| Author | Message | ||
     Toomanytoys |
What damage (if any) will occur from running my bike without a pipe on it? It is a 99 Lightning, so it is fuel injected. will it run rich? | ||
| Leftcoastal |
The main damage will be to any amicable relationship you may have had with your neighbors and your local constabulary. AL PS do you mean MUFFLER? "pipe" usually means head pipe or full exhaust system, and you obviously know that you need some kind of header from the heads. It'll run like crap unless you re-map to compensate for the different flow. | ||
| Ingemar |
I would never recommend running it without header pipes. I think you CAN damage the bike. Small things can get sucked or blown in. | ||
| Toomanytoys |
coastal is correct. i meant to ask if you can run the bike without a muffler. it sounds really mean that way. my muffler is off for welding needs (broken exhaust mounts) and i started it up just to hear how it would sound. header pipes are still on. i know enough not to run an engine with no headers. | ||
| Ceejay |
Ooh boy those do sound mean that way, try a force if you like it that loud, but beware of fires on you lawn from p---ed neighbors and getting chased by the boys in blue. BTW I was told it is still possible to warp a valve when running with just the open header, due to the short distance and large tubes. | ||
| Soundman |
I agree with Ceejay, I have some experience with drag cars, and we overheated the exhaust valve when we switched to open headers (dump valves). when I asked a more experienced mechanic about it, he said there was not enough scavenging with such a short pipe that it overheated the valves & seats. This of course would not apply to real race prepped heads (stainless or TI Valves, better chambers etc.) FYI-we were running an older AFX Pontiac with limited mods. If the bike has stock valves & heads, I would not risk it. Soundman........ | ||
| Toomanytoys |
well i will hold off then. just thought it sounded awesome. hopefully having the muffler welded tonight, and then i can throw it back on. | ||
| Rammons |
Have you thought about a D&D pipe? Mine is LOUD as hell!  Bob | ||
| Panic |
Yes, that would explain why all those Rolls Royce, Allison, Mercedes V12 aircraft engines always blew up - short exhaust stacks. Oh, that's right... they didn't, did they? | ||
| Soundman |
Eh....What the hell do I know anyway? Sorry -my bong was all clogged up. Soundman...... | ||
| Buell_by_buhle |
Yep, it will run like crap, and longer term, you will kill the exhaust valves and seals with the extra heat not extracted by a properly scavenging exhaust. I ran the race headers and car Supertrapp muffler on my S2 without any baffles once, just to see what it was like--performance sucked big time! Typical H-D motors like lots of scavenging, and good mufflers help that function... | ||
| Outrider |
Help...Could someone define scavenging to me. The last I really knew folks that talked about it was in the 1970's and they were into drag cars. Since then, I must have killed a few too many brain cells as I can't remember the principle. Thanks, | ||
| Soundman |
Outrider, Scavenging refers to the natural vacuum that happens when an exhaust gas pulse that is exiting the pipe actually helps pull the next set of exhaust gases out. The shape / size of the pipe can maximize this effect. That is why there are so many pipe designs out there-it is a trade off. In general, the longer the primary pipes are (within reason), the more velocity the wave can attain. Also, keeping the pipe hotter before it hits the out side air can help. The hotter the exhaust gas is than the ambient temp is, the more it will expand. Since the next pulse wave is coming from the valve area-or the upstream valve is now closed, it only has one way to go. Since the exhaust pulse is "overheated" , it escapes with more velocity, thus pulling the next wave in the pipe even faster. Since the exhaust is leaving the chamber faster, the vacuum created pulls the intake charge in faster-thus more flow-thus more power. Mr.Panic-brings up a good point, even though he left out the mighty Packard engines. The "Short stacks" he spoke of would be only natural since pipes equal weight and real estate (drag), and the props would create a natural low pressure area anyway. The faster the craft goes the greater the pressure drop would naturally be. Low pressure = vacuum. The best scavenger there is. The air up there is really cold. I'm pretty sure the huge difference in air temp would aid in scavenging as well. But then again, I freely admit I'm probably full of shat. I've been breathing Naptha all day and it turns out that I've been having a political conversation with a pine tree for the past half an hour. Soundman....... | ||
| Trac95ker |
You won't damage your valves. The header is'nt that short. It'll be loud and you'll lose performance because of no back pressure. I had an 85 sportster, hacked the drag pipes off right at the clamp. I rode that thing everywhere, through rain and snow. It was my only transportation. No bent valves! If there was cold air coming in contact with the valve, that may happen. The header will keep that from happening. | ||
| Koz5150 |
I think I need to make me a straight pipe for those HOG events.... | ||
| Panic |
What's the temperature of the air when the aircraft engine shuts down in Greenland... -30F? Grand Prix cars built in the 1920s-30s used very short straight stacks, Auto-Union V16 among others. Gordon Blair recommends 100mm/3.94" pipes for dyno tuning intake systems to remove exhaust pulses as a variant. The annoying reversion (scavenging off-cycle) normally caused by open pipes disappears when the pipe is so short that the reflection occurs at an engine speed way above the practical limit. The amount of traffic (multiple positive and negative waves super-imposed on each other, forward and backward gas flow) going on inside an exhaust pipe (let along a multi-cylinder system) is vastly more complex than I can summarize, and there are no reliable formulae that give anything but cut-n-try starting points. Damaging the motor is yet another "fact that everone knows" (along with "you need backpressure" ). | ||
| Soundman |
Yep, I was right. I'm full of shat! Maybe someone else can explain scavenging for Outrider.... Soundman........ | ||
| Jersey_thunder |
I've been breathing Naptha all day and it turns out that I've been having a political conversation with a pine tree for the past half an hour. DUDE, LET ME GET SOME OF THAT MAN...  |
