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SuzukiSavage.com
/cgi-bin/YaBB.pl General Category >> Rubber Side Down! >> no baffle /cgi-bin/YaBB.pl?num=1302216606 Message started by creekhound on 04/07/11 at 15:50:05 |
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Title: no baffle Post by creekhound on 04/07/11 at 15:50:05 So i keep reading you need back pressure so you dont burn up your valves.I dont understand why?I dont see how that would make it any leaner either?Wouldnt all that be results of things on the intake side? |
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Title: Re: no baffle Post by einheit13 on 04/07/11 at 19:45:46 The exhaust won't scavenge correctly and actually get pulled back into the head and increase the temps on the valve. It will also affect the intake pulse. Its called reversion. You get stuttering, carb coughs, and a dead spot where it stumbles really bad when you give it throttle. It will go from lean to extremely rich. causing the exhaust valve, guide, and seat to run very hot. It can't be timed or tuned out. Not to mention that running lean increases the temps of the cylinder, causing piston and ring damage. A car has a long intake tract/runner length that can handle exhaust changes a lot easier. On a bike, the exhaust is a key to tuning. When you make it flow more 'air', it does the same to the intake side. You get more air, but no extra fuel. Same with a change to a free flowing air cleaner. You also lose lower RPM power and push peak power farther up the RPM range. An open pipe makes carb tuning impossible because simple things like ambient temp, humidity, and barometric pressure will change the flow characteristics of the carb on a daily basis. Baffles allow you to make power wherever you choose by changing their length and increasing/decreasing the openings. You must also pay attention to total exhaust length. Too short and a baffle does no good. Too long and you can cause it rev like a slug and build excessive heat because it fills the pipe quicker than it can escape. Nothing beats a good performance type muffler/exhaust. I copied a Buell XB12 engine perfectly. I could get no closer than 12hp and 19ft/lbs of power less than a Buell. The only reason was the exhaust. I could not copy the flow characteristics without being an eye sore. I took an old frame and cut it up to make a Buell system fit for a dyno run and it was within .46hp and 1.1ft/lbs. That was the key...the exhaust. So i simply bumped the displacement to get the same numbers. It cost the owner an additional $1200 in parts because he wanted to keep the Sportster looking stock. Anyway, unless you wanna 'look cool', be obnoxious, or drag race-leave the open pipes for the track. I've fixed many a motor because people think they know how to make power. My project now is a Yamaha XS 650 with the top lands of both pistons melted and the rings fused to the piston and ate the walls so bad that I have to replace the jugs. The heads need new exhaust valves. Pretty much a rebuild because the guy cut the pipes off at the bottom of the frame and added a new main jet to make it richer. problem is, there is also a pilot/slow jet that runs the bike to mid RPM range when the main takes over. He putts around town mostly and after the last rebuild (2600 mile before) when it was stock (1900 original miles) he got to enjoy it for only 9 months. The repair will cost him more than he paid for the bike and the last rebuild! All he had to do was 'read' his plugs after he and his buddy made the 'performance mods'...... |
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Title: Re: no baffle Post by Bubba on 04/08/11 at 11:56:54 einhiet, you sound like you know exhaust...what would you call this? Straight or baffled? http://i823.photobucket.com/albums/zz155/onelunger/IMG00224.jpg P.S. that's the floor behind the big tab... |
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Title: Re: no baffle Post by einheit13 on 04/08/11 at 13:43:34 A funky baffle. Buy one from a catalog and install no closer than 2" to the outlet. You tune it by increasing the hole diameter of half of the holes 1/8". Want more flow, do the other half....keep doing it in 2 steps till ya find what you want. With yours, I would open/close the tab till I found what I want. Always give it at least a trip around the block at low and high RPMs and read the plug to find out if you need to rejet up or down. Now, really important here, Your carb should have 2 jets and a needle. Almost NEVER do you need to replace/modify all three unless you have internal engine mods. Lancer has a very nice kit and others on here have some nice carb tuning info. |
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Title: Re: no baffle Post by Bubba on 04/08/11 at 14:01:21 Thanks, I've already had it on my bike for about a year. I LOVE the sound and I've tuned the carb pretty well(see signature line) . I bought the jets from Lancer here. I was just reading the post and was concerned about burning up my engine. Thanks for your input. I've thought about throwing a little after market baffle in there but if you look closly at the pick you can see there is the one BIG tab and then a bunch of smaller (more baffle like) tabs running down the pipe to the end. |
