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2 into 1 High Performance Exhaust System - 1035

  • Part #:
    4406474
  • Mfg Part #:
    1035
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2 into 1 High Performance Exhaust System - 1035

  • Part #:
    4406474
  • Mfg Part #:
    1035
MSRP: $845.00

Price: $675.38 20% off!
Make sure this fits your ride
Item is no longer available

Thunderheader 2 into 1 High Performance Exhaust System - 1035
  • Designed to give maximum horsepower without sacrificing low-end torque
  • 2-into-1 systems with patented collector design that directs spent exhaust gases in a spiral motion through four acoustical dampening chambers
  • Exhaust travels through these chambers at high velocity to scavenge spent exhaust gases from the combustion chamber and bring in a fresh charge of air/fuel mixture
  • Anti-reversion design works to impede reverse flow through the system -- reverse flow can contaminate the incoming fuel/air mixture, which reduces performance and throttle response
  • As reverse flow enters the collector, the diffuser deflects it through vents; the pyramidal trap and apertures impede the reverse flow, allowing time for the exhaust valve to close
  • Flow director has equal area at each end, allowing exhaust gases to travel at a constant velocity over the entire length to improve exhaust scavenging
  • Utilizes (2) 12mm O2 sensor ports
  • For heat shields, order the following:
    14 in. Top Front - H25-035
    23 in. Top Rear: H25-034
    13-1/2 in. Collector - H25-029


Included Items:
(1) Exhaust header
(1) 5/16-18 x 1-1/4 in. Hex bolt
(4) 5/16 in. Plain washers
(3) 5/16 in. Lock washers
(3) 5/16-18 Nuts
(1) 1-3/4 in. Clamp
(2) 5/16-18 x 3/4 in. Hex bolts
(1) Mounting bracket

For the best performance, A free-flowing air cleaner and adjustable fuel management system is recommended with this pipe.

Fits models listed with center and forward controls

Not all products are legal for sale or use on pollution controlled vehicles. Check your local laws and the manufacturers information

There is no warranty on exhaust pipes and mufflers with regard to any discoloration. Discoloration (bluing) is the result of tuning characteristics, cam timing, carburetor jetting, overheating, etc., and is not caused by defective manufacturing. See the CHEMS/LUBES section for products that will help prevent or remove bluing.

Installation of a new exhaust system may change your motorcycles fuel-air mixture requirements. Please consult the exhaust manufacturer directly with questions regarding any modifications that may need to be made during, or after, installing their product. If a jet kit or fuel processor is recommended, see the FUEL/INTAKE section



The Air Resources Board (ARB) does not permit the use of aftermarket emission-related parts that alter the air/fuel ratio of an emission-controlled vehicle. Due to these legal restrictions this part cannot be shipped to California.

Specifications
Part #: 4406474
Mfg #: 1035
Color Chrome
Finish Chrome
Style Tapered Tip
Type 2-Into-1 System
Units Each
Weight 22.45 lbs
WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov
Resources & Manuals
Fitment for Thunderheader 2 into 1 High Performance Exhaust System - 1035

Part 4406474 fits the following machines

Harley-Davidson
  • Dyna Fat Bob - FXDF 2012-2017
  • Dyna Low Rider - FXDL 2014-2017
  • Dyna Street Bob - FXDB 2012-2016
  • Dyna Super Glide Custom - FXDC 2012-2014
  • Dyna Wide Glide - FXDWG 2012-2017
  • Low Rider S - FXDLS 2016-2017
Reviews & Questions
Start typing your question and we'll check if it was already asked and answered. Learn More
Browse 13 questions Browse 13 questions and 25 answers
How muchmore horse power than stock pipes ?
A shopper on Mar 11, 2017
BEST ANSWER: The manufacturers do not provide us with Horsepower ratings so cant tell you how much more power they will have.
Where can I get thunder header to fit 08 roadking?
A shopper on Nov 22, 2016
BEST ANSWER: Here is a link to the Thunderheader products we carry for a 2008

