My home made exhaust

[1st Gen]

For those of you that told me welding my own exhaust would be hard, you weren’t kidding! If I had a pipe cutter and a lift it would be a lot better. Since I’m using mandrel bent pipe, and since I don’t have a bender, I have to cut everything to fit. I have an industrial size pipe cutter that will cut the straight pipe okay but it leaves a huge ridge on the inside of the pipe that I have to file or grind away. It’s jut time consuming.

My first plan was to buy a welder but I found that I could rent one for $40.00 a day. That made the decision a lot easier for me to make. I also get Sunday for free since Interstate Rentals are closed on that day.

I got my down pipe made, and the bracket that hold the pipe to the block had to be modified. I also got the cat in but,,,,,,,,, that’s where the system is starting to get out of shape a little. I accidentally mounted the cat so the heat shield is down instead of up like I think it should be. There are not directions that came with it but I’m pretty sure that’s the way it was supposed to be. Note to self, PAY ATTENTION! The cat is also about a ¼ of an inch to far back to fit right. It fits but there is a certain amount of tension on the rubber hangers. I should not have left it like that but I had made that one piece for between the end of the down pip and the cat 3 times already and I was too tired to do it again.

My biggest problem is fitment. It’s hard to eyeball it and get it right. I can measure but it’s hard to get the bends right. I decided that I was trying to emulate the stock system and that wasn’t the right way to go. I should use it as a general guideline but exactness is not necessary.

The flex pipe that I’m using is taking the bind so the system is doing what it’s supposed to do. I’m a little worried about the rubber mounts but I think it will be okay. I can always change it later. I might be putting a resonator on it later so I’d probably fix it then if it turns out to be a problem.

I still have to go up and over the suspension which is going to be hard I’m pretty sure. It looks like that’s going to have to wait though. Right now, it’s family time. I made a promise for my time before I knew about the free Sunday welder.

All in all, it’s not too bad, but it is very time consuming to get it right.

[tehstocker96]

...worthless w/o pics!!

props on doing ur own exhaust tho, hope it works lol

[1st Gen]

I'm a little embarrassed about the last pic because it shows two of my mistakes. I figure if it helps someone else to not make the same mistakes, I can get over being embarrassed.

I think I figured out how to fix my fitment problems while we were on our way to the water park today. I’m going to have to cut and re weld the DP again. Oh well.

[Intruder]

Hey, it beats paying someone else to do it. If it fails, you can re-do it and make it better.

Good job, dude. :)

[kitty]

Eh atleast you didnt weld your cat in the wrong way.
Budy of mine did that. And didnt realize it.

[1st Gen]

Eh atleast you didnt weld your cat in the wrong way.
Budy of mine did that. And didnt realize it.

A stock cat might be different than this this one, but I couln't tell that it had any kind of directing. I looked too. The only difference I could see was that it had a heat sheild on one side, and that was it. It's just a standardj 2.5" cat.

[kitty]

"The first thing to know is that they are designed to work with the gas flow in one direction only, and won't perform effectively if reversed," says MVRIA spokesperson Colin Brown. "This is because the deposit of precious metal on the ceramic brick or bricks is not uniform. On all universal and most direct fit converters the direction of flow is indicated by an arrow somewhere on the converter body or heat shield.

"It is extremely important that this be checked before installing the unit. "Some direct-fit converters may lack the arrow but in these instances the flanges are positioned so that incorrect fitting is impossible.

"The problem is that a catalytic converter designed for one car can be reversed and fitted to a different model. "To make sure a new catalytic converter works properly ensure that the gas is flowing in the right direction."



You might want to check with the manufactuer.

[tehstocker96]

yeah dude it's an exaust, it's not like everyone is gonna see it, and plus u saving money! as long as it sounds good and doesn't leak!!

[MD323]

looks good,

One tip, i would wire brush one area on each piece for your ground for good contact and try to keep the tip no more than a quater inch from the base metal. the weld on the cat look like you did not have a stable arc which is usually cause by the 2 things mentioned.

looks awsome! :cheers:

[1st Gen]

I got it all done. I still need to get the end out past the bumper but I can do that in my spare time.
I know my welds look like crap. It was just hard to get a good bead going. I just hope that it holds together.

[Lex]

looks good and functional!

after you have it all up in the car cup your hands around the welds with the car running to check for leaks. If there are no leaks, you're golden and I don't think those welds will break. If you want to hide them for some reason, use some exhaust wrap or header paint.

Word of warning, if you live in a rust prone climate, the welds will be the first to rust, especially if you used aluminized steel - so some high heat paint on the welds may not be a bad idea.

[1st Gen]

At the end of the first day, I took a flashlight and shined it through the welds while I looked down the pipe. The holes showed clear as day.

I was able to get a lot more done yesterday because I changed the way I was approaching the job. I began fitting the pieces on and spot welding them into place while it was on the car. Then after I got a bunch done, I would pull the whole thing down and finish welding it. I don’t think I have any leaks but the workmanship wasn’t as good. I started having troubles with the welder too. The guys at Interstate Rentals were cool about it and only charged me for 1 day instead of 2 because of it. Very cool.

[THEGOLDPRO]

looks bettetr then mazkids exhaust, so your on the right track.

[Mazda96Protege]

Yeah looks very good!, and must feel good to do your own instead of getting raped by a shop lol

[mazdaracer]

dude, much respect for building your own exhaust with jackstands and no lift! that alone deserves the badge of honor. Your neck muscles will be HUGE!

