Shopping Cart

Your cart is empty.

Your cart is empty.

Flowmaster 817674 Flowmaster American Thunder Cat-back Exhaust System

Free shipping on orders over $29.99

$518.54

$ 99 .00 $99.00

In Stock

1.Style:Base Product


About this item

  • Provides Maximum Clearance for Off-Road Driving
  • Super HP2 Laminar Flow Technology
  • Uses the Factory Hanger Locations
  • Stainless Steel Construction
  • Quick and Easy Installation


Flowmasters new American Thunder cat-back system for the 2007-2014 Jeep Wranglers is perfect for the person looking for maximum performance and ground clearance from their exhaust system. This 2.50 inch system features a 409S stainless steel mandrel bent tailpipe with a 3.00 inch polished stainless steel tip and fits both 2 and 4 door models with the 3.6L and 3.8L V6 engines. This system replaces the factory transverse muffler and relocates the Super HP-2 muffler behind the factory catalytic converter, providing a moderate to aggressive sound level. This relocation allows for better ground clearance when driving off-road. Because the tailpipe is tucked up so high, an aftermarket metal bumper is recommended. The exhaust system is manufactured in the USA and is covered by Flowmaster's Lifetime Limited Warranty. Designed for an easy fit, this system includes all necessary parts and hardware for installation.


