One thing to keep in mind is that modern car companies, especially with vehicles like the "gas guzzling" Jeep are spending a lot more time and money engineering fuel efficiency. In the case of intake and exhaust, efficiency also equals performance. So the exhaust is already pretty efficient. On the intake side, when you upgrade to a cold air intake, you really aren't doing anything to the intake, but only the plastic ducting in front of the throttle body and intake, if you really wanted to make gains, you would have to make changes to the throttle body and intake manifold.

Also, generally while there are some gains in both exhaust and CIAs, they are minimal, and mostly at the peak of the power band, as is with most performance upgrades, and most Jeepers aren't running around with their right foot welded to the floor screaming at 5,500+ RPM.

Small gains at high RPMs make sense of you are looking at the 1/4 mile, but not nearly as much for a vehicle like the jeep.

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your giving a lot of credit to the car companies.
While engineering has come along way, most of these innovations were spawned by government regulations and not by choice. Car companies get away with the bare minimum only and use only what they have to. Have you taken off the stock JK intake or looked at your probably already leaking stock exhaust system? Junk.
Now if you bought a Ferrari or Bugati and told me the same thing, I would agree. But a mass produced Jeep, no way.

 

I will agree with you. Companies cut exhaust outlet and air intake along with very lean fuel to get lower emissions. It is all about fuel economy and emissions, not performance based. Performance improvements are just a plus for them

I do believe an actual tune is required for real performance gains tho. On variable timing motor the tunes can a lot at low rpms and high.

 

The ECU controls air and fuel, Without the appropriate tune to go with it and exhaust you will see little gain. The engine can only breath so much before it has the opposite effect. In order to breath better it also needs bigger valves and higher lift cam(s).
You already have a 2.5" exhaust on a V6 we use to run that on bigblock V8s with 500+ hp. Put a bigger throttle body on like what we tried with the 3.8 (2008 Viper 74mm throttle body is plug and play) and see where that gets you. Better yet Do this test for max flow, Go take your exhaust system off and take the throttle body intake tube off an see how well it runs. That is the best flow you can get without doing motor work.
This is no different then arguing that the throttle body spacer works on Multi port injection.

You want gains instal a supercharger or a Hemi.

 

This statement is simplifying something that is no simple. A 4" intake tube vs a 3" intake tube can completely change an engine operation. Do you know for a fact the exhaust can flow the 2.5" flow? I do not think anybody here is talking about 50+ hp gains but maybe 3-5 hp. It is minimal but can completely change the way the motor runs if done right. More power does not require an engine build or power adder. A simple exhaust and ecu flash on a bike can bring 30 hp on a stock machine. That is on a 155 hp motor to 185 hp. Your whole idea is bogus. Air velocity, intake tunnels, throttle bodies, ignition timing, and on and on. All can drastically affect power, throttle response, fuel economy

 

Exactly my point, without a custom tune (ECU flash) exhaust and intake mods are pointless.

 

A simple tune from superchips or diablo will work just fine. Your point was it does nothing without a valve job and cams etc. Pick you point. Which one do you need? A tune or a engine overhaul?

 

Agree that a custom tune will get the most power out of your mods, but even with a canned tune that may leave some power on the table for a performance modded vehicle, many still enjoy the sportier sounds created by aftermarket exhaust and intake.

 

It was not a lot of hassle. It was actually very easy because the PCM is so easy to switch out. Rest is the same as any other flash tune. An added benefit is you still have your original PCM with the original flash to throw back in if you ever need to seek sealer ship service for engine issues - no evidence of flashing back-n-forth left behind.

The downside is you have to pay$$$ for this.

 

Reread my post again you missed my point then ... Engine work or Supercharger if you want more then minimal gains. The Superchips tune gains come in its ability to run premium fuel properly and address run ability issues like throttle response. For the average guy the programmer is more bang for the buck then exhaust or intake.