starting turbo header/up-pipe build (pics)

[Myxalplyx]

Measured the factory exhaust tonight. 1.75 out of the head, both sides, to 1.50 at the base of the turbo. I searched for TWE specifications for the OD/ID and couldn't find it.

MY piping for this project is 2.75 O.D.Jay

 

From my post--->

http://www.ultimatesubaru.org/forum/showthread.php?t=28432&page=2&pp=10&highlight=Techworks

 

Hey Spanky_Pete,

 

The price for my header/uppipe and downpipe was:

Header -> $399US

Down-pipe -> $219US (for use with the GT17 turbo).

GT17 Turbo -> $395US

 

 

 

As for Garner (or anyone else who wants to know), here are the diameters of various things I measured under the car earlier today. Mind you, I may have made a mistake in my measuring but I did the best I could.

 

Stock engine exhaust port

2"

 

Header-Uppipes

Stock: Inlets- 1 1/2", Outlet(Uppipe)- 1 3/8"

Techworks: Inlets- 1 7/8", Outlet (Uppipe)- 1 5/8- 2"

*Note* Outlet of uppipe is oval in shape.

 

Turbos

*Note: Turbo inlets were difficult to measure since they are recessed somewhat inside the turbo housing.*

Stock VF7: Inlet- 1 5/8", Outlet- 1 6/8"

Techworks Garret GT17:

Inlet- 1 7/8", Outlet- 2 1/2"

 

Downpipes

Stock: Inlet- 2", Outlet 1 6/8"

Techworks: Inlet- 2 1/2", Outlet 2 1/2"

[Myxalplyx]

http://stores.ebay.com/VertexNow

 

these guys are out of delaware. lots of supplies for custom intake and exhaust projects.

 

This is where I got my piping for my intercooler inlet/outlet. Cool guys! Nice to be able to drive down the street to them.

[Myxalplyx]

Myx, I do want mine to sound like a boxer, but it's not that important. Special thanks for the picture and the advice.

Jay

 

Jay,

 

Here are links to two quick sound clips of the car. One I revved while idling and the other I did a little drive by. Please excuse my wife's voice. Man...she cries for attention.

 

Copy and Save Please!

 

http://www.we-todd-did-racing.com/wetoddimage.wtdr/wOTY1ODA3NnM0MTNkZmQzMXk1NDE%3D

 

http://www.we-todd-did-racing.com/wetoddimage.wtdr/wOTY1ODA4NnM0MTNkZmQzMXk1NDE%3D

 

Links will only be up for a few days. Download if you can.

[Do It Sidewayz]

i built my own header a while back, as i was putting on a VF-11 turbo.

 

I used 1.75 x .120wall tubing. i think it could have probably been a little bit smaller.

 

I ran most of the season at 5 PSI of boost, and it was easily as quick as the stock turbo at 8 PSI.

 

I upped the boost to 9 PSI at the end of the year, and it pulled like a beast.

 

One thing i can recommend..you need to be carefull when welding. have the flanges bolted to the heads, and weld it while it's bolted down tight. if you do not they will warp and you will have no end to the leaks

[gravelRX]

Thanks for the data on the TWE pipe. I downloaded the sound clips onto my computer and listened to them. I don't think it sounds like a motorcycle, a bit raspier than mine. That's not a bad thing. What muffler are you running and what size pipe out the back? Cat?

 

 

Will, not to continue poking at you but the last picture I saw of your RX says different. I'm sure whatever car you build next will be a nice one. With many well thought out bolt-on modifications. Without sending the Turbo off to someone how would you suggest the best way to polish the port on the exhaust side? Grind out the ugly and make it shiny? Seriously? I have an extra.

Maybe now would be a good time to upgrade the turbo, Eh?

 

I'm thinking the 1.75 OD with the factory turbo is going to be a smidge on the large side. I doubt I'll buy another box of 36' mandrel bent tubing at 1.50" OD unless I was going to build more than one set.

 

I was going to cut the original pipe off the flanges and use those flanges but I do have enough scrap steel laying around I could just make my own. What is it? 1/4" 3/16"?

 

How well does the four mounting holes work for you TWE folks?

 

Sidewayz: Thanks for the warping advice. I am going to weld the pipe to the flanges bolted onto the engine.

 

Haven't looked to see if I can make the full circles around the pipe without taking them loose yet. Hope so. I'm more worried about getting the collector under the turbo pretty. No, not pretty, Functional. Just functional.

I haven't mastered the "warp and warp it back" school of welding yet. My father could weld sheet steel to steel block and not get a single bow. Practice, Practice.

 

 

Regards,

Jay

[Guest shadow]

For flanges when welding your own, I always say the thicker the better, the minimum I would use would be 3/8", preferring 1/2" or even 5/8". With these little puppies you can probably get away with less thickness, as long as your bolted on four corners.

