Hay JEFF, Like I Said, It's Always Something
 

Well, I pretty much just got done installing a CJM Stage 2 Fuel System with DW300 Pump and did a bunch of other stuff while I had it apart.

So, I've been working on the Tune the past few days and last night on a WOT Run to Redline when the exhaust sound changed. I freaked out, after listening some more it sounded like I blow out an exhaust gasket and putted it home.

Today, I found the Passenger side Header was cracked at the collector flange. After removing the Header I see it's cracked about 80% of the circumference. It's also cracking at the other end of that same piece where the tubes meet the collector.

After further inspection it looks to me as if the collector tubing is different material than the the rest of the header as this piece only has turned black with no shine, and different than the Drivers side.

The Drivers side (installed) still has shine to the collector like the rest of the Header. This Header Looks Fine, No cracks. All looks like same material. Hard to see in the pic.

These Headers are AlphaWearks Headers.

Opinions of Pro's.......????

sure doesnt look like the same metal to me man.

And id bet thats your issue t be honest. im sure someone else who has done the same will chime in, but thats MY first idea for sure. very very hot area of the world of your exhaust...

Check it with a magnet. If it is 300 series stainless it would not be magnetic.

I haven't heard someone talk about Alphawerks/Nexus in years. Good luck OP.

the difference in color could be because the exhaust gas was getting all over it from the crack

That crack will definately cause that side to get super hot and discolor way different. I dont think you can saw its different metal from just the look.

too bad you dont have EGTs. I wonder if your passenger side has been running way hotter.

the tubing has almost None, but the flanges have a ton....

Check out there Add

holy schnikes! :eek:

That's a bummer Tim!

I would talk to the company about that. I've had these cheap JVT headers in for 3 years now of rain, snow, crappy weather and all the heat from my built engine and they are holding strong. It shouldn't have cracked like that.

I hope they warranty them and get you back on the road.

On a brighter note, how do you like that stage 2 fuel system??

Company is nowhere to be found.......I have a Local guys Tig welding it up....

I like the fuel system a lot, still Tuning......... Closed Loop was a Breeze to Tune and ALL of the Drivability Issues Gone, Transition into Decel, and Surging, All Gone... Boost is also easer to Tune, just need to Finish up the Upper Boost Levels, Then I'll Post up the Numbers.....

that's good to hear.

i think you'll be the first 350z in the 10's with such little power.

its pretty common for headers and exhausts to use mild steel flanges and stainless pipe.

the first thing i would look at with a crack in the header like that, is mounting and alignment. the engine moves, of course, and exhaust piping expands, and the exhaust needs to have quite a bit of play to allow engine movement and heat expansion.

make sure your exhaust is not mounted too solid to the chassis. Make sure the motor mounts are in good condition. make sure the exhaust lines up well enough naturally so that there isnt a ton of preload on it when you snug it up... all the preload can absorb a lot of the play the system would have had.

flex joints on your test pipes would help if you dont already have some.

an interesting side note that is somewhat on topic... i was surprised to learn how much exhaust piping will naturally expand when hot. i didnt really notice it until several years ago when i was working on lots of vipers. Most of the exhausts for that car use slip joints at the side pipes. You have to align the tips in their rotation and position forward/back by installing/removing the side skirts several times. If the exhaust tip was going to have 3/4 inch space around it in the opening of the side sill, I would have to line it up to be about 1/4" from touching in the front. Then when it warmed up the piping would expand and center the tip.

Long tube time

All Fixed.......

The guy did a nice job, tig welded it inside and out, then put a doubler sleve over, that was longer and tied into the main tubes..

looks good!