Need Guidance on DIY Downpipe

[ppctx]

I am having a real hard time trying to find pieces to build a DP and the mani manufacture no longer sell the DP (revhard), custom is the only option. ANY HELP APPRICIATED! ATP seems to have everything (flex section, turbo outlet flange, tube, bends...) in SS except for SS flanges, that mate up to the stock system (old 60mm Greddy). I don’t have to go SS, it just seems more pieces are available in it. I want to do 2.5" for now and will do complete system later in 3" if needed (think my current turbo is equivalent to a garret super 60 so I don’t expect to go over 250hp), I think the 2.5" should suffice. Anyways, if you did a DIY downpipe, what did you make it out of (SS or aluminized), what wall thickness is required, where did you get your stuff from, is it possible to just take straight pipe, heat one side and bend with decent results... Again, any help appreciated, this dp seems to be my final roadblock to KA-T

[Florida240sx]

http://stores.ebay.com/MC-Motorsports

[spooled240]

With my ebay mani, i also had to get a custom dp. I got a 3" 5 bolt turbo outlet flange, 3" ss 90" mandrel bent pipe and 2 v-band clamps from ATP then went to my local muffler shop for the fabrication. It cost me $150 and took about 3-4 hrs. I then v-band clamped it at he bottom...works great though

[480sx]

I look at the SS Vs aluminized debate this way... Why try to save a little money in initial payment on something that a few snow seasons down the road you will need to replace?

IMO the only area aluminized is even an option is in areas that see no snow, and arnt coastal regions.

You will never regret spending the extra cash and going with SS.

[ppctx]

I can pick up 14, 16 and 18 gauge SS tube locally. what's normal wall thickness thats used in exhaust.

[ppctx]

Thanks for your help everybody! THE NICO COMMUNITY SEAMS TO BE AS USEFULL AS A HOLE IN A BUCKET

[neverlift]

also seems to be full of force spoon fed fools.

pic what you want, think bro.

[spooled240]

for real, custom work requires some thinking and planning, we can't hold your hand for the whole damn trip

[WDRacing]

Look look...everyone relax. I have made all kinds of exhaust systems and intercooler piping with mild steel. It's cheap, easy to weld and can be found ANYWHERE.

Are you welding it yourself? If so what method of welding, mig, tig or oxy/ace?

Summit racing sells ALL kinds of bends in various sizes. You can use anything from 16 to 20 gauge so long as it isn't supporting a huge load. Try to us a flex pipe if you can, but I didn't. The flanges can ALL be found on EBAY or 1 MILLION other stores that a simple Google search for turbo flanges will pull up.

Don't EVER get an attitude on MY forum because the replies are slow, especially when 4 minutes worth of looking will yield fairly good results.

Answer the questions I asked and I'll walk you through what you need to do.

WD

[ppctx]

Thanks, going thru several online vendors, I've been able to find all the pieces. I'll be mig welding, all SS(most specifying 304, some just say SS), will use a flex section, weld bungs for egr and o2, bring it to the cat, make a test pipe, wrap all with exhaust wrap. Wish I could get revhard to send me their design sheet (as they no longer produce the mani I have or DP which I don’t) so I know what bends to purchace…

This isn't a matter of me not searching, I've searched the crap out of it, called local exhaust shops but didn’t ask anybody to hold my hand. Out of all the knowledge a hobby specific forum would have, it just seems that is would be easy enough to help somebody out with a few key strokes and clicking the post button. I can see for a very common or repeatedly asked question someone would ignore or tell them to search, but Search for yourself and see how much info is out there on DIY exhaust.

I've wanted to comment on "Search" being used as the generic answer to so many questions, especially to those with low post number who obviously haven’t been around long enough to have the same knowledge as someone with high post counts. This is your forum and I'm just a guy on it, but dam, why have a post button if no one can ask a question or answer a question. Even the guy I bought all my stuff from commented the other day that it doesn't seem anybody wants to help. I actually think he said the site sucks, wasn't what it was when he was trying to figure things out. Granted, WDRacing, Flordia240sx, and several other are consistently the ones answering the questions... a handful of guys out of how many members? That either means there the only ones who know about moding a 240 or... I dont know...

This has gotten way off topic. I should have just kept my mouth shut, I should not have posted what I did. No ones forcing me to be here. Maybe I'm relying to much on the forum as a technical resourse as opposed to a social. Again, thanks to those do share the knowledge, sorry for posting what I did, I will now take my place in the back row.

[neverlift]

no your wrong this is one if not the most technical forums on nico, post count has little to do with intellegence that what makes it great...

I'm with yah if its not gonna be constructive as to get you help stfu. I was all willing to come in and give the wealth I had gained LOOKING FOR YOU, till I saw your post filled with childish spark and insult. We helped and told you to make an informed choice. here so you wont have to worry anymore. s/s 18gasummit should have everything but your flanges. IF any question of money go aluminized steal.

so feel free to post away, have patience and dont get smart. Its gonna benefit you the most.

[WDRacing]

Nonsense, I've always made it my policy that any question can be asked no matter how dumb someone might think it is. The dumbest question is the one you never ask

Personally I wouldn't use SS on anything. But I'm a cheap fvcker...lol. Not to mention the majority of the flanges available are made from mild steel. You really don't want to mix the two because they both react to heat differently and expand differently. SO you increase the chance of something cracking.

