Cheap Exhaust

[JackB]

Has anyone bought one of those cheap exhaust's from eBay.
Brand names are hundreds of dollars but on eBay they are about 50 bucks or less.

51mm Inlet Stainless Steel Motorcycle Exhaust Pipe muffler For BMW Harley Honda 6847024962730 | eBay

 

[Smallville]

You would have to come up with some sort of link pipe to go between the muffler and header pipe. Then if you have a center stand, there is no bumper.

If you want a cheaper exhaust that still retains quality, buy a Delkevic.

 

[superdedooperman]

Ditto on the Delkevic, mine was about $185. I have the stainless steel 9" Oval. It is great quality and sounds really good. It has the centerstand stop included.

 

[Mainsail]

Here's my 14" Delkevic

Fit was perfect and has the bumper for the centerstand. I wouldn't take a chance on a one-size-may-fit ebay brandless that will require even more money and work to fab up the parts that are missing. If you work in a muffler shop I can see it.

 

[Rapturee]

+1 Mainsail..! I chose the DanMoto and really like it. Mine was about $140 shipped to my door and an easy install i did myself. It came with all of the necessary parts and looks great IMHO. :{)

 

[potter0o]

I would be concerned about an ad that distorts the logo.

 

[Jos]

An exhaust is not just a straight pipe. Each bike has a specific exhaust flow which is critical for proper engine operation. I just can't see how an exhaust can be universal.

I would not trust that kind of 0-design Chinese knock-off. Or any unknown brand.

 

[b_rubenstein]

Each bike has a specific exhaust flow which is critical for proper engine operation.

Seriously? The engine in the NC produces less than 75 Hp/liter. That's 2 Hp/liter less than the engine in my Honda CR-V. Exhaust tuning is critical for racing engines, but not so much for street bike engines. Street bike engine exhaust requirements are primarily driven by pollution / noise emission requirements and aesthetics.

 

[Jos]

And the fact that the ECU piloting injection is expecting specific behavior for the flows. When you change exhaust flow you alter intake flow, the ECU usually does not compensate that (measures "only" concern temperature, throttle opening, outside air pressure, O2 level).

And the worse part is altered shock waves propagation that if not properly tuned may damage exhaust valves.

Well, do what you want, there is a reason most owner do not install cheap pipes.

 

[mahbin]

Seriously? The engine in the NC produces less than 75 Hp/liter. That's 2 Hp/liter less than the engine in my Honda CR-V. Exhaust tuning is critical for racing engines, but not so much for street bike engines. Street bike engine exhaust requirements are primarily driven by pollution / noise emission requirements and aesthetics.

The nc700x pulls about 48 to 49 HP at 6,000to 6,100 rpm! go to youtube and put in Dino nc700x!

 

[670cc]

The nc700x pulls about 48 to 49 HP at 6,000to 6,100 rpm! go to youtube and put in Dino nc700x!

Yep. That’s about 73 hp/liter, less than 75 as stated above. This assumes we’re talking about the 670cc engine.

 

[b_rubenstein]

670cc engine, because that's what's sold and measured here. Again, this is a low performance engine. One could spend lots of time doing pulls on a dyno and remapping the ECU (If anyone actually knows how to do that for this ECU, since this bike doesn't get much/any attention from the go fast crowd.), and the performance increase will be negligible. The only performance increase comes from a better power to weight ratio, since typically aftermarket exhausts weigh less than the OEM one. With a 475 lb. wet weight and a 175 lb. rider, a 13lb drop in exhaust weight gives a, try to contain yourself, 2% better power to weight ratio. The only perceptible difference from an aftermarket exhaust is sound and aesthetics.

 

[Jos]

Worse, with a cheap exhaust you may loose power (torque in useful ranges) without remapping.

 

[superdedooperman]

Only speaking for the Delkevic, there's no felt power loss or gain over the OEM muffler. Just sound and aesthetics as mentioned above. I'm sure most of us can agree that we don't get an aftermarket exhaust (on the NC) for a power gain!

