Hey guys,

I've already spent a few weeks searching far and wide on here and on the VWVortex. I've come up with a lot of good info, but have a few questions.

I'm going to be building a tubular style top-mount manifold for my VW 1.8T motor. I'm trying to decide whether I want to make it of SCH 10 or SCH 40. I've settled on using 304 stainless, as I simply cannot afford 321.

I was just wondering if anyone would have any friendly advice for someone who is doing this for the first time ...

I am a little bit concerned about welding in tight spots, (collector to runners etc.). I have only one torch, and it is the standard one that comes with the Precision 185 ...

I will be getting a pre-cut collector, as I don't want to start learning that art just yet.

Q: Will schedule 10 304 pipe hold up if I weld it correctly and run a turbo brace? I plan on backpurging.


Collector : http://www.bmcrace.com/product...id=84

(This one is a 3", I will be getting the 4" I think).


I also have to make sure the runners clear the rear engine mount. :S



I'll take anything you have for me! Good or bad!

Thanks a lot for your time!

 

Hey fellow quebec Racer !

I got a few tip's and don't just from the top of my head.

Clean the **** out it it dude, when you are shure it's clean, pass on another time just to make shure it is really...

don't try to weld in one pass, it's not the best, do a root pass, then two other to finish with filler.

Make shure everything fit before you assemble anything, tack, test fit... mesure closely, twice preferably.

when welding the pipe to the flange, bolt this flange to a head you are not using anymore. Heat WILL warp it if not bolted, then it will leak before the turbo and it cost big HP.

Get a back cap, shortest one you can find, it's the **** to weld in the runner to the flange.

alway's take 1/2 thick flanges.

Think of Wastegate placement BEFORE starting the project, cause it will be a major factor in boost creeping of you manifold.

that's it dude

Moste important : post pic of the process and final product!!

JP

 

the sch10 vs. sch40 is controversial.

i personally used sch40, but alot of people swear by sch10... but the test of time will tell...

 

Thanks for the help guys!

I was definitely going to do multiple passes for each joint. I'm not sure if it's best to leave a gap?

Any advice as to what order is best to assemble in? I have a scrap head, and will be building it off of there. I want to be able to fit a GT30R with the compressor outlet pointing towards the front, right over the valve cover. Hoping I can get the fit right using a smaller T3/T04B ...

Is it best to assemble from the collector to the headflange?

Thanks again for the help!

 

i find going from collector to head flange easier. sometimes i'll just start with one runner to get the turbo flange positioned where i want it, then do the other runners and meet in the middle if it will be easier.

 

Cool, thanks for the advice!

 

little tip.


Don't just bolt the flange to the head. Leave it bolted on there until it is COLD.

 

I personally would not use 304, but if you must, use the sch40 thickness. I work alot with SS and in very high heat environments (i.e. 5000F). For thermal cycling, the best to use is 330, it gives you cycling up to 2100F. The next closest is 309 and is much cheaper. It will withstand constant thermal cycling up 2000F. 304 tends to, over time, work harden and get very brittle and break. This considering your exhaust temps could run close to these temps depending how hard and how long your driving the car. i.e. road coarse vs. drag strip.

 

Hmmm, this was my worry about 304. I have heard time and time again that it is not ideal for temps this high.

Would I be better off using mild steel pipe? I will definitely be easier to weld, but costs a little more.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hucoreyCRX &raquo;</TD></TR><TR><TD CLASS="quote">I personally would not use 304, but if you must, use the sch40 thickness. I work alot with SS and in very high heat environments (i.e. 5000F). For thermal cycling, the best to use is 330, it gives you cycling up to 2100F. The next closest is 309 and is much cheaper. It will withstand constant thermal cycling up 2000F. 304 tends to, over time, work harden and get very brittle and break. This considering your exhaust temps could run close to these temps depending how hard and how long your driving the car. i.e. road coarse vs. drag strip.</TD></TR></TABLE>

i highly doubt any manifold will ever see 2000f...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by shortyz21 &raquo;</TD></TR><TR><TD CLASS="quote">i highly doubt any manifold will ever see 2000f...</TD></TR></TABLE>

I used to see a max of 1800°F in my log manifold, with the probe in one runner, one inch from the head, but this was on long highway runs. 2000°F is not that far off ... I wonder how long a 304 manifold would last with extreme abuse ...

 

a long time i guess. I have a full race manifold here im putting on a customer car, and they didnt polish off all of the bend writing on them 304/304l schedule 40 1.5" the only way this manifold is going to crack is because two of the runners actually physically touch one another. The robot and other welds besides one on the collector by the turbine inlet flange are flawless, cyl 3&4 just touch at one spot...

