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Post by wayne on May 19, 2016 23:26:26 GMT -5
I used to think that the fresh air tried to exit through the glass packing but that's not the case. It's a big advantage having a sectioned exhaust in your hands to see this. There is a bell like air scoop right at the back. The cool air is blocked from flowing any further back in the pipe than the bell and is gathered and directed into a pipe that sits around the tip of the actual exhaust pipe. The fresh air mixes with the exhaust prior to all the gasses (fresh and exhaust) exiting via the inside of the "spark arrestor" (ie the bit externally wrapped with glass packing). Essentially the fresh air flows freely through the pipe. When you put the spark arrestor back into the pipe you'll know that the tip that you insert fits into a pipe inside the end of the exhaust. That pipe is actually the end of the bell that I mention. The actual hot exhaust pipe tip is smaller than this and is concentrically located inside the tip of the bell cup. Take your spark arrestor out and use a torch to look down the pipe PS If you're new to the RE5 the thing in the second picture with multiple holes in it is the "spark arrestor". The holes are normally covered by a thin wrapping of some sort of fibreglass thread or string. PPS Andy, the mental image of you blowing into the back of your RE5 exhaust pipes is priceless ! The full sectioned exhaust is here: re5rotary.proboards.com/thread/1511/exhaust-section
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Post by kanonkopdrinker on May 20, 2016 3:40:30 GMT -5
I am sure there is Suzuki advert which shows how the air enters the exhaust at the front and mixes with the hot gases at the rear, you know the one ... the line drawing on a black background?
I have removed all the glass packing around the exit pipes to assist this with no adverse effect - and to no advantage either if I am honest.
David
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Post by wayne on May 20, 2016 5:42:18 GMT -5
First of all, you're correct. The exhaust gasses, as Suzuki claimed, do mix with the fresh air at the end of the pipe, just not quite at the very end.
Secondly, your empirical observation would be correct re removal of the glass wrapping. There would be no advantage in removing the glass packing because the mixing of fresh and exhaust gas occurs before the glass wound tubes (spark arrestors). In fact it appears the glass windings prevent the mixed combustion gas and fresh air from leaving the stinger into that last section of the pipe as they exit the exhaust. The gases have already mixed, nothing (substantial) is meant to enter that last section of pipe beyond the bell cup.
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Post by timpa136 on May 20, 2016 9:42:38 GMT -5
Sorry Jeff but I just went and check the sink and the water dose turn differently to you guys up there , but becouse we are DOWN UNDER the air is heavier (more oxygen ) so ALL our bikes are faster than yours , and not to mention the riders are always better !!!!!!!!!! Also Al, The kill switch backfires up here are sharper and crisper due to the lighter Oxygen. Tim
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Post by jm0406 on May 20, 2016 10:25:19 GMT -5
Love the sectioned pipe, makes everything easier to understand. I wonder how much science went into that, or if someone just drew it up. As far as faster, that is why Burt Munro came up here to go faster. And before someone comments that he was a Kiwi, you guys are all the same down there. Jeff
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Post by wayne on May 20, 2016 16:48:16 GMT -5
As far as faster, that is why Burt Munro came up here to go faster. And before someone comments that he was a Kiwi, you guys are all the same down there. Jeff I hate to say it, but, Touche !We like to think there ain't much difference between a yank and a Canuck, but don't make the mistake of calling a Canadian a yank down here !
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Post by jm0406 on May 20, 2016 21:29:27 GMT -5
That's probably a pretty good analogy , the Americans and Canadians vs Australians and New Zealand. I need to be a bit nicer to Wayne, or he is going to block my entry to Australia when I go. Jeff
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Post by Jess on May 20, 2016 22:35:49 GMT -5
If you want to know the difference between an aussie and a kiwi... ask a sheep...
(Just kidding fellas)
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Post by wayne on May 21, 2016 1:55:42 GMT -5
If you want to know the difference between an aussie and a kiwi... ask a sheep... (Just kidding fellas) No Aussie's going to be offended by that............ Hey Jeff, you're welcome anytime mate, come down, come for a ride, I've got a dinky put aside for y'all.
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Post by pmcburney on May 22, 2016 3:15:13 GMT -5
I once asked a Kiwi if he sheared sheep.
He replied "no, get your own."
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Post by timpa136 on May 23, 2016 13:09:52 GMT -5
Seeing the cut away is helpful. I'm wondering if laying some material, used to wrap around header pipes, into the baffle cavity before reinstalling the baffle might dampen any decibels?
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Post by wayne on May 23, 2016 18:37:40 GMT -5
Tim, I've tried that. Removed the spark arrestor and filled that cavity (the rusty area of the outer pipe in the photo) with acoustic Rockwool insulation. I packed it carefully so that it was both tight and left a hole big enough for the arrestor to fit snugly back in (I was amazed at just how material will fit in there).
Made no appreciable difference to sound measured by DB meter on a couple of different tests. I ended up removing it.
However, I found packing the accessory exhaust tips with rockwool in the same way reduced sound at, from memory, 4000 rpm by about 4 dba which is significant. That's been backed up by people noticing independently that it's a bit quieter than a regular RE5. Either method would have no detrimental effect on the exhaust's operation as far as I can see.
Roger produced some beautiful accessory tips and achieved a noticable sound reduction by the shaping of the spark arrestor fitting in his products.
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Post by timpa136 on May 23, 2016 20:16:57 GMT -5
Thanks
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Post by timpa136 on May 23, 2016 20:20:10 GMT -5
Thanks for all that. The J&R silencers even stated in the directions to repack every so many thousand miles, I forget the recommended interval. The stock material was much more durable in the Suzuki exhaust spark arrestor. This from Wayne, Roger produced some beautiful accessory tips and achieved a noticeable sound reduction by the shaping of the spark arrestor fitting in his products. Yes they are quite beautiful. Either method would have no detrimental effect on the exhaust's operation as far as I can see.
I was once told from a friend that had spent time with our bikes, that he thought a, then silent in comparison,1975 gold wing exhaust, would probably not significantly hinder performance. I have an extra set of exhaust silencers I had made up. These are quite functional and have proven to hold up after many cross country trips and have not loosened or rattled. I will post in the parts for sale column.
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Post by cresco750 on May 29, 2016 15:23:13 GMT -5
I came came across this ad in an old mag, giving Suzuki's take on the exhaust...
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