Fabbing my own catback

[Brentd]

Alright, I am back lol. Got started on it this past Friday morning ( I had just come off a 12 hour night shift, and didnt really expect to get very much done). I decided it would be demo day, and a test to see how long it would be before my energy ran out lol, turns out I was able to rock and roll all day (thank you makers of vyvanse, and yes it is prescribed lol). Put the front end on stands, read somewhere to not even try to do it from above, so I pulled the wheels and wheel wells, and I can report it definately is the best way. Used a thick canvas drop cloth to cover the dirty ass suspension and brakes, and it ended up serving as a great tool and bolt holder as well.

Pulled plug wires and heat shields, almost all the heat shield bolt heads snapped off, didnt matter to me as long as I could get them off

Pulled the dipstick, just unbolted it and gently pulled and rotated it and it came out with the o ring no problems.

Used lots of PB Blast and used a hammer to rap each bolt with a center punch in preparation and all the factory header bolts came out with no problems (except the one that was already broke of course)

Tried for about 10 minutes to put all of my Hulk like strength on the manifold to cat pipe flange bolts, think I may have a hemorrhoid from that lol..then said screw it, I didnt need it anyways so I went on a sawzall tangent and finished up the day chopping everything under the truck.

The guy that tried to call me out on my choice of exhaust components would probably have a heart attack, but I bought my header bolts at, drum roll please, LOWES lol...A2-70 304 stainless 30mill M8 bolts. Including the grade 8 bolts,nuts, and washers for the intermediate to Y Pipe flange, I spent about 20$ on fasteners. The budget minded part of me continued to soldier on I guess...flame away I guess

Saturday was Christmas for the family with my mom who had flown in so I attacked the install Sunday.

Install went good, had a snag when trying to connect the y pipe to passenger side headers, i had them bolted on but not tight and slipping the y pipe on was not gonna happen unless I unbolted them or dropped the tranny crossmember. I considered dropping the crossmember because I was doing this by myself and its hard to hold headers up from the wheel well and slip a y pipe on under the truck at the same time, but I got creative and just zip-tied the headers up and away so that I could slip the y pipe on. It really is a tight fit, but once installed and put in place it fit perfectly. Once I got the y pipe on, I went ahead and bolted the headers in place (didnt torque till the end), thankfully the flange fitting for the "catback" exhaust was on an angled piece of pipe so when it came time to see if the intermediate pipe would work I was able to twist and turn each one till they lined up, and as an added bonus the inter. pipe even tied into the stock rubber hanger. I attached the muffler to the inter. pipe and tied it to my factory tailpipe. Reinserted the dipstick, put the plugs back in (they looked great, so I didnt change them) put some dielectric grease in the old boots (had to modify the heat shield on one so that the rubber of the boot wouldnt touch one of the passenger primaries. Everything got torqued down, wheel wells went back in (did not break one of the plastic fasteners when I removed them so that was something to be proud of) wheels went on, cranked her up and instantly threw a cel. Drove it around to try and get the temps up, noticed my temp gauge wasnt working, brought it home to try and figure out the issue. Went to restart it and the engine just turned over but didnt crank, found out I had accidentally unplugged the coolant sensor on the drivers side, its only a couple of inches to the left of the header flange so i prolly yanked it when pulling the factory manifold. Plugged it back in, gauge was working, CEL turned off. Oh yeah, i just zip tied the rear O2s to the frame till i go get it retuned this weekend. Still have a few leaks at some of the clamps but I will get that sorted after this work week. Sorry for the long post but I figured why not tell it like it was lol. Heres the pics of the install.

[JC03SS]

Looks good. Glad to see that it worked out well for ya. How does she sound?

[Brentd]

She fires off with authority but mellows down some at idle...I can feel and hear it idle in my house in the mornings when I remote start it to warm it up lol...have some leaks at the clamps so I havent really got on it too hard but she gets loud loud over 2700 rpms lol..typical stainless header attributes, can hear the valvetrain now, which I read was common with ls motors and headers, needs a retune for sure because my fuel mileage dropped 2.5 mpgs in about 7 miles of driving it and I have been really easy on her. It was running pretty rich before and I figure its running even richer now so a retune shouod get her in line and then I can pull the tacky ass zip tied O2 sensors out. Still havent thrown a cel so thats good. I will be getting a resonator though lol..sounds straight piped...and unfortunately I am not quite redneck enough to keep it that way but I will secretly enjoy it till then.

[Cramer]

Looks good Brent.

Did you put that ultra copper silicone in the joints when you installed the pipes? That will help those band clamps seal better it you didn't.

