Intake Runner Length for 19,500RPM engine

Hello

I'm currently undergoing a university engineering project of efi swapping an old 1989 Honda CBR250RR MC19. For those who don't know about the bike, it's an Australian/Japanese only 4 cylinder 4 stroke motorbike that can rev to 19,500rpm. It's also super light for a super sport motorbike at 150kg wet. Engine specs and details are in the attached PNG

The bike was developed back in the late 80's and through the 90's by pretty much the same engineers who made the Formula 1 cars of the time. It's gear driven cams, meaning it's a set of straight-cut gears running from the crankshaft to the cams, leaving 0 way for it to skip timing. The entire thing is aluminum, making everything extremely light. The 2 models of the bikes are the MC19 (1988-1989) and the MC22 (1990-1999). The key differences engine-wise wise is the 22 has much smaller cams and a slightly different crank. Most people on the internet will say the 22 is a better bike, but after speaking to a man who's owned and raced over 300 of the bikes, he said the 19 is better for a race bike, so that's what I'm doing.

In terms of where I am in the project. I've rebuilt the entire engine and polished the intake of the head, the ports are already a perfect size, just the casting is a bit how you going. I've conducted some research on the calculations to use for determining intake runner length. The main equations I've come across are those related to calculating harmonics. The intake cam has a duration of 232 degrees and has 30 degrees of valve overlap with the exhaust. It's also 92mm from the valves to the edge of the intake port. From the spreadsheet I've created (Image attached) I've noticed some lengths appear across most rpm ranges and harmonics, which makes me believe that "theoretically" that's the best runner length when tuning for harmonics across the power band. But I am going for peak power track bike over a daily driver, which made me wonder. Do I want a shorter runner length ~180mm to allow for better breathing, but only utilizes the 4th harmonic at peak rpm, over a slightly longer runner at ~240mm, which would utilize the lower 3rd harmonic which in tern would give more power? I feel like the only way to really know is by testing it in the real world on a dyno and was wondering if anyone had any experience with something like this? Due to such a high rpm nature I'm not sure how different everything acts compared to a standard low rpm of sub 10,000rpm. Any guidance or experience would be incredible.

Thanks!!

Excel:

Blue: Harmonics 1-10

Red: Wont fit in engine bay (too short or too long)

Green: Will fit

Orange: What I've noticed to appears across the largest range of rpm

What were the specs of the original intake? Maybe you can measure one in a museum or something. I would think that would be a good starting point.

My experience is the shorter the intake, the more power at higher RPM.

Hey David,

The original intake is 4 individual carbs that are 300mm - 320mm long. It's got 2 different size rubber stacks 1&4 320mm 2&3 300mm. This distance optimizes for peak power much lower down to make it more dailyable at 10,000rpm, they are also old complex carbs so take up a lot of room because the thing does make usable power from 2000rpm to almost 20,000rpm so they have a butterfly and a air speed regulated slider that opens at ~10,000rpm to allow more air therefore more fuel. My goal is peak power closer to the 15,000-17000rpm range so I'll be running just 1 throttle body instead of 2.

Thanks