Exhaust limitations

[N-gin]

I have a Boarzilla D&D pipe on my 09 Dyna. 107 inch with 660sm cam.
It seems to be doing fine, but what it the limits of this pipe if I go bigger engine? It does NOT have a stepped head pipe and it's the perferated baffle.

[FLDavetrain]

 There are some exhaust experts that think stepped pipes are not the way to go for making power. Your DND Zilla was meant for big inch motors

[Ohio HD]

My Boarzilla does have a stepped head pipe, as far as limitations, I've been told by a guy who has tuned a lot of them, 150 HP is pretty much the threshold to needing a better exhaust system. If you want more than 150 HP, it's time for big league exhaust systems like Burns. 

[TXChop]

My Boarzilla does have a stepped head pipe, as far as limitations, I've been told by a guy who has tuned a lot of them, 150 HP is pretty much the threshold to needing a better exhaust system. If you want more than 150 HP, it's time for big league exhaust systems like Burns.

I agree and can vouch for that statement. Then even when stepping up you game on pipe, low end tq loss may be at the expense of top end HP.

[Ohio HD]

My Boarzilla does have a stepped head pipe, as far as limitations, I've been told by a guy who has tuned a lot of them, 150 HP is pretty much the threshold to needing a better exhaust system. If you want more than 150 HP, it's time for big league exhaust systems like Burns.

I agree and can vouch for that statement. Then even when stepping up you game on pipe, low end tq loss may be at the expense of top end HP.

He said the exact same thing regarding the torque.     

[N-gin]

What's considered big inch motors? Im guessing 117 and higher. However the pipe seems to do good with this 107. Is it the steps in the pipe that make it better for bigger inch. As stated before my pipe doesn't have steps and it is a Boarzilla.
I did some research on the head pipe and come to find out they did not step the head pipe for Dyna models..wonder why? So would I be better finding a stepped head pipe for this muffler.

[kd]

My Boarzilla does have a stepped head pipe, as far as limitations, I've been told by a guy who has tuned a lot of them, 150 HP is pretty much the threshold to needing a better exhaust system. If you want more than 150 HP, it's time for big league exhaust systems like Burns.

I agree and can vouch for that statement. Then even when stepping up you game on pipe, low end tq loss may be at the expense of top end HP.

He said the exact same thing regarding the torque.     

Bigger engine but same cams. Here's the Burn's example of that. One pipe (blue) is the Dragula 1 w / 2.55 baffle and very similar to the Boarzilla headpipe. The other (red) is the Burns on the same day but it has a 3" baffle and is approximately 14" shorter. (My Burns is 6" or 7" longer in the last primary step than their new production pipe like Ray's) I have an adjustable endcap in the works (with SuperTrapp discs) that may pick up the bottom, but for now I think you can see the larger baffle of the Burns producing from midrange on.


http://www.harleytechtalk.com/htt/index.php?topic=99409.0

[Ohio HD]

My Boarzilla does have a stepped head pipe, as far as limitations, I've been told by a guy who has tuned a lot of them, 150 HP is pretty much the threshold to needing a better exhaust system. If you want more than 150 HP, it's time for big league exhaust systems like Burns.

I agree and can vouch for that statement. Then even when stepping up you game on pipe, low end tq loss may be at the expense of top end HP.

He said the exact same thing regarding the torque.     

Bigger engine but same cams. Here's the Burn's example of that. One pipe (blue) is the Dragula 1 w / 2.55 baffle and very similar to the Boarzilla headpipe. The other (red) is the Burns on the same day but it has a 3" baffle and is approximately 14" shorter. (My Burns is 6" or 7" longer in the last primary step than their new production pipe like Ray's) I have an adjustable endcap in the works (with SuperTrapp discs) that may pick up the bottom, but for now I think you can see the larger baffle of the Burns producing from midrange on.


http://www.harleytechtalk.com/htt/index.php?topic=99409.0

That's one of the reasons I stayed with the Boarzilla. The low end should be very strong, without compromising the upper end power much. The motor may not reach it's maximum potential on the upper end with the Boarzilla, but I'm sure I won't miss the 8 to 10 HP on a bike that's street ridden. Especially when the HP should be in the 140's somewhere. If the calculations made are close, I should see 100 torque just after 2,000 RPM, and it climb quickly after that.

