| Author | Message | ||
     Leoallafila |
So I did a quick mod and blocked the valve always open: http://img534.imageshack.us/img534/7423/img0228uja .jpg http://img98.imageshack.us/img98/7623/img0227p.jpg I simply cut a hard rubber hose to the length it needed to keep the exhaust valve open, sliced it down the middle, slid the wire in it, put two zip locks in place to keep the wire from slipping back out, works like a charm. The sound tone changed a little bit, especially at idle, but I feel like I lost tons of torque down low... Is it just my assometer? Does anyone have figures about how much is lost? I also asled myself if this happens also when you install a slipon exhaust... Is the loss of low end as noticeable? | ||
| Froggy |
The change in the powerband you experienced is normal, and is the reason the valve exists. The stock muffler is essentially two mufflers in one, when the valve is closed it routes the exhaust gases to provide better low and mid range torque, but it will open up when a straight through path will provide more power. Similar can happen when you change the exhaust, but every exhaust will affect the bike differently. | ||
| Rwcfrank |
Your assometer is right on the money. you gain a bit on top but lose a ton on the bottom and mid. | ||
| Luftkoph |
attention attention Ourdee didn't he have an electrical switch on his bike to open and close the valve, at will,I would like to know just out of curiosity, how he did it. | ||
| Yjsrule |
I think I had the opposite problem with my uly, I wondered why it was so much different feeling on top than my STT. I was checking the filter one day and noticed that the cable seemed to be stuck in the closed position. So I oiled it real good. Took a while but now it feels a lot better on top. | ||
| Ourdee |
NOTE: DO NOT GROUND THE ECM WITH THE WHITE WIRE! Doug, I have a toggle switch that has 6 pins. The white wire from the valve's servo to the ECM is cut and hooked to it. Along with a ground wire. Let me see if I can get this right. I used three of the pins on the switch. We will call them 1., 2., and 3. 1. is the white wire from the ECM 2. is the white wire from the servo 3. is wired to the ground When the switch is to the right it closes 1. and 2. This has 2. and 3. open Valve will operate as the OEM intended. When the switch is to the left it opens 1. and 2. This has 2. and 3. closed Valve will stay open as long as the white wire from the servo is ran to ground instead of to the ECM. After 5 seconds the CEL will light up. 5 seconds after the ECM is reconnected the light will go out. This has worked for me. But I offer no warranty. On an interesting side note, with the race ECM, a cold engine, and the valve forced open: a quick opening of the throttle stands my bike straight up. NOTE: DO NOT GROUND THE ECM WITH THE WHITE WIRE! | ||
| Luftkoph |
Ourdee thanks | ||
| Leoallafila |
I tried to keep the bike in that configuration but did not like the big loss in power so I went straight back to stock. I would love to get a little bit more growl from the exhaust, but now I am fearing I will loose bottom end with an open muffler. I was looking into a D&D slipon (the black one with dual outlets) because I like the fabrication and I know the brand, but will it give me the same kind of bottom end loss I experienced with the stock exhaust with open valve? | ||
| Ourdee |
You could go with a Drummer and then get a race ECM from Erik Buell Racing already tuned for it. For myself, the stock sound inside a full face helmet is loud enough and neighbor friendly. You can get away with a lot more if you don't call attention to yourself. EbR sells an ECM for stock too. |
