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Discussion Starter · #1 ·
Well I am finally getting around to installing my Xmas present to myself: a new 3" Summit exhaust with Hooker Aeroflows. And as I started laying parts out under the El Camino it looks like I will need to do some trimming and fitting as I expected.

Which got me to thinking that perhaps there are some tricks or hard-learned approaches that might make this job easier? Things like "start from the headers and work back" or is it "start from the mufflers and work out"? How "tucked" in to shoot for?

I know I am stuck violating one of the fundamental tips and only using jackstands rather than a lift. But sometimes you run what you brung.

I have a chop saw for cutting pipes (much better than a hacksaw) and a gas welder to make it whole. Other recommended tools?

I also want to put some bolt-together flanges in the middle so I can get stuff out if needed in the future. I was thinking of putting the flanges just behind the mufflers? Or should they go in the down sweep just behind the axle?

I am thinking of a welded system rather than clamps. Probably tack weld on the car and remove to finish weld.

What about favored hanger locations and styles? Pictures?

Thanks in advance.
 

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I guess I'll save myself a lot of typing & just copy my response from a thread in the perf section.. Here's my experiance..

Well, I know I'm late to this party, but if you want my opinion, ANY of these pre bent systems are going to need HEAVY mods if you expect them to fit like a custom system.. Now, if you're OK with an ill fitting system, they can probably be bolted right on out of the box with a little cutting & dinging..

Here are a few pixs from the nightmare I had with my Summit 3" kit..



Actually, here's a link to the thread I had going throughout the whoe ordeal, just in case anybody might be interested..

http://www.chevelles.com/forums/showthread.php?t=133719&highlight=summit+exhaust and this was the followup http://www.chevelles.com/forums/showthread.php?t=134712&highlight=summit+exhaust
The second link has some pics of the completed system..
 

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Discussion Starter · #3 ·
Thanks Scott, I had read through your threads a while back. My impression is that individual mileage seems to vary significantly when it comes to exhaust system installation. I know I have the variables of the extended wheelbase of the El Camino and the extended version of the mufflers I am fitting. It looks like they left enough pipe for the longer wheelbase so I will need to trim for the muffler length.

Then there is the variable of where the header collectors land...

The special cut you made... that appears to be in the front axle up pipe?

I am thinking I will put a muffler on a jack and put it about where it looks like it should go and start working the fitting from there. Perhaps put some wood spacers on top/sides of the muffler to insure clearance. Then probably go forward fitting pipes first. Then work the hanger problem. Finally finish up with the tailpipes.
 

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Steve, you must start with the tail pipes where they need to be and work forward. You don't want to start from the headers and god back - your tailpipes will not end up where they need to be and you won't be able to adjust they out.
 

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Discussion Starter · #5 ·
That should be fun... thanks Vince. And that is why I posted the question. I figure everybody learns a bit the first time they do one of these things and has a few things they would do differently if/when they do it again. This being my first, I thought I might jump start the process :beers:
 

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i put on a 3 in. pypes system on with a x pipe on my 70 velle and a torque tec 3 in. system on my bro's 84 monte. definately !! start with tail pipes ! get them where you want them, than mufflers ,than x or h pipe, than header pipes . and used stainless band clamps so i could take it apart down the road if needed, and looks better than the old u bolt clamps ! you will have the best luck doing it that way !good luck take your time .
 

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Discussion Starter · #7 ·
I must really work slow... I have spent most of the day worming my way under and out and under and out. I can see why a lift makes such a difference.

Well I tried to start with the tail pipe... fitting pipes is a pain in the... figured out that a 2x4 over the top of the frame with a loop of rope makes a darn fine pipe holder. It also allows the pipe to be move in and out and back and forth.

The tail pipe only got me so far so I bounced to the mufflers and mounts. I at least have the hangers fabricated up and flanges on the back of the mufflers. I also think I am going to put in a straight pipe instead of the second S bend mid-pipe on the Summit system. I just do not see how moving the mufflers 4" out would do anything good. I note that the Pypes systems only use one S instead of two so there is a precedent...

I guess it could be worse, but it seems like everywhere I go I have too much pipe. Part of that is the 22" long Aerochambers but even in places like the tail pipe ends and over the axle.

