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Discussion Starter #1
Anybody running emgo reverse cones on there TB? I have Dunstall replicas on mine and would like to change them to the reverse cones, but I am wanted to know if there is a big difference in the sound?
 

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I hate to answer a question with a question but, how loud are the Dunstalls?
 

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Discussion Starter #3
They remind me of a tractor trailer when they hit there retarder to slow down the truck. If you know that sound. I like the sound but can't seem to get rid of the backfiring. Triumph dealer put them on and said there was nothing they could do about it. So I thought I would try A new pipe.
 

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They remind me of a tractor trailer when they hit their retarder to slow down the truck. ...........


...air brakes ! cool ! :D


My pipes are drilled out stock, you'd be hard to beat the sound ! (and were part of tweaking the bike for extra power)


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Ride on ! :)
 

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I heard a TBS with them and they sounded much nicer, more musical, than my (and yours) Dunstalls.
 

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They remind me of a tractor trailer when they hit there retarder to slow down the truck. If you know that sound. I like the sound but can't seem to get rid of the backfiring. Triumph dealer put them on and said there was nothing they could do about it. So I thought I would try A new pipe.
What have you done to try to mitigate the backfiring? Did you richen the mixture? Bigger main jets? When I did this to my Mikunis it reduced the backfiring dramatically. I still have a slight intermittent backfire coasting against a closed throttle below 2Krpm. I am going to try taking the pilots one step up to 42s and see if I can quiet even this down. I read somewhere that the T3 motors fired on every stroke and that made them more inclined to backfire than other motors. I don't know if that is true, but I do know my 95 didn't backfire until I started messing with the exhaust and leaned up the mixture.
 

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I like the backfiring, its a good way of alerting inattentive pedestrians that you are approaching the crosswalk. I've had people step out on me.
 

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Discussion Starter #8
What have you done to try to mitigate the backfiring? Did you richen the mixture? Bigger main jets? When I did this to my Mikunis it reduced the backfiring dramatically. I still have a slight intermittent backfire coasting against a closed throttle below 2Krpm. I am going to try taking the pilots one step up to 42s and see if I can quiet even this down. I read somewhere that the T3 motors fired on every stroke and that made them more inclined to backfire than other motors. I don't know if that is true, but I do know my 95 didn't backfire until I started messing with the exhaust and leaned up the mixture.
The dealer said that it was already running rich and and even said to keep the stock jets in. The plugs were black like coal.
 

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Triumph dealer put them on and said there was nothing they could do about it. So I thought I would try A new pipe.
Different pipes are not going to make any diff. If you reduce the back pressure in the pipe, you are going to have popping on decel (it ain't backfiring :rolleyes:) unless you richen the mix.

I went up to 42 pilots, and it went away. I truely doubt your mix is rich across the range.
 

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Discussion Starter #12
Different pipes are not going to make any diff. If you reduce the back pressure in the pipe, you are going to have popping on decel (it ain't backfiring :rolleyes:) unless you richen the mix.

I went up to 42 pilots, and it went away. I truely doubt your mix is rich across the range.
Well another reason I want to change them is that I like the reverse cone style. Emgo makes two version, The dunstall reverse cone w/ a removable baffle and one without. Question is do they both sound the same and is it better to buy the one with the removable baffle? I have the megaphones and want to tone it down a bit.
 

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there are some good threads on the backfiring/popping issue if you search this forum. Largewhite posted a pretty good explanation with Jimmyj adding some detail. Explains how by enrichening the mixture to eliminate the popping you are actually detunig your motor. You may want baffles to quiet things down.
 

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I have a set of TOR's that I took off and put in the EMGO's. No mistaking them, they are loud. On longer runs I wear ear plugs. I like the sound so it's not an issue but I am sure for some they might be over the top. You aren't going to get any increased performance from these just noise. The fact that your running stock jetting and your plugs are black makes me think that your running rich from lack of air....
 

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Discussion Starter #15
I have a set of TOR's that I took off and put in the EMGO's. No mistaking them, they are loud. On longer runs I wear ear plugs. I like the sound so it's not an issue but I am sure for some they might be over the top. You aren't going to get any increased performance from these just noise. The fact that your running stock jetting and your plugs are black makes me think that your running rich from lack of air....
WHICH EMGOS ARE YOU RUNNING? GOT PICTURE OF THEM ON YOUR BIKE?
 

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Same as the ones shown above on the Thurx. They are cheap..only around 50 bucks a side and the universal shim sucks.....if I trusted the pipe to hold up for the long haul, I would weld but like any cheap exhaust part, you get what you pay for and I don't expect these to last too long. One thing you do need to consider.....any deceleration back fires are also amplified...so if you don't like the decel popping, I would reconsider.
 

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embo rc's

Elsabella: I assume you are referring to the 17" reverse cones. I have a 98 TBS, and installed a pair to mainly see how loud they were. They are as loud as straight pipes! I removed them and pulled the baffles to inspect the packing, and found the typical cheap yellow fiberglass covering less than 1/3 of the length of the metal baffle. This stuff would easily burn out in about 100 miles of highway use. These "silencers" have excellent flow!

I purchased the FMF 4 stroke 1/2" thick white packing ($9), and repacked them. The results is awesome. The original silencers I have are the TORs, which have a nice gutteral growl when you get on the throttle but are relatively quiet during idle and easy acceleration. The Emgo's, repacked, dropped the tone at least one full octave, and resulted in an immediate performance improvement, with only minimal backfire on decel. The carbs need to be rejetted to compensate for the increased air flow. I will be removing my airbox and replacing it with K&N pods, then sort out the jetting. Has anyone out there done this? I've done this on an 01 Bonnie and it resulted in 68 rwhp! On a 95 Trophy 3, the same carb work with Micron exhausts increased the rwhp from 89 to 98, with no change in gas mileage! I also did it on a 95 Trophy 4 with the dyno showing a rwhp increase from 95 to 107.

My plan is to locate a set of Trophy 3 or Daytona 3 cams for my TBS, which, once rejetted will essentially be a Trophy motor. According to the shop manual, the only difference in the specs between the TBS and the Trophy/Daytona 3's is the cam lift and duration. Howdja like a TBS with 100 rwhp, and the reliability of a Trophy/Daytona? Has anybody out there tried this, and if so, what jetting did you use? tommyturbo2
 

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My plan is to locate a set of Trophy 3 or Daytona 3 cams for my TBS, which, once rejetted will essentially be a Trophy motor. According to the shop manual, the only difference in the specs between the TBS and the Trophy/Daytona 3's is the cam lift and duration. Howdja like a TBS with 100 rwhp, and the reliability of a Trophy/Daytona? Has anybody out there tried this, and if so, what jetting did you use? tommyturbo2
Yes, LOTs of us have been playing with this for years. I think you will find that the compression is also slightly less on the T-Bird/TBS motors, the airbox flow is entirely different, plus you need to improve the flow on the pipes end.

I have done most of this with exception to compresssion, and have gotten up to just over 90 rwhp on the dyno.

There is a whole thread out there on the jetting - look it up. You are going to have to like tinkering A LOT - go ahead and get a new set of float bowl gaskets....
 

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TBS mod

You say you've done most of this. Did you do the Trophy/Daytona 3 cams? What jetting did you finish with? Thruxton needles? I rechecked my Triumph shop manual, and you're correct about the compression ratio, TBS is 10:1, and the Trophy/Daytona 3 are 10.6:1. That's gotta be worth at least 8-10 hp. What air intake did you come up with? Thanks, tommyturbo2
 

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I love my new 27" Dunstall Reps from Emgo and they were about $50 each. I have about 400 miles on them and there you have it.
 
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