home register FAQ memberlist calendar

Go Back   Turbobricks Forums > Mechanical > projects & restorations

Reply
 
Thread Tools Display Modes
Old 04-25-2020, 03:18 AM   #976
Tfrasca
Board Member
 
Tfrasca's Avatar
 
Join Date: Apr 2015
Location: Ben Lomond, CA
Default

Well, I have been playing with the TIG welder I got last month quite a bit, so I decided to make some things. First, a stainless 4" downpipe. It still needs the wastegate routing, and some o2 bungs, but it's mostly done, and it fits, so I'm calling it a win. I went with 4" because there's enough room with the engine upright, and it has to help with spool, at least a little. That's what I'm telling myself.



The plan with the exhaust manifold was to bring it to Noah for finish welding. Coronavirus has been preventing that, and I got impatient. It took a while, and of course I made some mistakes, but overall it went pretty well for my first big TIG project. One significant downside to doing it myself is that I wasn't able to purge it, like we would have at Noah's. Maybe this will **** me later on, but I was getting full penetration anyway, so I'm hoping it will hold up. I think I want to media blast, then pressure wash the inside of it before I run it, in case there's any small sugar clumps in there.

Related to penetration, if you're making a weld el manifold, make sure you give yourself big enough bevels. The factory bevels are almost knife edged, which will allow full penetration. My bevels were much smaller. Oh, and the cast collector I used is pretty sweet, but the super short connections for the runners make it very tricky to weld out. I actually have to try to bend a tungsten to get the last 10mm or so. And in some spots it just wasn't possible to use filler, so I had to just fusion weld them without filler. A few people said they wanted to build weld el manifolds, and as a beginner welder, I now have some advice on what not to do.





Tfrasca is offline   Reply With Quote
Old 04-25-2020, 03:33 AM   #977
culberro
Ronald Culberbone III
 
culberro's Avatar
 
Join Date: Feb 2010
Location: Portland, OR
Default

Looks solid!
__________________
Cult Person. Pissing in your Kool-Aid.
culberro is offline   Reply With Quote
Old 04-25-2020, 03:43 AM   #978
Harlard
Hurlurd?Harland?Bueller?
 
Harlard's Avatar
 
Join Date: May 2007
Location: PDX
Default

This looks awesome.
__________________


Herr Harlard am Erstens

1979 242 DL

Quote:
Originally Posted by t8fanning View Post
My knob has a big chunk of steel on it
Harlard is offline   Reply With Quote
Old 04-25-2020, 04:00 AM   #979
Sjeng
Board Member
 
Sjeng's Avatar
 
Join Date: Sep 2017
Default

Looks great!

Last edited by Sjeng; 04-25-2020 at 04:04 AM.. Reason: Answer found already.
Sjeng is offline   Reply With Quote
Old 04-25-2020, 09:22 AM   #980
smoothdurban
I do my own stunts
 
smoothdurban's Avatar
 
Join Date: Jan 2013
Location: LaSalle ON
Default

I have to get in the TIG game. Looks great!
__________________
1983 242 Turbo w Tremec T5 152,000 km's B230FT LH2.4

2019 VW Golf R w 6 Speed w 1320 kms NEW DD

@smoothdurban on IG
smoothdurban is offline   Reply With Quote
Old 04-25-2020, 11:04 PM   #981
Tfrasca
Board Member
 
Tfrasca's Avatar
 
Join Date: Apr 2015
Location: Ben Lomond, CA
Default

Thanks, guys. This has been really fun, and something I've wanted to figure out for a while.

The next thing will be the waste gate routing. Wondering if anyone has any input on routing two waste gates back into the down pipe. Should I try to keep them separate all the way to the down pipe, or should I join the two together, then into the down pipe?

If I do join the 2 1.5" tubes together, what size should the "collector" tube be?
Tfrasca is offline   Reply With Quote
Old 04-26-2020, 12:26 AM   #982
Alex Buchka
8 cylinders
 
Alex Buchka's Avatar
 
Join Date: Apr 2004
Location: Los Angeles
Default

Good work dude. Can highly recommend getting a purge setup going. Obviously a dual flow meter regulator is nice but It doesn't have to be that complicated or expensive. In a pinch I've gotten by with sticking a tee fitting in the hose from the regulator to the welder and regulating the purge flow with a ball valve.

