arrow headers

[twinrider]

I wonder if any of these exhaust systems are properly modeled for maximum area under the horsepower curve. My racing partner and I have spent thousands in dyno testing, many hours in fabrication, many hours in modeling using PipeMax and other software, to extract the best area under our usable RPM range for our race motors.

While that's probably overkill for a bike application, I'm thinking a little R&D along with some properly sized Burns merge collectors could really pay dividends for the Super T engine. And once it's done and the knowledge is known, it doesn't cost any more to make a perfectly matched set of headers as it does to make a crappy version (as long as we're not talking too crappy). More or less thinking out loud, but a set of headers for the SuperT might be a pretty fun winter project.

Step one though would be to get cam specifications on the intake and exhaust cams. Is that information available? Clearly I could measure the cams in my motor but if the information is out there it'd save a lot of work. Step two is going to be some flow numbers from the head as well as physical dimensions of the ports, valves, and seats.

The Arrow headers add a lot of power. Here are dyno charts of my bike, lower line is the bike with a flash and Akra slip-on, higher line is the addition of the Arrow headers and PCV.

HP

Torque

 

[Rasher]

I once posted dyno results, the headers with no other mods added 6BHP (same dyno just a few weeks apart) with a full dyno setup another 4-6 was added - not exactly sure as I went to a different Dynos at various times and had two ECU Flashes so not easy to put exact numbers, but what was plain to see was adding the headers gave more power throughout the curve.

Looking at my dyno results it would appear that with the headers and dyno setup it was making as much power by around 6,000rpm as it made at peak in stock trim - so max original power 1500 rpm earlier, my butt dyno told me it pulled noticeably harder through the mid-range and had gained a lot of top end whack and no longer felt lethargic towards the red line.

Glad I had mine done.