Although, with the really cheap ebay cans, I can't imagine you'd lose so much power the bike wouldn't function well. If anything, I would think it would be a few HP at most. Not condoning a super cheap one, just my $.02!

Personally, I didn't want to go any lower than the Delkevic. It had proven quality, welds, and a centerstand stop. The only other I considered was the Danmoto XG-1.

 

[b_rubenstein]

Worse, with a cheap exhaust you may loose power (torque in useful ranges) without remapping.

There are a near infinite number of thing which may happen, but you have no first hand knowledge or experience with any of this to know what the most probable outcomes would be. You are just a poser regurgitating stuff you've read somewhere.

 

[Jos]

There are a near infinite number of thing which may happen, but you have no first hand knowledge or experience with any of this to know what the most probable outcomes would be. You are just a poser regurgitating stuff you've read somewhere.

There is also experience and real world cases. I troubleshooted multiple cases of engine misbehavior due to untuned exhausts solved by remapping (when a map exists) or putting back the stock. I had to remap one of my bikes after putting an Arrow as performance was noticeably decreased with the original map. I witnessed one case of engine breakdown due to broken exhaust valve most likely due to a bad exhaust and overheating.

You keep thinking an exhaust is just a pipe, whose diameter, length and shape do not matter, that's your opinion, I do not insult you for it. Let's talk again when you have a few tens of thousand miles with a universal exhaust on a bike.

 

[JackB]

Thanks the Delkevic exhaust looks like the way to go. I would like a little more noise but not loud.

 

[superdedooperman]

Thanks the Delkevic exhaust looks like the way to go. I would like a little more noise but not loud.

Good choice! Definitely no where near obnoxious, but adds just enough rumble to hear while riding and enjoy (if that's your thing).

 

[b_rubenstein]

That's a fairly strong reaction to Jos' comment. What is it that leads you to believe it is not accurate or is invalid?

4 stroke engine performance tuning is based upon pressure waves and exhaust geometry to increase engine performance. The classic reverse cone megaphone increases performance by first having a long increasing diameter cone with a short decreasing diameter cone at the end. When the exhaust valve open a pressure wave is created and when it travels to the long cone, the speed of the wave speeds up and creates a low pressure that helps to scavenge the exhaust gasses. When the pressure wave reaches the reverse cone reflects the pressure wave back up the exhaust to decrease the amount of fresh charge that would otherwise escape from the cylinder. Like a musical instrument it's tuned by its geometry to most strongly work at a single frequency. Reciprocating internal combustion engines are fundamentally air pumps and are most efficient when tuned to work at single speed/frequency. This is why vehicle automatic transmissions keep getting increasing numbers of gear ratios, or infinity variable ratio transmissions. This is also why variable pitch props were developed.

So, when one changes the muffler only a part of the exhaust system is changing and it's not part of the tuned system. The tuned part of the exhaust is the header pipe out of the engine to the muffler. What the muffler does is disperse the energy in pressure waves in the exhaust. So long as the stock muffler doesn't restrict the bulk flow out of the exhaust, an after market muffler won't increase engine power. The NC engine has two other things that diminish the ability to tune the exhaust: the catalytic converter that disperses the energy in the pressure waves, and, just like the intake, the exhaust ports are siamesed in the head co-mingling the exhaust pressure waves.

Design elements specific to the NC engine eliminate, or severely limit, the usual approaches to increasing engine power by changing the exhaust system.

 

[eastbayandy]

When i bought my used '12 700x it came with an aftermarket Danmoto can. one of their cheap ones. it looked and sounded fine but developed a crack at a weld , so I bought another brand off Amazon. Think I paid $60 for it. You could run it full baffle. the baffle w/o plug, or no baffle. I liked the medium setting. I was pretty happy with it , but I sold the bike so I can't attest to the longevity.

NICECNC Carbon Fiber Painted 1.5-2"Inlet Exhaust Muffler with Removable DB Killer for Street/Sport Motorcycles and Scooters with 38-51mm Diameter Exhaust Pipes