DIY: Straight Pipe *Edited*
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DIY: Straight Pipe *Edited* Yea so over the past few days i built my straight pipe in my spare time and will be writing up the DIY sometime tonight... stay tuned with pics 
OK.. Materials needed:
(1) OEM downpipe
(1) 18" piece of 2 1/4" Exhaust tubing
(1) 2 1/4" to 2 1/4" exhaust pipe connector
(1) Save the original flange
(1) Table saw or miter saw with 10" metal cutting saw blade
ALSO a couple pieces of sandpaper to help clean up the locations you plan on welding
On the the DIY part...
Steps:
1) jack you car up in a recommended spot, and make sure to put a jackstand in on the other side to make sure the car is study, nubs...
2) once the car is stable and the front of the car is as high as you can get it off the ground, then you can slowly start removing the 2 manifold spring bolts connecting the manifold to the Downpipe, but DON'T undo them all the way as this will make it EXTREMELY difficult to remove the 3 nutz connecting the back flange of the downpipe to the Catback!
3) Don't forget to remove o2 sensors and keep them in a safe spot
4) now that the downpipe is off the car fire up the table/miter saw and make sure your cuts are Perfectly cut, you don't want bad angles with this project, so remember the old saying, "measure once do twice the work, measure twice and and do it right"
Your going to cut the downpipe in the two locations marked off in the caption... again don't forget we are saving the flange so cut it nice so that it will be reuasable and save you some more time and money.
5) now that the cat has been deleted you can now measure the length of cat so that you know the length of straight pipe that needs to be cut to fit in its place, I measured off 15" therefore i cut 3" off the 18" piece of 2 1/4" straight piping that you purchased at "discount auto"
6) now take the section of straight pipe that you just cut and grind down the edges a little on the end that was just cut, then sand it down, keep doing it until it appears a little roughed up but is not sharp to the touch.
7) now grab the forward section of the cut up downpipe and grind that edge down just as you did with the straight pipe.
8) you may bolt back up the forward section at this point to the manifold and put the bracket in its hanger.
9) This is the test fit, finger tighten the two spring bolts holding the top section up to the manifold and put the bracket in its hanger as stated in step 8... once you've done that place the connector on the end of the straight pipe... now jack up the straight pipe with the connector facing the top section and make 3 or 4 marks with a permanent marker to make sure your welds are lined up and you dont' get a cockeye'd pipe that doesn't end up working... do the exact same thing with the flange to the back of the straight pipe, make 3 or 4 marks going from one pipe to the other.
10) unbolt the top section once again
11) now we do what we call a spot weld or a Tac weld... basically you weld a tiny little dot on one of those marks you made previously on the connector and straight pipe... then do another test fit with the top section finger tight and in its bracket and make sure its going straight to the catback... if all is correct and good unbolt the top section once again.
12) finish the weld all the way around both ends of the connector, welding the connector to the top section and the connector to the straight pipe.
13) now we make a spot weld on the flange... bolt up the DP assembly now once again, notice how its an assembly now
... once the top two spring bolts are pretty tight in place then squeeze the flange bolts in the catback holes... put the nutz on the back of the flanges studs and tighten em up at tight as possible
WE do this because if the flange may have been a little off this makes sure A) it will bolt up properly when fully finished and B) it will bend the flange to how it needs to be if it was a little off on its angle that you had spot welded... so in turn it correct it for you when you tighten it all together.
14) unbolt the whole assembly once again, and be sure not to bend the flange anymore because it's been molded to where it needs to be at this point after the previous step. Finish the flange weld... once your done with that get a gasket bolt it up and your good to go...
NOTE: Run the pipe under cold water after every weld helps cool the pipe down and hardens the welds
NOTE: I will be adding to the DIY when i bore out the hole in the straight pipe to build the mechanical o2 simulator
NOTE: New pics with the welds soon
anywayz... there it is... I will be offering my services to doing this for you, i will be asking $75 for labor plus your core OEM downpipe, and i'll do this all for you
OK.. Materials needed:
(1) OEM downpipe
(1) 18" piece of 2 1/4" Exhaust tubing
(1) 2 1/4" to 2 1/4" exhaust pipe connector
(1) Save the original flange
(1) Table saw or miter saw with 10" metal cutting saw blade
ALSO a couple pieces of sandpaper to help clean up the locations you plan on welding
On the the DIY part...
Steps:
1) jack you car up in a recommended spot, and make sure to put a jackstand in on the other side to make sure the car is study, nubs...
2) once the car is stable and the front of the car is as high as you can get it off the ground, then you can slowly start removing the 2 manifold spring bolts connecting the manifold to the Downpipe, but DON'T undo them all the way as this will make it EXTREMELY difficult to remove the 3 nutz connecting the back flange of the downpipe to the Catback!
