[chiefjudge]

hey guys do i need the muffler on my bike? would it run with just the stock headers? only reason i ask is because i wanna pull off my muffler and maybe ride it a bit to see how i like the smaller exhaust look beforei drop 700 bucks into an exhuast system.

 

[armystar]

I do not run one but I also have a BAK and bumped the computer

and added a 2 1/2 in tip that is mounted to the heat shield bolt.

 

[Scissors]

I recently removed mine and left just the stock header. There's nothing you need to do except maybe bump the fuel mixture up by 3 in the ECU for both cylinders. Oh yeah, and buy earplugs.

 

[chiefjudge]

i didnt know if the warrior required the back pressure to run properly. i know my old bike did, and without a muffler on it it would run terrible, and destroy the engine.

 

[BJMartin]

I took mine for a spin with the exhaust on, didnt hurt nothing, but I didnt go crazy either.


KILLER LOUD. And SLUGGISH at best. No back pressure = no torque.


Quite a few guys run em with just a tip on it though. Cant imagine its doing much harm.

 

[jfreeman1111]

When I put speed* headers on without a muffler I noticed a dramatic gain in power over my old 2-2 street sweepers (w/o baffles). I think that the 2-1 headers must create enough backpressure to make a difference.


I did mount a Supertrapp muffler for a run or two, and the torque that created was even more noticeable than w/o a muffler. I just couldn't live with the scooter sound though...

 

[BJMartin]

I actually run an exhaust that is designed to have equal length headers. They have a few extra bends in em to create enough back pressure and a great sound. They connect and exit through a small MegaPhone.


I get 89.5hp and 113.2ftlbs torque.


PICS IN GALLERY!

 

[freerider8]

In my experience with my warrior and I have thevance&hines longshots on it that I had lots of backfiring and the bike ran real lean because the moron that put the pipes on didnt put on a power commander to help change the fuel mixture. I had the bike to the local dealership and they werent able to help me, they also told me that you cant change the ECU thats on the bike cuz its programmed at the factory and there arent any downloads for it so a power commander or other power pack is needed. I was able to find a privately owned business that works on bikes and has a dyno to make sure everything is running like it should. I had to spend some money but I did notice a big difference in the response of the bike and power it put out. It was well worth the cost considering I want to have her for quite awhile. The guy that dyno'd the bike told me that if the bike runs lean then it runs too hot and of course is getting robbed of fuel which then causes loss of power. With that in mind the pipes that I have on my bike were pretty much open with no baffles really, atleast the ones that were in them werent really much of one since you could see right through them. The reason why I say this is because that is what your bike will most likelydo if you do remove the muffler, you can do what you think is best for you but this was my experience so I just thought I should share it. hope it all works out for ya.





chuck

 

[Scissors]

There was absolutely no noticable change in performance or how the engine runs after I removed the exhaust.


The "no backpressure=no torque" thing is a myth anyway. Manufacturers have to meet noise requirements, which requires restriction in the exhaust. Because of this, they use said restriction to tune the reflection of the exhaust pulses to make fine adjustments to the torque curve (changing volumetric efficiency at specific RPM ranges). But these changes are a compromise, torque is lost somewhere in order to increase it elsewhere in the range. This can make it seem like you've lost torque, but only because the curve may have evened out and become less "peaky."


In big-bore, low-revving engines, the tuning is generally done toshift the torque curve toward the low end, so removing restriction (backpressure) canmake it seem like torque was lost becausethe curve shifts back toward the high end, lowering that initial "punch" a bit. But as long as your engine isproperly tuned, you will maximize performance by minimizingrestriction in your exhaust.


For maximum torque over the entire range you want no restriction/backpressure. That's why top fuel dragsters have very short headers, and why all racecars minimize restriction in their exhaust. A small bit of pipe is needed simply to keep cold air from hitting the back of the exhaust valve and cracking them.


The popping in the exhaust is indicative of a rich condition, particularly the louder "gunshots." With the stock exhaust with the baffles lightly drilled, I got quite a bit of popping. As soon as I removed the exhaust, the popping went away until I richened the mixture. Now it pops like it did before, only louder due to the lack of muffling material. Contrary to popular belief these pops and bangs are not backfires. By definition, a backfire is when your engine fires back into your intake. That would be bad.

 

[armystar]

you cant change the ECU thats on the bike cuz its programmed at the factory and there arent any downloads for it so a power commander or other power pack is needed

use the search function, yes you can change the ecu there is a jumper wire on the ECUthat you ground and adjust your fuel mixture. it is too easy.


Instructions for how to DIY are 1/2 way down the page at this link:

http://www.rswarrior.com/forums/topic.asp?TOPIC_ID=25288&whichpage=1

 

[freerider8]

well then I was misinformed by the dealer then cuz that is what they told me so I didnt know any other way to do what I needed for my bike, I didnt know about this site at that time. HadI know I could have saved a whole lot of money but too late now. Thanks for the tip.


chuck

 

[chiefjudge]

my dealer told me to only trust them not the internet.. better chance of me putting pink highlights on my bike. dealers want money, if you can fix it yourself, they dont make any, therefor, theydont want you to do anything on your own, and try to scare you out of anything if you mention "ill just do it myself".

 

[southboundchicken]

make your mods then have it proffessionally mapped and dyno'ed for it to run the best it can. playing around with settings and having to pull the tank so you can pull plugs to read them is a pain in the a$$ and you always risk cross threading or breaking/damaging something. it was a whole lot easier for me to write a check to have mine mapped and the bike runs like a mo fo and the popping/backfiring was greatly reduced. it was the best $250.00 i have spent on it

 

[dekkota]

Some of the input I have gotten on this sight has led me to believe that the AIS removal actually gets rid of the exhaust popping. Before I knew about this sight I brought it in to a place to have them manually tune it (PCIII) to try get the most power and eliminate the popping. $100 in labor later, it still popped. I have done the AIS removal but haven't been for a ride yet, I'm hoping it doesn't do that anymore.

