Walshmo Racing - Honda S2000 K2F Exhaust Header
For a stock Honda S2000 there really isn't an exhaust header that makes consistent gains over the OEM header. Some of them offer more peak or mid-range but sacrifice some power here or there... The only real benefit is the weight savings over the stock header.
The same scenario happens when it comes to K24-swapping a Honda S2000. The other aftermarket headers make less power but they do weigh less. We've found that the best option to go with is an OEM Honda S2000 header with a welded K-series flange (from Vibrant Performance).
Trying to find a local fabricator or exhaust shop to perform this operation can be hit or miss. The two middle exhaust runners do not line up so they need to be spaced out to fit their new flange (the K exhaust ports are more evenly spaced than the F exhaust ports). The "easy" option seems to be to cut the middle runners and re-weld them to fit however this can be a time consuming process that yields a lot of internal imperfections in the once smooth header runners.
Instead of worrying about your exhaust header cracking or robbing you of power in your K-swap have Walshmo Racing send you a ready-to-install header. We heat and bend the middle runners and smooth the internal passage after welding the new flange to them - no messy cuts, no rough exhaust runners.
We have a stockpile of already modified K2F OEM Honda S2000 headers and can provide you a ready to install header (the core is included for an extra $200) or you can send us a core and we will modify it and return the exhaust to you!
This is the Vibrant Performance exhaust flange we use: https://vibrantperformance.com/mild-steel-exhaust-manifold-flange-for-honda-acura-k-series-motors-14610k/