I don't think the wastegate plumbing is super critical, you just want to make sure the tubes have approximately the same number of bends and total bend angle so the pressure drop across the tubes is about equal. A good guideline is to dump the wastegate gasses back into the exhaust as far away from the turbo as packaging allows for. This will minimize the impact you have on flow out of the turbine housing. If you do combine the outlets my gut check says 2" tubing should be more than adequate.
Alex Buchka is offline   Reply With Quote
Old 04-26-2020, 12:27 AM   #983
Duder
Comes with a free Frogurt
 
Duder's Avatar
 
Join Date: Dec 2009
Location: Torrance, CA
Default

Nice job man, that thing looks great and stout too. Most of the weld el manifolds I've seen were a bit...lacking in the aesthetics department. Great effort for a first TIG project!

I don't see any glaring reason not to join the wastegate outlet tubes together prior to merging with the downpipe, especially if that's easier for packaging and/or fabrication. Wastegate flow should be as unrestrictive as possible both pre- and post-valve, to make the best use of the valve size you've got and to avoid boost creep.

Flow area of a 1.5" tube is 1.77 square inches, x2 = 3.53 in^2. Solving for the diameter you'd need a 2.12" tube to match the flow area of 2x 1.5" tubes, not accounting for losses due to bends or dynamic effects. If you can fit a 2.25" or 2.5" tube you should be ok, as long as bends aren't too tight, like 1D or bigger.
Duder is offline   Reply With Quote
Old 04-26-2020, 12:33 AM   #984
Duder
Comes with a free Frogurt
 
Duder's Avatar
 
Join Date: Dec 2009
Location: Torrance, CA
Default

Jinx on the reply, Alex.

Quote:
Originally Posted by Alex Buchka View Post
A good guideline is to dump the wastegate gasses back into the exhaust as far away from the turbo as packaging allows for. This will minimize the impact you have on flow out of the turbine housing.
Also this ^. I can see that we have taught you well.

The effect of dumping wastegate outflow too close to the turbine wheel exducer (as in an old-school internally wastegated housing with a common open discharge section) is effectively a restriction on flow through the turbine stage, which gets accounted for during boost control but will inevitably increase your pre-turbo exhaust backpressure. Join the wastegate back in down by the bellhousing or at the bend where the exhaust goes horizontal under the car, if you can. Use a flex section too, which hopefully goes without saying.
Duder is offline   Reply With Quote
Old 04-26-2020, 10:12 AM   #985
Tfrasca
Board Member
 
Tfrasca's Avatar
 
Join Date: Apr 2015
Location: Ben Lomond, CA
Default

Quote:
Originally Posted by Alex Buchka View Post
Good work dude. Can highly recommend getting a purge setup going. Obviously a dual flow meter regulator is nice but It doesn't have to be that complicated or expensive. In a pinch I've gotten by with sticking a tee fitting in the hose from the regulator to the welder and regulating the purge flow with a ball valve.

I don't think the wastegate plumbing is super critical, you just want to make sure the tubes have approximately the same number of bends and total bend angle so the pressure drop across the tubes is about equal. A good guideline is to dump the wastegate gasses back into the exhaust as far away from the turbo as packaging allows for. This will minimize the impact you have on flow out of the turbine housing. If you do combine the outlets my gut check says 2" tubing should be more than adequate.
Thanks, Alex. That's a good, cheap solution to the purge problem. Aside from not having a set up, I was also thinking that I'd be wasting a ton of gas if I purged this. To keep things from getting too hot and warping, I was welding maybe 1/2" at a time, then cooling it with compressed air. I figured I'd be losing all my purge gas for every single weld/cooling cycle. Maybe I was being too paranoid about heat build up?

Quote:
Originally Posted by Duder View Post
Nice job man, that thing looks great and stout too. Most of the weld el manifolds I've seen were a bit...lacking in the aesthetics department. Great effort for a first TIG project!

I don't see any glaring reason not to join the wastegate outlet tubes together prior to merging with the downpipe, especially if that's easier for packaging and/or fabrication. Wastegate flow should be as unrestrictive as possible both pre- and post-valve, to make the best use of the valve size you've got and to avoid boost creep.

Flow area of a 1.5" tube is 1.77 square inches, x2 = 3.53 in^2. Solving for the diameter you'd need a 2.12" tube to match the flow area of 2x 1.5" tubes, not accounting for losses due to bends or dynamic effects. If you can fit a 2.25" or 2.5" tube you should be ok, as long as bends aren't too tight, like 1D or bigger.
Thanks! I actually wish I'd tried harder in the aesthetics department, and run the long #4 runner underneath. I like the way the manifold looks from the bottom. Oh well.

