The decel pop isnt as bad as the crushing farting sounds I'm getting, is that bad for the bike or is that like you said extra fuel burning up in the exhaust? Just dont want to wreck my bike and I'd like it to sound decent.
I don't know what a crushing farting sound sounds like. But if it is doing that while accelerating, or while holding speed (cruising) it seems like it is some sort of misfire, and that is not good and needs to be addressed.
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I meant cruising.....and I know it's not a misfire. Im 100% positive on that
cruise farting (farting back through the carb) on a carberated bike is a sure sign of a lean mixture. I don't know if an injected bike will do that or not.
Things to note in that video... Yes the lollipops made improvements (they work by damping reversion), but the end result was still bad (still had - unacceptable in my view - reversion problems). As noted in the video, if you just have to have the look and sound and are willing to flush performance down to toilet to get it, then this might help mitigate the damage a bit.
I know DK promotes/sells TTI's. Good folks and all. I've bought various things from them and have been pleased with my purchases and the support they've provided when needed. But Lollipops and the like make me cringe. Especially if folks buy them thinking that they are some sort of inexpensive cure all. Even some of the before/after dyno examples on DK's site tell the same story as the S&S video. The system had reversion problems before and after the TTI install. Other examples had multiple variables change between runs making it difficult to tell what was really contributing to the improvements. Again, no argument that improvements can be achieved with TTI's, but the possible results (both positive and negative) I suspect are likely very system/situation dependent.
Now I might be interested if TTI's could be shown to make improvements - with acceptable trade offs - on whatever system that I might have interest in. Without that kind of data though, you don't know really what impact they will have (butt dynos are worthless). Say you might be interested in V&H Side Shots...
I picked Side Shots for the example because I have them on my bike and I know they have a little bit of a reversion issue down around 3700 rpm. Would lollipops and the like improve that situation? Maybe. What would the trade offs be? Pumping loses on the top end? Would the potential improvements even be worth it (particularly if there is a trade off)? IDK. But there's no real data to answer those questions (only on just a small handful of applications that I've seen). I would want something tangible before I decided to start drilling holes in my pipes. Without such data, it seems to be a gamble. To know for sure, you'd have to spend some coin to see what benefit - if any - you got for the price of a $20 part. If the results are favorable, then bonus. If not however, you just spent some bucks to verify a $20 part, only to end up with disappointment. You might say the part is only $20, so why go to the trouble of testing? Try it, and if you like it, be happy. But wonder if you actually did more harm (butt dyno is useless/subjective and may not detect negative impact or the evidence may be contradicted by the butt owners head telling them what they want to hear because it's the desired outcome) than good even though it's not terribly perceptible? And what about those holes you've drilled?
Then you got folks thinking that they can molest a properly designed system - whether it be stock or otherwise - and compensate for the molestation with the lollipops. An example - taking baffles out of stock exhaust to get the wanted sound and thinking that the performance hit will be undone with the lollipops. Sure, as noted the results may very well still be bad, but perhaps just less bad. Wouldn't it just be better to go with a properly designed system for the application? And when I say properly designed, there is much more to a properly designed system than just some conveniently (and aesthetically pleasing) bent and welded pipes.
Perhaps some food for thought... If lollipops and the like were truly magic bullets in all applications, wouldn't you see their use be more widespread? In fact, why wouldn't you see them in various aftermarket/manufactured exhaust systems designed for street use?
Things to note in that video... Yes the lollipops made improvements (they work by damping reversion), but the end result was still bad (still had - unacceptable in my view - reversion problems). As noted in the video, if you just have to have the look and sound and are willing to flush performance down to toilet to get it, then this might help mitigate the damage a bit.
I know DK promotes/sells TTI's. Good folks and all. I've bought various things from them and have been pleased with my purchases and the support they've provided when needed. But Lollipops and the like make me cringe. Especially if folks buy them thinking that they are some sort of inexpensive cure all. Even some of the before/after dyno examples on DK's site tell the same story as the S&S video. The system had reversion problems before and after the TTI install. Other examples had multiple variables change between runs making it difficult to tell what was really contributing to the improvements. Again, no argument that improvements can be achieved with TTI's, but the possible results (both positive and negative) I suspect are likely very system/situation dependent.
Now I might be interested if TTI's could be shown to make improvements - with acceptable trade offs - on whatever system that I might have interest in. Without that kind of data though, you don't know really what impact they will have (butt dynos are worthless). Say you might be interested in V&H Side Shots...
I picked Side Shots for the example because I have them on my bike and I know they have a little bit of a reversion issue down around 3700 rpm. Would lollipops and the like improve that situation? Maybe. What would the trade offs be? Pumping loses on the top end? Would the potential improvements even be worth it (particularly if there is a trade off)? IDK. But there's no real data to answer those questions (only on just a small handful of applications that I've seen). I would want something tangible before I decided to start drilling holes in my pipes. Without such data, it seems to be a gamble. To know for sure, you'd have to spend some coin to see what benefit - if any - you got for the price of a $20 part. If the results are favorable, then bonus. If not however, you just spent some bucks to verify a $20 part, only to end up with disappointment. You might say the part is only $20, so why go to the trouble of testing? Try it, and if you like it, be happy. But wonder if you actually did more harm (butt dyno is useless/subjective and may not detect negative impact or the evidence may be contradicted by the butt owners head telling them what they want to hear because it's the desired outcome) than good even though it's not terribly perceptible? And what about those holes you've drilled?
Then you got folks thinking that they can molest a properly designed system - whether it be stock or otherwise - and compensate for the molestation with the lollipops. An example - taking baffles out of stock exhaust to get the wanted sound and thinking that the performance hit will be undone with the lollipops. Sure, as noted the results may very well still be bad, but perhaps just less bad. Wouldn't it just be better to go with a properly designed system for the application? And when I say properly designed, there is much more to a properly designed system than just some conveniently (and aesthetically pleasing) bent and welded pipes.