 

I think I should cover anti reversion a little more, just so you know what I'm talking about. In a pipe you never want to expose the gas flow to a step down in the direction of flow - a step like this (i.e. the stock exhaust 1.75" manifold port -> 2" head port exit) is a reflection point for the initial shock waves and following gas pulses. An anti reversion step is a slight step up in diameter in the direction of flow, commonly .030-.050" on the radius. So on a 2" head opening, you would have a 2.06 - 2.1" header port.

 

You can use a 2" ID 90 bend and cut pies out of the end to step it down to your primary ID size. Use a tailpipe expander to stretch the other opening for the head side, beware that stainless is extremely springy, so it will shrink back some after the expansion each time. Pie-ing the output side and expanding the inlet is how I accomplished this on my header build.

 

The TWE "oval" on the turbo flange I assume was to fit both turbos without having the port blocked. Unfortunately this scheme will cause that step down effect and in turn a reflection point for the shock waves. Match your flange exactly, or slightly smaller than, the port on the turbo. Avoiding the step down at all costs is generally the best idea.

 

If you use a proper merge like a Burns, you can step the output, which will invariably be too large, by pie cutting the tubing or by making or buying a premade cone, which is a fairly simple task as well. Again this method is used to avoid that step-down syndrome and reflection point. The Burns and other well-made merge collectors will all have some anti reversion designed into them by thier high angles of attack, which are very difficult for a home welder to do correctly with such precision. Even TWE does not have a tight merge on thier header, although it does look good regardless.

 

Porting a turbine on a turbo is childs play. I sent my TD04 to deadbolt and almost cried at the cost after seeing the ease of the job, if you've done any porting at all before its about a simple matter as they come. Radius and blend the wheel exit and matching the out flange wasthe extent of the work. Porting the wastegate is another worthwhile mod if you are using an internal wastegate turbo, since technically that will see the majority of airflow at higher rpm - this to prevent creeping. If you are designing for external wastegate, you will notice many good designers will not tack it on as an afterthought, but put it in the direct path of the flow with the turbo as a 'side' exit. Porting the compressor side, my TD04 as done by a shop was just enlarged at the exit. I can take pictures of mine to guide you if you'd like, I still dont have it installed. All 'polishing' is purely cosmetic but people that sell ported things like to make them look good in pictures, and so it has caught on. A mirror finish does not show up on a flow bench, so do whatever you feel like. I leave the cartridge roll finish on everything.

 

The way I do contructing of tubing systems is a part/section at a time, for tacking I use a proper sized hose clamp and cut a 'window' in it.. . The hose clamp holds the joint perfectly while you tack, rotate and tack, 4 tacks for each joint, then weld. This hose clamp method I learned from a very respectable master of the trade, Ron Covell. Remember to use the Solar flux on the backside of the joints, You can get this from Burns or any number of welding shops that supply for stainless welding. You have to use this if your not using a purge system. Also, there can be no air gap, and I mean none at all, in the joint you are welding on stainless. Take the time and finish the cuts to perfection.

 

Last thing I'd recommend is to make up a few extra flanges and fix a air adapter on on of them, and pressure test the unit before you do your final install. I tested mine at 50 psi and left it to test for leak down overnight, I made up some gaskets out of gasket material for the test.

 

The extra mile as I would call it and also would suggest it, is getting some 321 SS sheet and making some heat shielding, I made full wraps where possible and just a curved shield on the inside of bends, etc. Protect the oil pan/oil filter, engine mounts - I just wraped the whole merge collector and under turbo area. Any full wrap heat shielding will keep the heat in better and the surrounding air will be warmer, which can only help spool times. I do not recommend any kind of wrap however. Keep as much of the stock shielding or make your own for above and around the turbo and downpipe too. DP I'm making is 3" with a bell mouth.

 

4 mounting holes I would say are mandatory. They make the welding less stressful and if you don't have any slipjoints it should keep the expansion of the SS from working the gaskets over. Either way the extra holes are a good investment. I saw Sidewayz used .120 wall, that is very thick for SS. Most systems are 16 guage, .065. The thicker stuff will have more expansion force, I don't even know where to get SS that thick. If you do mild steel, then thickness is a good thing though as the heat retention of mild is far lower. I used 304 for expense purposes for tubing, and 321 sheets for my shields, because I had a cheap source. Remember you can weld SS to mild, which is sometimes done on the turbo flanges to prevent housing cracking, esp. on 4 bolt ones.

 

Well I think that is enough babble for one post.

[JWX]

how'd you learn all this stuff shadow?

[subyrally]

all bow to the shadow!!

 

now if only i could get you out here to help me out with my rx.

[BoostedBalls]

I built a header for my T3 setup last year. You can save yourself a lot of time and grief if you run the two pipes together and then cut it off right past the passenger head. This will let you install the thing without lifting the engine. This will also make it easier to make the end section of the up pipe to go exactly where you want it. I used crossover flanges from some v6 GM product in the JY. It has 3 holes, it's thick rump roast hell and gaskets are easy to find for it.

