Hey guys,

I'm working on building a set of headers for my project S10. Anyways, I took an old set of 1 5/8" headers and cut all the tubes off so basically I have the flanges and a little bit of original tubing left. Here's the question... Is it better to butt the tubes against each other and simply weld them together that way, or is it better to flare one end slightly so it will slip over the next piece and weld them together that way? Oh, I should probably mention that they will be supporting twin T04B turbos, so some strength will be required here.

 

I think it'd be tough to match something up with tubes that are already cut. Especially if those cuts are on angled and radiused sections of the tubing. I would much prefer swedging the primaries and then slip/weld the other pieces. I think there'd be a bit less fabrication time involved and it should be very strong if the weld integrity is there.

-Mindgame

 

a good, quality butt weld wouldbe my choice. should look cleaner too, IMO.

 

Ok, so I've got one vote for each. I'm thinking the slip fit will be easier to fabricate and that it would be much stronger as well. Hey MG, know where I can find a flaring tool for pipe? Also, I know I want a good, thick flange, but what size wall tubing should I use? Keep in mind, these will be turbo headers.

 

Good swedgers are probably a bit pricey. Check with an exhaust shop, they might can help you out.

Good luck.

-Mindgame

 

Don't know what swedgers are. How about an exhaust pipe expansion tool?

 

How about that.... sounds good... ask them for that.

-Mindgame

 

Turbo headers need to be strong as you said to support the turbo, but you also want to retain as much heat as you can. I vote for slipover tube joints with heavy-wall tubing. Something like .083 wall if you can get it in bends. Even thicker would be better. The thin section stubs on your original headers will be the weak points. Try to get the heavier tubing all the way to the head flange.

FWIW, keep the headers short. Long equal length headers dumping into turbos give up lots of heat and energy before they reach the turbo, which is counterproductive. I don't buy the "off-boost" exhaust scavenging argument. If you are off boost you are probably "off-throttle" also, and when you go WOT to get boost, there is considerable back pressure, so the gasses don't see the same tuning conditions as a non-turbo engine. If they do, the extra cooling from the longer tubes is worse than the slight scavenging effect. Turbos need HEAT to work.

My $.02

 

Very informative OldSS, I appreciate it. I have already contacted a few companies about some 1 5/8" mandrel u bends in 14 gauge mild steel. I see your point about the little bit of tube left on the flanges being the weak point. I'm trying to find some decent flanges that aren't more expensive than a new set of headers. I hope I can find some. One of the companies I was looking at offers CNC cut mild steel flanges up to 1/2" thick that I would like to use, I'm just waiting for them to call me back.

For the design, I am trying to come up and out so the turbos will hang about 3 inches from the accessories. I figure that will clear all the brake lines and not heat up the powersteering pump and alternator.

 

Here's one I found in a couple seconds on ebay. Looks like what you need and it's ten bucks.

http://cgi.ebay.com/ebaymotors/ws/eB...spagename=WDVW

 

Thanks nosfed, I saw those earlier as well, but 1/4" seems a little thin considering the kind of heat and weight they will be subjected to.