I doubt I could fit anything bigger than a 2" tube, and get far enough down the down pipe. I'm pretty sure it's going to have to go in right before the 90 degree bend at the oil pan, but maybe I can sneak a smaller tube further down.
Tfrasca is offline   Reply With Quote
Old 04-26-2020, 10:35 AM   #986
SquareD
An Anomaly
 
SquareD's Avatar
 
Join Date: Nov 2002
Location: The STL
Default

Dang, nice work on the dp and manifold! Looks great!
__________________
1994 945ti | 15g @ 15psi, Turbosmart EBC, AEM Failsafe WB, 3"/2.5" exhaust, do88 intercooler, iPd cam, STS cam gear, Ostrich LH tune, sbabbs EZK chip, green giants, K&N, Yoshifab CCV/Can/Cap, iPd SS brake lines, TME, Eibach, BNE, Koni suspension, iPd sways, iPd panhard, TME upper/CT lower braces, forged BBS RG-Rs, Michelin Pilot SS, ecodes, V90 bits.
1985 744ti | 13.8 @ 100.5 mph - Sold after 20 years.
SquareD is offline   Reply With Quote
Old 04-30-2020, 10:59 PM   #987
Tfrasca
Board Member
 
Tfrasca's Avatar
 
Join Date: Apr 2015
Location: Ben Lomond, CA
Default

Has anyone used this type of flex hose on a waste gate, or any other exhaust?



I first saw it used (poorly) on a friend's BMW 535 turbo. It was just hosed clamped on, but I'm thinking if welded, it could work well. The much lower profile would be nice.
Tfrasca is offline   Reply With Quote
Old 05-01-2020, 01:35 AM   #988
Harlard
Hurlurd?Harland?Bueller?
 
Harlard's Avatar
 
Join Date: May 2007
Location: PDX
Default

I don't think a thin wall flex tube like that would survive very long at all...
Harlard is offline   Reply With Quote
Old 05-01-2020, 10:48 AM   #989
RvolvoR
Board Member
 
Join Date: Jun 2003
Location: PDX
Default

I've seen the swedish dudes use it a few times, but it looks really cheesy and kind of half assed.
RvolvoR is offline   Reply With Quote
Old 05-01-2020, 11:12 AM   #990
Tfrasca
Board Member
 
Tfrasca's Avatar
 
Join Date: Apr 2015
Location: Ben Lomond, CA
Default

Yeah, I could see it not looking great, if you made the whole run out of it. I was thinking about just welding in 2-3" of it instead normal flex bellows. I probably won't, though.
Tfrasca is offline   Reply With Quote
Old 05-01-2020, 11:54 AM   #991
RvolvoR
Board Member
 
Join Date: Jun 2003
Location: PDX
Default

https://vibrantperformance.com/catal...75ffc8ffbed5c7
RvolvoR is offline   Reply With Quote
Old 05-01-2020, 11:57 AM   #992
matt b
Board Member
 
Join Date: Apr 2007
Location: Tucson
Default

Quote:
Originally Posted by Tfrasca View Post
Yeah, I could see it not looking great, if you made the whole run out of it. I was thinking about just welding in 2-3" of it instead normal flex bellows. I probably won't, though.
It was on an Amazon I bought out of SF. It leaked like crazy and was all dented from rocks being kicked up and the PO pushing against it to get to the car. It's a POS solution.
matt b is offline   Reply With Quote
Old 05-01-2020, 12:50 PM   #993
Tfrasca
Board Member
 
Tfrasca's Avatar
 
Join Date: Apr 2015
Location: Ben Lomond, CA
Default

Quote:
Originally Posted by RvolvoR View Post
Yup, that’s what I used on my last setup. Will use those again.
Tfrasca is offline   Reply With Quote
Old 05-01-2020, 12:50 PM   #994
Tfrasca
Board Member
 
Tfrasca's Avatar
 
Join Date: Apr 2015
Location: Ben Lomond, CA
Default

Quote:
Originally Posted by matt b View Post
It was on an Amazon I bought out of SF. It leaked like crazy and was all dented from rocks being kicked up and the PO pushing against it to get to the car. It's a POS solution.
Ok. This is what I needed to hear, thanks.
Tfrasca is offline   Reply With Quote
Old 05-01-2020, 01:43 PM   #995
Stiggy Pop
Board Member
 
Stiggy Pop's Avatar
 
Join Date: Feb 2011
Location: Granville, MA
Default

Quote:
Originally Posted by RvolvoR View Post
considering the fact that these bellows crack with some frequency I can't imagine that length of corrugated tube would survive long. Not a direct complaint on the Vibrant piece, I think it's just the nature of the beast. Tate and I have both replaced them on our headers.
__________________
'79 242
943 pickup
Stiggy Pop is offline   Reply With Quote
Old 05-01-2020, 04:23 PM   #996
Duder
Comes with a free Frogurt
 
Duder's Avatar
 
Join Date: Dec 2009
Location: Torrance, CA
Default

Another vote for staying away from the "hose."

