Found huge crack in crossover pipe-losing boost!!!

What is the crossover pipe made of ? I wonder if my fluxcore welder can handle it??

The crack is near the turbo flange. How to make a new crossover with turbo flange?????

Thanks
Jeff

If your's is anything like the stock pipes they weld very nicely. Don't know about flux core, I use regular mig.

ttt for the solar powered workers

If you are running a turbo and if you installed a commercial kit, the crossover pipe should be made of stainless steel. You've got high heat levels in that pipe and soft mild steel doesn't hold up well. You can use mild steel everywhere else in the exhaust and it will provide some life but the croosover pipe is a demanding application. If you don't have SS there right now, you'll be fixing the leak again soon.

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87GT 3.4 Turbo- 0-60 5.2 seconds
2006 3800SC Series III swap in progress
Engine Controls, PCM goodies,
re-programming & odd electronics stuff
" I'M ON THE LOOSE WITHOUT THE JUICE "

I didn't build it so I really do not know.

Going to have to remove the cross over and either have it welded or rebuilt.
Anybody know who fabricated these things with a turbo flange?

Jeff

Anyone know if it would help to send the crossover out for ceramic coating after having it welded before installing?

Also---does anyone know for certain if the stock crossover was stainless or not??

The stock crossover is more than likely 409 stainless steel. This type of stainless will rust mildly and is magnetic. It has about 12% chromium and no nickel. The stuff we typically think of as stainless like type 304 has 18% chromium and 8% nickel. It will not rust and is non magnetic.

Type 409 stainless can be prone to cracking. In industrial applications it would be welded with a lot of preheat and then post weld heat treated at fairly high temperature (>1000 'F) to anneal the metal and restore ductility.

304 and 316 stainless would be less prone to cracking. Mild steel is less prone to cracking but will oxidize rapidly at exhaust temperaures. Ceramic coated mild steel might be your answer but I have no experience in a turbo application. I do know a guy with ceramic coated headers on an SBC for several years and they have held up amazingly well.

I have never heard of a crossover rusting out, so yes, id put money on what he ^^^^ said.

We spent several hours yesterday trying to remove the crossover. Got to love exhaust bolts. Unbolted the turbo flange and the four bolts that hold the crossover to the manifolds but I cannot get the pipe out yet. It is so tight in there--my arms are all bruised and cut this morning.
At the end of my downpipe where a stock 2.8 would have a catalytic converter is where my wastegate valve is. The wastegate is welded to the pipe and will not clear the a/c lines and the slave cylinder to remove the pipe so I have to move the slave cylinder today and hopefully will be able to get the crossover out. The crack has turned into--pipe broken 95% of the way through.

[This message has been edited by jeffndebrus (edited 06-10-2007).]

Mig Weld It ..Just Dont Go Nuts On it ..

If You Have The Cash For Sure Get It Coated Afterwards

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"This car is so good looking its almost indecent. - AutoWeek on the new 1986 GT"

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Bizarre to say the least!

That is not what I thaught that I would see you pull out. That piece is a factory crossover rather oddly and obviously poorly modified to feed a turbo.

By the looks of it, Replace it completly with something custom that at least has two dedicated feeds to the flange, and a proper waste gate with dump tube. I do suggest cutting the two flare and bracket ends off and starting from there. Turbo flanges are easy to come by on ebay, as well as wastegates if you don't reuse the one off this set up. Some various mandrel bends and a fairly skilled welder, stainless mig wire and a bottle of straight argon gas should do the trick. After that, you may want to create some brackets to help support the weight of the turbo. Obviously you know what happens when the crossover itself supports the weight of the turbo on its own.

Have to say, that is the wierdest crossover I have ever seen, by far. Some design changes can yield a heck of an improvement in performance and durability.

Wow.. pretty bad way to convert the factory Y pipe into a turbo feed. Is that a wastegate where the exhaust normally hooks up?
You should definitely have a shop do a proper Y-pipe for you. It won't be expensive and you'll gain some power. It will also look better.

