Hi to all,

I plan to change the OEM exhaust on my 2013 JK 2 door, for a dual exhaust. I want a much fatter sound (even if it remains a V6 sound) and try to gain something noticeable in throttle response.
(my girl has a 2000 XK which throttle response is much better)

I use the JK mainly on road (offroad in Switzerland is ... er ... quite strictly forbidden) or dirt trails, the global height of the pipes is not a problem (i.e. the Gibson Mulisha)

By (close as possible, was a V8 and not a Jeep) comparison with my previous vehicle (Durango), The Borla Catback added all that except that the throttle seemed to "live its life" (between 1000 and 2000rpm at idle). Bad installation ? Maybe a sensor issue ? Dunno. But for my JK I want the new exhaust run without that issue...

Questions :

- Choice : catback only, muffler, rear exhaust (i.e. Gibson), or else ?
- The Brand : Borla was fine but Gibson (Mulisha or other) is tempting, any other brand you've used ?

(I'm a bit new to the JK structure so if I said something dum, thanks to correct )

Thanks for your experience and knowledge.

Have a great Jeep day !

 

No aftermarket exhaust will noticeably change the throttle response or gain perceivable power.

Properly installed, bolt-on aftermarket exhausts on Wranglers pose no problems.

Gibson say about the Mulisha --

Benefits
Fuel Economy
Improved Performance Acceleration
Enhance Low and Mid Range Power
Maximum Horsepower & Torque Gain

It’s either fuel economy, or the other three, unless they found a way to both eat the cake and keep it...
I tend to stay away from companies which make such false claims and regard their customers as ignorant.

I’d suggest a stainless steel one, not “metal” and not “Aluminized”, and not packed with fiberglass.

Many exhausts emit annoying ricey or drone sounds, you may want to listen to sound clips.

For not too loud growl and no annoying drone or ricey sound, I picked the Magnaflow # 15237 , cat-back, over the axle.
That's for the 4-dr, the model No. for a 2-dr is different.

 

Hope I'm not too late. Just giving my thoughts. My personal opinion. I had the Gibson mulisha on my 2012 jk. Maybe they improved the painting / quality since. But...mine rusted horribly in like 4 months. Winters is PA and the road salt probably contributed. Here's a pic after one month. Rust forming. I eventually removed the extensions. They definitely looked cool........for a month.

 

Wow, I would NOT have been happy with that. Thanks for the heads up!

 

Its pretty funny to see pipes sticking out the back. I cut mine back about 6" and still pinched it a bit on the Rubicon. Those chrome tips would be completely flat if they get within a mile of the rocks.

 

Thank you (for the rest of your answer) !

I also don't believe too much in power gain (at low rpm anyway) from partial exhaust change, but the throttle response of the JK seems really far from my friend's XJ (4 L) and even my old CJ7 (V8). Maybe I'm wrong and that's the normal feel for JK ...

It's awesome from 3000 rpm and above, but below, ... (as previously said) throttle response is really "soft"

I'm a bit off thread here, but what would be the solution, apart maybe for exhaust modif ??

 

The 285 bhp and torque of the Pentastar, on a 2-dr, shouldn't be sluggish, if the gear ratio suits the wheel size. What's your gearing and wheel size?

More power? -- a Hemi or LS engine... or a super/turbo charger...

 

Also, maybe the gas pedal connection is not tight ?

 

I must check what's the gearing ratio is on this JK. Don't know it. It's been imported from the US (California). But the tires are 185/70-17 (on 2'5 lift and OME nitro).

I wonder if it's not a tuning question.

I will check the AEV plug to see if there's something to do from there.




One feel a really big difference below and above 3000 rmp. Driving it, under 3000 is like driving a very average car. The sound is dull and thin and whiny (maybe that's a clue of something wrong to you) . That is what I don't understand regarding a V6 with 285 HP, which is already fine for its weight (even if the 285 are not at 1500 rmp

More power is difficult here. I will do 3 day with a TS before getting caught and asked the JK to be put back to stock It's already been tough offroadin' only to get them to accept the 2'5 lift ... LOL

Fab car anyway but just a bit frustrating at low/mid rpm.

 

No problem. Hate to see someone else have the heartache I did. Found another pic. Last one I took before I took the extensions off & tossed them. Sent this pic to Gibson to see if they'd do anything. Never replied back. Eventually the outside looked like the inside.