Are any of you guys using the DK Thunder Torque inserts? I just put a decat headpipe on my new limited and have freedom racing slipons with the regular open-ended baffles. I LOVE the sound, very deep, good bark on the throttle, but still stereo friendly. The downside is that while I gained in the mid-range power, I can tell I lost a little on the bottom end. Still very drivable for cruising but maybe a little more shifting. So... I was looking at throwing a set of those on to work along with the baffles to try to keep most of the sound, and gain a little back pressure. Is this the route to go, or am I working backwards? Also, if anyone can recommend the right size to get, please do. The mufflers are 4", but not 100% sure the size of the opening in the baffle.

 

we say 'back-pressure"- what it really is a widened or enlarged exhaust tract- which means that the exhaust gasses slow in the exhaust pipes ( narrower pipes= faster gasses/ wider pipes slower gasses).

High gas velocity is essential to scavenging which is why you feel lost low end power, how exactly to cure this is difficult to say- it could be the change in your header- it could be the change in your muffler.

most mufflers have an internal core diameter of 2" ( the 4" outside diameter means almost nothing) through which the gasses flow. often the core is perforated with packing or wading to absorb tinny high frequency noise.

You can try altering what you have, but you may in the end by stuck choosing between "sound" and "go".

Not that you have to worry much about climbing hills, canyons or twisties or running city traffic where you live


Mike

 

I do a fair bit of traveling. Been through all of the Blueridge Parkway, ect... So it does make a difference. And I did have the Freedom slipons on before adding the decated headpipe, so that is the only difference. There is obviously the option of going back to the stock pipe, or to add the quiet baffle to the mufflers, but if the DK option actually works as advertised, it is by far the best bang for the $.

 

DK are pretty active on the forums, ask them what they think.


I use a tuneable supertrapp pipe and I often retune the pipe for "in-town" vs touring where I am in high gear 90% of the day ( torque vs horsepower)

lollipops or welded washers have long been used to "tune" straight pipes.

Mike

 

See if Big City Thunder makes a baffle for yours. I use them in both my 03 egc and my 02 wide glide. I'm quite pleased with the low end grunt and they will still let them wind up. They seem to cut the crackle on the high end but still give nice sound.

 

I have looked into those and everyone that uses them seem very happy. I'm hoping to hear from a few people that have first hand experience with the Thunder Torque inserts since they are a very low cost for (as advertised) the result that I am looking for. At least if they don't work out I'm really not out much $. Big City is a possibility, but if it comes to that, I might end up going with a different muffler all together. The Freedom had a nice look and sound, but not super impressed with the quality.

 

I have a full setup from freedom performance (true duals... free flowing pipes from the exhaust flange out to the cans).

I also bought the inserts. I went with the recommended size (per the opening) and have found that the inserts are FAR TOO restrictive and wish I would have bought the smaller size.

What I have found is the bottom bolt which secures the baffle (regardless the baffle they sell) is not at the same ID as the exit opening. Also... the bolt that is welded onto the insert is larger than the circumference of the bolt hole so it wasn't a simple insert. I did drill out one hole in my can... and found I had to shave down the actual portion of the insert that (essentially) narrows the ID.

I dunno. yes... do I feel a slight loss of low end torque... sure but personally... I'd have to buy the smaller DK insert and I kind of lost interest for now.

 

I installed the 1-5/8 inch Thunder Torque inserts in the 36 inch Fishtails on my Road King. I noticed a loss in bottom end power after installing the new Bassani 2-1/4 inch fishtails and the inserts brought back the lost power with a little bit of difference in sound. The inserts can be turned or adjusted in your pipes to allow a little better flow and there are a couple different sizes available. For $30.00 it worth giving them a try before looking at more expensive options.

 

Thanks. Good to know. I'll have to do some drilling I imagine since the bolt that holds the baffles in threads into the baffle but doesn't go all the through, so I'd have to put a hole right through the side of them. I want to know I'll at least get some gain out of them before I go drilling holes into my exhaust.

 

When I went catless, installed new slip-ons and cams, I had the bike tuned. Bike ran like the wind but was very loud. I have installed TTi's, which have lessened the dBs but the bike has lost the responsiveness that it had when I got if from my tuner. Luckily, I saved the map before I started messing with "fixing" the extra back pressure. It runs better, but still not the way it did before I put the TTI's in. I can either get it re-tuned or take the inserts out and install the map... time will tell.