Perhaps some food for thought... If lollipops and the like were truly magic bullets in all applications, wouldn't you see their use be more widespread? In fact, why wouldn't you see them in various aftermarket/manufactured exhaust systems designed for street use?
This post is extremely biased. The thumb screw lollypop is a pitiful example of a fair trial. They obviously want us to buy expensive exhaust systems which according to Hammer Co. dyno test, most are very poorly designed.
I am in the process of doing some test of my own. Acceleration through a measured distance of 500 ft. in 4th gear starting at 40mph and wide open throttle. Obviously this will not give the whole picture but will be better than a butt dyno. Will share later.
With open pipes, decel pop is common, and does not damage your engine.
HOWEVER, if you are getting any farts, pops, misfire when there is throttle applied, that is indicative of a tune in need of help.
Decel pop alone is not so much a matter of a good tune vs. a bad tune, but more a matter of exhaust configuration. Decel pop is Not indicative of a bad performance tune, only that the tuner did not know that you wanted it tuned out for your ears pleasure...or that they did not know how to tune the decel pop out.
Decel popping does Not damage your engine...it is simply unburnt fuel that is burning in the exhaust tract after exiting the engine.
Decel popping occurs when one of two things are present.
1. The bike is so lean the exhaust is superheated and is burning the unburnt fuel that is in the pipes (there is always some unburnt fuel in the pipes no matter how lean). This is very rare.
2. The AFR IN THE pipes is just right to burn the unburnt fuel. This is quite a common occurrence when free flowing pipes are installed (whether or not a free flow A/C is installed). It can also occur if there is an exhaust leak that is introducing extra air into the exhaust tract.
Also, check for intake leaks at the intake manifold/heads.
Another way to change the AFR IN THE Pipes is to install Thunder Torque Inserts. Not only will these reduce/eliminate decel pop, they will give a good boost in torque in the low and mid range. See details & dyno charts HERE.
It is absolutely possible for a tuner and someone who knows how to use it to tune the decel pop out.
HOWEVER, the methods used to tune the decel pop out of very open pipes are almost always at the sacrifice of performance and/or MPG.
An open pipe with the best performance tune is almost always going to have some decel pop.
To get it tuned out, without just dumping gas in it, you will need to find a tuner that understands how to do it...it is possible.
Do you have any dyno charts on the Sprtster and larger for our tired old eyes.
Bias? In what I said or the S&S video? Let me save you the trouble of answering. The answer is neither.
Originally Posted by misput
...The thumb screw lollypop is a pitiful example of a fair trial. They obviously want us to buy expensive exhaust systems which according to Hammer Co. dyno test, most are very poorly designed.
I'm not selling anything.
Originally Posted by misput
I am in the process of doing some test of my own. Acceleration through a measured distance of 500 ft. in 4th gear starting at 40mph and wide open throttle. Obviously this will not give the whole picture but will be better than a butt dyno. Will share later.
If you are doing this for personal entertainment value, then I'd say knock yourself out. But, if you think this is going to produce any meaningful results, then I might recommend that you not waste your time.
Bias? In what I said or the S&S video? Let me save you the trouble of answering. The answer is neither.
I'm not selling anything.
If you are doing this for personal entertainment value, then I'd say knock yourself out. But, if you think this is going to produce any meaningful results, then I might recommend that you not waste your time.
It's obvious you nor s&s have any answers and in case you have not noticed, none of the major exhaust manufacturers offer any meaningful dyno results. Hammer Co. has posted the best info I can find and lo and behold the system that came out on top and cost the least has vanished. Wonder what happened there???
It's obvious you nor s&s have any answers and in case you have not noticed, none of the major exhaust manufacturers offer any meaningful dyno results. Hammer Co. has posted the best info I can find and lo and behold the system that came out on top and cost the least has vanished. Wonder what happened there???
What's your point? Answers to what? What was the question? What's any of that got to do with Lollipops? As to the S&S's video, there was nothing controversial about it's content. It was essentially just a regurgitation or well known/established facts. Don't really see anything controversial about what I said either.
I wasn't making a comment on the dearth of data on pipes. But if I were to comment, I would say there's actually more out there than one might think. I've seen many third party test results on various popular exhaust systems installed on Sportys. The Patriot Defender is a good example - since you alluded to it. Not only do you have 3rd party performance shops producing PD test results on various build stages, I've seen many owners/consumers post their own results with the pipe (their results essentially duplicating/verifying the results from folks like Hammer). I think the PD's performance potential has been well documented/accepted over time and that's why that pipe had such a following.
With lollipops, on the other hand, I'd say the dearth is certainly real.
Do you have any dyno charts on the Sprtster and larger for our tired old eyes.
There are a bunch of Dyno Charts at this LINK and there is a report on the Myths & Facts of exhaust at this LINK
Here is just one of the many dyno charts (pulled from the link above) where the ONLY difference is that TTI's were installed.
As is clearly shown, with the TTI's there is a significant increase in torque from 1700 RPM thru 4000 RPM, including getting rid of the big dead spot down low.
The "cost" of this big increase in torque is that at 4700 RPM and higher there is a slight decrease in torque and hp.
The vast majority of HD riders spend 95% of their time between 1700 and 4500 rpm's which is all better with the TTI's. For the few riders that primarily live above 4700 rpm, the TTI's are not for them.
Regarding another comment made:
We do believe that one day many exhaust systems will utilize the TTI technology by licensing it from us...it is patented, so it cannot be copied. In the world of combustion engines, it is a relatively new technology that will take time to mature.
08-08-2018, 05:33 PM
