Just got a 2008 Dyna super glide, what's the view in relation to slip ons vs the rest? Is there anything I need to know, is it just a noise factor difference? - Prabs
missread the post nvm
Same as Hilly said. Also the longer pipes make more torque (grunt), thats why the touring bikes have the pipes extending past the back wheel and part of the reason they make more power with the same size motor. The stock pipes are not as bad as most people think, the crossover valve between the pipes if fitted is there for a reason and gives a wider torque band. The problem is the standard mufflers which need to pass the Gov noise regulations worldwide. S&S have some good slip on's (check web site for dyno graphs), read on here somewhere, someone passed the noise machine with them fitted (use the search function on this website). Supertrapp make slip on's too. Stay away from the short loud pipes as they are best for making noise, looks if thats what you prefer, attracting cops and needing a hearing aid. Short pipes give less power down low where you spend 99.9% of your time on a street bike and drop the fuel economy as well, hearing loss is permanent and increases with age, hearing aids are how much?
I prefer a complete Supertrapp system due to the extra length, they are 2:1, which helps the torque and tunable if you are constantly upgrading the motor, its much cheaper to add or remove a few disc's than buying new pipes each time, move the torque curve up and down or make it quieter. More discs, more flow and less back pressure, less low end power, more top end and more noise. Less discs is less flow with increased back pressure for better bottom end power, less noise and less top end. A bit like what Harley tries to do with the crossover valve in the exhaust system. Nearly everyone puts too many discs in them though. Guess its like having the biggest throttle body or tyre you can fit on there but it might not be the best size. Try taking all the discs out of a set of Supertrapps and see how well your bike goes if you think a straight through pipe is best. It's a safe bet you will end up putting less discs back in than what you had before. I've got exactly half the number I had a year ago and my bike is faster and quieter=less cop hassles and having to swap pipes to keep it registered, plus the time and cost involved. I started off with second hand Supertrapp slip on's fitted to the standard pipes, for about $200 on ebay which worked well and got a, as new, complete Supertrapp system, when some one wanted to off load them cheap after passing the noise test on a big budget custom chopper. Supertrapp have several different mufflers (outright performance or quiet cruise) which can be swapped without removing the header pipe. Sold him my standard mufflers a couple of years later to pass the noise test again. Whinging about the cops is not going to change anything.
I my opinion, best result for dollars spent if buying new gear is slip on's, personally don't think much of any of the Screamin Chicken stuff, especially for the price they charge. Keep the standard mufflers in case you get caught out as they are not worth much to sell. Be careful, modifying a Harley is addictive and expensive, lol.
EDIT IN, My Supertrapp muffler is one of the quiet ones, it has a centre pipe about 2 inch with hundreds of little 3 mm holes in it surrounded by some fibreglass. In the middle of the pipe was an insert which forced the exhaust gases to do a Z or go through the holes and fibreglass. One or two bolts has the muffler in pieces, used the dremel to cut through the tack weld that held the restrictor in and now the exhaust gases can go straight through without any restrictions. The fibreglass does seem to make it quieter and have kept it in as it does not restrict the flow or performance. Ever noticed that the two standard mufflers have different internals, look the same but they are different.
Well put, Captain Hook! I liked your "hearing loss is permanent and increases with age, hearing aids are how much?" HOW MUCH? PARDON ME, CAN'T HEAR YA! After refitting its V&H Big Radius 2x2 on my US import Fatboy (post compliancing with the standard sewing machine pipes), I very quickly realised that I was on a fast track to deafness (as well as financial ruin) and had to put in some custom quiet baffles asap. Don't know if the US spec exhausts are louder than similar exhausts sold here, but it was a relief not to ride round like one of those hear-me-from-the-next-suburb-how-cool-am-I morons.
Hi fatbat, Just to clarify, my custom-baffled V&H BR 2x2's are in no way quiet (like a standard bike) nor will they ever pass an EPA test. But, the harsh bark has been toned so that one does not come back from every ride with a splitting headache. Also, as I mentioned, at low throttle openings, one can trickle through built up areas without attracting undue attention. But, say, if your are in a flowing country road where you are shifting up/down through the gearbox and accelerating hard, then it is really loud. Cold starts are still bloody LOUD! Even though I live in a suburban house, I open my garage door only after the bike has warmed up / quietened down - this startup noise would be a big problem if you live in a townhouse / apartment complex. Well, I had an acid test yesterday: I was riding down a main road, coming up to the lights at the entrance to my housing estate, I need to turn right, I find a police car ahead of me waiting in the right turn lane, I pull up behind him, 30 seconds later another cop car materialises out of nowhere and sits behind me so that I am sandwiched, my V&H BR2x2's are going THUD THUD THUD (or maybe it was my heart), I am going "Sheeet, This does not look good" but I am not worried as I am just an ordinary suburban dad with a whistleclean record, the lights turn green, the cop car in front does a U-ey at the lights (interstaters: this is legal in VIC), I turn right, the cop car behind me follows me, "Oh frigging Hell, Must be the pipes, There goes $600 or whatever is the bloody fine".. I accelerate very very very slowly so that the BR2x2's just burble, another 100m down the road there is a break in the divider, he also does a U-ey and goes back to the main road! Well, I am now with fingers, toes etc crossed, will know within a couple of weeks if my luck has finally run out!
