3.9 Headers

[Migraine]

Hi guy's i was thinking of saving up to start doing a new exhuast system. i would like to start off with new headers then work my way to the cat back set up. could anyone who has a 3.9 with new headers tell me if there is any improvement with aftermarket headers?

if you guys know of a good exhuast setup that works good for a 3.9 please let me know thanks.

[daksprt4x4]

read my post a few down that says jba headers. u might want to rethink getting headers, well at least not jbas.

[Migraine]

Hey daksprt4x4, i read your post that sounds kinda scary i hope that if i go out and pick up a set of headers i dont have this kinda problem. maybe it was just a bad batch? how did your truck run with these headers installed did you notice any improvement's at all?

[Slow97dakota]

gibson headers, jba y pipe, run 4 feet of 2 1/2 inch exhuast pipe ( no cat) to a muffler of ur choice and done.

[DEMONiAM]

How do you get by emissions tests without the cat?

[addicted2blue00]

gibson headers, jba y pipe, run 4 feet of 2 1/2 inch exhuast pipe ( no cat) to a muffler of ur choice and done.

i agree that would be the best, as emissions or you do wanna run a cat jsut get a hi-flow cat from summit or someone.

[Blue Streak]

the earlier 3.9 manifolds were larger. pre 94 or 92 cant remember. anyone know if the y-pipe was bigger too? from what ive gathered. dodge shrank the exhaust from 3" to 2.5" when the magnum came out. would this be a good alternative to headers? maybe the larger manifold, y pipe, and a 3" pipe

[sailsurf7713]

Someone correct me if I'm wrong. I'm pretty sure your correct about the earlier 3.9 liter manifolds being larger, however this wouldn't really compare to headers and also...again correct me if I'm wrong. Running 3 inch pipe would be terrible for back pressure. Headers, stock or better Y pipe, with high flow or no cat, and a good muffler...2.5" pipe throughout would be ideal for hp and torque. And I understand the college thing. I'm in the same boat...poor as hell.

[DaKoTa-BoY]

gibson headers, jba y pipe, run 4 feet of 2 1/2 inch exhuast pipe ( no cat) to a muffler of ur choice and done.



hit the nail right on the head........the ideal exhaust for the 3.9....or you could run 3 inch, you dont get tons of loss like people say, plus it sounds awesome

[Blue Streak]

anyone know where to get the y-pipe from jba? their website is terrible and I can't find it on there.

[daksprt4x4]

from what ive read the earlier manifolds net u about the same gain had headers. mine didnt sound much different than with the manifolds. ive also had 3 different mufflers since i had the headers put on. 3 inch is too big for the 3.9 stay with 2.5 and if u go duals go wit 2.25 i didnt ive got 2.5 duals out of the muffler and ive noticed a low end loss. jba is also not such a great company to deal with directly, their warranty blows. if u want headers id try gibson or get the older manifolds if u can find them im havin trouble myself finding them.

[DaKoTa-BoY]

i think the part number for the ypipe is jba-2945y , go to summitracing and look up that number. Also, dont get the jba headers, they have a bad tendancy to crack, so go with the gibsons for headers

[Brian98]

I see that the Gibson headers for the 3.9L are for the 2WD. I have a 4WD and they don't make a set for the 4WD. Does anybody know if the 2WD headers will work?

Thanks,
Brian

[Greg555]

the manifolds have always been the same size. the gen 2 y-pipe is 2.5 while the gen 3 is 2.25

[ScatDak]

The 92-93 are 2.5" the 94-96 1 5/8" the 92 -93 Exhaust manifolds are really good from what I have seen from them, compared to headers you only gain maybe 1-5 hp over the manifolds now for $300+ dollars. I don't think its worth the money to gain 5 hp. Now the later Model Dakotas with the smaller exhaust yes they could use some help in the exhaust department. But if you use the 92-93 Manifolds your going to need the Y-pipe and also 3" exhaust. The 92-93 use 3" tubing after the Y-pipe the into the Muffler then exit 2.5 out. I have 3" all the way back on my Gen2 3.9 and I love the sound from it. But I don't like my FM 40series Muffler it resonates to much in the cab. I'm going to go with a Magnaflow and quiet it down some.

[MoPaR DaK]

gibson headers, jba y pipe, run 4 feet of 2 1/2 inch exhuast pipe ( no cat) to a muffler of ur choice and done.
Wow you really sound like you know what you're doing! Whats that beast of yours run??? :D

[Greg555]

Wow you really sound like you know what you're doing! Whats that beast of yours run??? :D

ahahahahahaha oh wow................. that was too much

[MoPaR DaK]

:biggthump

[FASTDAKOTA]

I have Gibson headers and a Dynomax ultra flow dual exhaust cost me around $850 for the whole thing. Theres sure more power and torque with the exhaust. Which would also help the truck breath better use a Ram air intake.

[dakota_john]

Just wanted to add my 2 cents! Don't get the JBA headers, they tend to crack, at least mine did! Gotta save up for some Gibson headers.

Also, is it possible to pass inspection without a cat????

[DaKoTa-BoY]

Just wanted to add my 2 cents! Don't get the JBA headers, they tend to crack, at least mine did! Gotta save up for some Gibson headers.

Also, is it possible to pass inspection without a cat????


yes, dont get the jba headers, i have some cermaic coated shorties and they have cracked all to hell.....i pass emissions, but if we had a visual inspection, you wont be able to pass....legally

[Slow97dakota]

passed emmisions with out a cat and a visual :) they asked where the cat was told them the muffler was the cat.......they bought it

[Shatto]

My 98 3.9 auto has Gibson headers, and would have their complete system (They claim they are tuned for the way you drive, ie; around 2,000 RPM, where my engine lives) but I already had a noisy Flowmaster.
The improvement is substantial AND I picked up about 2 MPG.