 

Equal length?? I really wouldn't waste the time to fab up a complex header for use with the stock turbo. What I would do, and I'm gearing up for it myself with stainless- is to make the passenger head angle towards the turbo instead of "T" towards the turbo and other head. IMO that will show the biggest improvement in throttle response and power. I have seen 1000+ HP drag boats with huge budgets NOT running equal length headers. Flow is way more critcal than pulse timing when talking about a mass produced engine with mass produced heads. I'll be taking a 90 degree bend and fusing it into the header then install a flange right at the merging point. This will give you the option of making 2 or 3 different final up pipe extensions for different turbos. You can make one for the stock turbo, the WRX turbo and a garrett T3 would make your car very adaptable to what you are doing at the time. Drag race? OK, go with the T3, rallycross, go stock turbo, etc.

There are some forged steel pipe adaptors that you might want to look into. They are made to be welded together and are very thick. A lot of guys are using them for turbo headers. They are groved for easy welding with great penitration.

 

I'll be starting on my stainless header soon and I'll be using the plans I just described. I'll post some pics of it as I progress. I need to also get out some pix of the water-to-air intercooler that I'm working on. It's about 95% done but I just ran out of argon...

 

ps: I think the 1.75 tubing is just right. I'm going with 2" but I'm only using this car for racing.

-Chuck-

[BoostedBalls]

I also forgot to comment on the header to head flanges, yes, use the 4 hole pattern and if you are going to use 1.75" tubing, you can even cut the flange holes big enough for the tubing to slip through them and into the head to that ugly step where the ports meet eachother, that will eliminate the reverberation step that Shadow was talking about. If you do that make sure that you get a calliper in there and measure and don't forget to ad the gasket thickness.

 

I just blended mine to match the 2" tubing though.

-Chuck-

[ausubaru92]

The benifits behind tuned or equal length pipes is that each pipe has a volume that matches the volume of the cylinder/s that feed it, in our case, the pipe before the collector should have a volume of 900cc. (2cyls = 1/2 of 1.8lt) this is so that one pulse of air comes into the collector exactly after the other one stops. this results in a constant flow of air.

In a non tuned system, two pulses of air are entering the collector at once, or there is a gap between pulses, creating turbulence and backpressure.

 

Think of it as trying to pour 2 cups of water down the sink at once, compared to pouring one after the other,... and if there is no gap between pours, the momentum of the first pour will suck the next one down

 

I think that can be roughly compared to exhaust systems:drunk:

 

Hope this helps

 

Gannon

[subyrally]

The benifits behind tuned or equal length pipes is that each pipe has a volume that matches the volume of the cylinder/s that feed it, in our case, the pipe before the collector should have a volume of 900cc. (2cyls = 1/2 of 1.8lt) this is so that one pulse of air comes into the collector exactly after the other one stops. this results in a constant flow of air.

In a non tuned system, two pulses of air are entering the collector at once, or there is a gap between pulses, creating turbulence and backpressure.

 

Think of it as trying to pour 2 cups of water down the sink at once, compared to pouring one after the other,... and if there is no gap between pours, the momentum of the first pour will suck the next one down

 

I think that can be roughly compared to exhaust systems:drunk:

 

Hope this helps

 

Gannon

 

 

 

i have to agree with that.

 

 

my main reasoning behid getting tuned length is that it brings out the boxer rumble;) i love the way the borla headers made my impreza sounds. once i start working again, im going to have the rx fiixed and get a set of headers made for it as well.

[BoostedBalls]

I'm not saying equal length headers aren't a bonus in spinning the turbine wheel. I'm just saying that directing the passenger head primary pipe towards the turbo will make the biggest torque increase from stock and way simple.

More pipe = more heat/velocity loss. I would use my money and efforts elswhere on the engine unless I was doing serious competition.

 

I read in a previous post that the stock up pipe is very narrow, I just measured it at 34mm, just over 1.25" ID, yeah, that's small. I am still running the stock up-pipe only because of time constrains and multi-tasking projects; but my RX pell pretty damn hard though. It is my biggest bottleneck right now.

 

Porting turbine housings- Bling bling factor all the way. It is almost impossible to port the critical areas in the housing so most shops will just hog out the inlet and 3 or so inches into the housing. This porting is being done in the area where the SLOWEST flow is taking place in the housing. It may give slightly better heat retention fron the reduced surface area of the inlet but the really critical area is where the passage necks down and flow is very high. You cannot get the tool around the corners to smoothen that area out. I guess you could blast some steel shot through the housing to knock the casting burrs down.

 

I applied at a turbo rebuilding shop in Lake havasu, AZ a few years back and they also offered the porting to the "more dollars than sence" turbo jetboat crowd. I saw a lot of beautifully polished turbos on the shelf, the guy there told me that the porting doesn't help flow through the turbo but that it seemed to reduce cracking.

I still take the sander wheel to the inside of my T3's but they still seem to crack at the casting seam.

-Chuck-