WRC 04 (Europe) lagging.

[JoelDB7]

Hi all, I was playing WRC 04 (Europe) on Nightly v2.1.105 and it kept dropping down to 30-35fps then back to it's usual 50fps every 5-10 seconds, I have played WRC Rally Evolved (Europe) (aka WRC 05) and it ran fine, no lagging at all.
Please help.
Thanks.

specs: GTX 1070, Ryzen 5 5600x, 16gb ram, game is an .iso file running off of a 1tb m.2, Windows 11 pro.
pcsx2 stuff:
Renderer: Direct3D 12
Adapter: GTX 1070
1920x1080
aspect: auto standard
fmv aspect: auto standard
deinterlacing: auto
bilinear filtering: bilinear (sharp)
anti-blur: checked
no-interlacing patches: checked
internal res: 4x
texture filtering: bilinear
anisotropic filtering: 16x
dithering: unscaled
blending accuracy: high
texture preloading: full (hash cache)
spin gpu during readbacks: checked
spin cpu during readbacks: checked
mipmapping: checked
contrast adaptive sharpening: none
fxaa: checked

[Zkybi]

How does the game run with everything set to its default options? not sure if it would help but it might.

Think there is a site where you can look at how well games will emulate in pcsx2 aswell so you might want to have a look there and see what its score is.