I could be dorking with it still but I ran out of quiet work and it is quiet time in the neighborhood... so I will wait until tomorrow to make loud power equipment noises :).
 

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Steve, I installed a Jegs 3" system on my fiends 71 Buick, amd there was indeed alot of cuts. It did take the better part of the day and this was on a lift! Now, we were installing a 3" system so that probably did take a littl more fiddling.
 

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My install took almost 3 weeks, but that was in between the kids baseball games & practices.. In actuality it probably took me 12-15 hours to get the system on (this was on jackstands)...

As far as the S pipes go in the mid pipe, I actually used the rear ones in the front & the front ones in the rear, it just fit better that way..


The best thing to do would be to get the tails set, get the mufflers where you want them, then fab the rest to match up...

One thing to keep in mind, is if the mid pipes don't run pretty close to the driveshaft, the entire system will tend to hang low enough to see it when you are STANDING next to the car, can you say UGLY??

Like others have stated, just take your time & it will all come together :thumbsup:
 

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Discussion Starter · #10 ·
Spent Sunday afternoon on the project and learned that this is a job better done during the day with the garage door open. Seems there is just so much more light everywhere that you can see much better.

And a corollary: look at the fit from as many angles as you can. Where the muffler looked good from the front it looked too low from the back. I reworked my mounting to raise the back of the muffler a bit over an inch. Now I am pondering if that is too much because of the angle the muffler sits at. It seems like it would look better closer to horizontal than kicked up in the rear. I may do that rear mount one more time...

There is a lot of space above the muffler but you cannot get the muffler high enough to use it without pipe hitting the floorboard in front of the muffler. How high is high enough here? Right now the front of the muffler is probably around 1.5" lower than the driveshaft.

I did try the header to Summit front S to straight pipe to muffler setup out and it did not fit as well as I thought it would. So back to using the back S from Summit too.

So far I figure I have cut 11" of pipe out between muffler and header and can now plug all of those parts into place. I could tack weld it... apart from considering tweaking the muffler angle and needing to check the angle coming off the header. I think my headers may have a "down" angle that conflicts with the "level" angle of the pipes. I may need a slight bend in the pipe to match to remove a bit of tension here. Any good ways to get a few degrees bent into 3" 16g tubing?

The other question I ponder as I go through this is how much clearance is needed? Based on assembly manual drawings it looks like the factory used about 3/4-1" in general. So that is what I have been shooting for. It can look like a lot under there.

I am sure the second side will go a lot faster :)
 

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I changed some of my bends by makng a square cut through some of them, then grinding a slight angle (miter) into one of the cuts... a little off the inside to tighten it or a little off the outside to loosen it...Then weld it all back up..

I hope this helps..

Scott
 

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Discussion Starter · #12 ·
That was what I was thinking. Figure cut about halfway through with chop saw that makes about a 3/16" cut. Follow up with another 1/4 way pass with hacksaw of Dremel cutoff wheel. Bend. Weld.

But you never know if somebody has come up with a better answer until you ask :thumpsup:
 

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$507 and change. 2" into 2 1/2" ( still don't have headers but anticipate having them one day :)). a couple of hours sitting at "Mufflers West" in Temecula reading their magazines and I have a fine "one" piece dual FlowMaster" exhaust system. By "One piece" I mean there are no clamps. The system is all welded, including the "H" pipe.

That was several years ago and since that time I have had a couple pieces break and when I rolled the Chevelle in they took it in instantly and solved the problem, handed me my keys and sent me on my way with a satisfied smile on my face and that was a couple of years after I had them install the system. All for no charge!

I am guessing that if I went there today with a complaint they would do the same thing again with no charge. You pay good money and you get good service.

I will never again lay on my back and do that kind of work. Its just not worth it to me. Course thats easy for me to say. Unless I wreck the car I am confident that the exhaust system I paid so much for will last as long as I want to drive the car.


This was my first all welded system ever. Its interesting to hear it shrink as it cools. It makes some very audible noises as it shrinks.
 

