Hey all, i looked up the internet to know why is the jeep only 285hp & the charger and ram are 305hp though they all have the same 3.6l engine, the only different I found is that the charger and ram has a true-dual exhaust and the jeep has a Y-pipe that connects 2 pipes to make them one which means they have a better air flow.(maybe they have a different tune, but Ive got a bullydog tuner anyway) **if anyone knows another difference please reply**
I attached a picture of my idea, I want to do a custom exhaust as shown (The orange lines are the OEM joints & ignore pipes size they'll all be 2.5 oe 3 inches). As I know the X-pipe will make it sound better and will give a small hp gain so i thought of putting it. And the mufflers away from each other because there is no space for 2 next to each other.
the only thing that make me hesitate is the different length of pipes on the 2 sides (from engine to xipipe) and (x-pipe to mufflers).
what do you guys think about it? should I do it? any comments about it? would you recommend 2.5 or 3 inches?
Thanks in advance!
I apologize if my English is not that good, its not my first language

 

An exhaust is tuned for a specific engine. In this case, there's more than one exhaust for the engine, but they are tuned to give specific b.h.p. and torque curves.
It takes an engineer and experimentation to design an exhaust.

Making an exhaust "by feel" is a gamble, and there's good chance that you'll end up with worse performance than the stock exhaust.
Even if you do get some more b.h.p., you don't know where, along the r.p.m., you will get it -- low, mid or high r.p.m. . There may be more power at certain r.p.m., and less power at another r.p.m. .

The 2 pipes should make the engine 'see' the same resistance, that's why they are usually of the same length.
The left pipe on the Wrangler has a loop, for balancing the longer right pipe.
In your drawing, one pipe is not only longer, it has one more bend. Each bend creates resistance to gas flow, so overall it is like you made the pipe even longer.

For getting more b.h.p., flow is typically improved at both ends, at the intake manifold too.

BTW, the 3.6L works better with 2.5" than with 3" pipe.

 

Actually few of my friends have no cat-back, they only run with the stock muffler before the cat-back, or exchanging the muffler, and theyre having great performance results and a great sound, but the exchanged muffler has better performance, i took the idea from them, but with adding the x-pipe and another muffler.
Thanks for the info that 2.5" is better than 3", but if you watched closely, the joint is after the loop, so resistance will still be same, except for the distance from x-pipe to mufflers will be different, except if make 2 long pipes to the cat-back area and put 2 mufflers down there.
if you are talking about "specific b.h.p. and torque curves", with my friends' performance difference i'd definitely go with this setup, other than that, is there any other issue?

 

Curious to see what ya end up doing. Looks like a cool idea though.

 

With my 20 plus years experience as a mechanic I don't think you'll get 20 HP from it. Exhaust kits or custom designs on naturally aspirated engines usually yield single digit HP gains. You're adding more weight and a complicated system. Not trying to be a negative Nancy. Not worth the time or money in my opinion.

Dyno the Jeep before and after and prove me wrong.

 

I'd lay odds that it is in the programming. I'd imagine the tune in the jeep is more drivable in that application @ 285hp than 305 or whatever in the Charger.

 

Unfortunately we have no dynos in my area or i would definitely dyno it! with your 20 years+ experience, tell me what do you else think is the difference between charger&ram and jeep? why is there a 20hp difference?
Im considering non carb compliant magnaflow universal cats, they'll let all the carb out, opposite of what my corsa is doing, i can smell all the carb coming out if i hit down the pedal, the carb-free engine will run better i guess?

 

Thanks bud! ill post it once i do it ( IF i did! ) im a bit hesitant about it!

 

^^^x2. Especially considering Wranglers can be up to 1,000 pounds heavier.

Doesn't the performance tune on aftermarket programmers increase HP?

 

well, i got a CAI, a cat-back & bullydog tuner & a stock charger would still be faster that my jeep!
it may be the programming, but there is definitely something else!