3) Don't forget to remove o2 sensors and keep them in a safe spot
4) now that the downpipe is off the car fire up the table/miter saw and make sure your cuts are Perfectly cut, you don't want bad angles with this project, so remember the old saying, "measure once do twice the work, measure twice and and do it right"
Your going to cut the downpipe in the two locations marked off in the caption... again don't forget we are saving the flange so cut it nice so that it will be reuasable and save you some more time and money.
5) now that the cat has been deleted you can now measure the length of cat so that you know the length of straight pipe that needs to be cut to fit in its place, I measured off 15" therefore i cut 3" off the 18" piece of 2 1/4" straight piping that you purchased at "discount auto"
6) now take the section of straight pipe that you just cut and grind down the edges a little on the end that was just cut, then sand it down, keep doing it until it appears a little roughed up but is not sharp to the touch.
7) now grab the forward section of the cut up downpipe and grind that edge down just as you did with the straight pipe.
8) you may bolt back up the forward section at this point to the manifold and put the bracket in its hanger.
9) This is the test fit, finger tighten the two spring bolts holding the top section up to the manifold and put the bracket in its hanger as stated in step 8... once you've done that place the connector on the end of the straight pipe... now jack up the straight pipe with the connector facing the top section and make 3 or 4 marks with a permanent marker to make sure your welds are lined up and you dont' get a cockeye'd pipe that doesn't end up working... do the exact same thing with the flange to the back of the straight pipe, make 3 or 4 marks going from one pipe to the other.
10) unbolt the top section once again
11) now we do what we call a spot weld or a Tac weld... basically you weld a tiny little dot on one of those marks you made previously on the connector and straight pipe... then do another test fit with the top section finger tight and in its bracket and make sure its going straight to the catback... if all is correct and good unbolt the top section once again.
12) finish the weld all the way around both ends of the connector, welding the connector to the top section and the connector to the straight pipe.
13) now we make a spot weld on the flange... bolt up the DP assembly now once again, notice how its an assembly now
... once the top two spring bolts are pretty tight in place then squeeze the flange bolts in the catback holes... put the nutz on the back of the flanges studs and tighten em up at tight as possibleWE do this because if the flange may have been a little off this makes sure A) it will bolt up properly when fully finished and B) it will bend the flange to how it needs to be if it was a little off on its angle that you had spot welded... so in turn it correct it for you when you tighten it all together.
14) unbolt the whole assembly once again, and be sure not to bend the flange anymore because it's been molded to where it needs to be at this point after the previous step. Finish the flange weld... once your done with that get a gasket bolt it up and your good to go...
NOTE: Run the pipe under cold water after every weld helps cool the pipe down and hardens the welds
NOTE: I will be adding to the DIY when i bore out the hole in the straight pipe to build the mechanical o2 simulator
NOTE: New pics with the welds soon
anywayz... there it is... I will be offering my services to doing this for you, i will be asking $75 for labor plus your core OEM downpipe, and i'll do this all for you
Last edited by REDchirp; Jul 6, 2006 at 11:30 AM. Reason: Correct way of doing this project now...
Hope you haven't taken too many orders, got this off JB-Weld's Website
Q: How much heat can J-B Weld withstand?
A: J-B Weld (Part # 8265-S, 8265, and 8280) can withstand a constant temperature of 500 degrees F. The maximum temperature threshold is approximately 600 degrees F for a short term (10 minutes).
Q: Will J-B Weld work on an automotive exhaust?
A: Because of the extreme temperatures of exhaust systems, we do not recommend J-B Weld for use on exhaust manifolds and catalytic converters. Nor do we recommend the product for repairs within the combustion chamber.
Q: How can I remove J-B Weld after it is fully cured?
A: When fully cured, J-B Weld can only be removed by grinding or filing it off, or by directly heating the product above the 600 degree maximum temperature threshold.
Q: How much heat can J-B Weld withstand?
A: J-B Weld (Part # 8265-S, 8265, and 8280) can withstand a constant temperature of 500 degrees F. The maximum temperature threshold is approximately 600 degrees F for a short term (10 minutes).
Q: Will J-B Weld work on an automotive exhaust?
A: Because of the extreme temperatures of exhaust systems, we do not recommend J-B Weld for use on exhaust manifolds and catalytic converters. Nor do we recommend the product for repairs within the combustion chamber.
Q: How can I remove J-B Weld after it is fully cured?
A: When fully cured, J-B Weld can only be removed by grinding or filing it off, or by directly heating the product above the 600 degree maximum temperature threshold.
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or you can buy the megan downpipe on ebay for like $50 shipped and not completely destroy your cat for emissions inspections.
