Has anybody put on new headers? If so, I would like to know what kind you put on, if you noticed a difference in the power, and do you think it was a good or bad investment.

 

bump...i am curious too

 

It's been over a year since I installed headers, CAI and an exhaust. As I did them all over a weekend, I can't exactly say where the power came from, but my butt dyno suggested about 20 hp. Banks headers and exhaust, AirRaid CAI. If I had it to do over again, drop in K&N, Woods muffler relocation kit and still keep the Banks headers.

I definitely have smoother power and don't have the dead spot between 2,000-3,000 rpms. The caveat has been a few weeks later I also purchased a Hypertech Max Energy and I can't see that it does a thing outside of leaving my Jeep starved for fuel. Lots of tinkering with Octane ratings and settings before settling on 94 and the performance tune which if nothing else has my plugs looking right.

Currently waiting on a Superchips Flashpaq to see if that releases any additional power and if it plays better with my exhaust and intake modifications.

 

Like Jpop I put on a CAI and chip. The CAI was a noticeable improvement, and probably the reason for jpops performance gains. I later added the Banks headers. I have noticed no improvement from them, and would not install them again if I had it to do over. When I compared them to the stock headers I saw no real difference in the design other than they are welded tubes and not cast like the stockers. I expected to see some modification in the port size or flow paths, but I could not tell.

 

Which CAI did you use??

 

On this v6 motor, there is no need for headers. The stock manifolds are efficient enough for natural aspiration. Now if you supercharge it or drop in a v8.....well, that's a different story.

 

A GOOD drag racer will tell you that it's a stupid proposition to do "shotgun" changes. You absolutely never know what something will do to your specific vehicle and situation until you try it. I don't care what some high cost advertising agency says. The thing is, in their excitement to "have it all right now", people slap everything on at once. You're going to be hard pressed to find anyone who takes the time to do mods like this correctly and give you an accurate answer. Since everybody does it all at once, theres no way of knowing where the power came from. Did the headers add it? Was it the chip? Was it the CAI or the exhaust? There have been many instances documented on this forum where an exhaust by itself diminished power. Same with a CAI. So in my mind, doing them all at one time makes no sense whatsoever. Certainly don't trust whatever company makes the header. They'll tell you anything to get your money. Before you spend a wad of dough, I have some advice....take it or leave it. The 3.8 is a 60 degree v6. It's never going to be a powerhouse short of supercharging it. Best you'll be able to do is "fill in the gaps" so to speak. Such as the gap at around 2K RPM. Do your homework and you can do that with a good cat back. I did. CAIs are for two kinds of people. People who will NEVER see wet conditions in the LEAST while wheeling, or for people who don't wheel at all. Even those who don't wheel at all can still hydrolock their engine in a puddle on the street. So, to me....for MY money a CAI is OUT. Headers....now what to say about them. The Jeep already has headers. A header by definition is a manifold with individual tubes for each exhaust port that may or may not come into a common collector. So, again, for MY money, headers are a gamble at best. WIll they make more power than stock headers? Maybe. WIll you be able to feel that difference in your butt. Probably not. I spent under 200 bucks on a custom cat back with a Magnaflow straight through muffler. Best money I've spent on it so far concerning power. I can clearly tell a difference and it didn't clean out my bank account. The extra power is right where it needs to be. On the bottom end. In the end, it's your money. Waste it like you want to.

 

Excellent post! I'll keep that in mind when I get mine.

 

What works for drag racing isn't going to work for dealing with the ECM. Most changes on the exhaust or intake will take 3 tanks full of fuel for the ECM to get it figured out. That's nearly 10,000 miles of tests to get a CAI, headers and exhaust figured out and then add in some different Octane ratings and a programmer and you have the useful life of the engine taken up with testing.

When I purchased my headers I had them heat barrier coated with black satin. Perhaps the headers did nothing at all for performance, but reducing under hood temperatures by 20-30 degrees certainly does. Keeping more heat in the exhaust gas increases velocity, scavenging and perhaps if I could have waited a few weeks to get the cast exhaust manifolds coated while being without my vehicle it would have brought the same.

I'd really like to get my hands on a clean Y pipe so that I could have that heat barrier coated as well. The cats are where the first big heat sync are and whatever dissipates heat reduces exhaust gas velocity. Might be overkill, but could have some moderate increase in power.

I've done my share of drag racing as well and I've always taken a car that had headers, intake manifold, cam and exhaust already installed. The at the track changes I made were tweaking jetting, suspension and tire pressure. A little easier to figure out what's going on when you get to make another run in 30-45 minutes and no ECM that needed to scratch it's head for a couple tanks of fuel.

I've watched my big block Chevelle lose ET but gain MPH when I went from a 2.5" to 3" exhaust, later to be remedied with a beefier cam. After installing AFR heads I didn't see a big improvement, but every subsequent modification I did they handled it well and pushed through all the air and fuel needed. I believe that to be very much true of what headers will do for the 3.8L JK engine although unfortunately the only programmer I have used (Hypertech) doesn't play well with them.

So while I certainly understand the merits of testing components individually without full control of the ECM it's just not practical. Some of this stuff just needs figured out on paper and you hope the ECM plays along. Cooler air on the intake side equates to more power. Lower under hood temperatures equates to more power. Higher EGT equates to more power. The real trick is getting the ECM to understand what's going on and a programmer that will make good use of the bolt on parts. I'm hopeful the new Superchips Flashpaq will address that and my past experience with their product suggests it will.

 

In terms of showing power gains, what works for drag racing WILL show the same results. One piece at a time. Whether you know it or not, carburetors work very similarly in this respect, although manually. If a change is made requiring more fuel, then re-adjust the mixture or change jets. If those changes become too much to adjust out or overcome by changing jets, then a larger carburetor is in order. Same principle, just different methods. All engines will make more power as their condition gets more "lean". Just like a blow torch when you turn up the O2. Three tanks of fuel to figure out? Yeah, right! These aren't late 70s early 80s pre-OBD vehicles we're talking about here. They're state of the art well advanced OBDII equipped vehicles. I can unbolt the exhaust and start it up and get a check engine light. Why? Because the O2 sensor sees a difference in the exhaust mixture RIGHT NOW, not three tankfuls away. Same is I disconnect a vacuum line. The data the computer sees is LIVE. There's no learning curve. The only possible exception is the drive by wire computer. Because it is such that it requires learning the driver's habits, it does require a learning period. Once learned however, it's a done deal.