[Oo=[][]=oO]

To determine the UTS ultimate tensile strength of the tubing, and strength of the weld, destructive testing was done in the form of bend test, break test and hardness or embrittlement test to the material after testing. It passed with flying colours. The material of the clamped tube failed, and the base flange that was held tightly in a Hydro Vise, gave way and deformed the base flange as you can verify in the pics, but the welds did not fail.

[Oo=[][]=oO]

The only visible anomaly that was present is shown here on the bottom left of the attached pic. You can see a slight deformation where the mandrel bender clamp actually dented the tubing. It is superficial at best, and it was only present on one of the four sets of headers.

[Oo=[][]=oO]

This picture clearly shows the visual quality of the TIG welds. Also, the 12 mm thick stainless steel 304 flange plate is clean and free of "breakout" found on parts that have been processed in a "compound die". You can see there is no "rounding" or "rolling" of the shear edges of the flanges. This is a result of a fine blanking process that utilizes a punch and die with minimum clearance, with a "counter punch" which acts as a pressure plate, guide, and ejector to keep the part flat. As a final process, the flanges are machined on an orbital grinder that ensures the mating surfaces are flat and parallel, resulting in much better mating surface for welding as well as bolting it up to the head of your N-52. If it isn't flat, you don't get even torque and pressure across the entire surface which leads to leaks, poor alignment and difficulty in fitment.

Incidentally, the flange sets were very consistent on the hole positions and diameters, with the largest variation on any part measuring 0.27mm, or less than 1/64th of an inch!

[Oo=[][]=oO]

This is a picture from the outlet flange. Those of you who have any experience in porting and polishing will appreciate that the primary tubing extends through the flange to ensure the free flow of exhaust gasses. If the primary tube was "surface welded" to the flush face of the outlet flange, it could never be lined up to ensure the transition between both parts was smooth, with no weld slag or porosity. They do the same thing on the inlet side as well. All six plenum openings have the secondary tubes protruding into the head for perfect line up and engagement.

[Oo=[][]=oO]

This is a picture of the secondary tube cluster before the collector. I defy anyone to look at those bends and find any imperfection. One guy at the shop said it was "instrument worthy", and I can see a lot of similarities between a tuba or French horn and a set of headers. The radius transitions are incredibly smooth, no tool marks, no excessive thinning or stretching of the material, and most importantly......they ARE ALL EQUAL LENGTH.

[Oo=[][]=oO]

The picture following is one of a series I will post to explain how they eliminated the problems associated with creating "compound bend" in a short length of tubing.

Some of those problems arise because there are tight bends needed to fit into a desired shape. The first bend is easy to do, however the second (compound) bend is too close to the first bend and there is not sufficient straight tube for the mandrel clamps to hold the part being subject to the bending forces. Other companies (don't take offense Stig) but weld two similar sized tubes together with a series of tack and stitch welds. Warping and mismatch are common problems, and either of them kills the flow dynamics and increases back pressure.

These guys creat a positive ferrule fitting by swaging (expending the diameter of one tube) so the other tube can fit tightly inside the expanded tube. Now you have positive locating, so no diametrical mismatch, and the weld is only on the outside diameter of the tube and no weld or slag is present on the inside of the tube, resulting in better flow.

I won't know until we test the tubes on the dyno, but I worry that the joints which are sewage sad have more mass of material, so it makes sense they will heat up and cool at varying rates. I will minimize this in the race car by coating and wrapping the tubes with insul-tape.

[Oo=[][]=oO]

For all the guys who PM'd me, thanks, I enjoy doing this stuff!

I didn't buy the cheapest tubes fro ODP Auto Parts, I found the actual factory that private labels headers for other retailers. They are called;
Hangzhou Auto Autoparts co. Ltd.


Keep in mind they come a minimum of two in a box, so you must buy two or four sets to benefit.

The quoted price in USD is FOB mainland China.

The shipping is extra and they use International Economy Freight. Opt for air freight and the stuff gets "silk glove" treatment and is very nicely packed.

So, when you pay for air freight, brokerage, duty, taxes and HST up here, all in American dollars you end up about $450.00CDN. ($418.00USD)

The weakest thing thus far have been the SS HHCS. I've opted to buy Unbrako SS SHCS. THE SOCKET HEAD CAP SCREWS ALLOW YOU TO USE A BALL-LOK HEX KEY AND IT IS MUCH EASIER TO INSTALL THAN GETTING AN OPEN END WRENCH ON THE CHINESE HEX HEAD CAP SCREWS.

TomB

[Route 16]

Originally Posted by Oo=[][]=oO

For all the guys who PM'd me, thanks, I enjoy doing this stuff!

