My buddy is selling 6.1l hemi exhaust manifolds from his Jeep srt8, should I buy them, will they fit my 5.7, and most importantly are they worth the time to install them?
Ya they are worth it. I noticed a big difference when i installed mine, it was a big job though. There are a couple of thread'sout there on how to do it. And if i had to do it again i would just pulled the heads off and remove the old manifolds like that and so much easier to put the srt one one and you can torque them properly.
That seems to be the one area that people don't talk about. 6.1 mid pipes seem to be non existent. How big of a mod are we talking about to the stock mid pipe?
Took me a month to find mid pipes. I put them on and fiddle for hours. Best I could do was get 1/10 of an inch clearance with tranny pan and had to use tons of washers to drop the cross member for the tranny. Drove around for a week with the entire srt8 exhaust on, but didn't feel comfortable with having the cross member bolts being held on by just a few threads. To do the job right you have to replace all 8 bolts with longer ones... They are frickin hard to find and super special order metric... Very long. Fastenal doesn't have them. My advice is call magnaflow directly and beg them for the flanges, they build srt8 mid pipes and make the flanges. I am going to eventually chop the mid pipes up and fabricate a set a 2.75'' or 3'' mids with the cats.
You have to shorten the stock pipes and add the flanges. I was utterly confused because the stock mid pipe is dual walled and I couldnt figure out how to weld to the inner tube which obviously carries the flow. You might need to plasma cut the piping out of the inlet of the cats and then refabricate the bends up to srt8 manifolds. I have seen guys open their cats up to 3'' in rhe ram forum. If the pipes were bolted to the exhaust with the hanger on the tranny connected, you could tack weld it easy and then take it all down and weld it fully. I believe the stock mid pipes are 2.25 diameter for the internal pipes and around 2.5'' for external. So welding 2.5'' pipe is probably the way to go. You will need a couple reducers, I used 3-2.5'' and got them from stainless works. The flanges are bigger and this reducer is essential mating them to 2.5'' piping.
One more thing, the threads on the collectors on most used srt8 manifolds completely suck. I have had a hell of a time getting bolts in and out of them. One completely froze and I had to drill it out, another the threads are almost cooked and I fear the next time I take the pipes off. When I got mine in the mail the previous owner had cut the head one of the bolts to remove the mids. I have seen many for sale where all four bolts are still stuck in the collectors with their heads chopped off. It would be prudent to tap these holes a bit larger and convert them to a SAE size while not attach to the jeep. That way you are starting with fresh threads. Try threading a bolt into them and see how it goes, if its hard then imagine after a few years how much harder it will be.
A little lip that juts out into the path of the srt8 manifolds. It does not serve any purpose and likely there just because the 545 rfe is a used in so many different applications. You will have a little hole into a cavity area were the tranny mounts to the crankshaft. You can jb weld a piece of metal onto this hole, or if your good at welding aluminum weld something on there. There is no fluid or anything to worry about in this area. Likely if you could see down in there you'd see the rear main seal and crankshaft.
Please explain what the issue is with installing SRT8 midpipes in a 5.7 WK platform. What is the difference between a WK with 5.7 and the SRT8 with 6.1 that causes the SRT8 mid pipes to not work correctly and require dropping the cross member. Seems to me the WK platform would be the same whether it was a 4x4 limited or an SRT8 when it comes to running the exhaust from engine out to the rear of the vehicle.
The platform is the same, the basic engine is similar in outside dimensions (except for the exhaust manifolds, but the transmission is different and that causes some clearance issues. Once you get behind the transmission everything is about the same, except the SRT doesn't have a spare tire so the exhaust routing behind the differential exits where the hitch goes on a standard WK.
