Custom Exhaust Building

YJJPWrangler

YJJPWrangler

Well-Known Member
Joined
Jul 19, 2005
Location
Charlotte
The time has come to start taking a long, hard look at the exhaust for the Willys build. Right now, I only have headers on it(oem manifold on the driver side/header on the pass side). I'm running a 4.3 TBI. Fuel lines are routed down the driver side framerail. My plan is to route the main exhaust line down the passenger side framerail and have it dump out behind the rear axle. I'll throw in a crossover pipe from the driver side and connect it to the pass side somewhere along the way. I've never built exhaust before but my plan is to buy some tubing/pre-bent pieces and then pie cut away. I have a vertical bandsaw, chopsaw, and sawzall at my disposal. Welding would be with a Hobart Mig. Planning to wrap heat shield around most of the exhaust. I would rather do the exhaust myself then take it to a shop. Is there anything else I need to look for?
 
YJJPWrangler said:
Is there anything else I need to look for?
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An exhaust shop. A friend of mine did his own exhaust, and I guess it works, but it looks like he did his own exhaust. Depends on how much you value your time though.
 
I would take it to an exhaust shop too but with a complete plan on how you want it done. Will your crossover pipe be able to be run over the driveshaft as opposed to under the transfer case? Exhaust shops don't understand our off roading needs to keep the belly clean.
If you do it yourself have fun! Keep in mind that They can bend the pipe where you will have to cut and weld. But you are pretty persistent so I'm sure you'll do good job if you do it.
 
RJ's custom piping. These guys are damn good!!
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I built my exhaust fairly easy, box of bends I ordered from summit had less than $450 in mine including headers. But I’ve got more time than a lot of people.
 
Tim at aps muffler in rock hill is who I have always used.
 
The correct way to do it is to treat it like roll cage tubing. Buy the stick, buy the die with whatever radius desired and pull a tape measure. Problem with that is, dies cost a lot (around $300 for a JD2). The rest is cheap, but very time consuming.
I've done quite a few with just store bought J bends and I always kick myself because it usually looks like ass.
 
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Welds suck but didn’t leak, probably could have finished it off better. I really need to get into TIG welding to do stuff like this cleaner.

This is with a Hobart 190 MIG

Edit found more pics including mocking it up and stuff.

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Whoa, y’all are talking bout a lot of money for an easy solution. Myself, @Curtis_H and @Chris_Keziah have used this dude in Lexington and he is GOOD and reasonable. He understands off road suspension and what to work around, and has plenty of new/used muffler options.
He works out of his home shop semi-retired so his overhead is almost nothing. He done a killer job on Chris and Curt’s Jeep working around suspension components, lines and everything with limited space.

‭(336) 309-0954‬
Roger
T.r.e exhaust
 
iwaxmyjimmy said:
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You do realize you are creating a massive pressure differential that way, right?
That is going to affect performance and life expectancy...as a rule both banks need to be as close to equal length and total bend degree as possible.
 
77GreenMachine said:
Whoa, y’all are talking bout a lot of money for an easy solution. Myself, @Curtis_H and @Chris_Keziah have used this dude in Lexington and he is GOOD and reasonable. He understands off road suspension and what to work around, and has plenty of new/used muffler options.
He works out of his home shop semi-retired so his overhead is almost nothing. He done a killer job on Chris and Curt’s Jeep working around suspension components, lines and everything with limited space.

‭(336) 309-0954‬
Roger
T.r.e exhaust
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I second this advice. I've never had my stuff done by him but I've seen his work on @Chris_Keziah and @77GreenMachine jeeps. Top notch stuff and a very quick turn around (same day)
 
Ron said:
You do realize you are creating a massive pressure differential that way, right?
That is going to affect performance and life expectancy...as a rule both banks need to be as close to equal length and total bend degree as possible.
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I understand what you’re saying, but how much life expectancy will it be? How many automakers use this style Y pipe? Are they not factoring that in as well? Also this was done to clear the driveshaft and NP205 clocked flat. There isn’t any space.
 
I don’t like muffler shop work. It tends to be what I’d see under a 1994 Honda prelude; just enough to get paid.

I think spending a little time with tube and bends will give you a better product and will be exactly what you want. And, by doing it yourself, you can work around the exhaust and everything else along the way and take the needed time rather than waiting till the end and having to work around components already installed. You can essentially build and modify anything as needed if you see it needs it.
 
iwaxmyjimmy said:
I understand what you’re saying, but how much life expectancy will it be? How many automakers use this style Y pipe? Are they not factoring that in as well? Also this was done to clear the driveshaft and NP205 clocked flat. There isn’t any space.
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I understand the space constraint, and sometimes it just is what it is and has to be what it has to be.
But Ive never seen an oem where one cylinder bank had 12 pipe run and 45 degree total bend and the other had 60" and 270 degree.

At an absolute bare minimum Id oversize the collector pipe at least 150% or so. By the time the left bank gets to the merge the pressure drop is going to be significant compared to the right bank. Meaning it wont blend it will be free flow on the right bank and the left bank taking near 100% of the back pressure IF THE COLLECTION POINT IS INADEQUATE. Capped because that is the key. If its oversized for the conditon then it'll never be an issue other than some inner pipe turbulence.
 
Ron said:
I understand the space constraint, and sometimes it just is what it is and has to be what it has to be.
But Ive never seen an oem where one cylinder bank had 12 pipe run and 45 degree total bend and the other had 60" and 270 degree.

At an absolute bare minimum Id oversize the collector pipe at least 150% or so. By the time the left bank gets to the merge the pressure drop is going to be significant compared to the right bank. Meaning it wont blend it will be free flow on the right bank and the left bank taking near 100% of the back pressure IF THE COLLECTION POINT IS INADEQUATE. Capped because that is the key. If its oversized for the conditon then it'll never be an issue other than some inner pipe turbulence.
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If it makes you feel any better I have to redo it and it’ll be much more equal length with the 5.3 and block hugger headers
 
Lot of good responses. Half of them have been exhaust shop vs build your own. Me being the cheap bastard that I am and always up to a challenge, I think I'm going to build it myself. I don't have a trailer right now and aside from renting/borrowing one I have no way of hauling the Willys somewhere. I have all the tools that are needed and would only need to source the tubing. Speedway/Summit has kits from 150-250 and my time in the garage is extremely important to me so spending hours on the exhaust won't be that big of a deal. As far as routing constraints, I have a pretty clear shot from the back of the transmission all the way to the rear axle on the passenger side. The only tricky part will be the Y pipe where to tie both sides together. I'll probably run some kind of flowmaster muffler. I don't want it to be overly loud but I do want it to have some character.
 
Last time I had my CJ re-piped, I went to Rick's Muffler, off Hickory Grove Rd., near McAdenville. Showed him what I needed, & watched him do it. Custom, from manifolds, [V8] crossover over top of driveshaft, all inside frame rails, single exhaust & muffler. Band clamps used for any adjustments or changes I may need. Less than $200.
 
Build it the way you want. I just did mine a while back and it was easy. A little trying, but not bad. I ordered some mandrel bends, straight pipes, muffler, hangers, and ball sockets(for easy removal). I think I had about $200 in all of it. I'm pretty happy, minus the shitty welds. My build thread has a decent pic of the Y. They sell some pretty cool ones too. That's what I wanted to do, but didn't have room.

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R Q said:
I still have the F/M waiting for you...:D
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I know, I still need to make a trip out there.

@justjeepin86 That looks good and is similar to what I want to do with mine. where did you order your bends from?

NCJeeplover said:
I would stay away from exhaust wrap on an offroad vehicle. It tends to collect dirt and moisture.
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Thats good to know. I can only think of some certain places where it would be useful. I wasn't planning on wrapping the entire thing.
 
YJJPWrangler said:
I know, I still need to make a trip out there.

@justjeepin86 That looks good and is similar to what I want to do with mine. where did you order your bends from?



Thats good to know. I can only think of some certain places where it would be useful. I wasn't planning on wrapping the entire thing.
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I ordered the stuff from summit. I hung out under the jeep for a while measuring to make my best guess at what to get. I didn't waste much, so I was happy.
 
After some more thought and price checking, I called around to several muffler shops. Rick's Muffler can do if for around $200. The pre-bent kits from Summit or Speedway start at 150 and go up. Looks like I'll be heading to a muffler shop in the near future. Thanks for the replies guys :beer:
 
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