DK Custom Products

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Thunder Torque Inserts 118 For Increased HP & Torque

Availability: In stock
Item #: DK-TTI-118
Manufacturer: DK Custom Products

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 DK Custom Thunder Torque Inserts Increase Torque & give Flexibility in sound volume increasing inertial scavenging reducing engine pumping losses, increasing exhaust gas velocity Harley Davidson


Increases Low & Mid Range Torque

Adjustable Sound Volume & Tone

For Your Exhaust

 MADE in The USA!


DK Custom Products


  • High-Temp Powder Coat Finish
  • Stainless Steel Studs (5/16" diameter)
  • Includes All Hardware
  • FITS 1.5" diameter & larger Slip-ons (other sizes available)
  • Increases Low & Mid Range Torque
  • Increased Exhaust Gas Velocity
  • Increased Inertial Scavenging
  • Adjustable Sound Volume & Tone
  • Option for only 1 TTI for 2-1 exhaust systems
  • E-Z Installation  Bolts into the end of the slip-on muffler (using the baffle bolt hole)
  • Patented Technology
  • Made in The USA!

Watch these videos on how to get a better sound AND increase torque!

Take a listen to the following sound clips of 5 Different Bikes that all have an increased amount of Power from Thunder Torque Inserts™ Being Installed.


***The Video Below shows how to Remove Baffles from stock OEM Mufflers that do NOT have a Catalytic Converter in them.  This process does NOT work on Mufflers that have Catalytic Converters in them.***


Do you want Louder Exhaust? 

Quieter Exhaust? 

A Deeper Tone? 

A More Aggressive Bark? 

Do you want More Torque?


The Video Below shows how to Remove Baffles from stock OEM Mufflers that DO have a Catalytic Converter in them. 


Another Video showing how good the stock exhaust can sound, and how much power they can have, with the baffles removed and replaced by Thunder Torque Inserts™.


All the Vance & Hines Systems and Slip-ons we've tested produce more power, and a bit deeper tone with TTI's Installed.  The V&H's respond particularly well to TTI's, with or without the baffles!



Without getting too technical, we've spent thousands of hours testing shape, size, thickness, & surface coatings to find the optimum combination that increases power across a wide RPM band, AND gives maximun flexibility to deliver different sounds.

The Increase in Torque is accomplished by reducing engine pumping losses, increasing exhaust gas velocity and increasing inertial scavenging.

More about how exhaust works at this LINK



Thunder Torque Inserts™ are designed to perform well when used on slip-ons with and without baffles, drag pipes, shortys &   2 into 1 Systems. 

The Patented design  will produce a bit deeper sound/rumble all the way through the RPM and Throttle range.


If you feel that your current exhaust is too loud, the Thunder Torque Inserts™ will noticeably reduce the decible levels.


The comparison may seem subtle but decible measurements are not linear.

For Example, 90 decibels is four times as loud as 70 decibels and 110 decibels is about 16 times as loud.

These particular results belong to a customer that had this to say...

"My impression of the sound is that it lost some higher pitched bark at roll-on and there was a reduction in low pitch reversion "echo" (kind of a flabby chuffing sound). To my ear, with these pipes, the tone isn't significantly lower but it is a bit cleaner or more refined sounding"

(Twin Cam at Full operating temp, mixture corrected, and idling at 1000 RPM.)




When ordering you have an option of getting just ONE TTI if you have a 2-1 exhaust system that has only One slip-on, or to choose TWO TTI's for exhausts that have Two Slip-ons.

The "Q" model is no longer being manufactured.

Click this LINK to see Pictures and Fitment Information, to choose the Correct Size TTI for your Exhaust


A small change can make a BIG Difference!!!



Check out the Dyno Charts Above!


"Just wanted to give you a heads up. I received my Thunder Torque inserts (W118)a couple of days ago, put them in and finally was able to ride today. Great product.

It toned down the idle and low rpms on my Vance and Hines Shortshots. The increase in the mid range is awesome. I was expecting to buy new pipes, but not now. The Shortshots have become a performance pipe with great sound." -John


"I do not usually thank people, but I just got the W118 much better pulling out...Big Improvement...Anyway thanks, another satisfied customer.  Bike is a 2012 FLHTK with Stage IV Harley kit, dresser duals and street cannons.  

It did change the exhaust note as well, a bit crisper is the only way I can explain, that's also a win in my book! -Eric



"Just wanted to take a minute and let you guys know how pleased I am with the W258 TTIs.