[Brentd]

Thanks ryan and no I didnt lol...bought the shit and didnt use it ...im going to pull it in the garage and spray the seams real well and the inside of the clamps then reinstall the clamps and see if that does the trick

[canadianVRss]

I had a leaking issue with my mid pipes, I just cut a piece of fiberglass fire blanket and wrapped it around the joint and slid the band clamp over it. No mess and its all sealed up.

[Brentd]

I had a leaking issue with my mid pipes, I just cut a piece of fiberglass fire blanket and wrapped it around the joint and slid the band clamp over it. No mess and its all sealed up.

That sounds like a good idea...if the ultra copper doesnt work then i might give that a try

[Brentd]

Well got it retuned today. Over a week with long tubes and no tune and it was getting old! MPG's were dropping like flies and the ecm didn't really know what to make of the headers and to be honest it wasn't running or idling very good. After the tune, I saw 19 mpg on the way home on the freeway and that is better than it was before the headers so that is a plus, and it is running, idling, and boogying better. The resonator issue is still on standby, not nearly as loud as I was expecting. Cold Starts are pretty loud but once it warms up it is pretty quiet (for straight-piped exhaust that is). I can hear the exhaust when I am cruising at 65+ clearly but I wouldn't say it is droning into the cab, its just loud enough to hear it at those speeds. I figured since I had it retuned I would go ahead and pamper it some more. It hadn't had a bath since I plastidipped some things on it about 3 months ago so I washed it, and polished the wheels, then i pulled a lot of the plasti dip off except for the LT badges, tailgate emblems and the chrome on front/rear bumper, bumpers will get undipped tomorrow. I forgot how expensive it looks when it shines lol. Now I just need to get some 420s and I will be good for a few months till tax returns come in.

[JC03SS]

Sounds good. Glad to see it all worked out. The exhaust manifold bolts are the best part lol they came out.

[Brentd]

Oh I know man...i figured since one was broken to begin with I would end up breaking a couple and in turn piss the wife off because of the bill I would incur getting them drilled out. But some PB blast and a wack with a chisel before cranking on them and they came out easy peasy. I was worried about header flange leaks but the flanges were really thick so they compensated for the missing bolt with GM gaskets. I also worried that I wasnt able to put two passes with different torque on them. My torque wrench only goes as low as 20 lbs so I just torqued them once to 20 and rechecked them a few days ago, seems to be ok, no leaks

[JC03SS]

That's great news. I had to re tighten my drivers side rear about half a dozen times and finally she never loosened up again. All swell that ends well. See you said you were gonna get some 420's? What size?

[Brentd]

Man I gotta be honest, I am torn. I sit higher than you guys so i have a little bit more wheel well to fill, which makes me think 305/50 because its taller and then I get the pleasure of 12 inch wide tires which I like, or i could do 285/50 and lose some rolling weight, drop 1/2 inch in width and roll close to stock height leaving wheel well gap still too empty.

[JC03SS]

Well I got the 305/50/20 and it rolls really close to stock. Love the look. The back could go down a little more but overall I'm happy with the ride and look. I'm sure you would like the 305's. Plus from the back the tires look fat so no penciles lol.

[Brentd]

Yea, I really want to go 305, I like the tire width, just not sure about them on 8.5 inch wheels, just seems like they would be really swollen off the rim....i wish i had ten inch wide wheels. Then i could go even wider without having to have a tall profile. I miss my 24x10s sometimes. There is also the fact that I am not putting down huge power so the weight of the tires come into play. Who knows, i might bite the bullet and go 305 anyways lol

[onebadmax]

 

certified auto tech LMAO... you muther fvckers cant fix a damn sandwich. All you do is read and take a damn test. So all you have proved here is that you can read and remember what you read. You have TSB's and other written material to get you through a problem. Most the time all you do is flat rate shit to make a living.

 

Oh I have a clue. I make parts where people haven't or couldn't make something work. I work on shit that cost over 250,000 and is all hacked up by some "certified autotech" that talked some poor old man into whatever cobbled crap they tried to pass off as quality. Yes off the shelf parts you bought about the best you could... however they can be improved. Corsa could always fit better and the mufflers weigh a metric shit ton. On the headers they are the best off the shelf however a custom tailored set of tubes would be far superior to what you bought. So go on with your bad self and fix some shit Mr. Master Mechanic!

Post up some pics of custom tubes that look better than ARH that you have made for these trucks. Also post up some flow numbers and dyno graphs proving they are indeed of superior quality/performance.

 

I won't hold my breath