Did some wrenching on the old 2003 FLHTCI today. Decided to replace a cracked Y-pipe with a Fullsac True Dual kit (http://www.fullsac.com) after reading so many great reviews on the Fullsac kit in this forum. Got almost 60K on the bike before finding a crack in the Y-pipe. The kit was delivered quickly, well packed, complete, and easy to install. I started by soaking all clamps, nuts and pipe joints with penetrating oil for a few days before starting the install. Everything loosened easily and then assembled quickly following the instructions with all of the parts supplied. I plan to re-torque all clamps and the rear exhaust flange after a few heat cycles from various rides.

As their web site says -- "The Fullsac conversion replaces the factory Y-pipe with two high quality 16 gage Jet Coated parts. A mandrel bent J pipe directs 100% of the rear cylinder exhaust and heat to the left muffler." The factory pipe from the front cylinder now directs 100% of the front cylinder exhaust and heat to the right muffler so the bike has a true dual exhaust. Kept the Vance & Hines Oval slip-on mufflers. Reused all clamps and heat shields except the one that covered the pipe from the old Y-pipe to the right side exhaust since that pipe no longer exists. Might wind up putting one of the 24 inch one piece heat shields from VtwinGoodies (http://vtwingoodies.com) on later. Want to run the Fullsac kit for a while and see how things perform. Fullsac claims the change does not require a remap of the Power Commander.

First impressions from test ride -- seems like I lost a little low end torque (butt measurement only, no dyno numbers to back this up) but the bike idles smoother and runs great throughout all normal RPM ranges. Nice and strong at highway speeds. I've been chasing an intermittent slight miss around 2300-2500 RPM when backing off the throttle...it seems to be gone now! Figure the cracked Y-pipe was causing this even though the crack was very small and hard to see under the heat shield. Yes, the left leg gets a little warmer because so much more heat now goes out the left side. Looks like I'll be doing some business with Captain Itch (http://www.capt-itch.com/) soon! The right side is cooler because the exhaust that was routed through the Y-pipe to the right exhaust is gone now and the right exhaust pipe is all routed below the floorboard. Love the new sound!

Hope this helps anyone considering the Fullsac kit.

 

just ordered mine today because of a cracked y pipe... nice write up.

 

A good friend I ride with recommended this kit, as he installed it on his '08 S/G.
I don't notice any ill effects except for more heat on the left side.... I do enjoy the sound of my Big Louie's more now

 

Thanks for sharing. I will sure do it when i'll have another cracked y pipe, a lot less expensive...

 

Thanks for the post............I've been thinking about one of these!

 

I put the FullSac True Dual kit on my 2000 FLHT earlier this summer. Installation went very smooth. Just followed the instructions. I have a carbed model and no rejetting necessary. Bike runs great and love the new sound.

 

hi! ive put the fullsac true dual kit on my 07sg in 08 I like the sound better than stock, I also put the front extended hd shield, and motorcycle goodies 24" shield behind it, looks an works great. the only thing ive noticed is the coating on rear crossover is turning gray color but that's bout it worth the money. bud

 

have had mine on since last summer , the heat on the left side is not that bad and after a few rides you don't even notice , it's just new to you now

 

does anybody make an aftermarket heat shield for the rear exhaust for the Full-sac??
I bought a used kit...didn't come with one...

 

I reused the factory shields for my 2003 (both left and right sides). Might be able to find some decent take-offs on eBay. Will probably get one of the 24 inch one piece heat shields for the right side from VtwinGoodies (http://vtwingoodies.com) a little later. Just a thought.