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-   -   SRT Exhaust conversion with Dual In - Dual Out Muffler (http://www.jeepgarage.org/f183/srt-exhaust-conversion-with-dual-in-dual-out-muffler-55632.html)

therock2 03-01-2013 11:01 AM

SRT Exhaust conversion with Dual In - Dual Out Muffler
 
I have a 5.7L Hemi that I'm in the process of changing the rear bumper to the SRT and installing a center exhaust and I'm considering a true dual setup from the cats back. Does anyone have experience with cutting the y-pipe right after the cats and attaching a dual in - dual out muffler?

I have been researching sound clips for the Magnaflow 12599 muffler but I'm not sure if converting the factory y-pipe to a true dual out would decrease back pressure and hurt performance. Please chime in if you have any experience with this conversion and let me know your thoughts.

Much appreciated.

DannyVtCa 03-01-2013 12:13 PM

Re: SRT Exhaust conversion with Dual In - Dual Out Muffler
 
With a dual inlet muffler the muffler will equalize the pressure. True dual is when each side is independent with two mufflers... Which is really hard to do considering the space we have to work with between the frame and rear driveshaft. The only good way to true dual is to remove the rear tire and put a couple mufflers back there. You will lose back pressure no doubt going with a dual exhaust setup... I would probably go with 2.25 duals if your engine is stock, since the stock mid pipes are around 2.25 also.

therock2 03-01-2013 03:24 PM

Re: SRT Exhaust conversion with Dual In - Dual Out Muffler
 
Thank you for the feedback. I misused the term "true dual" exhaust since my intention is to have a setup like the OEM SRT exhaust...one muffler for both outlets. Tire will be removed to allow for center exit. I have the Overland model and didn't realise the mids were only 2.25 in diameter. Long term goal is to add the SRT manifold and mids since I've read that is where the biggest choking point is with the 5.7L. My goal is similar to what you have already done with yours.

Thanks again for your input/advice.

DannyVtCa 03-02-2013 12:24 AM

Re: SRT Exhaust conversion with Dual In - Dual Out Muffler
 
I have a set of srt8 manifolds... Mid pipes... And full srt8 cat back if your interested. I bought another set of manifolds for backup and was going to go the total srt8 route... But now I think I want to go with a 3.5 or 4 inch pipe. Pm me if your interested and ill email you some pics.

therock2 03-02-2013 10:17 AM

Re: SRT Exhaust conversion with Dual In - Dual Out Muffler
 
PM sent.

therock2 03-04-2013 06:39 PM

Re: SRT Exhaust conversion with Dual In - Dual Out Muffler
 
Would it be possible to cut the OEM Y-pipe off right after the O2 sensor and simply adapt an X-pipe to the end of the 5.7 mid-pipes to allow for a dual-in, dual out muffler? This would allow me to install and retain a permanent "cat-back" setup until funds allow me to later add the OEM SRT manifolds and mids to compete the setup.

http://i1180.photobucket.com/albums/...psfd661cc8.jpg

Gojeep 03-05-2013 02:57 AM

Re: SRT Exhaust conversion with Dual In - Dual Out Muffler
 
No reason why not.

DannyVtCa 03-05-2013 10:45 AM

Re: SRT Exhaust conversion with Dual In - Dual Out Muffler
 
I would save yourself a lot of aggravation trying to mate an x pipe to your mid pipes and just get a y pipe, turn it around and you will instantly have two outlets to put into your muffler. The x pipe will cost more money to install and most likely give you marginally better performance. The o2 sensor on the passenger side looks like it is pretty close to where you are cutting for an x pipe, and the pipes kind of do some funky angles to clear the transmission cross member. Plus with the y pipe you are basically only cutting the flange off your mid pipes so if you ever want to go back it will be easier.

therock2 03-08-2013 06:08 PM

Re: SRT Exhaust conversion with Dual In - Dual Out Muffler
 
Did you use the M8x30x1.25 flange bolts to attach the manifolds to the heads? Also, is there a gasket needed between where the manifolds attach to the midpipes?

therock2 03-26-2013 09:45 PM

Re: SRT Exhaust conversion with Dual In - Dual Out Muffler
 
Well, my patience paid off. I found a set of SRT manifolds and SRT midpipes and I'm in the process of gathering all the hardware to take on this project. Here a few photos of the parts I acquired. A HUGE thanks goes out to DannyVtCA and Viking757 for all their knowledge and experience they've shared with me so far taking on this project.

SRT8 mid pipes

http://i1180.photobucket.com/albums/...psaaf934d0.jpg

SRT8 exhaust manifolds

http://i1180.photobucket.com/albums/...psa1e8c246.jpg

I found the manifold gaskets from an '09 5.7L and they match up perfectly to the "D-shaped" ports of the SRT manifolds.
The gaskets are made by Fel-Pro. Part # MS970 and I found them at rockauto.com. The backside have the cushioned gasket material that mates with the surface of the manifold that you can't see in the photo.

http://i1180.photobucket.com/albums/...psb735e4d3.jpg

Marking up the EGR port and extra bolt hole using the gasket as a template.

http://i1180.photobucket.com/albums/...ps16e8be9d.jpg

The faces of the manifolds are a bit corroded so I dropped them off at a milling shop yesterday to have the faces resurfaced.
The first machine shop I took it to informed me that the steel was so hard it was difficult to refinish them with standard rotary disks so they referred me to another milling shop that had the milling lathe. This is truly the best way to resurface the faces.

Here's an example of how they looked when I dropped them off.
I'll post photos of the resurfaced faces on Friday when I pick them up.

http://i1180.photobucket.com/albums/...ps630ecbb0.jpg

Here's an example of the milling machine that is being used to resurface the manifolds.

http://i1180.photobucket.com/albums/...ps3d5e7b0d.png

Stay tuned for more info.

DannyVtCa 03-27-2013 12:01 PM

Re: SRT Exhaust conversion with Dual In - Dual Out Muffler
 
Looks good man! I'm subscribed, hope you have better luck with those damn mid pipes than I did. Remember you have to drop the cross member 2 inches. Also, when mating the muffler flanges to the mid pipe flanges you need to drop the hangers over the axle.... Because you are dropping the mid pipes 2 inches the hangers are too high and the muffler flanges don't mate up very well and leak.

DannyVtCa 03-27-2013 12:03 PM

Re: SRT Exhaust conversion with Dual In - Dual Out Muffler
 
I haven't have a problem with my manifolds... I just wire brushed them really good. Resurfacing them may be overkill. Plus if they remove too much surface your going to have problems mating the mid pipes up because they would have essentially made the distance between your manifold outlets narrower. Cleaning the surfaces of your heads is going to be pretty tricky.


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