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Title: Re: no baffle Post by creekhound on 04/09/11 at 19:01:00 I just feel i am in a tight spot i want more sound from my stock bike.I hear the dyna swaps are nice but dont like chrome!So i dont know where to go i have looked at the BCB muffler but have a hard time paying that kind of money for a pipe and a baffle i could make.But then again i read on here drag pipes are not very good for your bike i am torn on what to do and it is holding up my project.I know i will need to rejet the carb and i am waiting on lancer to get better to get his kit just cant find another option that fits my wants.Any ideals? |
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Title: Re: no baffle Post by splash07 on 04/10/11 at 08:00:25 You can go ahead and get most if not all the jets you need from the local stealership, most are good about keeping them in stock and they dont charge much. You just got to know what you need before you go. |
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Title: Re: no baffle Post by creekhound on 04/11/11 at 14:33:52 Has anyone ever used power cones?It goes in the header pipe and is suppose to give u that back pressure you need while still letting you run drag pipes. |
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Title: Re: no baffle Post by houstonbofh on 04/11/11 at 16:04:17 "Power Cones?" Also known as plumbing reducers for a lot less money? :) A buddy came over this weekend with them in his Marauder. Just stuck in was a bit quiet, so he drilled additional holes until it sounded right. Less than $20 all in. |
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Title: Re: no baffle Post by creekhound on 04/16/11 at 20:39:47 Had an ideal today what about a 4 inch baffle installed in the header and a turn out tip.Or maybe install baffle in turn out tip.what do you think would it be enough back pressure? |
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Title: Re: no baffle Post by splash07 on 04/17/11 at 06:32:01 I had the same set up for a while and it was VERY loud, ran well but it was really hard to tune the carb, and I am afraid that I might have done some dmage to my valves. My baffle was very small though. |
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Title: Re: no baffle Post by Routy on 04/17/11 at 06:52:29 I'm sure not a tech on it, but I doubt the lack of back pressure in itself will do any valve damage. Its would be the cold air dumped on the valves at shutdown that can cause damage. I can remember rodders capping stacks quickly after shutting down. But, God knows I've run a lot of strate pipes in my day, and I never seen any valve damage. |
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Title: Re: no baffle Post by creekhound on 04/17/11 at 09:27:46 Was your baffle smaller than 4 inches? |
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Title: Re: no baffle Post by einheit13 on 04/17/11 at 12:51:45 28273D263A3C2F2D252B3C4E0 wrote:
Thats the difference between cars and bikes. Cold air isn't the issue unless you have a very short pipes (like open headers on a car), then you would have to worry about bending valves. You may have run straight pipes for years, but you have evidential ran you carb rich too. I have run straight pipes for many years also, and have become very good at valve jobs because of it. if you read the above explanations, you'll see that there are many factors that come into play. Torque cones that go in at the pipe at the head have not been proven to do anything. A 4" baffle is the best place to start. The end (outlet) of the baffle should be no closer than 2" from the outlet of the pipe. If you pipe is long enough, you may be able to get away with 'lollipops'. And here, this is from a burnt exhaust valve (open pipes and improper tuning) from a lean condition. Valve face split bounced around long enough to do this.... http://www.nrhsperformance.com/images/KBPiston.jpg And for torque cones.... http://www.nrhsperformance.com/images/arcone.jpg Anti-reversion cones are a device you put into your head pipes, near the cylinder head, to discourage reversion (i.e. a positive pressure wave in the pipe that interferes with cylinder fill if it arrives during overlap). Some are bell shaped like pictured above and others are a pure cone shape. At various times I've tested these things (both styles) on exhaust systems that both showed and didn't show evidence of reversion. The results have always basically been about the same ... http://www.nrhsperformance.com/images/arcones.gif They always seem to either cause a small loss over a wide range, or on occassion I'll see a small loss at only higher rpm's. My guess is they'd be more effective on a system where the pipe was oversized for the motor size and target rpm. I'll continue to test these as I get time and if I get a result on a particular setup where they show a real advantage. In the meantime, it's not high on my list of worthwhile performance mods. |
