-Whitey-

alot of people are asking me how i made my own 2.5 test pipe so i decided to make a quick easy diy thread for them

parts needed:
1-2.5 inch exhaust flange with 3 bolt holes
1-2.5 inch collector flange with 2 holes
1-3 inch collector flange with 2 holes
1-2.5 donut gasket for collector
1.2.5 metal exhaust flange gasket with 3 holes
1-lenght of 2.5 steel tubing i chose 12 inch and ended up cutting it down to 10 3/4 in lenght but this will be diffrent for some cars so get 12 inch and use what you need and cut the rest off.

its a shitty drawing but it does the job

first thing you do is clean all the areas you will be welding with a wire brush or a wire wheel. after the areas are all clean weld the 2.5 inch exhaust flange with three holes to one ond of the pipe.(position dosnt matter yet so just weld it and shut up) after that cools to the touch bolt it to your exhaust with no gasket and roughly see where it will meet the collector make a mark to where you think you should cut it (leave a little extra on the pipe incase you cut to much off)use a hack saw. its better to make 10 cuts and still have pipe left than to make one cut and have to start all over again after you roughly have the pipe cut to where you want it with a little extra left over put the pipe down for a while and start cutting the 2 bolt flanges on the 2.5 collector flange to make it into a steel ring (see pic above) it dosnt have to be a perfect ring but make it close enough. then weld that to the collector end of the steel pipe and let it cool for a while. after it cools climb under your car with the pipe and the 3 inch collector flange. hand tighten the bolts on the exhaust flange( do not use the gasket for the exhaust flange) and then align the 3 inch collector flange with the holes on the header and mark where it should be connected to the ring you just welded to the pipe(mark it a few places with diffrent marks so you can easily put it back to where its supposed to be when you climb out from under your car) once your happy with the alignment of every thing and you made your marks take the bolts you hand tightened out and align the 3 inch flange on the steel ring. put the flange on face down(header collector side is the face)and align the steel ring you welded to the pipe on top of it using the marks you made while under the car. then clean it if necessary and tack weld it in place just to hold it enough so you can once again get under the car and make sure everything lines up correctly..if it dosnt simply knock the little beads off and re tack it until you get it right. if everything lines up good then you can runa thick bead all the way around the 3 inch flange welding it to the 2.5 steel ring. let it cool for a a while until its cool to the touch( put it outside if its cold where you are to cool it faster) once everything is ready to be bolted on its time to taper the inner diameter of the 2.5 steel ring to help seal the 2.5 donut gasket on the collector..if you dont under stand what i just said..just stick the donut gasket in the collector end of the pipe and you should be able to see what i mean you have to cut the 90 degree angle of the inside of the 2.5 steel ring on an angle to make it seat against the gasket properly. after that step is done and your happy with the way everything seats test fit it once again with the donut gasket on the header (dont use the exhaust flange gasket yet) tighten everything up make sure its all good and sealed then take the exhaust flange gasket and install it and retighten it all down and start the car while its still on jacks then climb under the car and check for leaks if you did everything right you should have no leaks if you find a small leak take it off and find the leak or the reason it leaks and fix it (most likely you will have to remove more metal from the area where the donut gasket seats.
if you want you can use high temp paint to make it look good and prevent rust like i did.
i used a mig welder the total project cost me about 25 bucks total and i have an extra 2.5 donut gasket so the complete one piece test pipe cost about 20 bucks

its nothing special really its just somthing i had the time to do. i think it works damn well! if you dont like it i dont care, if you like it cool,any questions ask in this thread. sorry for the shitty drawing..ill post pictures of the finished piece later

Chris y0!

hahaha, your drawing is PIMP. ms paint owns.

good tutorial

acydphryck

man....and i thought i couldn't draw....that's still a pretty good representation of building a test pipe...DIY stylezzzzz....

-Whitey-

hahah yea as you can see my ms paint skills are damn good i really need to buy a digital camera for times like this

VTECVillain

That is a work of art my friend!

Jeff C

Yep, that is exactly what I was thinking.

-Whitey-

glad i could help jeff c

this thread was made mostly because of you

pennies_hatchie

iTrader: (1)

i think i might try it for my setup thanks panda

pennie

-Whitey-

no problem guys any questions ask and ill help the best i can

One2chi

nice

Mr. Thunderlips

Just one problem...99% of us don't have welding torches sitting around in our garages.

EDIT: Why don't I send you $30 bucks and you make me one? A little $10 dollar profit for you 'aint that bad...


[Modified by ThunderLips, 4:50 PM 1/27/2003]

-Whitey-

im not interested in making them and selling them if your unavble to DIY then try testpipes.com they sell them for about 75 bucks for all you DIY guys this is the best way to go i just bolted mine up adfter i let the paint dry and no leaks at all now all i have to do is take off my hks hiper cat back and install the JIC 505 catback

Jeff C

Glad to hear there are no leaks. Good job.

-Whitey-

thanks

i just got done installing my new cat back exhaust and it has to be shortened about an inch or so..all of the hangers are being pushed towards the back of the car about 1inch from where they are supposed to be so now i have to go uninstall it cut about an inch out and reinstall it

viCeVerSa

will a test pipe pass emissions? ....................im just wondering i dont know anyone who runs one

-Whitey-

no it will not pass emissions but you will feel the diffrence if you go from a cat to a test pipe

viCeVerSa

well it IS jsut bolting and unbolting right,...... ill jsut get one and put the cat back on before emissions heh heh heh

-Whitey-

thats what everyone does


<--Panda who still needs to get a cat before april 1st

White Lightnin

We've got an arc welder and cutting torch at my fraternity. How steep is the learning cureve for this? I wanted to weld a new cat into the paiping I already have.

sloppy_seconds

i don't want to know why there's one at your FRAT!

White Lightnin

Well ill tell you anyway

Every year we have a parade for homecoming, and since we are ga tech we build "Rambling Wrecks", vehicles made from junked cars. Im in charge so I need to learn how to weld anywasy.

Crazy Cooter

You can get a muffler dhop to make one too. In my area, there is a "ma & pa" muffler shop that will do it for about $50. Bring in your old cat and leave with a test pipe. You'll have to install it yourself of course. The big name shops will charge more I'm sure.

-Whitey-

bring in your old cat and leave with a test pipe? sound to me like "ma and pa" just knock the **** out of the inside of your cat and return it as a huge bottle neck for 50 bucks you can build one like mine thats not a bottle neck and for half of what "ma and pa" charge

as for the guy who asked about the cutting torch and other kind of welder im sure it will work just use a spare piece of metal to practice on until you get a nice bead then go to town

becarefull when welding thick flange to thin tubing it usually will burn a hole in the thin tubing because of the high heat needed for the thick tubing...thats why i recommend you practice welding a small piece of similar tubing that you will be using for the testpipe to a thick flange ..so you know what to expect

redcxhatch

Get one made at the muffler shop for $20.

TheHater

ahahahaha....nice drawing...