As you noted, the TTI's do not do much to lower volume...they do, however, deepen the tone. A lower exhaust tone of the same decibel rating will sound quieter to the human ear, but as you can see from the decibel charts below, there is not a big drop in volume. There is some drop in decibels and the lower/deeper tone, which adds to it sounding quieter.
If you read the entire link I posted, you will see-
"If you have decel pop and you don't like it, (some of us do like it) then you need to do something to change the AFR in your pipes.
Changing the AFR in your pipes, to get rid of decel pop can be accomplished by two different methods, or a combination of the two.
1. Install some TTI’s. This will reduce the reversion, which will result in a change of the AFR in the pipes, resulting in an elimination or reduction in decel pop.
2. Use the decel enleanment strategies on your tuner to reduce/eliminate the decel pop. Do NOT richen your entire map, this will result in a loss of performance AND decreased MPG"
It i is entirely possible you had a good tune, but Jamie adjusted some of the tables specifically to get rid of the decel pop. That does not mean that your new tune was any better or worse, just adjusted to get rid of the decel pop.
Below is a video that covers some of what is in the above link.
Interesting, I have shittier MPG after intake, exhaust and tuner.
- G
Stage I Upgrades (The Good, the Bad & the Ugly)
We’ve seen it countless times; a Customer does a Stage I Upgrade and sees little to no performance increase. This is becauseStage I Kits are not all created equally. Read this REPORT on Stage I Upgrades where the differences are outlined.
The Stage I Upgrade is one of the most important areas to Do It Right The First Time. If you ever go to do a Stage II, III or IV, it will be built on the foundation of your Stage I. Having a mediocre Stage I will compromise potential benefits of all future improvements.
If you want performance the last thing you want to do is take it to a dealer. They will neuter your ride. A well tuned motor with an open, performance exhaust will pop some on decel. A tune that gets rid of it is a tune that's too rich.
We’ve seen it countless times; a Customer does a Stage I Upgrade and sees little to no performance increase. This is becauseStage I Kits are not all created equally. Read this REPORT on Stage I Upgrades where the differences are outlined.
The Stage I Upgrade is one of the most important areas to Do It Right The First Time. If you ever go to do a Stage II, III or IV, it will be built on the foundation of your Stage I. Having a mediocre Stage I will compromise potential benefits of all future improvements.
Thanks for the info. I do notice a performance boost to the bike. And still only pay $45 a month in fuel costs so I guess I cant complain too much.
I have a 2017 Sportster 1200 Custom XL. I recently purchased a Cobra slip-on exhaust from Harley Davidson; switching from stock exhaust to the new ones. After installing it, I rode the bike around for a while and kept noticing a popping/crackling noise every time I would decelerate. Not necessarily when I would apply the breaks, more-so when I let the engine decelerate on its own. It sounds kind of cool however it does raise questions about engine damage and if I should go get it looked at.
Disclaimer: This is my first HD and the first motorcycle that I have changed the exhaust on. Please keep the comments nice as I'm only looking for answers.
Thanks in advance!
Nice 2017👍🏼 I ride a 2007 HDSPORTSTER 1200 custom and after installing S&S slip ons the same issue with mine. The power is there but backfire on a quiet night makes the neighbors dislike me more 😁. I'm buying a tuner and a Air filter when my VA direct deposit arrives November.
08-15-2019, 11:09 AM
