Pros and Cons of "True Duals"

davessworks · #1 10-30-2009, 01:54 PM

Please help me out here -

I'm waiting fr my Ultra Limited to show up so lots of time to think.

I want to eliminate the catalytic converter (in the head pipe) and so I figure I'll be changing out the head pipes. This gives me options.

I like the stock look and figured "True Duals" give me that.

I've heard in the past that performance is not as good when you keep the exhaust separate (versus cross-overs for instance).

On my 2001 Fatboy I eliminated the cross-over and have what I consider to be excellent performance.

So - what are the advantages and disadvantages?

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MiddleAgeCrisis · #2 10-30-2009, 02:12 PM

on my 08 softail custom I had true duals. I felt as if power suffered a bit. Had stage 1, ness sucker. On the 08 Heritage I put V&H big shots on. they have the crossover in them, same stage 1 and ness sucker and performance was up.

Now on the 2010 SG, the system is a true 2 into 1 and performance is the best IMO. The true duals sounded the best

but power lacked.

So, out ot three diff set ups, 2 into 1 is tops in performance while true duals is tops in sound.

HarleyGoodies · #3 10-30-2009, 02:14 PM

6 of one, half dozen of the other. More power with a 2 into one, amybe a litle more sound with a true dual setup.

BigGdawg · #4 10-30-2009, 02:16 PM

True duals will move the torque (power) curve into a higher rpm range. Probably not as accessible during normal driving. More for flat out racing performance.

davessworks · #5 10-30-2009, 02:41 PM

Interesting - the torque issue is concerning. I'm planning to use SE 255 cams - would that counteract the shift towards higher rpm?

1931jamesw · #6 10-30-2009, 02:46 PM

I really like the performance and sound of my thunderheader. It also has a "falsee" making it appear that its duals.

heywood727 · #7 10-30-2009, 04:41 PM

I'm not sure that the "Average Joe" is really going to be able to tell just how much your really going to lose. It's not like a 1/10 of a second or 2 is going to be that big of a deal? It is a bagger, not a dragster.

Go with what you like IMHO. 2-1, TD's, cross/ no cross, falsee. You'll be the best judge on the looks and sound that you like. The few HP/ TQ gains or loses should be secondary.

davessworks · #8 10-30-2009, 04:56 PM

Quote:

Originally Posted by heywood727

I'm not sure that the "Average Joe" is really going to be able to tell just how much your really going to lose. It's not like a 1/10 of a second or 2 is going to be that big of a deal? It is a bagger, not a dragster.

Go with what you like IMHO. 2-1, TD's, cross/ no cross, falsee. You'll be the best judge on the looks and sound that you like. The few HP/ TQ gains or loses should be secondary.

Good to know - I'd keep the stock headpipes if it wasn't for the cat . . . (and the 2009 don't work particularly well thanks to the 12mm O2s - but let's not let this thread become another EFI system debate.)

UltraTheo · #9 10-30-2009, 05:03 PM

Had true dual on my last bike and like others have said, torque was lost a little bit but it did sound really good.

mjb765 · #10 10-30-2009, 07:21 PM

Quote:

Originally Posted by davessworks

Good to know - I'd keep the stock headpipes if it wasn't for the cat . . . (and the 2009 don't work particularly well thanks to the 12mm O2s - but let's not let this thread become another EFI system debate.)

Want the cat removed...go to www.fullsac.com and read what they have to say. Call Steve and talk to him--very heplfull and knowledgeable. He can remove the cat and send your pipe back to you in a few days. Stock look and no cat!!