The type of flex bellows I like to use has stainless braided sheath over the bellows section. It should increase abrasion resistance and help tie the room together. Vibrant has some listed under the name "TurboFlex." I like to think that's what it's called when you rev up your turbo for intimidation.

https://vibrantperformance.com/catal...75ffc8ffbed5c7

Edit: there's no material listed on the Vibrant parts above, but here's a different one that is listed as 304 stainless:

https://www.maperformance.com/produc...upler-4-length
Duder is offline   Reply With Quote
Old 05-01-2020, 04:57 PM   #997
Harlard
Hurlurd?Harland?Bueller?
 
Harlard's Avatar
 
Join Date: May 2007
Location: PDX
Default

I'm running one similar on my gate from this eBay seller: https://www.ebay.com/usr/wyntonmspeed

No problems so far.
Harlard is offline   Reply With Quote
Old 05-01-2020, 04:57 PM   #998
cwdodson88
Board Member
 
Join Date: Oct 2011
Location: The Dalles, Oregon
Default

TIP: when prepping to tig those on, hose the whole thing down with acetone, and blow it off, then dunk the ends and wipe it before welding. They're usually a lap joint for the tube OD you select and the ferrule that holds the braid down is right up to the end, and sometimes there are contaminants within the braiding that shows it ugly lil face when you hit it with heat.
__________________
Quote:
Originally Posted by mikep View Post
Build it, break it, build what broke stronger, lather, rinse, repeat.

The Build Thread
SVEA - PUSHROD TURBO!
cwdodson88 is offline   Reply With Quote
Old 05-01-2020, 06:35 PM   #999
Duder
Comes with a free Frogurt
 
Duder's Avatar
 
Join Date: Dec 2009
Location: Torrance, CA
Default

Quote:
Originally Posted by Harlard View Post
I'm running one similar on my gate from this eBay seller: https://www.ebay.com/usr/wyntonmspeed

No problems so far.
Wow, I'm surprised at the price. Even lower than the proverbial TB $14.99. Wonder if there's any appreciable difference in quality to the $30 - $60 stuff.

https://www.ebay.com/itm/2-5-Braided...8AAOSw7NNT5VQN
Duder is offline   Reply With Quote
Old 05-04-2020, 02:30 PM   #1000
Alex Buchka
8 cylinders
 
Alex Buchka's Avatar
 
Join Date: Apr 2004
Location: Los Angeles
Default

Quote:
Originally Posted by Tfrasca View Post
Thanks, Alex. That's a good, cheap solution to the purge problem. Aside from not having a set up, I was also thinking that I'd be wasting a ton of gas if I purged this. To keep things from getting too hot and warping, I was welding maybe 1/2" at a time, then cooling it with compressed air. I figured I'd be losing all my purge gas for every single weld/cooling cycle. Maybe I was being too paranoid about heat build up?
I usually purge a tube for 3-5 minutes at 15cfh or so, then turn the purge flow down to 5cfh, this saves quite a bit of gas. Those purge plugs you can buy are nice but I've built many headers with just aluminum foil to cap the ends. A large gas lens helps immensely as well, I use a 1" diameter cup and lens from an automation torch that I hacked together but the SPW or furick stuff is also very good.
Once you have your sweet spot for welding current just weld short sections and jump around to different joints on the tube. This will keep the interpass temps reasonable so you don't have to wait too long. You'll notice pretty quickly if things are getting too toasty. If I'm in a hurry I will purge several runners simultaneously so I can keep skipping around to different tubes while others cool down.

Quote:
Originally Posted by RvolvoR View Post
I've seen the swedish dudes use it a few times, but it looks really cheesy and kind of half assed.
Agreed, those spiral wound tube things both look and are ****ty.

Quote:
Originally Posted by Stiggy Pop View Post
considering the fact that these bellows crack with some frequency I can't imagine that length of corrugated tube would survive long. Not a direct complaint on the Vibrant piece, I think it's just the nature of the beast. Tate and I have both replaced them on our headers.
Unsupported bellows are finicky. They really shouldn't be flexed at all on installation to maximize life and should only be strained in one direction if possible. It looks like vibrant sells lined bellows and it's very important to make sure the liner is oriented correctly with regard to the gas flow direction. Overbraided bellows are usually more resilient to cracking since the braid effectively works as a travel limiter and a friction damper against the convolutions which makes the bellows less likely to fatigue crack.
Alex Buchka is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -4. The time now is 02:09 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.