I did this about 3 years ago to my 09limited..... Full srt8 exhaust reso delete. Best bang for the buck as you can usually buy the exhaust pretty cheaply.... I had to slice a bit off the trans and my exhaust was still kinda new so it came off pretty easy....... 09 Eagle head exhaust port matches up perfectly to the srt8 exhaust. The earlier 5.7 heads are round ports I believe but the largersrt8 ports should be ok........ Stock 5.7 single exhaust and suitcase muffler is a huge choke on the engine....... Let the 5.7 breathe and you will be surprised how fast it is! I have buried the speedo with ease and still pulling with normal bolt on mods. Let it rip! TBF
I did this about 3 years ago to my 09limited..... Full srt8 exhaust reso delete. Best bang for the buck as you can usually buy the exhaust pretty cheaply.... I had to slice a bit off the trans and my exhaust was still kinda new so it came off pretty easy....... 09 Eagle head exhaust port matches up perfectly to the srt8 exhaust. The earlier 5.7 heads are round ports I believe but the largersrt8 ports should be ok........ Stock 5.7 single exhaust and suitcase muffler is a huge choke on the engine....... Let the 5.7 breathe and you will be surprised how fast it is! I have buried the speedo with ease and still pulling with normal bolt on mods. Let it rip! TBF
What issues, if any, did you have using the SRT8 midpipes in your WK? As you can see from posts above by DannyVTCA, he had to use washers to lower his tranny crossmember to allow the SRT8 midpipes to fit properly. It seems there is a difference in transmission size or placement between SRT8 and Hemi WK's. I would love to see a comparison pic between standard midpipes and SRT8 midpipes.
No problem. Dan did have fits with his exhaust though. He did it all when he changed the heads/cam. Haven't heard from him lately either. I know he moved back to Vermont from CA (don't blame him), but I imagine he's pretty busy. Dan, you out there??
Ok, I'm back. The 545rfe pan sits much lower and has a bulge in the pan where the spin on filter sits--- for 4wd versions. The nag1 pan is very shallow, flat and squarish. When I tried installing the srt8 mid pipes on my 4wd 5.7 they immediately hit the transmission pretty badly. With the flange connections on the mid pipes and srt8 manifolds you can change the angle of the mid pipes a little, which makes a huge difference where he outlets end up. Changing the angle of the mid pipes, I found that I could get 1/10 of an inch clearance with the transmission pan, but this caused the mid pipe outlets to drop considerably. The only way to remedy this is to drop the transmission support cross member with spacers. But then you need to get much longer special order metric bolts. At this point I said screw it and put my fabricated 2.5'' mid pipes back on that utilized the original cats.
Hey jeepcogman, yup all settled back in California with the wife. Jeep made it back and forth across the country again. Now it has 110k miles on it and it has been 30k since my heads/cam/exhaust. I just changed the transmission fluid and seems to be much better. 3000 mile trip in 3.5 days-- it sucked down 1 quart of oil. I managed about 18.5-19.3 mpg if I did 65 mph. It dropped to 16.5-17 when I did 80-90mph. I just got a job that requires a 25 mile commute one way, I'm thinking about buying a four cylinder beater and parking the jeep for weekend trips to Tahoe.
Sorry to bring back an old thread, but there is not a lot of info on this swap. I have the newly built 5.7 Hemi engine with the 6.1 Hemi exhaust manifolds on. Trying to locate a set of Mid-pipes to bolt up to. After that, I will get it to a exhaust shop to finish the system. Having a tough time trying to find the pipes that would bolt up to the 6.1 manifolds. Anybody have some laying around?
That said, what a difference visually. These things are a night/day difference from each other, performance wise. Unbelievable the chocking the 5.7 manifold is compared to the 6.1
Good luck finding the mids, as I've also heard they are hard to come by because of the type of connection to the manifolds. Have you checked with your local muffler shop to see if they can get the parts. I am sure, by now, that SRT's have had to have this stuff replaced, and buying a whole to mid section would be very costly. Anyway, I hope you can find what you need, as a good header back exhaust system makes a HUGE difference.
When I saw the stock manifolds off the engine, I knew I had to do something to improve it. I didn't want to go the 6.1 route because of the "minor" issues regarding the install.....midpipes, transmission case, etc.
I finally found a local performance exhaust shop that would build me a custom set of ceramic coated headers and a complete 3 in. cat. back. The guy knew his stuff and built me a superb system for $1400.....but that was a little over 7 years ago. He initially said he would build sets for others, but after doing my job he said he wouldn't touch another one because of the tight fit. Here's a few pix of my build: