So I think most of us agree true duals rob low end torque although by how much is subjective. When using a power commander and it's available on line maps they have maps specifically for true duals. are we to assume said maps help compensate by adjusting the fuel management to make up and recover the lost torque? I have heat shields and the right side is fricken hot when driving through town at low speeds. I have an 03 RK classic with the PC5, slip ons and breather.

Randy

 

That might be the intent but unfortunately a "canned" map (regardless of its name) is a "one-size-fits-all" compromise.

In the case of a lost of torque, much of the loss is due to reversion. Larger exhaust pipes tend to reduce the air/fuel/exhaust momentum and that generally results in a loss of power.

 

So a stock 88 with 3.5 slip-ons, high flow breather and a power commander will show less torque loss than the same engine with 4 inch slip-ons given the same configuration. The power commander 5 has the ability to tweak each cylinder and I know a dyno is the way to go but where I am, the closest dyno is 200 miles away. Ive been mulling this over for some time now. Its not so much the sound I'm after, but the heat on the one side is significant. Recently I can hear a tick from the exhaust high up at the back and I'm assuming given all the discussion on this, it's a cracked rear head pipe. I don't know what one of those are worth but if I have to pull that off and replace, I might as well go to the true duals. I live 70 miles east of Detroit Michigan on the Canadian side, and another earlier post I did once, I was given a couple places that did dyno work close to me. Unfortuneately they are not in business any more. I cant justify $1200 bucks either for some of these exhaust systems. The pricing is getting out of hand on those anymore. Rhinehart in particular. And of course me being in Canada, land of the polar bear and nation of sheep, we just bitch and go with the flow.

randy

 

If indeed your plpe is cracked, take it off and go to a muffler shop and have them weld it. But 1st cut the pipe below the O2 sensor go to the auto parts store and get 2 1 5/8" freeze plugs and have them welded in at the same time. That's what I did. Less heat on right leg, better sound out of left pipe, and a whole lot less $.

 

Which head pipe is split? I put on a B&E true dual conversion kit (same as the Fullsac) and eliminated the Y pipe. I am running a V&H fuelpak and got an updated map from them('06 Ultra). Maybe a slight loss in low end but upper end is very nice. Just a suggestion

 

A PC5 map doesn't compensate for lost low end torque. It does try to make the most of what you have, regardless of what that is. That said it's generally agreed that low end loss is less with the closer to stock you get. I got V&H dresser duals and they sound great and are reasonably priced. Power duals give you the best of both worlds and are only slightly more. The Fuelmoto guys have a great 2-1-2 setup that uses stoch heat shields and is pretty economical. I don't know what they have for your year and model but I'd look there first. I bought a PV there and they installed a great map out of the box. If you don't already have the PC5, I would seriously recommend you get it from there.

 

Someone with more knowledge than me may correct me but the loss of torque with true duals compared to the 2-1-2 shows more on the paper than the butt dyno. I've had all three types of pipes ( duals, 2-1, 2-1-2 ) and I still love my Rinehart True Duals on my RKC the best. The sound is awesome and they run the coolest. I don't care that it has a few ft lb's less than it could be with other pipes.

When a bike is tuned well, can you really tell the difference between 100 ft lb's and 95 ft lb's?

 

Have you considered a 2-1? The V&H ProPipe is on sale on amazon for $649.00 US. You will not lose low end and you will reduce the heat. I ran the Reinhart 2-1 on my SG. Killed the heat. Held the torque. Looked great. Sounded great. I'll be putting the Propipe on my RGS in the spring. If you don't already have the PC5 look into the FP3. As of right now my FP3 tune feels so good I'm not considering a dyno tune.

Just a few options to consider. I had true duals on my 11. Hated them. No ***** until I was over 3 grand. And it was 100hp/110 TQ with heads and cams. Differentcams may have helped.

 

For what it is worth I helped a friend out by ordering a V+H system for his 09 SG build. He wanted power duals but dresser duals were shipped, put on and dyno tuned by mistake first then removed and replaced with the power duals he wanted. His bike made 10HP more on the low end at the wheels with the power duals.

 

That's consistent with what I was told by a V&H guy at there trailer at Sturgis last year, he said it was 8 hp. I have true duels on my 12 FLHTK and I don't care for them, but it's subjective to each individual. JMO