It's all a learning process and if you can move along and correct mistakes, while still saving money and learning a new skill...more power to ya. And the fact your able to notice mistakes, is a step in the right direction.

As an experimental system, looks shouldn't be the main concern, the learning of the technique and the process of building an exhaust should be your focus (of which is seems to be)

I think it's awesome and i too hope to one day learn to weld. Mad props to you :bigthumbup:

[1st Gen]

It took me 26 hours all together, not including the planning. It would have been unbearable if I hadn’t been enjoying myself. I really had a good time doing it. I work that hard for other people all the damn time. It’s nice to be able to do that for myself. It’s sure better than sitting on my ass in front of the TV.

This is that cat that I bought. I was going to call the guy today and see what the specs are on this model as far as directional requirements. I hope I did it right anyway.

http://www.roadraceengineering.com/exhaustparts.htm

2.5" High Flow Cat OBD2 Legal 93506 $99.00

[SgtRauksauff]

Looking pretty good for never doing it before!!

I did my dad's '98 Intrigue and my '85 volvo, before getting into my "fast" cars, just for the practice.

For cutting the pipe, I just use a 10" radial chopsaw, with a $3.00 metal-cutting blade on it from Menards/Home Depot/Lowe's. Doesn't really make too much of a ridge inside, but I clean the ends anyway, because you get a better weld that way. A couple things I've found out, use thinner wire (like .023 or .025) instead of .030 like I started with, because it won't blow through if you've got the heat too high.

As far as cutting angles out of U-bends, you can get a carpenter's protracter to find what angle you need, then use a degree wheel (there are a couple online that you can print out) to measure and mark your pipe. What would be just awesome was if I had a bandsaw.

Isn't welding just fun?

--sarge

[1st Gen]

Those are some excellent ideas. I was using .30 wire and I was getting a huge bead on the pipe itself. I welded a piece of bracket at first and the weld turned out great. I thought it was because of the problems I was having with the wire feeding through the stinger in such a jerky fashion. That was the reason the guy gave me a day for free. The thing was worn to the point of not working properly.

My plan was to do the system on my pick up first since it’s all falling apart but the option to rent the welder kind of put the pressure on. One thing I did buy that helped out was a grinder from Kmart/Sears. I didn’t use it to cut with because it seemed too small. It was useful for removing metal from poor hacksaw cuts though. I can’t cut a straight line with a hacksaw for crap.

I called RRE just now and found out two things.
1 that the cat is non-directional meaning that it doesn’t matter which end goes first
2 that it won’t make any difference that I put the heat shield down instead of up.

I would have rather put it in with the heat shield towards the car but oh well now.

I still want to buy some high temp paint for the whole thing still. That just seems like a good idea, and it’s custom too. I think I’m going to let it go for another couple of weeks until I get some more days off.

[MD323]

all in all the system turned out awsome and probably cost alot less than a shop. :cool:

[1st Gen]

My last pics.
The comparison of the two down pipe openings are between the stock GTX and the one I made.

[1st Gen]

I had some welds fail and I was feeling pretty down about my options. I decided to go on to the welding forum and post some pics and see what developed. To my surprise, I found that the problem wasn't the machine, other than it having some maintenance issues, it was the settings. I plan to rent it again with a new liner for stinger installed I hope and re-weld the areas that have failed. It will be a LOT easier this time as everything is already cut and placed. All I have to do it line it up again and weld it.
Tenacity FTW.

[1st Gen]

As of yesterday, the exhaust is all done. I rented the welder again, put the care back up on jack stands and went for it. I had talked myself into thinking that the whole thing was falling apart but that wasn't the case. I had two welds that had failed but the rest were looking pretty decent. I did a little grinding, painted some areas, and did my best welds yet on the trouble spots. I'm getting the hang of this:)

[MD323]

As of yesterday, the exhaust is all done. I rented the welder again, put the care back up on jack stands and went for it. I had talked myself into thinking that the whole thing was falling apart but that wasn't the case. I had two welds that had failed but the rest were looking pretty decent. I did a little grinding, painted some areas, and did my best welds yet on the trouble spots. I'm getting the hang of this:)

thats the spirit:bigthumbup: It took me a year of being screamed at by my boss to be able to make flawless welds consistently so your doing better than me if your doing exhuast work already. :cheers:

now on with some pics of the completed work;)

[1st Gen]

I wouldn’t go so far as to say that I’m even close to being flawless, or consistent for that matter.
I did a couple of things differently this time. First off, I used a shorter extension cord so I wouldn’t get a power drop to the machine itself. Second, I turned the power all the way up on the welder and turned the wire feed down a bit. That made a huge difference. I also made sure to keep the ground close to my area of work for a good connection. These changes allowed me to be able to get the bead to melt into the metal more so it would be stronger and look better. I also practiced more before I started. The popping was minimal this time and the beads where I was able to keep a steady pace were straight and looked good. Unfortunately, I was going over the ugliness that I had done before so in many cases, my work had all the charm of a covered up tattoo.
I feel the job turned out pretty well and I am very pleased with the end result. I still need some type of tip to get out past the bumper because I’m afraid a long drive might heat that sucker up to the point that it could be a problem. I should have done that yesterday but I was distracted by the urgency of the other welds and forgot that needed to get done too.


Thanks for all the input and support.