I'll be honest, when I first read about these things I figured it was somewhat gimicky so I didn't expect much. But, after removing the baffles from my Wild Pig slip ons and installing the W258's I was blown away by both sound and performance!


It has the potato potato sound at idle (noticeably louder than before) and also sounds great at cruising RPMs. It actually reminds me of the way my old shovel head sounded.


What really surprised me though was the very nice torque gain that you can really feel. After installing true duels and the wild pigs, I noticed a loss in torque. The TTIs brought all of that back, and maybe then some!


Best money I've spent on my exhaust system for sure. Thanks!" -Dewayne





Customer Reviews

Works as advertised Review by Jay
I installed these on some Lowbrow Customs shotgun pipes. Definitely can feel the difference in low end performance. (Posted on 12/29/2020)
satisfied Review by 1999 flstf
everything looks to be quality, i won't be able to install these until spring 2021. sorry i can't say more about them right now. hopefully i can update my review in the spring. very fast shipping, i will say they are smaller than i was somehow expecting. (Posted on 11/12/2020)
Quite Satisfied! Review by rantinron
I installed some Python 2.5" slip-ons on my '19 Iron 1200. They are "loud" and I too noticed a drop in low-end torque as some others have said. Also brought on some decel pop(which I don't mind too much). I saw some people recommending these TTI's from DK and thought I try it out before dropping money on a tuner and such. Glad I did. They have cut down on the decel pop and have helped with my low-end torque loss. Plus they have somehow made the exhaust sound better. Not quieter but maybe a deeper sound. Excellent product. (Posted on 10/28/2020)
Nice upgrade Review by Galt1 Harley
Not an overbore with carburetor and cams, but nice, easy, inexpensive upgrade for 2012 Dyna 103. Improved low-tone sound without significant change in volume. No negative impact on performance at idle or acceleration.
Fit as described. Enjoy your ride! (Posted on 10/27/2020)
Interesting approach Review by Keith
So I have a highly modified Triumph Speedmaster from 2005, it has been Bored and Stroked and has a set of Custom Drag pipes, the noise from these was too high pitched and the motor lost some of its power - fitted the 118’s over the week end and the power is back plus the pitch of the exhaust note is much more to my liking - need to see if the bike will pass it’s MoT next year (Posted on 10/27/2020)
Absolutely Amazed Review by Lee
Riding my 2006 CVO Fat Boy is even more fun now with the 118 Thunder Torque Inserts. They make the bike sound vintage like I'm on an older scoot of yester year.

Taking off from stop lights is easier too with the added torque and horse power. The TTs are everything everyone says they are! Hope all this stays good forever.