Yes that is my wastegate and it is vacuum operated by a knob under the dash. It is wet because it has PB Blaster all over it. I've written to Ryan at Sinister Performance to see if He can fab me up a new one. We will see. I also do not have a blow off valve in the intake which might be something to have done as well.
The position of the turbo really cannot change without rebuilding the lower end of the exhaust which I would rather not do. What is wrong with the position of the wastegate? It dumps down by the front of the cradle.

Looks like you could just JB weld that together and it'd be okay!


As it's probably gonna cost an arm and a leg and another arm to have a new one made, I think I'd go for stainless, have it coated, and never have to look at again.

If you're going to use a MIG (or flux core) welder you should flood the pipe with shielding gas to prevent slag from forming on the inside of the pipe. Pieces of slag can break off and destroy the turbo.

Welding thin stainless tubing with a MIG even with the proper tri-mix gas and back purging is no picnic. Hesitate for a nano second and you blow a hole through. TIG is ten times easier for this kind of welding. My recommendation would be to tack it together with a MIG and take it to a pro to have it TIG welded.

If you have a good MIG welder with dials for variable wire speed and heat setting you can weld the stainless without much of a problem. Your biggest problem will be relocating the turbo in its proper position so that you can fabricate a brace to hold it in place so that a replacement crossover can be made for it. As some have already mentioned, your crossover pipe design probably robbed the engine of quite a bit of potential and as I mentioned to you already its design probably caused a hot spot to develope at the brake point. A pipe from each manifold flowing right into the flange will make a big difference instead of the 90 degree exit turn the exhaust had to make before.

The best stainless I have found so far for this application has been OE stainless header manifolds from the salvage yard for 3 reasons; price, several degrees of mandrel bends in one manifold to cut from, and the general has a good habit of using 14 gauge tubing and a bonus would be the stainless expansion bellows that can be found on the crossover used on a large number of GM V6s, that will help limit your exhaust tubing stresses to heat if it is installed in the crossover, otherwise there is a risk of future cracking and bolt sheering all of which I have experienced before taking the above approach myself.

Paint it with good heat resistant paint and you'll have little to no problem with corrosion, the above materials and method gave me the best and most dependable service of all of my turbo build ups. If you use mild steel it has to be 14 gauge and probably non heat wrapped but it will work fine as long as expansion stress is kept to a minimum.

Get yourself a cheap MIG or rent one along with a saws-all and some mandrel bent tubing and tack it up yourself or even complete it because as someone has already mentioned unless you have a Halo beaming over your head it will probably cost you considerably to have someone else do it for you.

[This message has been edited by Joseph Upson (edited 06-12-2007).]

quote Originally posted by Joseph Upson: If you have a good MIG welder with dials for variable wire speed and heat setting you can weld the stainless without much of a problem.

I must be missing something. I've got:

-a good MIG welder,
-the recommended tri-mix gas (helium/argon/CO2)
-0.023" 308 stainless wire
-a fair amount of brazing, gas welding and carbon steel MIG experience

I've made several butt welds on 16 gauge stainless tubing and in my opinion it's a real challenge. The last system I put together, I tacked it and took it over to a friend's and TIG'd it.

I've had stuff TIG'd here by a weld shop for $20 a weld if it's fit up and tacked first.

[This message has been edited by sanderson (edited 06-12-2007).]

quote Originally posted by jeffndebrus: What is wrong with the position of the wastegate? It dumps down by the front of the cradle.

It is heavily biased toward bleeding off exhaust gases from the FRONT cylinder bank only. It should be located so that it bypasses the turbo off both banks by about the same amount.

quote Originally posted by sanderson: I must be missing something. I've got: -a good MIG welder, -the recommended tri-mix gas (helium/argon/CO2) -0.023" 308 stainless wire -a fair amount of brazing, gas welding and carbon steel MIG experience I've made several butt welds on 16 gauge stainless tubing and in my opinion it's a real challenge. The last system I put together, I tacked it and took it over to a friend's and TIG'd it. I've had stuff TIG'd here by a weld shop for $20 a weld if it's fit up and tacked first.