RoadKing:https://www.denniskirk.com/thunderheader-racing-products
Has anyone tried to fit this exhaust successfully on a 2016 sportster 72?
A shopper on Apr 4, 2017
BEST ANSWER: They make a thunderheader for a sportster...but this particular exhaust won't work with a sportster...this headpipe is for a newer dyna, which a dyna has a bigger motor which means different size exhaust manifold and different angles on the head pipes. I suggest going to thunderheader site and getting a pn for what they make for a sportster 72
Does the system come with heat shields?
A shopper on Sep 12, 2016
BEST ANSWER: No, you purchase them separately. Love the look and functionality of the shields
Does this price include heat shield and brackets?
John B on Mar 3, 2017
BEST ANSWER: It comes with the mounting bracket for the headers but heat shields are purchased separate
Someone hit my bike and caved in the chrome tip on my header . Will it effect how my bike runs if I cut the only the tip off the header until I get one?
A shopper on May 25, 2018
BEST ANSWER: As long as it's not where the baffles are located, you should be fine.
Has this rust issue been fixed? I want a thunder but these comments are quite scary!
Heavy meat on Sep 20, 2017
BEST ANSWER: I have had 3 of them my last one was last year and had no issues with them at all. its still the best sounding and performing header out there I have worked on the dyno with these headers on several bikes awesome power and tq you wont be disappointed just make sue you have a good tuner that knows his stuff .
can you still get them in california ?
A shopper on Jul 22, 2020
BEST ANSWER: The Air Resources Board (ARB) does not permit the use of aftermarket emission-related parts that alter the air/fuel ratio of an emission-controlled vehicle. Due to these legal restrictions this part cannot be shipped to California.
What is the part number for heat shields ?
A shopper on May 23, 2020
BEST ANSWER: For heat shields, order the following:
14 in. Top Front - H25-035
23 in. Top Rear: H25-034
13-1/2 in. Collector - H25-029
How long before they break?
A shopper on Jan 3, 2018
BEST ANSWER: Generally it's not the pipe that breaks, it's the mounting bracket that usually gets a hair line crack from the rocking back and forth. Don't know why thunder header hasn't corrected this problem yet, but a small gusset welded across will prevent this from happening.
Will this fit a 2005 Dyna Superglide?
A shopper on Oct 1, 2017
BEST ANSWER: No, see fitment tab for correct fits
Is the right side ground clearance affected by the pipe? In the picture it appears very low to the ground.
David D on Nov 22, 2016
BEST ANSWER: Should be no ground clearance issues, simply just the way the exhaust is pictured in the image, it appears to be quite low.
How much with heat shields and brackets?
John B on Mar 3, 2017
3.4 / 5.0
5 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Star
3
0
0
0
2
Finish
2.8 / 5
Fit
4.5 / 5
Performance
4.8 / 5
Styling
4.5 / 5
Value
3.5 / 5
Loudness
Very Quiet
Average
Very Loud
Would you recommend this product?
Yes (4)
Finish
1 / 5
Fit
5 / 5
Loudness
Very Quiet
Average
Very Loud
Performance
5 / 5
Styling
5 / 5
Value
2 / 5
Would you recommend this product?
Yes
Rust is not good.
If I could put -5 stars I would. This thunderheader was in terrible condition. Must have been sitting in Dennis Kirk's warehouse for years. Rust coming through the chrome at the joint. And the inside of the pipe had rust. Pretty disappointing.
October 22, 2016
Purchased
over 4 years ago
Finish
1 / 5
Fit
3 / 5
Loudness
Very Quiet
Average
Very Loud
Performance
4 / 5
Styling
3 / 5
Value
2 / 5
Would you recommend this product?
Yes
Poor
Great performance, quality is horrible,rust on welds, welds around o2 sensors look like a 2 year old did them.
April 4, 2017
Finish
4 / 5
Fit
5 / 5
Loudness
Very Quiet
Average
Very Loud
Performance
5 / 5
Styling
5 / 5
Value
5 / 5
Would you recommend this product?
Yes
thunder header power
one of the best for HP and TQ hands down I did a 2014 103 air cleaner t man cam 555 and thunder header and got 98/109 hp/tq
dealer ship was amazed never seen that before on so little but I knew it would
September 20, 2017
Purchased
over 4 years ago
Finish
5 / 5
Fit
5 / 5
Loudness
Very Quiet
Average
Very Loud
Performance
5 / 5
Styling
5 / 5
Value
5 / 5
Would you recommend this product?
Yes
Thunderheaders all the way!
This is my second Thunderheader. That should tell you first off how good they are. The first one I had on my FXDB was black. The black one started to fade though a little over several years into a lighter colored black. I also go a little bit of pitting on the heat shields. Decided to change it up with a chrome TH and it looks great. Top quality from Dennis Kirk. Not sure why some complain. Not my experience at all. I've run both Thunderheaders and Bassani Road Rages before. Hand down TH. It is the loudest at low and high RPM but not by much. TH's have a distinct sound. You hear that sound in the distance and you immediately know its a thunderheader
April 12, 2020
Ride:
2016 HD FXDB
Just now fixing 2 get them installed.will tell later.love Dennis kirk,inc.
November 9, 2017
Purchased
over 2 years ago