[imwright1985]

i have built quite a few choppers and dont remember useing stock pipes on any of them.as far as break in,if you put me on a chopper i will break it in.

its better for the break in to leave stock on, temp differences through the pipes cause the metals in the valves/heads to react differently (look up Precipitation hardening or age hardening) stock exhaust allows more of a controlled environment for this to occur since machines only go sofar then it requirements change on operating conditions, which is why you should vary throttle position, not rev much at beginning and progressively build up to being able to run wide open

 

[imwright1985]

it sounds like you know your stuff, but most people who can afford and want the new pipes at original purchase. i imagine those same techniques you described will be good for new pipes, are there any other techniques for those that do get new pipes at original purpose, like making shorter runs with the bike at first, then building up milage? just curious

its mostly from how hot and how long the temperature differences are. That is why alot of Dragsters run wrapped pipes to help sustain higher temps through the inside of the pipes when not running to allow a more gradual cooling. along with some instances keeping areas outside of the pipes from getting too hot. You want to kinda simulate that gradual cooling. If you look at the stock muffler design it is chambered like a standard car muffler then has a catalatic converter built in on the front side. the cat has a chemical reaction which builds heat in the exhaust gasses so it provides an effect of like a temporary heater element too. Most aftermarket pipes are a straight shot with a glass packed or meshed lining that comes in a certain distance from the walls for a certain length of the tube. So cooler air will flow back through the pipes more rapidly

Pipes arnt hard to put on, and if its like the dealers down here with pipes and cobra FI2000r they raise the cost by about 2k which is way over priced since it will set you back about 1k or less to DIY

Roughly 600 for pipes and about 200-250 for Cobra fi2000 or 260-360 for powercommander

My look into it would be Ride it stock for break in to help insure that everything is ontrack, then while doing that shop the other options rather than just Cobra Swepts like the Fuggin, Roadhouse, Vance & Hines, the other cobras, Samson, and modded options Like i did with my Jardines. Then i would go with either the Cobra FI2000 for the ease of tweaking, or power commander for getting everything set more precisely. It would allow you time to familiarize yourself with the bike and not annoy the neighbors too much, and clearly think out the setup you want