Sorry, but I'm not having that kind of headache, you said good MIG welder, mine has a 0-10 dial for wire speed and heat setting and a switch for 90 amps and 100 or so amps, if you don't have that many settings on your unit maybe that's why I'm not having as difficult a time. Then again I've delt with burn through during general use a number of times using mild 18 gauge steel so maybe I've adapted to dealing with the threat and it just doesn't seem like a problem to me.

It looks like the collector box is difficult so I am thinlink of taking a premade piece like this and cutting off the head flange--cutting off and blocking welding shut two of the four pipes and welding tubing to the two remaining pipes to meet my exhaust manifolds. This part also has the wastegate flange right there at the collector box. I think it will heat that area up more but---
What do ya think?

quote Originally posted by jeffndebrus: It looks like the collector box is difficult so I am thinlink of taking a premade piece like this and cutting off the head flange--cutting off and blocking welding shut two of the four pipes and welding tubing to the two remaining pipes to meet my exhaust manifolds. This part also has the wastegate flange right there at the collector box. I think it will heat that area up more but--- What do ya think?

Don't do it, start from scratch with a new flange and go from there. They are cheap and welding on a tubing for a wastegate is easy once the manifold to flange tubing is welded up. That stuff is all over Ebay for small change.

The problem is that I only have a fluxcore welder and have only welded a few lawnmower deck cracks.
No experience + a limited welder = a probable disaster

That's why I was thinking of the above method---but-----

quote Originally posted by jeffndebrus: The problem is that I only have a fluxcore welder and have only welded a few lawnmower deck cracks. No experience + a limited welder = a probable disaster That's why I was thinking of the above method---but-----

MIG welders are pretty cheap now days and is one of the preferred methods of doing it, however, if you can practice with what you have just until you do a pretty good tack weld to hold everything in the necessary location, you could easily take it somewhere else and have the welds finished off pretty cheap. I suspect that header manifold costs well over $100, you can get small gasless MIGS for around $200 probably less and do a pretty good job of tack welding for starters with about 2 hrs worth of practice.

When I purchased my MIG welder I had no experience, just a plan to twin turbocharge my camaro, I read the instructions, tuned the wire speed to get the right phizzzz sound to the weld and that was it, I was welding my a.. off the same day. I compare the cost to pay someone else to do it to the cost of me buying the tools and being able to learn and do it myself repeatedly for every project that follows and if the prices are close enough I buy the tools. Next up is the plasma cutter so I can really do some custom stuff.

No harm intended to the fabricator, but as a beginner you can do a much better job than that thing called a cross over pipe you took off the car, it did you a favor by failing because it's a terrible piece of construction for a turbo feed.
You can do this, I have no doubts about it.

[This message has been edited by Joseph Upson (edited 06-17-2007).]

quote Originally posted by Joseph Upson: Sorry, but I'm not having that kind of headache, you said good MIG welder, mine has a 0-10 dial for wire speed and heat setting and a switch for 90 amps and 100 or so amps, if you don't have that many settings on your unit maybe that's why I'm not having as difficult a time. Then again I've delt with burn through during general use a number of times using mild 18 gauge steel so maybe I've adapted to dealing with the threat and it just doesn't seem like a problem to me.

I've got a Hobart 175 which has 4 voltage settings and infinite wire speed adjustability.

Are you welding the stainless with 308 stainless wire or carbon steel wire?

quote Originally posted by sanderson: I've got a Hobart 175 which has 4 voltage settings and infinite wire speed adjustability. Are you welding the stainless with 308 stainless wire or carbon steel wire?

I have a Century/Lincoln with two Amp settings 90/100, and two dials, one each for variable wire speed and variable power level to help better adjust for metal thickness. I have used the basic wire which is probably carbon steel for everything from cast iron to the OE stainless. I was told years ago that I would have to lay down a flux core bead on cast iron before gas welding, but after that mess I started gas welding directly to the cast iron because the Mig layed down such a hot penetrating bead it didn't make sense to go through all that trouble, plus the weld was cleaner. I have never had a weld break or crack and have made a total of about 5-6 different turbo setups including the one on my car currently that was subjected to a vicious impact a few months ago when I hit a cement median at about 50 mph and bounced on top of it with the driver side tires. The turbo is positioned directly behind me.

