Ready for some pipes!
Grand HDF Member
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From: Dubuque, IA
Last edited by 60Gunner; Dec 31, 2021 at 04:02 AM.
Tourer
Joined: Jan 2021
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From: Arizona
Not always the case. Even a true dual can out perform a 2in1. Here's one that out performed the pro pipe and the fat cat on this build. Pretty impressive for a 98 incher.
Road Warrior
Joined: Mar 2013
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From: Alorton, Illinois
That is pretty impressive. I don't know enough about it. Every tuner, speed shop, and mechanic, that I talked, to said that 2 into 1s are better for performance. I didn't research it I just took their word for it. Something about scavenging. Those guys haven't steered me wrong yet.
Dyno operators can only report what they see. We aren't trying to lead anyone astray. If 2-2's would constantly show better results over a 2-1. Why would we hide that? Then ask these dyno guys and performance engine builders what pipes they have their own bikes. I bet they are running what they see is making best performance for the combination they are riding.
Grand HDF Member
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From: Dubuque, IA
That may be but to say good power can only be made with 2in1s is misleading too. Some real nice numbers coming from some cross under X pipes 212s too. The Khromewerks comes to mind.
Unfortunately choices are limited for Softails for those of us that can't stand the looks and sound of 2in1s.
I talked to dlj and I'm quite confident those pro streets will perform quite well on my 107 build. Going with turnouts.
Max has a set of custom made duals with glasspacks that do real well too. Extremely flat torque curve across the entire rpm range. The key is stepped headpipes in both cases.
Unfortunately choices are limited for Softails for those of us that can't stand the looks and sound of 2in1s.
I talked to dlj and I'm quite confident those pro streets will perform quite well on my 107 build. Going with turnouts.
Max has a set of custom made duals with glasspacks that do real well too. Extremely flat torque curve across the entire rpm range. The key is stepped headpipes in both cases.
Last edited by 60Gunner; Dec 31, 2021 at 06:18 PM.
Grand HDF Member
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From: Dubuque, IA
Of all of them I've heard in person I'd say the Thunderheader sounds best and performs well. RB Racing's LSR maybe but haven't heard it in person.
The pro pipe is hollow and has a drone at Hwy speed.
Nothing sounds better than true duals but most suffer low end loss due of lack if scavenging. My Rush 212 has a great deep sound and performs well but gives up a little top end hp to a good 2in1 but worth a few hp to me. But the pro streets are a real rare exception in a true dual that performs great across the entire rpm range due mostly to the stepped headpipes and is going on my new build. Khromewerks hp p!us is another great sounding slip on 212 that performs well. Their cross under X pipe performs great but doesn't work on Softails. There's a few other X pipe 212s hat perform great too. Softails just can't use a cross under exhaust. Too low.
There are a few good options for those of us that don't care for a 2in1. But beware, not all 2in1s are worth a crap either. In fact a lot of them suck and have major reversion issues down low.
Last edited by 60Gunner; Jan 1, 2022 at 06:36 PM.
Road Warrior
Joined: Mar 2013
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From: Alorton, Illinois
I try and not talk in absolutes. Learned not to with things I have seen. But the reason a 2-1 works. Is the same concept of 2-1-2's. Same concept has headers on cars or H or X pipes. It's all about tying cylinders together or banks of cylinders together, slugs of air, scavenging, and equalizing pressure.
I also think cam design has a huge influence on how well a particular exhaust works. Seems cams with little or no overlap aren't as pipe selective sensitive as one with overlap or exhaust bias lopes.
Disc pipes aren't magic. They just give a means to tune the exhaust. Just as bending baffle in a thunder header. As a tuner. I like the option. I have learned a bunch playing with discs with different cam profiles, and different cubic inch. Pushed me into more testing. Pushed me into more test equipment. Which has helped my general understanding on exhaust and cams. BUT all of that doesn't help how a disc pipe sounds or looks.
I also think cam design has a huge influence on how well a particular exhaust works. Seems cams with little or no overlap aren't as pipe selective sensitive as one with overlap or exhaust bias lopes.
Disc pipes aren't magic. They just give a means to tune the exhaust. Just as bending baffle in a thunder header. As a tuner. I like the option. I have learned a bunch playing with discs with different cam profiles, and different cubic inch. Pushed me into more testing. Pushed me into more test equipment. Which has helped my general understanding on exhaust and cams. BUT all of that doesn't help how a disc pipe sounds or looks.
Grand HDF Member
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From: Dubuque, IA
I think in the case of the pro streets here its the stepped head pipes keeping the velocity going and a high compression build making up for the !oss of scavenging and doing a good job of maintaining cylinder fill at a decent rate. That's my theory and the reason for my pushing compression so high.
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Grand HDF Member
Joined: Sep 2017
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From: Dubuque, IA
I know you're not implying that djl's dyno numbers above aren't legitimate numbers or that it involved some dyno trickery.
Road Warrior
Joined: Mar 2013
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From: Alorton, Illinois
I would suggest going to Texas and having this conversation with Nick. He will be the 6'8", 280lbs guy standing by his dyno. One of the nicest guys I have met, but I haven't questioned his integrity on a public forum without even knowing anything about the man.
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