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Maybe so, but ask them if they have a mandrell bender in the shop....That's the reason I did my own system.. Heck, I have friends in the exhaust business that could have given me a sweet deal, but they can't do mandrell bends in house..
 

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Discussion Starter · #16 ·
To take it somewhere you have to have faith that they are going to do a good job. Many of the shops today just want to get you in and back out as quickly as possible. They are not going to take the time to optimize and tweak the fit. Unless you want to pay them by the hour... and at the $85 an hour I was quoted that can be a dicey proposition.

But I do know what you mean, after all I did ask about it which is a lot more than I usually do for car part installations :thumbsup:
 

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Discussion Starter · #17 ·
I am getting closer on this project... one last hanger, cut for the tip, cut for the 3.5" header adapter, weld up the header adapter, weld on the SS rolled angle tip, and ONE side is done ;)

I will take some pics later but I did have to put in a filler wedge like Scott, except that I think his was in front of the axle and mine is behind. And I am glad I am welding the system up so I can be more flexible with connection angles. I can see where the recommended 14" mufflers would be a lot easier than the 22" monsters I bought.

One tip for anyone contemplating installing an exhaust is to have lots of short rope lengths. I have found a number of locations where I can put a board across over the frame and then loop rope over to suspend the pipes in place. This has helped a lot with the "not enough hands" problem. I used 3 of these on just the tail pipe segment to get it just right. Another on the muffler. And one on the transmission cross member.
 

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Discussion Starter · #18 ·
Well it is finally all in... :beers:

Amazing (and almost depressing) that I started this thread 2 months ago. As Scott said about working around kids and other family activities, sheesh how the time flies by and the project crawls.

Obviously I made a few changes to the Summit system. One change I made was the back end of the mid-pipes. The system out of the box has S bends that bring the pipe 4" back away from the center of the car. This was way too far and would put the mufflers into the lower control arm pickup. Perhaps with shorter mufflers these pipes would rotate and offset less, but not with the 22" long Hooker Aerochambers. By cutting a wedge out of the front turn of the S, I reduced the offset down to 2". Then I cut off the back turn of the S at 90* and welded the muffler on.

I had to cut a lot out of the down pipe behind the axle and then weld the tail pipes on with some complex angles and matchup.

I also cut a chunk out of my old exhaust to add a 2.25" crossover up front. This triggered a lot of learning. After cutting and fitting I put it all up in the car and put some tack welds on it in place. I tried to put significant tack welds as there is a lot of weight and leverage in this assembly. It is basically the whole front of the exhaust including mufflers. Then I pulled it out and finished up welding it. When I went to put it back in the header collectors had pulled in between 1/2" and 1" and no longer fit. #(&%&&$#^!!! The BFS (Big Stick) corrected that, but then the fitted PS tail was squeezed in. More language... more application of BFS plus some pipe heating/shrinking. Finally last night after it was all mounted up and I was cleaning up, I noticed that somehow the PS pipes are sitting much lower after the H weld up too. Not sure what I am going to do about that one...

I did custom hangers for the entire system. The muffler hangers use a 3" muffler clamp to bolt a 10" length of angle iron on. On each end I used bolts and spacers to mount rubber hangers. On top I used 1" strip bent on the inside and straight on the outside with more bolts/spacers for the rubber mountings. I used the original factory exhaust mounting holes in the frame. On the tailpipes I used more 1" strip and 3/8" rod to make alternating post hangers using the same type of rubber hangers. The mounts bolt to the frame in the factory side location.

I have not had it out of the garage yet to find out how it sounds outside. But with the little startup I gave it, I may have over achieved with my acoustical upgrade. Sounded pretty mean. Certainly any kind of stealth is no longer possible. Quite different from a simple dual system with 2.25" front pipes, stock type turbo mufflers, and 2" tails :thumbsup:
 

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I have never been a fan of fully welded exhaust systems personally. But thats just my own opinions. Too permanent for me I guess. I like the idea of removing a pipe if I need to. I prefer to use stainless band clamps for a leak free seal.

I have worked at muffler shops in the past and can tell you I wouldnt bring my car to one of those shops even if they were offering thier services for free. Any good aftermarket system can be installed by anyone without having to pay some so called professional at a muffler shop that only uses compression bends.
 
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