I have something I've really wanted to try out as a matter of fact. Let me run it by you and see if it's something you'd like to try. If it is, maybe you can document it and I'll write an article about it and add it to the tech forum and our beloved KAT sticky.

You can buy flex pipe from places like Autozone or and Napa. But I use http://www.mcmaster.com/ as much as I can. They have literally everything you've ever wanted.

I would like to use a J Bend on each end of the flex pipe.



A flex pipe section in the middle for easy plumbing.



A coupler on each end to attach the two.



Then whatever flanges match up to your particular turbo and exhaust system.

Would be cheap and easy to do.

[neverlift]

lol you would love my diiy exhaust system wd 3 18" straight pipes and a piece of flex to the cat/testpipe

op dont forget about hangers.I'm missing one and it makes my eaxhaust hit my subframe. Also make sure you just tack weld till you know its a perfect fit, the remove and finish weld it. Good luck

[ppctx]

hangers - I didn't think there was but one hanger for the DP located at the front of the cat, that attaches to the transmission mount. Does the DP section have more?

I'll have to check out that parts list, I thought those clamps were expensive (V-flanges or something). I dont need SS, I was just trying to get all the metals the same. the SS flanges ended up being fairly expensive $18 a piece (and only found them made by Vibrant) as opposed to the more common mild steel at ~$6 a piece. bungs all seem to be SS or aluminum. I have to admit I have not checked out mcmaster (get kinda lost on their site), but will do. If I can cheaper materials will certanly use.

Again thank you and I do feel bad about my comments, got a little fustrated that after 2 day there was no responce to the pipe gauge question, but in the end, I have given just about Zero back to the forum but have been able to take quite a bit. If it wasnt for Nico, I would have never known I could turbo the car to begin with... Looking at it that way, y'all are costing me a lot of money!

[neverlift]

lol yah we make alot of people spend money, but its cause we have a great common goal. POWER(especially in here), and the love we have for our cars.

as wd said its slow in here most of the time(why I'm always here), but q's get a's , didnt get to respond before your tude due to my personal stuff...

from your posts, go with aluminum, save up for a bit then get youself a real nice s/s IF you feel you need it, or blow saved money on turbo goodies. I have a s/s d/p but I picked it up for a skimp 20 dollars. Had I made my own it would have been in alumized steal. My cat back is **** you can buy from auto zone.

[crzycav86]

get it from summitracing.com make sure you buy "aluminized" mild steel, or else it will rust fast.

[spooled240]

sorry about my last comment that wasn't helping anybody..

My dp has mild steel flanges on a ss pipe (from ATP) and like wd said this increases the chances of cracking, etc. but there's no extreme load placed on it which helps. O and BTW, using a mig welder w/ mild steel wire on ss doesn't work too great i found out the hard way..lolI went to the muffler shop cuz they have tig welders and they did some great welds.

like everyone else said, go with ss, make sure you don't have your exhaust system hang on the dp creating stress then forget about it.. should last you a lifetime. And use all the hanger supports on the car, some of my exhaust hangers cracked off because I only used 2 and the exhaust was moving around like a mofo.

[ppctx]

Thanks All, everything will be SS for better weldability (and if need be future sellability) and with shipping SS only cost a little more, SS flanges taking up the bigger portion of the cost. With a local seller willing to sell straight pipe by the foot, the SS route is slightly more expensive but easiest route for me. Currently sitting here going over my parts list to make sure I have everything needed. Bits and pieces for oil supply (oil feed tee and egr bung being the least common to find), gaskets of all sorts (AutoZone will supply some), pipe, exhaust wrap, walbro hp255L. Enough parts to build it in my head. there will be something I've missed or not shipped correctly, but I think I should have it together in no time.

All parts ordered, only need pillar pod, oil pressure and boost gauge. $760 incuding all bits an apexi neo. I need to post a parts list for my build, some of the little parts are never mentioned in the how to.
Modified by ppctx at 9:05 PM 9/17/2007

[480sx]

Personally I wouldn't use SS on anything. But I'm a cheap fvcker...lol. Not to mention the majority of the flanges available are made from mild steel.

Mostly becuase you live in a climate with two modes, hot, and so hot your better off nekkid.

In any temperate, or colder area stainless will be much cheaper in the end. Do it once, and never do it again. Its amazing how fast aluminized steel will start rusting, even after one snow season.

Heck, i go up to Maine often, talk about some aluminized exhaust horror stories.. My brother used to work in a shop up in Maine, where the weapon of choice for doing exhausts wasnt a wrench, but a torch. They coat the roads up there with a sodium chloride powder, oh man, you think salts nasty? Get some of this stuff on your already rusting s13 and watch your car disintegrate over the next year, its crazy stuff.

[WDRacing]

Mostly becuase you live in a climate with two modes, hot, and so hot your better off nekkid.

Yeah....the weather here is awsome for keeping cars corrossion free. I'm originally from Boston though, so I am quite familiar with the rust issue. I have a bunch of J abd U bends in the shed here and even they have surface rust on them.

I just like the price and ease of welding. Although they are better for IC piping since it gets painted.

WD