Had to down grade the quality of the picture in order to post it. This was my favorite and the one that taught me the lesson about the gauge of tubing that was sufficient, it was regular steel in 18 gauge, I had no idea I was doing all that work for nothing due to the thickness. I burned through one of the tubes in about 2 wks time. So now it's 16 ga stainless or better, or 14 ga steel between the turbo and the manifold. The plasma cutter will help me make much prettier configurations since I can cut with the precision in brings instead of a chop saw.

The expansion joint is crucial

[This message has been edited by Joseph Upson (edited 06-17-2007).]

quote Originally posted by Joseph Upson: I have a Century/Lincoln with two Amp settings 90/100, and two dials, one each for variable wire speed and variable power level to help better adjust for metal thickness. I have used the basic wire which is probably carbon steel for everything from cast iron to the OE stainless.

I'm surprised the carbon steel welds don't corrode out fast but I can't argue with your experience. Believe me stainless wire on stainless tubing is a whole new game with a MIG.

Joseph, I am wondering about the flange that you used---is it t3 or t4? square hole or round?

quote Originally posted by Joseph Upson: I have a Century/Lincoln with two Amp settings 90/100, and two dials, one each for variable wire speed and variable power level to help better adjust for metal thickness. I have used the basic wire which is probably carbon steel for everything from cast iron to the OE stainless. I was told years ago that I would have to lay down a flux core bead on cast iron before gas welding, but after that mess I started gas welding directly to the cast iron because the Mig layed down such a hot penetrating bead it didn't make sense to go through all that trouble, plus the weld was cleaner. I have never had a weld break or crack and have made a total of about 5-6 different turbo setups including the one on my car currently that was subjected to a vicious impact a few months ago when I hit a cement median at about 50 mph and bounced on top of it with the driver side tires. The turbo is positioned directly behind me. Had to down grade the quality of the picture in order to post it. This was my favorite and the one that taught me the lesson about the gauge of tubing that was sufficient, it was regular steel in 18 gauge, I had no idea I was doing all that work for nothing due to the thickness. I burned through one of the tubes in about 2 wks time. So now it's 16 ga stainless or better, or 14 ga steel between the turbo and the manifold. The plasma cutter will help me make much prettier configurations since I can cut with the precision in brings instead of a chop saw. The expansion joint is crucial

T3 square hole.

Can I weld a Y pipe to the flange and then extend the two legs of the Y out to the manifolds using an expansion joint on one side ???

quote Originally posted by jeffndebrus: Can I weld a Y pipe to the flange and then extend the two legs of the Y out to the manifolds using an expansion joint on one side ???

Absolutely, just try and do a good job of lining up the edges of the pipe. I have a hydraulic pipe expander also which makes it easy for me. Be sure to use reasonable diameter pipe at least 1 5/8 from the manifolds, if you use the GM expansion joint which you see in the picture along with a good portion of the OE crossover pipe it is joined to I believe that's 1 3/4". I beat on my last outfit for about 4 years before selling it and it never gave me a problem. That expansion joint takes a lot of stress of the system. Make sure you have a brace of some sort supporting the turbo even if it's just a rod to keep it from applying down force on the crossover because that is the greatest force it can be subject to considering the vehicle bouncing up and down continuously. You can weld directly to the rear exahust manifold if you want to eliminate one potential source of a leak.

I had so many problems with exhaust leaks when I first started turbocharging I modified front wheel drive cast iron manifolds to work because I new they could take the heat. I took two fronts manifolds and made a rear manifold by cutting off the ends and welding them on in opposite locations.

HMMMM

Looks like I am going to have to try and come up with something myself---at least the fabrication part.

I found a shop that will dyno tune but they have to have a bung for a wideband O2 sensor minimum 3 feet from turbo which I don't think I can do because my exhaust comes out of the turbo down the trunkwall splits into a Y and through resonator tips.
They charge $175hr with a two hr minimum and state it usually takes 2-3 hrs.

quote Originally posted by jeffndebrus: Looks like I am going to have to try and come up with something myself---at least the fabrication part. I found a shop that will dyno tune but they have to have a bung for a wideband O2 sensor minimum 3 feet from turbo which I don't think I can do because my exhaust comes out of the turbo down the trunkwall splits into a Y and through resonator tips. They charge $175hr with a two hr minimum and state it usually takes 2-3 hrs.

