Started MKIII swap headers

[cjsupra90]

Nice work.

Flex joints should separate the engine/headers from the secondary exhaust system. They should NOT take weight or load. The secondary system should be well supported.

So basically, the best spot would probably be just after the header to exhaust flanges?

 

[milisakeracing]

So basically, the best spot would probably be just after the header to exhaust flanges?

Or maybe a separate piece to bolt into place, making easier to replace if it gets damaged.

 

[Peewee]

Can someone explain to me why flexjoints are needed?

I've never had one on any exhaust I've had made.

 

[spf_lexus]

I guess it could be a big deal on a little honda d16 where the motor mounts allow the engine to rodeo and move the exhaust everywhere.

 

[cjsupra90]

Can someone explain to me why flexjoints are needed?

I've never had one on any exhaust I've had made.

Andrew, in longtudinally mounted engines, they are less needed as the motor twists from left to right. this does put a small amount of twisting force on the exhaust along with a tad bit of lifting force on the left side exhaust which usually is not a problem but if the entire system including headers is made of stainless steel, the flex unit does help in lessening to likelyhood of cracks forming due to extremely limited movement if no flex unit is there. Being that my entire exhaust and headers will be stainless, its extra security that cracking is not going to be an issue for the most part.

This also applies to the thermal expansion aspect too inherant to stainless.

 

[cribbj]

On turbo'd engines they are there to ensure no undo stress is put on the exhaust flange of the turbo.

 

[cjsupra90]

On turbo'd engines they are there to ensure no undo stress is put on the exhaust flange of the turbo.

that and also, turbo down pipes tend to experiance even greater amounts of thermal expansion and contraction (especially in stainless DP's) at a faster rate too due to the quike changes in EGT's that tend to be associated with turbo engines.

 

[Peewee]

Fair enough, I've just never seen one on any RWD of mine or any of my mates, and none of us have had any issues. Including one guy with both turbo and stainless. Admittedly his manifold was still the stock cast jobbie.

 

[cjsupra90]

well one thing that sort of does the same thing just your dont really notice it to much cause it blends right in is a ball socket. most OEM stuff uses ball sockets cause they are cheaper.

I most likely dont need the flex units, but probably will put them it just for the added security...

 

[cjsupra90]

Added more info and photos on the progress of the header project
here: http://lextreme.com/forums/showthread.php?t=10583&page=2