BIG--T
Member
Posts: 3002
1998 Standard, 2000 Interstate
The Twilight Zone
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« on: June 29, 2011, 07:58:58 AM » |
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I already posted "sick as a dog" and I just remembered that I took out the baffles out of my Cobras6-6 over a week before my trip. The group I ride with, all V-Twins/Harleys were so loud that I couldn't hardly hear mine with the baffles in which was ok until we were all stopped and some were idling, others engines off. So it was so loud I couldn't hear myself think and when to crank mine, hit the starter and it was already running! That happened twice so I wonder how the starter gear and flywheel looks.
I do love the sound and prior to the trip I would WOT in short bursts around town and never noticed a power loss. I just read on You Tube a guy said Cobras don't have to be rejetted unless you remove your baffles and the guy I bought mine from "thought" the original owner rejetted it. So I don't really know.
So could removing my baffles result in a loss of power and mpg and all the problems on the other post?
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Redline +
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« Reply #1 on: June 29, 2011, 08:31:22 AM » |
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So could removing my baffles result in a loss of power...
When I had the Cobras, removing the baffles was good for an additional 5 hp and 5ft lbs. Others will tell you it hurts performance...depends on the bike and how it's tuned. I don't think this is your problem. Redline  |
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Bobbo
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« Reply #2 on: June 29, 2011, 08:44:01 AM » |
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Exhaust baffles do two primary things. They help silence the sound by causing the the gasses to flow around the many "bends" formed by the baffles. They also reduce pressure harmonics (echos) in the exhaust. These pressure harmonics can cause higher or lower pressure at the exhaust valve outlet when the valve opens. Improper exhaust outlet pressure inhibits good scavenging, which is needed for both power and economy (efficiency).
To answer your question simply, yes, removing the baffles will reduce power and MPG in typical driving.
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Bobbo
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« Reply #3 on: June 29, 2011, 08:51:59 AM » |
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So could removing my baffles result in a loss of power...
When I had the Cobras, removing the baffles was good for an additional 5 hp and 5ft lbs. Others will tell you it hurts performance...depends on the bike and how it's tuned. I don't think this is your problem. Redline Unbaffled exhaust pipes can show peak power gains on a dyno at WOT and high RPM. That does not mean that same increase is available at different throttle settings and RPM. If you look at torque readings through the usable RPM, you will often see lower values for the majority of the range. Exhaust tuning is a very complex and dynamic thing. Most designs focus on overall power and drivability, rather than peak output. |
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The Anvil
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« Reply #4 on: June 29, 2011, 09:00:33 AM » |
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It's true. Open pipes add HP in the top of the rev range and usually hurt performance in the midrange and low rpm areas. Going to wide open pipes can also affect rideability, but not typically to the degree you're experiencing. Usually you just find some leanness and midrange power loss and sometimes some stumbling.
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Boxer rebellion, the Holy Child. They all pay their rent.
But none together can testify to the rhythm of a road well bent.
Saddles and zip codes, passports and gates, the Jones' keep.
In August the water is trickling, in April it's furious deep.
1997 Valk Standard, Red and White.
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9Ball
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« Reply #5 on: June 29, 2011, 09:30:17 AM » |
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running too lean will definitely rob power. You'll get a lot of popping and stumbling when the throttle is either applied or released rapidly.
Should be easy enough to put the baffles back in and take a ride to verify.
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VRCC #6897, Joined May, 2000
1999 Standard
2007 Rocket 3
2005 VTX 1300S
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BIG--T
Member
Posts: 3002
1998 Standard, 2000 Interstate
The Twilight Zone
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« Reply #6 on: June 29, 2011, 10:13:27 AM » |
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A big thanks to all. So this must have nothing to do with the sick as a dog problem I'm having. There is no popping and she runs smooth as silk, just not as fast. I wish I knew for sure if it needed to be rejeted putting on the Cobras.  |
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Bobbo
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« Reply #7 on: June 29, 2011, 10:21:51 AM » |
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A big thanks to all. So this must have nothing to do with the sick as a dog problem I'm having. There is no popping and she runs smooth as silk, just not as fast. I wish I knew for sure if it needed to be rejeted putting on the Cobras. The lack of baffles may be contributing to the problem. The only way to know for sure is a dyno run with a "sniffer" in each pipe. You will be able to see the A/F mixture at different loads and throttle settings. A good tuner will be able to set up your carbs and pipes for best performance, but it can be very expensive. |
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Redline +
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« Reply #8 on: June 29, 2011, 10:47:14 AM » |
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So could removing my baffles result in a loss of power...
When I had the Cobras, removing the baffles was good for an additional 5 hp and 5ft lbs. Others will tell you it hurts performance...depends on the bike and how it's tuned. I don't think this is your problem. Redline Unbaffled exhaust pipes can show peak power gains on a dyno at WOT and high RPM. Is there any other way to ride a Valk?  They do call me Redline.  Redline |
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Bobbo
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« Reply #9 on: June 29, 2011, 10:48:16 AM » |
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Hoser
Member
Posts: 5844
child of the sixties VRCC 17899
Auburn, Kansas
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« Reply #10 on: June 29, 2011, 08:04:32 PM » |
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I already posted "sick as a dog" and I just remembered that I took out the baffles out of my Cobras6-6 over a week before my trip. The group I ride with, all V-Twins/Harleys were so loud that I couldn't hardly hear mine with the baffles in which was ok until we were all stopped and some were idling, others engines off. So it was so loud I couldn't hear myself think and when to crank mine, hit the starter and it was already running! That happened twice so I wonder how the starter gear and flywheel looks.
I do love the sound and prior to the trip I would WOT in short bursts around town and never noticed a power loss. I just read on You Tube a guy said Cobras don't have to be rejetted unless you remove your baffles and the guy I bought mine from "thought" the original owner rejetted it. So I don't really know.
So could removing my baffles result in a loss of power and mpg and all the problems on the other post?
Lack of baffles usually hurts performance, as well as ears and relations with neighbors.  Hoser |
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I don't want a pickle, just wanna ride my motor sickle  [img width=300 height=233]http://i617.photobucket.com/albums/ |
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BIG--T
Member
Posts: 3002
1998 Standard, 2000 Interstate
The Twilight Zone
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« Reply #11 on: June 29, 2011, 08:53:05 PM » |
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I already posted "sick as a dog" and I just remembered that I took out the baffles out of my Cobras6-6 over a week before my trip. The group I ride with, all V-Twins/Harleys were so loud that I couldn't hardly hear mine with the baffles in which was ok until we were all stopped and some were idling, others engines off. So it was so loud I couldn't hear myself think and when to crank mine, hit the starter and it was already running! That happened twice so I wonder how the starter gear and flywheel looks.
I do love the sound and prior to the trip I would WOT in short bursts around town and never noticed a power loss. I just read on You Tube a guy said Cobras don't have to be rejetted unless you remove your baffles and the guy I bought mine from "thought" the original owner rejetted it. So I don't really know.
So could removing my baffles result in a loss of power and mpg and all the problems on the other post?
Lack of baffles usually hurts performance, as well as ears and relations with neighbors. Hoser Well I ain't got neighbors, almost deaf anyway...uh whadya say?  , but I don;t want to lose performance!   |
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