 

Cool! I'm going with 304.

Was going to order 17 bends, thinking it was enough, but now I'm seeing people are usually getting 19 to make a ramhorn-style manifold.

Thanks for the tips!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Agtronic &raquo;</TD></TR><TR><TD CLASS="quote">Cool! I'm going with 304.

Was going to order 17 bends, thinking it was enough, but now I'm seeing people are usually getting 19 to make a ramhorn-style manifold.

Thanks for the tips! </TD></TR></TABLE>

uh.... i think 12 90's and 2-45's would be good... maybe just 13 90's..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dturbocivic &raquo;</TD></TR><TR><TD CLASS="quote">uh.... i think 12 90's and 2-45's would be good... maybe just 13 90's.. </TD></TR></TABLE>

Cool thanks!

 

Update :

Got my stuff!

&lt;female chanting voices major chord&gt;AHhhhhhhhhhhhhhhhhhhhhhhhh&lt;/female chanting voices major chord&gt;










A good friend of mine was nice enough to lend me a scrap 20v head, which will really help me out. to generous friends!





I have to say, I am VERY impressed with both BMC Race and Ace Stainless. They respected their estimated time to ship, and the packaging was nice and solid.

The BMC parts are flawless. The flanges are beautiful and the collector fits together like a glove.

I would recommend BMC Race to anyone looking for DIY fab parts.



Wider end-holes to allow for expansion ...













Quick question : What do people normally do to fill the gap where the collector meets the turbo flange? Is it better to cut down the collector a little bit or fill in the gap with filler w/ backpurge?

Thanks for reading!

 

wow...........that's neat...........

 

you want to trim the collector down so it closely matches the turbine inlet flange. I just finished my first 1.8t ramhorn a couple weeks ago, if you search on here you will find my post in this forum. maybe the pics will help you out a litte.

One 1.8t specific tip i have, is to place the turbine flange perfectly center and parallel to the head flange. the posrt spacing on that head does not give you much room for anything but. you'll see what I had to do on mine in order to not cheat the bends. good luck!

 

Cool, so it'll be okay to cut it down. Good!

I actually checked those pics of your manifold not too long ago, and again today. I am going to make mine pretty much the same, except my WG pipe will point downwards because my 1.8T is in an MK3 Jetta ... Pretty tight back there. I'm hoping I can make it clear the rear engine mount without too much trouble.

For now, I will be running a small T3/T04B, but I have plans for a GT3071R ... hoping I can make it fit when the time comes.

Thanks for all the advice!

 

How much did all that cost you?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Agtronic &raquo;</TD></TR><TR><TD CLASS="quote"> I am going to make mine pretty much the same, except my WG pipe will point downwards because my 1.8T is in an MK3 Jetta ...
</TD></TR></TABLE>

it is tight but try and get at least the first part of the WG tube to point upward as much as you can. It will give you much better boost control (especially with larger turbine wheels) since the exhaust gas is not forced to turn back on itself to make the corner. the easier the flow to the WG the bettter.

 

The parts cost me about $310 USD in total.

Heh, thanks! I definitely wanted to make it come outwards first, same as in this design by BoostFactory :

 

$310 is a little much compared to buying a manifold already done isn't it?

Don't get me wrong I love to weld and make things but wouldn't it be easier to buy one.

I guess the satisfaction of making your own and saying that you built it is priceless.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by arcboy &raquo;</TD></TR><TR><TD CLASS="quote">$310 is a little much compared to buying a manifold already done isn't it?

Don't get me wrong I love to weld and make things but wouldn't it be easier to buy one.

I guess the satisfaction of making your own and saying that you built it is priceless.</TD></TR></TABLE>

Much compare to WHAT? boost factorys manifold $575.00 Vs his $310

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by arcboy &raquo;</TD></TR><TR><TD CLASS="quote">I guess the satisfaction of making your own and saying that you built it is priceless.</TD></TR></TABLE>

This is a big one for me. I don't mind spending money on my car, but when it is something that is fabricated, I want it to be my blood sweat and tears.

My Jetta represents so many things for me. I've had it since 1998 and I take pride in not constantly switching up to the most recent models like many people do. Every step in modifying this car has taught me something. When I started out with it, I basically knew how to change oil, and that was about it ... over the years, I have turboed it / programmed the standalone myself, did all the welding etc ...

Also, the BF manifolds were more expensive than that up until just recently.