[kd]

Ahhh, the quest to have it all.     IMO There's a huge advantage to having that immense chunk of early torque when easing it through the streets etc..  It's tough to maintain stealth mode at 2700 rpm. 

[Don D]

But this is for a dyna.
They are not the same as the bagger pipes they most often are compared to. There are not a lot of higher hp off the shelf dyna options. The boarzilla is decent for bigger motors.

[kd]

Good point. I kinda missed that it was a Dyna pipe.

[Matt C]

I have a Boarzilla D&D pipe on my 09 Dyna. 107 inch with 660sm cam.
It seems to be doing fine, but what it the limits of this pipe if I go bigger engine? It does NOT have a stepped head pipe and it's the perferated baffle.

You sure about no stepped head pipe? (My FatCat had stepped primaries). 

[98fxstc]

You sure about no stepped head pipe? (My FatCat had stepped primaries).

What year/model bike for the FatCat ?
Don't know about too many with stepped primaries

[evostroker]

From the D&D website

Year: 2006-2017
Make: Harley Davidson
Product Number: 581Z-31 Black 32 Chrome

Details:


Retail Price

Chrome $ 999.00     Black $ 1,149.00

Part Numbers and Instructions at bottom of page.

Will fit Fat Bob and Wide Glide see part#'s at bottom of page.



Will fit 2014-2017 Dyna Low Rider and Low Rider S

with minor adjustments to the brake pedal.



2006-2017 Harley-Davidson
Dyna motorcycles
D&D 2 into 1 Boarzilla Exhaust pipe.

2:1 Boarzilla is a stepped header system
at the head is 1 7/8" to 2" at collector
and 2 1/2" where the muffler goes to the header.

All Boarzillas full systems are equipped with
heat shields,exhaust gaskets, bolt kit and baffles.
Each exhaust system is designed and dyno tested
in our facilities.
Our testing is done with the Harley Tuner's.
Every pipe is designed to increase low-end torque
and horsepower.
Performance increases are about 8 to 10 percent on
stock motors but may very with built motors
with the proper tune on the bike.

[Matt C]

Mine (Fatcat) was on a 2006 FXST 88ci then 95ci. It ran really well on both.

[N-gin]

I have a Boarzilla D&D pipe on my 09 Dyna. 107 inch with 660sm cam.
It seems to be doing fine, but what it the limits of this pipe if I go bigger engine? It does NOT have a stepped head pipe and it's the perferated baffle.

You sure about no stepped head pipe? (My FatCat had stepped primaries).

I've have it off 3 times. The primaries are one piece. One straight shot, no cuts and welds, same size front to back.

[dirty jim]

Could they be "tapered" pipes?

[rigidthumper]

If they are the same diameter head to collector, then it seems you may have a Fatcat, not a Boarzilla. Whats the pipe ID at the head?

[FLDavetrain]

Could they be "tapered" pipes?

  exactly

[Matt C]

If they are the same diameter head to collector, then it seems you may have a Fatcat, not a Boarzilla. Whats the pipe ID at the head?

FatCat's are stepped. I'd check with D&D, The Borezilla should be too.

[Good_Apollo]

But this is for a dyna.
They are not the same as the bagger pipes they most often are compared to. There are not a lot of higher hp off the shelf dyna options. The boarzilla is decent for bigger motors.

100% this. Don knows that I am going through the same thing, wanting to ditch my RB racing 2" non-stepped on my dyna for something with more low end

[TheDog]

I have Bassani b1 on my fxdx S&S T124 B2 heads. Headers should be bigger. But still about 160 rwhp.

http://www.harleytechtalk.com/htt/index.php?topic=88026.0

[C-Cat]

http://i263.photobucket.com
SPF can build you a pipe to fit your build. Its not fast turn around but you should like end result.

[N-gin]

http://i263.photobucket.com
SPF can build you a pipe to fit your build. Its not fast turn around but you should like end result.

can't see pic.

[C-Cat]

Finally