I currently have baffles in my V&A Big Radius pipes. I may remove them and upgrade to the 158s for the sweetest sound! Next stop, Lord willing, is to order the lifetime oil filter. :-) (Posted on 10/5/2020)
Very Satisfied Review by 03Deuce
I have purchased these for every Harley exhaust I have ever installed. I absolutely love how they improve the sound. Most recent install on Bassani Radial Sweepers. Still loud but not annoyingly so. Very happy! (Posted on 9/8/2020)
Best bang for the buck ever Review by Jim
I installed these in V & H Eliminator 300s on an M8 Softail. I was able to install these to the baffles for a very clean installation. I removed the fiberglass packing in the mufflers and the performance increase with the Thunder Torque inserts is impressive. (Posted on 7/23/2020)
What a difference Review by jaeson
Used the 118 inserts a big difference in exhaust note & low end torque. So much so I want to try the 158s! Haha great job again DK! (Posted on 6/11/2020)
I own a 2016 HD 48. Everything is STOCK but the pipes (V&H SS's). I kept the baffles in and installed. WOW! Noticeable increase in POWER. I was shifting into 4th gear around 40-45 mph.... Now Im comfortably shifting into 4th gear at 55-60. I know removing the baffles will give even more POWER. Doing that tomorrow. Thank you DK, for a well made product and especially the information on your site about WHY YOU NEED TTi's. Convinced me to purchase TTi's and IM SO GLAD I DID! (Posted on 5/29/2020)
Oddly effective Review by Aaron M
So I’ll be honest, it took a good deal of internal coercion to drop almost $40 (after shipping) on a couple small pieces and steel and associated nuts/washers. I really didn’t think they would work, I was sort of rooting against them. I was wrong, completely. These are the real deal. The dead spot that I had in my midrange has now come alive, and it’s great. The front wheel on my XL1200C gets nice and light every time I crack on the throttle. And the drag pipes I have, which were borderline obnoxiously loud, are still plenty vocal, with a bit less overall volume. It’s a really nice soundtrack. (Posted on 5/7/2020)
Unbelievably effective!!!!!!!!!!!!!!!!!!! Review by Belal
I will try to keep it short lol! On my 2020 Softail Street Bob I’m running a stage 1 with a extreme flow air cleaner from screaming eagle and a 2into1 pipe from Cobra(El Diablo). So far so good, after tuning it and everything dialed in. There was still a little lag or it took an effort to come out the 3000 rpm. So I decided to give the TTI’s a shot. Believe it or not this bike pulls now from 1800 till 3000 in such an effortless manners that I was shocked. I am a little bit exaggerating but it felt like adding a low end torque cam. Now the bike is a complete Stage 1 in my opinion. Pulls hard from 0-120. Any gear, any speed and any time. This is the best bang for the buck ever!!! I’m not exaggerating!. Most importantly the rideabilitiy improved, I’m barely twisting the throttle to move around during cruising. I highly recommend it to everyone who’s missing that little uumph and get going. It’s been a long review but I wanna to make it clear!
Ps. Installation was super easy. No rocket science. (Posted on 4/21/2020)
Works good sounds good Review by Dave
These are easy to install. Great way to make straight pipes perform better. (Posted on 4/14/2020)
TTI's worth a try Review by Andy G.
Bought a pair of TTI 118's, the small ones, to put in Vance & Hines Straight Shots on a 1995 Fatboy. My initial impression is around town I can't really tell any difference but out on the highway my bike feels like acceleration and speeds are more effortless. The build quality of the inserts is excellent, was worth the money to me not to make them myself. Now for the con: For my application the threaded stud wasn't long enough. Tech support was readily available and the solution was to omit the inner nut and install the inserts so the circle was tight against the inner wall of the pipe, no longer centered in the exhaust flow. This way the stud protruded enough to the outside to get a nut on it. A great product would be even better if it had a longer stud available. (Posted on 3/31/2020)
Lightning fast shipping Review by CK
Took less than 48 hours from clicking order to being on my doorstep. Awesome shipping! Now to mount em up and see how it goes. (Posted on 3/31/2020)
Thunder torque inserts 118 Review by Hitch
As always my order arrived fast and the inserts i will be able to test soon . installing a set of cams . will give a full review later. (Posted on 3/10/2020)
The kind of lollipop my bike likes... Review by Terry
After installing Cobra Drag Pipes and removing the baffles.... I installed the Thunder Torque's and it does everything it's suppose to do... Thanks DK Customs for a great product.... (Posted on 9/10/2019)
Smokin Hot Torque Review by Rocket Ride
Installed in Short Shot Exhaust on 2019 FXDR.
Love the sound and this bike is like the title, 0-60 in 3 seconds. Thank you. (Posted on 7/24/2019)
Awsome Review by Jason turner
I purchased a set of 1inch and 3/4 paucho drag pipes and installed them the sound just wasnt there until I installed the w118 tti ON MY 1999 1200 SKIRSTER all I can SAY IS WOW WOW WOW AND THANK YOU TO DK CUSTOMS FOR THE BADASS PRODUCT FOR SURE A SATISFIED CUSROMER (Posted on 4/23/2019)
improved exhaust tone. you feel the increase in torque and power. (Posted on 4/17/2019)
Very surprised! Review by Bill
Installed a pair on my ‘03 Night Train running Vance and Hines Original Short Shots with baffles removed.
Improved exhaust tone to a deeper rumble, noticeably increased torque and power throughout all RPM range, and almost completely eliminated decel popping (exhaust backfire).
I was skeptical of DK’s claims and several YouTube reviews but decided to try them out before spending big bucks on a new set of pipes and was both pleased and surprised with the results.
Definitely recommend this product. Make sure you contact DK to get the right inserts for your application.
(Posted on 4/15/2019)
Woke my bike up Review by Canonball
Had some cheap emgo slip-ons for my bobber along with a dynojet kit but still left the bike kinda slug-ish in low RPM but now the bike rips! best bang for your buck performance mod I have ever gotten. 10/10 would recommend! (Posted on 2/18/2019)
TTI in LAF exhaust Review by Chouille
hello from Belgium. I bought LAF drag pipes for my 2015 48 to avoid torque loss i put 118 TTI in them...It works great.

(Posted on 7/25/2018)

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