and too big of a value will cause more accidents between cars entering and leaving pit stalls.

lane_merge_dlong = 1025.00 this is the dlong which you must remain on the apron when exiting the pits or you will receive a black flag. This point should be a few meters before the first value in this segment that marks the point where the spotters says that it is safe to merge.

Ok, this is another easy one after the last one it is needed Very Happy

; race control stuff
lane_on_right = 0 value is a 0 if pit lane is to the left of the racing surface and 1 if it is to the right. I believe that if you had pit lane to the left, but wanted the stalls to be on the right hand side, this value would have to be 1 and not 0 as it is explained above. Bascially, this values determines which way the pit crews face and not really what side of the race track pit road is on

lane_has_wall = 0 this value tells the game if there is a pit wall seperating pit lane from the track. A value of 0 means there is no wall and a 1 means it has a wall.

speed_limit_MPH = 45.0 This just determines pit road speed limit. Note that you can set this as high as you want, but that the spotter is not programmed to say any speed above 70, so even if the speed limit is 200 mph, the spotter will say it is 70.

This section tells the pace car what to do when getting into and out of its stall. Since the pace car is a ghost, the entrance values do not mean too much, as long as the values in other sections can get in onto pit road ok, but you will want this right for visual effects and it is easy once you can get all of the AI cars right in their section as you will have previous experience.

; pace car
begin_pacestall_entry_offset = 30.0 just like the AI, this is the offset at which to begin entering the pit stall. For more detail, see the AI explaination.

begin_pacestall_approach_offset = 55.0 just like the AI, this is the offset at which to begin approaching the pit stall. See the AI section for further detail.

pacestall_exit_goal_dlong_offset = 4.0 just like the AI, this is the goal point in meters dlong offset from the pit stall for exit. More detail in the AI section above.

pacestall_exit_goal_dlat_offset = -3 just like the AI, this is the goal dlat point for the pit stall exit that matches up with the dlong value directly above. See the AI section for more detail.

stall_pace = 239.64 43.60 -0.3 these values mark the center point of the stall that the pace car will use. In order, they are dlong, dlat, and rotation in radians. These are based off of the centerline. Thus, are car on a curved section will automatically turn itself with the centerline, so the last value is not always so easy to determine.


Instructions for putting the CTS Pace Truck into another NR2003 Series:

1. Find and unpack the cts.dat file in your series\cts\ directory with WinMip2

2. Browse to folder where the cts.dat was unpacked to. By default, this will be
a folder called ‘Unpack’.

3. Find and copy the following files :
– fast_pace.mip
– medium_pace.mip
– pacecar2.mip
– pacecar3.mip
– pacecar4.mip
– pacecar5.mip
– pacecar.3do
– pacecar.mip
– pacecar_lights.3do
– pacecar_shadow.3do
– shiny_pacecar.mip
– slow_pace.mip
– slowspec_pace.mip
– wheels_pace.3do

4. Paste the files you copied into your series\xxx directory, where xxx may be
cup, bgn, aero88, tptcc, pta. As usual, make sure to backup any pacecar related
files already in that directory.

Thanks to Zone15 for the original post over on the TLS forums.


Game files and mod install order – it is important to install the files and mods in this order:

Install patch:

All of the mods listed below can be found at on the left Nav bar under NR2003 -> Mods -> Project Wildfire

Install the PWF cup damage

Install the PWF gns mod

Install the PWF GNS Volumetric Shadow Fix

Install the PWF truck mod

Install the IROC mod

Install the PWF IROC Model Fix

Install the PWF Trans AM mod

Install any other mods in any order.


AI Tweaking Guide

Modify the track.INI file:


If they brake too early going into a turn, increase the value for:


If they brake too late going into a turn, decrease the value for:


If you find the AI brakes too abruptly, decrease the value for:


Turn Speed

If they are too slow through the turns, increase the value for:


If they are too fast through the turns, decrease the value for:


Straighaway Speed

If the AI pulls away from you on the straights, increase the value for:


If you blow by the AI on the straight, decrease the value for:



If coming out of a turn or on starts/restarts, the AI accelerates to slow, increase the value for:


If coming out of a turn or on starts/restarts, the AI accelerates to quickly, decrease the value for:


ai_dlongpad_scale =
This is what the AI use in braking Zones.

ai_inverse_slipcurve_k =
This is how much angle they need while cornering…less of an angle = decelerated corners

From SteveB at

ai_grip changes the AI speed ALL around the track

ai_accel changes the AI speed out of corners and at the restart

ai_decel changes the AI speed into the corners

ai_drag changes the AI speed down the straights. This is more important at tracks over 1 mile in length, but works for short tracks too.

ai_line_modifier makes them move from minrace to maxrace more erratically. This is a VERY sensitive value. 1.00 is default and 1.05 makes a mess. 1.02 is pushing it.

