Thunderheader VS SEII's
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Outstanding HDF Member
Joined: Apr 2006
Posts: 2,127
Likes: 3
From: Boonville, MO
Thunderheader VS SEII's
Don't do it, I sort of screwed up. I had the HD service rider tell me for a year that if i went to a thunderheader instead of my SEIIs I would get more power. So I went ahead and chgd out the SEII's for the Thunderheader, had it DYNO'd and low and behold lost 4 lbs of torque and 2 HP. I was all over the poor service tech, I was mad as hell. He took the bike back in a second day at their expense and Dynod and redynod what they could but still got the same results. I have to give these guys and this dealer a ton of credit, they offered to refund and take back the Thunderheader and put it back to the way it was with the SEII's at their expense. These guys always treat me right. Anyway, along the 3 day path of riding it inbetween dyno's and such i decided i do like the way the thunderheader looks and i really like the way it sounds. I can't believe after all the money i spent beefing up the motor i elected to keep the Thunderheader on. I still have the SEII's, which i will not sell, in case i change my mind again. I do feel what seems like quicker throttle response from my Thunderheader, but that may be alot of wishful thinking.
Road Warrior
Joined: Dec 2005
Posts: 1,644
Likes: 0
From: So-Cal
RE: Thunderheader VS SEII's
Can you really feel 2hp and 4 ft/lbs torque? I doubt it. I am a little different. Once I modify my motors -- cars I am pretty satisfied. These toys cost too much money to tinker tinker tinker. Be happy with what you have and move on sometimes is the best policy.
Seasoned HDF Member
Joined: Dec 2003
Posts: 7,090
Likes: 3,882
From: Murfreesboro , TN
RE: Thunderheader VS SEII's
Kinda makes ya wonder about the expertise of the mechs at that shop if you ask me. If they just put the pipes on, and didn't change anything (and realistically, you need to add a SERT, PCIII, or some other fuel re-mapping system), then I'm not surprised of a slight power loss. You're taking a bike that is probably running pretty lean, and adding freer flowing pipes to the mix!
I bought my Glide with the Stage 1 installed (SEII pipes, SE A/C, ECM upgrade), and after almost a year put a pair of Thunderheaders on and PCIII with the stock map (from DynoJet) for my configuration. Just the seat of the pants increase was noticable! (I haven't dyno'd it, but I did all the work myself). Just the fact that I can keep up better with my riding buddies (with various mods, normally I'd catch up to them after they hit cruising speed on the highway) is proof enough for me!
I bought my Glide with the Stage 1 installed (SEII pipes, SE A/C, ECM upgrade), and after almost a year put a pair of Thunderheaders on and PCIII with the stock map (from DynoJet) for my configuration. Just the seat of the pants increase was noticable! (I haven't dyno'd it, but I did all the work myself). Just the fact that I can keep up better with my riding buddies (with various mods, normally I'd catch up to them after they hit cruising speed on the highway) is proof enough for me!
Cruiser
Joined: Oct 2006
Posts: 107
Likes: 0
From: denver, co.
RE: Thunderheader VS SEII's
sounds like a solid dealer. least he's offered to make things right..
my dealer just announced a 'if our dyno tuning doesn't improve your bike's performance, it's free' policy..
just love to see people treating other people right..
my dealer just announced a 'if our dyno tuning doesn't improve your bike's performance, it's free' policy..
just love to see people treating other people right..
Thread Starter
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Outstanding HDF Member
Joined: Apr 2006
Posts: 2,127
Likes: 3
From: Boonville, MO
RE: Thunderheader VS SEII's
I think the mechanic is good, the bike already had a SERT and he did try different maps and ideas. He actually has done all the work and dyno's to the bike in the past. The real disconect came with the service writer who thought it was better and convinced me it was better. Pipes were ordered and bike was left for installation before I ever talked to the mechanic on what my goals were, more power! I sure he new better from the start.
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Outstanding HDF Member
Joined: Apr 2006
Posts: 2,127
Likes: 3
From: Boonville, MO
RE: Thunderheader VS SEII's
Sorry i didn't mention that at the start, it was the 2 into 1, i didn't realise there was a different one.
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Seasoned HDF Member
Joined: Dec 2003
Posts: 7,090
Likes: 3,882
From: Murfreesboro , TN
RE: Thunderheader VS SEII's
I just find it a little odd, as the Thunderheader pipes are some of the best pipes to get for performance gains (up to a certain size. T'headers are best between the 88-103" range.) There's even an article on the nightrider site about a 95" build pushing out 128hp (at the rear wheel!), and it's using a Thunderheader 2-1 pipe!
Even beyond just the Thunderheaders, the typical performance gains are almost always higher using a 2-1 pipe over a 2-2 set! Especially if you just have the SEII slip-ons, and are using the stock headers.
Even beyond just the Thunderheaders, the typical performance gains are almost always higher using a 2-1 pipe over a 2-2 set! Especially if you just have the SEII slip-ons, and are using the stock headers.
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Ultimate HDF Member
Joined: Apr 2006
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From:
RE: Thunderheader VS SEII's
Well the stock headers are pretty efficient, more so than true duals but I am really disappointed to hear about the 2 into 1 Thunderheaders. Everything that I have ever read about them has been positive (not counting if you like the look or not) and everyone that I know that has them raves about 'em. This merits further looking into. I agree 2 into 1 are generally the top performance exhaust for HDs.
Banned
Joined: Feb 2006
Posts: 20,836
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RE: Thunderheader VS SEII's
ORIGINAL: Cryptoboy
I just find it a little odd, as the Thunderheader pipes are some of the best pipes to get for performance gains (up to a certain size. T'headers are best between the 88-103" range.) There's even an article on the nightrider site about a 95" build pushing out 128hp (at the rear wheel!), and it's using a Thunderheader 2-1 pipe!
Even beyond just the Thunderheaders, the typical performance gains are almost always higher using a 2-1 pipe over a 2-2 set! Especially if you just have the SEII slip-ons, and are using the stock headers.
I just find it a little odd, as the Thunderheader pipes are some of the best pipes to get for performance gains (up to a certain size. T'headers are best between the 88-103" range.) There's even an article on the nightrider site about a 95" build pushing out 128hp (at the rear wheel!), and it's using a Thunderheader 2-1 pipe!
Even beyond just the Thunderheaders, the typical performance gains are almost always higher using a 2-1 pipe over a 2-2 set! Especially if you just have the SEII slip-ons, and are using the stock headers.
