700HP Inline 4? How?!

[CableTooth]

So, I have been trying to enter the Focer WRC exclusive Rally event which is also limited to class A vehicles. That means I have to get an Inline 4 engine to 700 or more horsepower. My problem is that the best I could do was 631HP with the Shimutshibu engine components, including the more expensive Shimutshibu turbo and methanol fuel.
Even after tuning the turbo to 2 bar and setting the fuel mixture to 16:1 A:F I could not get further. I tried to mess with camshaft timing, it did not help much though so I scrapped that.

Is there an engine configuration I am unaware of, cam tuning to be done or is it just not possible to build an engine like that anymore due to updates changing how power works?

Even if I cannot be done, I wouldat least like to know what is going on here.

[g13ba]

Here is the max i4 build
https://steamcommunity.com/sharedfiles/filedetails/?id=923994550

[Deputy Rage]

However adding the 20cv transmission to this engine setup gives the best drag times. Just saying.

[strike9716]

U need the duhen 20 block, duhen 1.5 conrods and pistons, then I think it's a shimutshibu head, I don't remember the cams, I think they're ishimas, methanol fuel rail, ishima superturismon turbocharger.