Pre-cat delete?

[ho bag]

So i was thinking of getting a header and loosing the pre-cat but a few things came to mind...

Going to a header will perty much loose some bottom end in return for high end however since going with a header ditches the precat it gains back some of the lost bottom end....

No what about building a pre-cat eliminator pipe? Would hardly be any work at all to make.

Does anyone think that loosing the pre-cat would boost performance across the board? probally onyl be 1-5hp but thats better then a kick in the ass for something that cost less then $50 to make on my own.

 

[NCZ13]

i dont think you would see a very big gain... it would be similiar to tapping out the cats. the piping is still small and restrictive.

 

[ho bag]

i dont think you would see a very big gain... it would be similiar to tapping out the cats. the piping is still small and restrictive.

Beating out the cats causes issues due to the difference in diameter of piping and the loss of velocity due to this.

Creating a eliminator section would remove the restriction to the exhaust flow without affecting the velocity in a negative way.

 

[NCZ13]

so you want a pipe that would go from the shorty (runners) of the header to the midpipe?

thats sorta downpipish...

 

[ho bag]

Basically yes.

Trace the header flange onto some steel. Cut it out, grab some mandrel bends and weld up the flange and get everything lined up and welded.

On every turbo car i have owned i have seen a large increase from removing the pre-cat all over the power band. So i would imagine it would not be hard to see a 5hp gain on the fs-de from this.

No mater how i look at it i see it as an exhaust restriction that can be removed.