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-   -   A better exhaust system for the 5.7 WK?? (http://www.jeepgarage.org/f5/a-better-exhaust-system-for-the-5-7-wk-19490.html)

jeepgcoman 02-26-2011 08:25 PM

A better exhaust system for the 5.7 WK??
 
3 Attachment(s)
I was checking out the stock exhaust manifolds from my 5.7 LX and 5.7 WK and noticed a pretty big difference. Looks to me like the LX (the bigger one) would flow somewhat better than the stock WK setup. It would obviously require some head pipe modification, but may be worth it if you can find a set of LX'ers at a good price somewhere. At least they would port match and have the EGR tap, unlike the stock 6.1 manifolds. The collector ID on the WK is 1 7/8 in. and the ID on the LX one is 2 5/8 in.

Chaoul1 02-26-2011 09:00 PM

Re: A better exhaust system for the 5.7 WK??
 
There's a member on here that has his shop making some nice Headers for us 5.7L dudes.

White Chocolate 02-26-2011 09:08 PM

Re: A better exhaust system for the 5.7 WK??
 
Quote:

Originally Posted by Chaoul1 (Post 365254)
There's a member on here that has his shop making some nice Headers for us 5.7L dudes.

That ended with a halt I believe.

jeepgcoman 02-26-2011 09:10 PM

Re: A better exhaust system for the 5.7 WK??
 
That would be me, Paul. Unfortunately the guy isn't going to do anymore, because of the amount of work involved, lack of time and help at the shop.

Chaoul1 02-27-2011 10:43 AM

Re: A better exhaust system for the 5.7 WK??
 
Ouch...then off to someone else!

jeepgcoman 02-27-2011 03:30 PM

Re: A better exhaust system for the 5.7 WK??
 
If you can't find someone to build a set of headers, the stock LX manifolds look to me like about 5-10 horsepower better than the stock WK's, and could be a good, inexpensive option. They're about a 1/2 in. taller and wider which means that the internal porting is a little bigger. The 3/4 in. bigger collector would also be a big help in all RPM ranges. The other option the guy was considering was to take a set of JBA shorties for an LX and modifying them to fit the WK. That may also be an option which may not be too costly.

TVI01 04-12-2011 05:56 AM

Re: A better exhaust system for the 5.7 WK??
 
Just curious, but has anyone looked into seeing if the JBA shorties designed for the Hemi Durango fit? JBA designed them so that you have to modify the y-pipe, so they already come with extension pipes.

http://buyjba.com/catalog/images/JBA/1962sjs.jpg

jeepgcoman 04-12-2011 05:35 PM

Re: A better exhaust system for the 5.7 WK??
 
It's hard to say without actually trying to fit them, because everything is so tight up in there. From the looks of them, I think they're tight enough not to hit the frame rails, but I know on mine all the pipes go back farther before they curve down. I think the stock SRT ones curve down earlier like the one you have here. I definitely think it would be worth a try though. Those are real sweet looking, and they have the EGR tap on the passenger side header. That mandrel bent tubing is so clean. How much do they want for those?

Also, do you know if the Durango has the 545RFE, the NAG1, or ?? transmission? There is a clearance difference and, for instance, the stock SRT's on the 5.7 with the 545RFE need to have a chunk cut out of the bellhousing on the right side to clear.

TVI01 04-13-2011 09:24 AM

Re: A better exhaust system for the 5.7 WK??
 
Quote:

Originally Posted by jeepgcoman (Post 394660)
It's hard to say without actually trying to fit them, because everything is so tight up in there. From the looks of them, I think they're tight enough not to hit the frame rails, but I know on mine all the pipes go back farther before they curve down. I think the stock SRT ones curve down earlier like the one you have here. I definitely think it would be worth a try though. Those are real sweet looking, and they have the EGR tap on the passenger side header. That mandrel bent tubing is so clean. How much do they want for those?

Also, do you know if the Durango has the 545RFE, the NAG1, or ?? transmission? There is a clearance difference and, for instance, the stock SRT's on the 5.7 with the 545RFE need to have a chunk cut out of the bellhousing on the right side to clear.

Well...as usual, JBA is proud of their stuff. The best prices I've found so far are about $570 for un-coated & $700 for ceramic coated (this is w/o S/H). But, they do make nice parts. It's still a hefty price for something that my or may not fit.

The V8 Durangos do use the 545RFE trans, though.

Another thing...IMHO, to take advantage of these JBA's we'll need a better option for a y-pipe. Something with smoother bends than the OEM piece.

jeepgcoman 04-13-2011 06:54 PM

Re: A better exhaust system for the 5.7 WK??
 
Yes, I'd say you'll have to ponder your course of action. FWIW, I'll tell you that after seeing the stock manifolds, I had to do something. If I had never seen pictures of them I'd probably still have those crappy things on mine. Since no one makes 5.7 headers for the WK, I think you're really limited to several fairly expensive choices if you want to improve the engine breathing, horsepower and economy:
1. $1200+ for 6.1 long tubes that need modification (EGR tap), and some have had rear O2 sensor problems.
2. Stock 6.1 manifolds (if you can find them), which will need the same EGR tap mod., and the trans. case cut.
3. Try to modify a set of 5.7 JBA (or some other brand) shorties (uncoated) for an LX vehicle. This may be the least expensive option, depending on how much modding needs to be done. I am betting this can be done fairly easily.
4. Buy those really cool Durango ones (uncoated) and see if they can be modified to fit. I am betting this can also be done fairly easily.

Everyone of those choices will require significant mods. to the "Y" pipe, both at the header collectors and at the tail pipe end if you're going to do a complete 3 in. system. I would definitely recommend that be done too, if you want full benefit.

From my own expensive exhausting experience I can tell you that having the headers built was both the single most expensive mod. (too date) I've done, and also easily delivered, by far, the biggest increase in power and economy. I still haven't gotten a real good mileage check without significant head/tail wind, but the gain is at least 1.5-2.0 mpg, and I am guessing between 30-40 hp. The top end difference is like day and night, and the low end is much better also. I am planning to go to the races on the 23rd, so I'll see how it compares with the basically stock (tuner and 3 in. exhaust w/o headers) times last year.

Maybe it's time to crawl under yours and a new Durango and see what you think the differences might be?

Chaoul1 04-13-2011 07:28 PM

Re: A better exhaust system for the 5.7 WK??
 
^^^Do you have any pictures of your Headers?

Gojeep 04-14-2011 04:07 AM

Re: A better exhaust system for the 5.7 WK??
 
Those header look the goods. I might use those instead of building my own custom ones for my project. Have to see as I will have a lot more room than a stock WK.


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