You should probably learn to use the Microsoft Application Compatibility Toolkit. Do that, go through the fixes and find out which ones break or fix things.

I've got that. Might have to do a "see what fixes the save game issue" step-by-step (as I did to fix NFSSE on XP), but the game takes a little while to boot up each time, so I might die of boredom! But yeah, it's probably one thing fixes it, and others break the input.

VirtuaIceMan wrote:

I've got a copy of Lotus Challenge, an Xbox port by Kuju, published in the UK by Sold Out Software. It has numerous interesting […]
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I've got a copy of Lotus Challenge, an Xbox port by Kuju, published in the UK by Sold Out Software. It has numerous interesting bugs on Win8.1 64bit, as follows:

2. When you run the game's config, don't set Z depth above middle or the game will crash saying your video card isn't good enough (this was the same on my older PC too).

3. There's no sound in the game (though the intro video plays fine). It seems to use HRTF audio from the log file, but is silent throughout

4. If you run the game without any compatibility mode it'll play fine, but you won't be able to load savegames (which are saved to the Documents/Lotus Challenge/SaveGame folder). However if you run the game with Win98 or Win95 compatibility mode then the savegames WILL load... but the cars will never leave the grid at the start of a race! Tricky one!

These are some important clues.
The Z depth above middle might be 32-bit Z Buffer, which Geforce cards can't handle (if it's what you have).
Regarding the sound problem it's worth to try Alchemy as it places a different dsound.dll inside the game's folder. "CorrectSoundDeviceId", "WaveOutIgnoreBadFormat" and "WaveOutUsePreferredDevice" are some flags in ACT that try to fix sound related problems.
About the savegames, the flag "CorrectFilePaths" might fix loading them. The cars never leaving the grid might be caused by the flag "IgnoreScheduler", which is present in Win9x compatibility mode.

Just tried all of them (incidentally ToCA Race Driver series run with 32bit Z Buffer (GTX 980)), but no difference.

Looking round the web, other people have reported the lack of sound in Lotus/GT-R 400, and also in Crescent Suzuki Racing, which uses the same engine. No one has any idea of how to fix it, the sound works in XP but not in Win7+.

I just had a go running GTR-400 in WinXP virtual machine (via VMware Player), and the sound worked fine. The game has a sub-folder called "savegame" and in the logfile.txt it has these 5 lines, which are entirely missing on Win8.1:

1Found sound device[0]: 'Primary Sound Driver' driver:''
2Found sound device[1]: 'Creative Sound Blaster PCI' driver:'es1371mp.sys'
3Soundmanager using 128 buffers - no hardware 3D
4Features: continuous rate,  
5 Sample rates: 4000 -> 48000

I tried using ALchemy (no difference), putting the es1371mp.sys file from the WinXP virtual machine into the game folder (no difference), tried IndirectSound (no difference), although IndirectSound's log says this:

1[[===========================================================================]]
2  This file is automatically generated every time that IndirectSound is used
3[[===========================================================================]]
4
5IndirectSound was loaded statically at process startup
6The IndirectSound library being loaded is located at D:\Games\gtr400\DSOUND.dll
7	Version -- 0.12
8The process loading IndirectSound is located at D:\Games\gtr400\GTR400.exe
9	File version info doesn't exist
10IndirectSound is being unloaded because the process is terminating

Copy dsound3d.dll from your XP VM's system32 to the game directory (tested with some random GT-R 400 and Crescent Suzuki Racing rips I found).

Perfect! This works fine, both on GTR-400 and Lotus Challenge, sound is back! I guess the games checked for that dll, which isn't included in newer DirectX.

If anyone else needs the file, you can download it here (unzip it into the game folder for GTR-400/Lotus Challenge/Crescent Suzuki Racing):

A bit off-topic, but any solution to get controllers working properly in this game?