? about EV27
Cruiser
Joined: Dec 2009
Posts: 157
Likes: 105
From: Tennessee
Last edited by TheVanillaThrilla; Sep 28, 2025 at 08:36 AM.
Seasoned HDF Member
Joined: Oct 2015
Posts: 13,488
Likes: 34,573
From: Pine Flat Dam/South Bay Area, CA
Fishtails with no baffles are the absolute worst for turning horsepower into noise, but radius pipes get the douchebag award for blowing dust on everything parked in the vicinity like a leaf blower.
HDF Community Team
Joined: Dec 2005
Posts: 5,402
Likes: 2,605
From: NC USA
Did you use a Mikuni intake with the rubber carb adapter or a CV tyupe setup?
Club Member
Joined: Mar 2009
Posts: 66,110
Likes: 51,396
From: Niles Canyon Ca.
There's 3 jockeying for that position, full open drags, extra long a foot out behind the bike drags with fishtail tips and f*cking thunderheaders. As if a shovel doesn't have enough vibration already the douchebag header amplifies it by a factor of 5 or so, constantly breaking mounts and the pipe atY joint and endlessly rattling the port bolts out since you can't use studs due to fit up issues. Seen exhaust ports on the heads crack running them.
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Grand HDF Member
Joined: Sep 2022
Posts: 4,417
Likes: 3,819
From: Florida
Couple things on the exhaust. Someone made a clone back n the day of those radius pipes that were three step tuned and they made great power at the track and on a dyno. I don’t remember the brand.. I actually have a pair squirreled away. But I’ve seen the numbers… “those” are no joke.
Again… broken record… Drag pipes are superior to everything else IF YOU TUNE THEM!. Specific steps, specific diameter at each step, specific length of each step. Superior as in MAKE MORE POWER ON THE DYNO AGAINST ALL including 2 INTO 1 PIPES. & Run faster times at the track. They are difficult to build and costly because they are one off for every bike to get right.
hot bike did a massive shoot out of different pipes. Like over 50 different pipes. At the end of the day (forget everyone crying about what happens at 2000 rpm)… drag pipes even the untuned just 36-40 inch long ones with a bolt in the end made within 2 hp from all other pipes. I know you guys don’t wanna believe that but all your crying is over 2 hp… these are averages from 50 different pipes.
I believe the test bike was an 80” EVO with mild cam, 10:1 pistons, dynatech ignition and performance carb. They also ran a mild hopped up twinkie with fuel…. Same results.
Here’s another FACT PROVEN BY their experiment… in the top 5 highest average hp and torque pipes… 3 of the top 5 were drag pipes with a bolt in the end… Thunderheader did not make the top 5 list. Look it up!
If memory serves the “worst” were especially long anything… Fishtails and massive 2 or 2 1/4 inch drags… yes those sucked. You really should look up the article. It’s fascinating and blows out of the water all the arm chair blanket statements that get made about exhaust.
Again… broken record… Drag pipes are superior to everything else IF YOU TUNE THEM!. Specific steps, specific diameter at each step, specific length of each step. Superior as in MAKE MORE POWER ON THE DYNO AGAINST ALL including 2 INTO 1 PIPES. & Run faster times at the track. They are difficult to build and costly because they are one off for every bike to get right.
hot bike did a massive shoot out of different pipes. Like over 50 different pipes. At the end of the day (forget everyone crying about what happens at 2000 rpm)… drag pipes even the untuned just 36-40 inch long ones with a bolt in the end made within 2 hp from all other pipes. I know you guys don’t wanna believe that but all your crying is over 2 hp… these are averages from 50 different pipes.
I believe the test bike was an 80” EVO with mild cam, 10:1 pistons, dynatech ignition and performance carb. They also ran a mild hopped up twinkie with fuel…. Same results.
Here’s another FACT PROVEN BY their experiment… in the top 5 highest average hp and torque pipes… 3 of the top 5 were drag pipes with a bolt in the end… Thunderheader did not make the top 5 list. Look it up!
If memory serves the “worst” were especially long anything… Fishtails and massive 2 or 2 1/4 inch drags… yes those sucked. You really should look up the article. It’s fascinating and blows out of the water all the arm chair blanket statements that get made about exhaust.
Last edited by Rains2much; Sep 30, 2025 at 06:47 AM.
Club Member
Joined: Jun 2024
Posts: 206
Likes: 379
From: Tukwila, WA
Love all the answers for worst exhaust. Just had to rile you guys up for that one! Haha
I had forgotten about Thunder Headers.
I had forgotten about Thunder Headers.