EuroAccord13, sounds like your current mods and tuning have made a big difference to the real-world acceleration of the car

Quote Originally Posted by EuroAccord13 View Post
What we've found with the single vs. dual outlet system is the same as what JTune has found, in short, the flow is much more optimum for the application I am using.

Mind you, there is nothing wrong with the single outlet setup, but it does have a limit to it if you are going to push maximum gains.
I'm still not sure why a dual outlet system would flow more than a well designed single outlet exhaust? Maybe the single outlet exhaust you initially tested had poor flow for a differnet reason (type of muffler used, workmanship etc.)

All of the high power k-series in Australia and in the US all use single outlet exhausts. The JDMYARD k24 is using a 3" single outlet exhaust and is making 178kw atw. I've also seen other cars in the states running single outlet 2.5" systems making 230whp or more. I still doubt a single outlet exhaust would be more restrictive. By adding a Y join all your doing is splitting the exhaust gasses, forcing them to travel through two mufflers and ultimately reducing the velocity of the exhaust gases/flow.

If I remember correctly, Jtune designed a dual outlet exhaust for cosmetic and noise reductions reasons. Since the product was "inteded for a mature market". I'm sure their design flows really well but I have a feeling it'd flow better if it was a single outlet 3" all the way through.