Its not an s2000, but pretty interesting none the less. I'll be taking what we're learning w/this to build a header for my 2.4liter motor thats coming together for my S!

The header on our shop car (EG hatch with k24) had a pretty crappy stamped collector on it that kept falling off and was generally irritating, so I bought a merge collector and a megaphone/reverse cone from mandrel-bends.com.

This is what we came up with



Here's the dyno - Orange line is the header how it was, green is after we changed the collector




Picked up a ton in the middle and lost some up top

The header has 1.75" runners that step to 1.88"

The megaphone is 2.5" to 5" then down to 3"

I picked the megaphone/reverse cone size with no rhyme or reason.

This is on pump gas

k24 87.5mm
+5cc wiseco pistons
stock crank with cheapo rods
RLZ CNC RSX-S cylinder head
Drag Cartel 4.5 cams
Excessive center inlet intake manifold with 58mm runners and q45tb


Here's the car

 

You should try moving the megaphone further away from the header collector.

Read up a bit about expansion chambers in 2 cycle motors, and it will start making sense how expansion chambers can play a big role in tuning a car with big cams.

 

we wont be doing anymore testing on this motor... chucked a rod on the dyno last night. 3/8" arp 2000 bolts are NOT ok for a k24 being beat to 9800 rpms... haha