 

[independent_lemming]

Some of the input I have gotten on this sight has led me to believe that the AIS removal actually gets rid of the exhaust popping. Before I knew about this sight I brought it in to a place to have them manually tune it (PCIII) to try get the most power and eliminate the popping. $100 in labor later, it still popped. I have done the AIS removal but haven't been for a ride yet, I'm hoping it doesn't do that anymore.

You can tune for performance or fuel economy which will have an effect on popping also. My 3 customs that I had done over the years all were poppers, that was with the AIS removal

 

[southboundchicken]

Some of the input I have gotten on this sight has led me to believe that the AIS removal actually gets rid of the exhaust popping. Before I knew about this sight I brought it in to a place to have them manually tune it (PCIII) to try get the most power and eliminate the popping. $100 in labor later, it still popped. I have done the AIS removal but haven't been for a ride yet, I'm hoping it doesn't do that anymore.

you will never be able to eliminate the popping 100% on these bikes but a properly tuned bike will seldom pop

 

[jfreeman1111]

The 0,2 and 5% settings on Rx_Warrior's map eliminated all of the popping in my bike. I have the AIS removal done as well.


You don't need a muffler if you have a 2-1 pipe or a 2-2 setup. If you have 12"-16" of straight pipe, no larger than 2-1/8 ID,after your merger or curves end, you can install Thunder Monster Baffles, retain your sound, deepen it, and gain your midrange torque and HP.


This is the route that I'm taking after speaking with these guys on the phone today. They were very helpful. I'll have it dynoed again after installation.

 

[chiefjudge]

justice, on a side note your plate holders are absolutely sick looking.

 

[arizonawarrior]

Thanks for the excellent post, but I don't know how to apply the example to themotorcycle world.

I guess I wouldn't want toremove the entire header and put small exit-pipes like a dragster on any bike because it would be un-rideable, except for those who don't mind burning their legs to ashes.We need some exhaust pipe length, and that's where the example begins to have problems for me.How much pipe length, maybejust enough toget the exhaust flames past our feet and legs? If we never carry a passenger, maybe just run the header to the collector? Okay, so does that length of pipe cause any problems in the real world? Like you said, yes of course it does. Even thechampionship drag bikes racewith a header. But then, why do the championship sportbikes use2-1or 2-1-2 pipes set-up for scavenging the exhaust pulses, with baffles? Like you said, it moves the curve to where the max HP needs to be. So drag racing exhaust needs to be one thing and distance exhaust needs to be something else.


Like a lot of guys here, I've built a few very fast and very relaiblehot rod cars in my day. But its hardto apply dragster exhaust solutionsto a motorcycle sincewe don't want to wear a fire suit on tour and our rides tend to exceed a quarter mile on most days. Plus, just from time in the tavernwatching the races on the tube with the boys,sport motorcycleracing differs from its4-wheeled counterparts likeNASCAR and Formula-1 racing. We have a few members holding world titles who will chime-in and tell me where I went wrong in this post, if I did go wrong

plus there's a bunch of guys with dyno charts showing the tale of their exhaust.


BTW you make a good point, its important to understand the difference betweenunintentional ignition in the header firing back to the closed exhaust valve and forced to escapethru theexhaust pipe, and unintended ignition in the jug firing back thru the open intake valve. Even though both are firing back to the extent they can, then exiting in any available open direction,its good to clarify that difference because both are managed differently.


Excellent post

sorry I wrote so much.

There was absolutely no noticable change in performance or how the engine runs after I removed the exhaust.


The "no backpressure=no torque" thing is a myth anyway. Manufacturers have to meet noise requirements, which requires restriction in the exhaust. Because of this, they use said restriction to tune the reflection of the exhaust pulses to make fine adjustments to the torque curve (changing volumetric efficiency at specific RPM ranges). But these changes are a compromise, torque is lost somewhere in order to increase it elsewhere in the range. This can make it seem like you've lost torque, but only because the curve may have evened out and become less "peaky."


In big-bore, low-revving engines, the tuning is generally done toshift the torque curve toward the low end, so removing restriction (backpressure) canmake it seem like torque was lost becausethe curve shifts back toward the high end, lowering that initial "punch" a bit. But as long as your engine isproperly tuned, you will maximize performance by minimizingrestriction in your exhaust.


For maximum torque over the entire range you want no restriction/backpressure. That's why top fuel dragsters have very short headers, and why all racecars minimize restriction in their exhaust. A small bit of pipe is needed simply to keep cold air from hitting the back of the exhaust valve and cracking them.


The popping in the exhaust is indicative of a rich condition, particularly the louder "gunshots." With the stock exhaust with the baffles lightly drilled, I got quite a bit of popping. As soon as I removed the exhaust, the popping went away until I richened the mixture. Now it pops like it did before, only louder due to the lack of muffling material. Contrary to popular belief these pops and bangs are not backfires. By definition, a backfire is when your engine fires back into your intake. That would be bad.

 

[arizonawarrior]

Justice would you please give me a heads-up on your dyno results? I don't want to miss your post and I'm still interested.

The 0,2 and 5% settings on Rx_Warrior's map eliminated all of the popping in my bike. I have the AIS removal done as well.


You don't need a muffler if you have a 2-1 pipe or a 2-2 setup. If you have 12"-16" of straight pipe, no larger than 2-1/8 ID,after your merger or curves end, you can install Thunder Monster Baffles, retain your sound, deepen it, and gain your midrange torque and HP.


This is the route that I'm taking after speaking with these guys on the phone today. They were very helpful. I'll have it dynoed again after installation.