Other lines to play with but these are not real speed issues but agression issues……..

ai_panic_decel – lower number makes them react to problems better

ai_dlongpad_scale = lower makes them brake more smoothly and not run into slowing cars (think of a car having a bubble around it; bigger the number, the bigger the bubble is in FRONT and BEHIND the car). A real low number will make an AI on the outside think he can fit his full car length into a half car length between two cars on the inside.

ai_dlat_pad – same bubble but beside the cars. Lower will make them try to get tighter and can cause more problems.

ai_squeeze_pcnt = not sure how this works, but increasing the value from 0.0 to 0.5 will make them move more.

ai_inverse_slipcurve_k – a low value makes the rear end wiggle as they go thru the turns. Increase the value to 1.0 and they’ll go thru the turns on a rail.


How to make separate series for cup years:

You have all your cars from various years in the cup directory. You could create a separate series for each year or set of cars.

Simply copy your Papyrus\NASCAR Racing 2003 Season\series\cup directory to a new directory. IE cup2006. Rename the cup.dat file to cup2006.dat. Edit the series.def file “given_name=NASCAR Cup” to match this new series. Copy the cars needed to the /series/cup2006/cars directory.

Just remember that the *.dat name has to match the folder’s name.

Convert a 800×600 image into mainback.stp (this is the splash screen) using WinMip and place it into your new mod folder. You can also download new mainback.stp files from various places on the Internet.

From MasGrafx:

This is a short and simple ” How to” for making custom backgrounds for NR2003

The BMP needs to be 800 pixels X 600 Pixels.

Step 1. Create or edit your image in Photoshop or Paintshop pro and save it as a BMP 24bit windows format.

Step 2. Open the BMp you just created with WINMIP.

Step 3. Save the BMP as an STP File

Step 4. Rename the stp you just created to main.stp

Step 5. Go to your C:\Papyus\NASCAR Racing 2003 Season\layout folder and if it is not there create a folder called bkgrnds.

Step 6. Place the main.stp in the bkgrnds folder you just created.

Step 7. Fire up your game and you know have a new background.

Note. this will replace the main background, to overwrite a certain mods background you will have to name your stp file mainback.stp and place the file in the appropriate mod series folder for example i want to replace the background in the arca mod with a custom one i would place my mainback.stp in the

C:\Papyus\NASCAR Racing 2003 Season\series\arca\ folder

Hope this helps everyone in making their custom backgrounds.


If you experience crackling or popping in your sounds, edit your CORE.INI file

Change the following lines. The CORE.INI file is located in your “<drive letter>:\Nascar Racing 2003 Season\” directory.

Papy CORE.ini suggested settings.



16 thoughts on “Various tips & tweaks to improve Papyrus Nascar 2003 Racing performance”

  1. i was messing around with the ai_drafting distance, and i went to daytona and i put the drafting distance to 1.22. that was pretty cool, they race pretty good and i was in the big one, but at the beginning of the race everything was calm and it was like a real race until i blew my motor and spun out while leading which caused a 26 car wreck. but later as the race was almost over 12 lead pack cars started to get in posistion for the finish and they were racing 3 wide 4 rows back and then a bobble and a wreck, i think what the ai_drafting distance does is make the race closer and the cars get up closer to ai opponets and then pass

    • Best way to get green flag from standing start to a shorter distance to start finish line, some tracks are are so far away the front row gets a ten second league

      Any ideas

  2. oh and actually you CAN edit the ai_line modifier, lets take atlanta for example, the line modifier is at 1.00 by increasing it to about 1.04 or 1.05 the ai will cause occasional wrecks, do not go over 1.10 because the ai will always wreck, the higher you go the more wrecks you get, i have changed this on all my tracks and it is awesome, take this line out for superspeedway tracks

  3. If u guys want to have alot of fun do this: at dega or tona take th ai_drag modifier and put it at -15.00, put it at negitive they should hit like 1700mph at end of straight and once they get there well u can imagine wat happens

  4. hows it going? im running a sim cup race at bristol (trying to get caught up to this weeks m-ville race. the two problems im having is that when the caution comes out, these 2 things keep happening:

    1) When slowing down, the AI cars run into each other and wreck (causes some to DNF).

    2) Pace car doesnt always pick up the leader when the leader is among lapped traffice (tail end of lead lap).

    how can i make it so that when the cars check up for a caution, they wont wreck each other, and how can i get the pace car to pick up the leader…and not trap the tail of the field.

  5. Iv’e Downloaded 2 Mods For nascar 2003. But both of thier Paint Shops Seem to not fuction properly. I Cannot Paint any Car At All. Is there something i can do to fix this?

    Many Thanks Jeff


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