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Title: Re: no baffle Post by splash07 on 04/17/11 at 13:28:02 Mine was a 2" baffle welded right on the end of the pipe with less than a 1/4" opening in the middle and a lollipop at the end of a straight 1' pipe. Very bad things started happening around 1K miles after the mod. |
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Title: Re: no baffle Post by creekhound on 04/19/11 at 14:15:34 What are very bad things?Also i am just try to find a good solution for a non chrome muffler for my bobber project. |
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Title: Re: no baffle Post by splash07 on 04/20/11 at 06:40:09 Bad things are; strange valve sounds, oil gushing from my crankcase breather, and heavy smoke. This could all be caused by some unknown problem but I am convinced it is related to the exhaust set up that I was running because there were really no other mods to blame it on. |
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Title: Re: no baffle Post by einheit13 on 04/20/11 at 08:41:33 41425E53415A0205320 wrote:
Hers a valve on its way out because of a bad exhaust system and improper tuning. This after I cleaned it! http://img.photobucket.com/albums/v214/bandersnatchreverb/IMG_3989.jpg |
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Title: Re: no baffle Post by creekhound on 04/20/11 at 14:06:36 So could you suggest a good non chrome setup? |
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Title: Re: no baffle Post by RidgeRunner13 on 04/20/11 at 14:54:38 I found some small tractor mufflers at Tractor Supply that might work. Very industrial looking. I haven't had a chance to measure any yet but there were several under $40. My 5 year old JCW 4" turnout is about to rust out & I'd like to find something a little quieter to replace it. 8-) |
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Title: Re: no baffle Post by dhoff024 on 04/20/11 at 18:34:56 I know that you are looking for something not chrome but I have a 2007 s40 that when I got it the baffle was taken out of the exhaust and it ran like absolute crap so I did some searching on ebay and found a supertrap muffler that was used that was for a sportster. It did not have the packing in it anymore so what I did is bought it took the end off, bought some packing, repacked it put it all back together. It runs really well now and sounds good to. The thing that I like about it is it has rings that you can add or take away to add sound or take it away it really gives you alot of options plus the bike runs very well and sounds good and looks good. I know this isnt what you are looking for but it is a really good option for these kind of bikes I am really glad I went that route. Also if you didnt want it chrome I am sure that you could buy some vlave cover paint or engine paint at the auto parts store that is high heat paint and just paint the exhaust black or whatever you were looking for. |
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Title: Re: no baffle Post by T Mack 1 - FSO on 04/21/11 at 12:52:24 7A7671777A766B2E2C1F0 wrote:
Hers a valve on its way out because of a bad exhaust system and improper tuning. This after I cleaned it! http://img.photobucket.com/albums/v214/bandersnatchreverb/IMG_3989.jpg[/quote] So EinHiet, Do you have a pict of your burnt front valve with the piece missing? T-Mack1 |
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Title: Re: no baffle Post by einheit13 on 04/22/11 at 03:13:09 0970103C3E366C5D0 wrote:
Hers a valve on its way out because of a bad exhaust system and improper tuning. This after I cleaned it! http://img.photobucket.com/albums/v214/bandersnatchreverb/IMG_3989.jpg[/quote] So EinHiet, Do you have a pict of your burnt front valve with the piece missing? T-Mack1 [/quote] Not yet but after a trip through the dishwaher, the edges do look like that. Looking through a big magnifier, the seat is prestine, and very hard.... duno if the fine lapping compound will even polish it! |
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Title: Re: no baffle Post by ralfyguy on 04/22/11 at 17:24:23 I bought mine with the gutted stock muffler some three years and 12,000 miles ago. It still runs like a champ. It did run like crap when i first got it, but reducing the white spacer, adjusting the mixture screw and putting a 150 main jet took care of that. The valves run nice and quiet and I only had to adjust them the first time, and the 2nd and 3rd year checkup showed no change. It gets ridden strong after warming up the oil and it sees lots of superslab high speed runs. Thing is when you gut a stock muffler is pretty much just taking out the sound control, as when you look up inside, deep in there is still two chambers, separated by plates that IMHO are the actual part for controlling the back pressure. It is not a straight through open scenario if you just take the baffle out. The Hartman Mod proves that. So in this case, I don't think the removal of the stock baffle is really critical to the health of the engine. I have no problems at all. |
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