I know on carbureted models there is a gain but apparently on EFI there is a loss of torque and HP unless there is enough back pressure. I have heard from 3 different tuning shops that Big Radius cost 7-8 HP on EFI bikes. The straight shots with cross over and baffles or any 2-1 system or even performance 2-2 like Bassani give gains. So say the shops I have tolked to that have been running the bikes through Dyna Testing.

Also, beware. Having installed the pipes and not having tuned with a PCIII or SERT can burn your cylinder heads and you fuel injection in short order. That is why people generally do the whole package on EFI bikes. Carburetors are more forgiving although less efficient. I hope you have not put too many miles on the bike. There will be a lot of carbon build up and loss of performance at the very least.

 

nope only a few miles. getting the pcIII. tomorrow. Had to wait to get it in the mail. I am not paying the stealer for something I can do myself. wierd how there can be so many opinions on one topic. The dealer here told me with the bike properly tuned with the new exhaust and a high flow filter that you will see some performance gains.

 

I put V&H Short Shot Staggered on my Bob and rode it for a day before putting on the PCIII. The bike ran well but did have popping ondecel under load i.e. going down hill. I put on the PCIII and all of the popping stopped, I used the map for the V&H Big Shots as they do not yet have a map for the Short Shots. There was no loss of power or loss of sound and I geta better throttle response than before in all gears. With the PCIII installed I was cruising at about 70mph in 6th gear and cranked on the throttle. Immediate response and jumped up to about 115 mph in no time at all. I think you will like what the PCIII will do for your performance, just make sure you use the correct map.

 

Thanks, I just looked at the V&H site. Looks like they have the identical map for my set up. Big radius, SE A/C. 06 Dyna Yippeeeee. Sounds like she will be running great. I have put about 100 or so miles on mine and did notice some popping. Glad to here that will go away. Stu is right about the 2in 1 getting more power than the Big Radius. But the Big Radius should still gain on the stock set up with the new A/C and map.

 

I've read that large diameter pipes reduce exhaust velocity which results in less efficient combustion chamber scavenging. If you're thinking about fat pipes--especially fat pipes without a crossover, which further reduces scavenging--you just need to know that you're not doing much for your bike's performance. That's why the best performing pipes are two-into-one pipes with more traditional diameters. Just something to think about when selecting pipes.

Addressing a couple of other points in this thread:

Yes, our bikes are relatively fuel efficient, but a bike produces between four and 19 times more exhaust pipe pollutants than a car does. So while we do help reduce fossil fuel consumption, we worsen the pollution problem. Just be aware that it's a trade off and we all should know about.

Weighing in on the noise issue (I'm just full of opinions today), as others have said we have to realize that our pipes aren't pissing-off people, they're pissig-off voters. With the huge increase in loud v-twins we've seen in the states over the past decade, those voters are making thier displeasure heard. If you have loud pipes (I'm running V&H Short Shots that came with my bike and I'll be to switching toslightly quieter 2-into-1 pipes soon), we have to be responsible. Here in California we can "whiteline." So I'm careful to keep my pipes quiet around pedestrians, downtown areas, residential areas and on the highway when I'm passing cars. I can only imagine how my pipes could scare the daylighs out of someone when I blow by them at WOT.

Okay, I'll get off my soapbox. Happy Sunday.

 

Yes the 2 into 1's do give alot more power. But I am not into racing down the road going a buck 50, or trying to break any 0-60 records here. I had a gsxr 1000 that did that for me. I am well past the speed machines. I wanted the Big Radius because for the money and the quality of V&H they are in my opinion a great sounding pipe(not too loud) and VERY good looking on the nimble Dynas.

 

I too dread the awful SOUND Police ...

I love the sound of the SE II's I have but I need to quiet them down some ... I get really bad vibes at work, at stop lights or anywhere I sit at Idle.

I need a set of quieter baffles ... I don't know what's hiding in there now ... but what ever they are ... they're not working ...Anyone have a set of stock baffles they wanna sell me?

 

The SE2's on my DWG are sweet also. My brother and I were out cruising the other day (well a 350 mile cruise) and he rode behind me most of the way. He still has stock pipes on his Heritage and he's now wanting to upgrade his pipes. There are louder, deeper, etc but not too overbearing. I don't think they're selling the SE2 slips anymore however.

 

Its not that I don't like the sound of the SE II's ... I live in CA. We can get some really picky cops out hear ... and I have had a ticket for modified exhaust before.

Of course that was a GS1100e with a Kerker ...
My Dyna sounds louder than that. The SE II slip-ons have a baffle in them, or at least there is something that could qualify as one, but they look like they are not stock ones and have been modified.

I need to replace these as much as I like the deep throaty rumble.
I cannot see how these can increase HP without some backpressure.

 

Hey guys -

I got the SEII Slip-ons on my 2006 Street Bob and noticed that it looks like the baffles are just held in with a couple of bolts. Are there some "better" (louder) aftermarket baffles that I can get for my slip-ons or can I only use those H-D ones that came with the pipes? The bike has already been remapped and stuff at the dealer when they did the pipes so I am looking for something I just just swap out myself if possible.

Updated: Found these baffles on the Big City Thunder site. Anyone know if these will fit right and if the sound is that much different from my stock SEII baffles?

// SINTAX