I didn't buy the cheapest tubes fro ODP Auto Parts, I found the actual factory that private labels headers for other retailers. They are called;
Hangzhou Auto Autoparts co. Ltd.


Keep in mind they come a minimum of two in a box, so you must buy two or four sets to benefit.

The quoted price in USD is FOB mainland China.

The shipping is extra and they use International Economy Freight. Opt for air freight and the stuff gets "silk glove" treatment and is very nicely packed.

So, when you pay for air freight, brokerage, duty, taxes and HST up here, all in American dollars you end up about $450.00CDN. ($418.00USD)

The weakest thing thus far have been the SS HHCS. I've opted to buy Unbrako SS SHCS. THE SOCKET HEAD CAP SCREWS ALLOW YOU TO USE A BALL-LOK HEX KEY AND IT IS MUCH EASIER TO INSTALL THAN GETTING AN OPEN END WRENCH ON THE CHINESE HEX HEAD CAP SCREWS.

TomB

$418 shipped is for one header or 2?

[MarkkyyMan]

Originally Posted by Oo=[][]=oO

To determine the UTS ultimate tensile strength of the tubing, and strength of the weld, destructive testing was done in the form of bend test, break test and hardness or embrittlement test to the material after testing. It passed with flying colours. The material of the clamped tube failed, and the base flange that was held tightly in a Hydro Vise, gave way and deformed the base flange as you can verify in the pics, but the welds did not fail.

Data sets for these tests?

What type of hardness testing?(Brinell? Rockwell?)

Typically it isn't the welds themselves that fail. The expansion of grain boundaries around the welded area weaken the material, making them almost like stress concentrations.

[Mike.]

anyone want to go halves with me...pending a dyno?

[Tim07e90]

Originally Posted by Emozoo

anyone want to go halves with me...pending a dyno?

Possibly me!

[SCMalum]

Originally Posted by Emozoo

anyone want to go halves with me...pending a dyno?

I'll go in halfsies, pending dyno obviously

[TheSt|G]

It's a little hard to tell as the photos are blurry, but it looks like those TIG welds are mostly cosmetic on top of MIG welds, which is pretty typical for the China header market.

Can we get some in focus shots of the collectors at all angles and the flanges on a level surface(as well as where that puts the pipe ends)?

[Taskmaster]

Originally Posted by TheSt|G

It's a little hard to tell as the photos are blurry, but it looks like those TIG welds are mostly cosmetic on top of MIG welds, which is pretty typical for the China header market.

Can we get some in focus shots of the collectors at all angles and the flanges on a level surface(as well as where that puts the pipe ends)?

I'm sure the collector looks like trash - they always do. But if these fit, they will represent a huge bang for your buck. I just wish SS were more affordable so more people could appreciate the gains AND craftsmanship.

[TheSt|G]

Originally Posted by TheAxiom

I'm sure the collector looks like trash - they always do. But if these fit, they will potentially represent a huge bang for your buck. I just wish SS were more affordable so more people could appreciate the gains AND craftsmanship.

Like the CPI stepped headers, definitely no assurance of power for having the right "look".

The difference in my outlook from most of the forum is that the replacement part I am using has to be of equal or better quality than the original it is replacing. BMW sets the bar pretty high in general, and I'm yet to see any parts from China that I would consider to be up to spec. Your priorities may vary.

[MarkkyyMan]

You really have it out for CPI headers huh?

[Taskmaster]

Originally Posted by MarkkyyMan

You really have it out for CPI headers huh?

Why not?

[b-man]

I don't even understand how he got only 4. When you try to buy 304, minimum order is 20. You can only buy 201 if you're buying less than 20

[Taskmaster]

Originally Posted by b-man

I don't even understand how he got only 4. When you try to buy 304, minimum order is 20. You can only buy 201 if you're buying less than 20

Depends on the seller, and you can request just one. If all goes well, you could ask a vendor to organize a batch sale for everyone who is interested.

[Mike.]

Originally Posted by b-man

I don't even understand how he got only 4. When you try to buy 304, minimum order is 20. You can only buy 201 if you're buying less than 20

believe my son.

imagine this was just a huge marketing ploy by the company, so we would buy their headers

let me get back on topic..


Looking forward to the results, since the headers were fitted on the cars this weekend!

[b-man]

Originally Posted by TheAxiom

Depends on the seller, and you can request just one. If all goes well, you could ask a vendor to organize a batch sale for everyone who is interested.

I get that. I contacted the same seller, and he won't sell 304 unless you order 20. It was $197 including shipping for 201.

I just want to get one and see the results myself

[b-man]

Originally Posted by Emozoo

believe my son.

imagine this was just a huge marketing ploy by the company, so we would buy their headers

let me get back on topic..


Looking forward to the results, since the headers were fitted on the cars this weekend!

lol. Wouldn't be the first time!