They should be able to give you an exact price in this instance because the design has to be planned before they do anything, the only exception being if something breaks. They charge so much per hour probably because OE exhaust systems are so darn good now they don't see as much buisness. Keep searching or do it yourself. I've built to many of these to buy that hourly rate. If I had the equipment a muffler shop has, once I laid all of my parts out I could have my pipe cut and welded up in no time. That's a very high hourly rate in my opinion. For what you will pay them to do it you can buy that MIG welder that was mentioned and enough supplies to practice and do this yourself to your satisfaction. It's up to you. They are not doing it for the reward they are doing it for the money and the sooner they finish the sooner they can move on to the next car so unless you know who you are dealing with and the quality of their work it's possible you might not be pleased with the end result. I know from the experience of paying a shop to install lift bars on my camaro, and I'm not kidding, I could have done a better job welding with the little experience I had at the time and a patch over one eye compared to what that nit-wit did. He dobbed the welds which looked like a beginners very first weld, and he installed the bars at the wrong angle which ruined them because they had to be torched off.

Time to make your decision and get it done.

I highly recommend making your own turbo manifold as I did. I used the Fiero ends where they connect to the manifolds and welded them to "Weld Els". Weld Els are thick steel short radius elbows used for welding up gas mains and gas supply lines by commercial contractors. I bought them at a pipe supply company. I welded them to a T3 flange I bought from Jegs. I too have a 110 volt Mig welder but use gas. The flux core wire produces the ugliest welds IMHO. If your Mig has the capability to use a bottle, I highly recommend buying one. Once the initial $75 or so cost of the bottle is out of the way, then you only have to worry about refilling it for $15-25 depending on what you use. I use pure argon as I weld aluminum too. It is more expensive than CO2, CO2/argon, or tri-mix.

I have not used an expansion joint but wish I did. I have already had to reinforce the crossover with 4 braces (had 1 originally) to keep the crossover from moving with normal expansion. My next one will have one.

crossover:


weld el(bow):


Summit racing flex pipe:


Sure is allot of room when you switch to the 7730 and use the 3.4L DIS.......

[This message has been edited by Hudini (edited 06-22-2007).]

Yes, thanks I found an article-----
http://sdsefi.com/techheader.htm
I also found out my wife works with a retired Navy SEAL who had achieved Master Navy welder at one time and he said he would weld up anything I need---whahoooooooooooooooooo
Now I just have to collect the parts and fabricate how it should look and he can go by a spare stock crossover I have to make sure my muncie shift cables wont get in the way.

Ummm? the prices I quoted before were for Dyno tuning not exhaust fabricating? Thanks

quote Originally posted by Hudini: I highly recommend making your own turbo manifold as I did. I used the Fiero ends where they connect to the manifolds and welded them to "Weld Els". Weld Els are thick steel short radius elbows used for welding up gas mains and gas supply lines by commercial contractors. I bought them at a pipe supply company. I welded them to a T3 flange I bought from Jegs. I too have a 110 volt Mig welder but use gas. The flux core wire produces the ugliest welds IMHO. If your Mig has the capability to use a bottle, I highly recommend buying one. Once the initial $75 or so cost of the bottle is out of the way, then you only have to worry about refilling it for $15-25 depending on what you use. I use pure argon as I weld aluminum too. It is more expensive than CO2, CO2/argon, or tri-mix. I have not used an expansion joint but wish I did. I have already had to reinforce the crossover with 4 braces (had 1 originally) to keep the crossover from moving with normal expansion. My next one will have one. crossover: weld el(bow): Summit racing flex pipe: Sure is allot of room when you switch to the 7730 and use the 3.4L DIS.......

[This message has been edited by jeffndebrus (edited 06-23-2007).]

So, other than asthetics---would there be an advantage to having stainless tubing over black iron weld els???