ABBain
Reviewed in Canada on February 19, 2021
Shipped quick, box was banged up but product was solid. Had a shop install, they said the clearance in the rear was very, very tight. And guess what - I hear it. I'm not talking about the throaty exhaust tone, which is great.I'm talking about the exhaust pipe banging around every time I go over a bump with any lateral movement. Sounds a lot like an over-sized spare on loose tailgate hinges, but louder and more. Which sucks because I just dropped a few hundred $ on the Smitybilt hinges to solve that issue.
Brandon
Reviewed in Canada on September 12, 2020
Just the right amount of growl I was looking for. Not too deep and not too loud. Perfect
LM
Reviewed in Mexico on May 10, 2020
Muy decepcionado y molesto por la transacción. No puedo juzgar el producto ya que la entrega fue incompleta. Le faltaba el silenciador (muffler 409S HP2) componente clave, también el kit de fijación y cualquier instrucción de instalación. No hay correo electrónico o teléfono para contactar y quejarse. Engañado.
L. Billingsley
Reviewed in the United States on September 4, 2018
I installed this on my 2018 JK 2 door auto. On a floor, with no jackstands, outside, by myself. It took me about 4 hours, taking my sweet time and only dropped the muffler on my face once.some points of interest that may help others:1) The old system is annoying to remove, even without any rust or dirt under my relatively new Jeep.2) People complain about the instructions being vague, but it's exhaust. It's not complicated.2.5) The only thing lacking in the instructions is that it doesn't tell you to remove the skidplate assembly to remove the factory piping.3) The instructions say to cut 20.5 inches off the long pipe for a 2 door, and that's exactly where I ended up4) The pipe that goes over the axle is a very tight fit between the sway bar and the body, but IT DOES FIT if you have it rotated to the correct angle.5) If you have a lift with spacers to lower the rear sway bar brackets, fitment will be a lot more forgiving.6) If you have exhaust spacers you will need to cut more from the pipe in front of the muffler. There is more than enough allowance for that.Overall this wasn't any more difficult to install than any other pre-made exhaust system I've ever installed.Sound was ricey at first, lot of hummy bass to the noise. I was worried I'd made a mistake. But in less than 30 miles it blew out the cobwebs and cleared it's throat and has settled into a much throatier better sounding exhaust. Slight drone at 1800 rpms under light throttle but I was doing it on purpose to see if it would; normal driving has mostly no drone. It's by no means a v8, but it's a very aggressive sound that is appropriate for this small of an engine in a Jeep. It took away some of the sluggishness of driving it too, which should translate into more mpg's.4 stars instead of 5 for making me pay for 20 inches of stainless pipe that i had to cut off and for having an annoyingly tight fit over the sway bar instead of including a small drop spacer which would have made this a super easy install instead of an average annoying one.
Customer
Reviewed in Canada on December 7, 2017
Louder than I thought it would be. Make sure you are ok with noise. The videos I watched on youtube didn't quite do it justice for the amount of noise this thing creates. If I could do it all over again, I'd look for a quieter system.I do however love the fit. It tucks up under the bumper just as I wanted.Sound is a nuisance only while city and highway driving. On the trails it sounds cool.
rexwen2000
Reviewed in the United States on November 6, 2017
Pro's:Install was easy IF you have done something like this before. Pulled in garage at 1, pulled back out at 4.Sounds great. Deepest sounding exhaust I have heard for the pentastar.Tucks way up in the frame, perfect for clearance.Con's:Install would be difficult IF you have never done one or don't have proper tools. I had to cut the long pipe a couple of inches on both ends to fit it perfectly but the result was worth it.You HAVE to take the five minutes to remove the transfer case skid pan and rear sway bar. Easy with the right tools, little more difficult with hand tools but it needs to be done.Tucks so far up in there that it is a picky job to get everything just right. For my install the muffler sits about an 1/8" away from the rear most cross member on my Unlimited. Amazingly after driving about 150 miles it has not touched.While this is the deepest toned exhaust I have heard for a pentastar motor it still aint no Hemi and no exhaust is going to make it sound that way.Good luck.
A.Wiederhold
Reviewed in Canada on June 11, 2016
At first I was a little shocked because the exhaust sounded unexpectedly loud. But I soon found that after a few days the sound seemed more subtle unless you push the car full throttle to 3000 RPM where it has a very notable race sound. Then again above that the sound is really not that different from stock while tire and engine noise take over. In daily driving and low RPMs there is a nice deep tone that still allows for music and conversation. It helps to drive a manual to have full control. Conclusion: break it in for a few days and you will get noticed without embarrassing yourself.Application:Off-roader: Yes - for off-road clearance you will not find a better exhaust. This one completely disappears under the car.Modified/accessorized Jeep: Yes - just remember it's called "American Thunder" for a reason. People will know it's there.Soccer mom and daily driver: Probably not.Install: Despite what various videos claim on YouTube you will most likely need help unless you are a mechanic. We needed a propane flame, angle grinder, and hammer just to get the stock system off. The Flowmaster pipes run really tight past various corners which may require adjustment if vibrations occur. But for me it was all worth it.
Dave H.
Reviewed in the United States on January 20, 2015
Installed on my 2009 Wrangler JKU with the 3.8 and it sounds amazing! I have always been against putting an exhaust on a v6 but this was worth it. you will have clearance issues on your rear sway bar and your frame. you can either buy the drop brackets or add some washers in there to move the sway bar down just a hair. you don't have to do either one really but you may get a rattle every now and then. I ran mine without moving the sway bar a few days but then went back and slid some washers in between the bracket and the frame just to keep that occasional rattle from coming about. seems like it only happened when someone was checking out the jeep lol. Very easy install. The Uninstall of the old exhaust was the hardest part.... mainly getting the hangers out to drop the old exhaust... I sprayed some PB Blaster on the rubbers to provide a little lube... made the job much easier but was still a pain. my old pipes were seemingly welded together by the heat that passes through them lol so some KROIL and a little elbow grease and they all separated in the end. install probably took about 2 hrs working on the ground with no jacks necessary and a couple of buddies for a few good laughs Installed with the Rugged Ridge XHD Snorkel, SuperChips Flashpaq 3872, AFE Silver Bullet Throttle Body Spacer, and Rugged Ridge High flow air filter. Very happy with overall results. Extremely happy with my new exhaust.no drone. I have floor plugs out and it isn't bad at all! has the sound of a jeep without a muffler, just not as loud. very sexy!
Recommended Products

$484.49

$ 99 .00 $99.00

4.4
Select Option

$1,014.99

$ 99 .00 $99.00

4.7
Select Option

$669.99

$ 99 .00 $99.00

4.6
Select Option

$828.99

$ 99 .00 $99.00

5.0
Select Option

$309.99

$ 99 .00 $99.00

4.5
Select Option

$415.82

$ 99 .00 $99.00

4.7
Select Option

$523.95

$ 99 .00 $99.00

4.5
Select Option

$1,273.00

$ 99 .00 $99.00

4.8
Select Option