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From: *UCF* Orlando, FL
Rep Power: 0 good thing you nubcakes haven't discovered industrial strength JB weld which is made for and sold in the exhaust section of any parts store
Thank you please drive through...
also... you can be ninny's and purchase a megan racing DP which does absolutely nothing for the car just to sound cool and tell all your friends you gained 15Hp from that cool mod cause thats what ebay says... orrrr you can not be such a ***** and have a straight pipe? either way i was just doing this because i know a lotta my friend in florida wanted it done and i had an extra DP lying around, but for DIY purposes i did the first one this way because "EVERYONE" can do it, you don't need to be a professional welder or take it to some place that'll charge ya out the *** because it's "illegal"... either way i'll be testing it out over the next week or so taking a few long trips... i'll be posting a Review as well
Thank you please drive through...
also... you can be ninny's and purchase a megan racing DP which does absolutely nothing for the car just to sound cool and tell all your friends you gained 15Hp from that cool mod cause thats what ebay says... orrrr you can not be such a ***** and have a straight pipe? either way i was just doing this because i know a lotta my friend in florida wanted it done and i had an extra DP lying around, but for DIY purposes i did the first one this way because "EVERYONE" can do it, you don't need to be a professional welder or take it to some place that'll charge ya out the *** because it's "illegal"... either way i'll be testing it out over the next week or so taking a few long trips... i'll be posting a Review as well
Last edited by REDchirp; Jul 1, 2006 at 06:26 PM. Reason: Automerged Doublepost
I'm not saying it won't work, I mean they advertise it for use to repair engine blocks. Just saying it ghetto as hell and there is better ways to do it such as taking it to Tuffy and have them weld it for $20.
good job on ur hard work, why not just go to an exhaust shop and have it welded instead of using silicone which will prolly just fall apart when driving..
I do not recommend driving like that at all, you shouldve just got the megan dp and saved ur cat
I do not recommend driving like that at all, you shouldve just got the megan dp and saved ur cat
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and... sorry to burst your bubble but industro weld can withstand temps up to 500F according to jb weld..
http://jbweld.net/products/industro.php
so... good luck with that i guess?
and... sorry to burst your bubble but industro weld can withstand temps up to 500F according to jb weld..
http://jbweld.net/products/industro.php
so... good luck with that i guess?
Joined: Oct 2002
Posts: 4,248
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From: Rockville, Maryland
Rep Power: 331
Originally Posted by REDchirp
good thing you nubcakes haven't discovered industrial strength JB weld which is made for and sold in the exhaust section of any parts store
Thank you please drive through...
also... you can be ninny's and purchase a megan racing DP which does absolutely nothing for the car just to sound cool and tell all your friends you gained 15Hp from that cool mod cause thats what ebay says... orrrr you can not be such a ***** and have a straight pipe? either way i was just doing this because i know a lotta my friend in florida wanted it done and i had an extra DP lying around, but for DIY purposes i did the first one this way because "EVERYONE" can do it, you don't need to be a professional welder or take it to some place that'll charge ya out the *** because it's "illegal"... either way i'll be testing it out over the next week or so taking a few long trips... i'll be posting a Review as well
Thank you please drive through...
also... you can be ninny's and purchase a megan racing DP which does absolutely nothing for the car just to sound cool and tell all your friends you gained 15Hp from that cool mod cause thats what ebay says... orrrr you can not be such a ***** and have a straight pipe? either way i was just doing this because i know a lotta my friend in florida wanted it done and i had an extra DP lying around, but for DIY purposes i did the first one this way because "EVERYONE" can do it, you don't need to be a professional welder or take it to some place that'll charge ya out the *** because it's "illegal"... either way i'll be testing it out over the next week or so taking a few long trips... i'll be posting a Review as well
dude the person that made this thread just did this cuz he had an extra one and to make a diy. so i would not flame on him. but if you are really gonna do this to your own exhaust pipe then HAHAHAHAHAHA. just go to a real welding place.
you have the idea but not the right way to go.
you have the idea but not the right way to go.
Last edited by civic05acer; Jul 6, 2006 at 04:27 PM.
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Rep Power: 0 no started out testing for all the cheapo's out there to see if the "Industrial strength" JB weld would hold up like they claim it will.. and it won't... its **** i had my friends come over last night we shattered all the JB weld's and cleaned the pipes back up and took a MIG weld to all the afformentioned locations stated earlier in the DIY... i have no edited the top post so that its correct .... new pictures are coming, but might not be for a few days because i'm a lazy **** and like to drive my car than jack it up hehe
.... new pictures are coming, but might not be for a few days because i'm a lazy **** and like to drive my car than jack it up hehe 
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Originally Posted by REDchirp
NOTE: Run the pipe under cold water after every weld helps cool the pipe down and hardens the welds
Last edited by KINGCHILE; Jul 6, 2006 at 02:00 PM.
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Rep Power: 0 First things first... TAKE OFF CAPSLOCK YOU JACKASS... second matter at hand, it wasn't immediately you fu< khole the pipe had already sat for a minute and then was run under tap water outside on a spicket, the welds were already hardened just needed a little cool down so that you can handle the piece... no structural damage happened with any of them smartass, funnier thing is the guy that does my welds is one of the better known guys around tampa for doing custom IC piping and exhaust piping... so trust me being that he's been in the business for 20 years, i'm pretty sure he knows what he's doing, something they don't teach you in the book you fu<king kook
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