HI John,
I recently upgraded to the V Star 950 in August, the light blue two tone, I now have 3,990 miles on the odometer, I also purchased the quick release back rest for my wife, and I also was thinking about changing the exhaust to a cobra 2215.
From what I have learned, if you modify the exhaust to get more flow and horse power, with a EFI O2 sensor ed fuel system such as the 950 employs, you will end up with a slightly leaner condition than stock, without re-mapping or installing a fuel management system.
And some folks believe that this slightly leaner than ideal condition will only result in more popping upon deceleration and only a slightly higher than normal temperature. then some opt to play it safe and install the fuel management system.
There are two schools of thought here. Some say if you only add slip ons after the O2 sensor, the system should handle the change in back pressure, without re-mapping or, fuel management.
But I haven't seen any actual Dyno data, done by those that do not install a fuel management system either. And they are reporting increased popping upon deceleration.
The people at cobra recommend one, and half of the mechanics that I spoke with disagree and say that you do and the other half say that you don"t.
It has been recommended to me, that if I'm going to modify the exhaust, I may as well go the whole distance to maximize the Horsepower output, by using a fuel management system and a better Air box anyway.
If you do install the fuel system, you will need to play with the POT settings for the Low Mid and High range settings, but this will vary depending on your slip ons and air box and atmospheric changes.
Personally, If I change the exhaust to the Cobra slip ons I will most definitely install the Fuel management system and a higher flow air box.
You're probably safe if you just add the slip ons, but if you change the whole exhaust system or modify the Air intake box then definitely get the fuel management system.
Dennis