Speed Daddy Headers and Smog

**bignose94015** · 01-10-2014

Last question of the night. I want to run mid to low 13's. Woulld necking down the SD down pipe to the Stock cat be to much of a restriction?

Thanks,

Eric

**Scottydoggs** · 01-10-2014

if you were to get a 3 inch dp, its gonna get reduced to the 2.25 pipe when it bolts to the cat back. its fine.

**bignose94015** · 01-10-2014

Ah, So the SD kit does not come with a DP. I will need to order one from ZZP.

**Scottydoggs** · 01-10-2014

ALL HEADERS COME WITH A DOWN PIPE.

its your choice with most brands if you want a 2.5 or 3 inch DP, catted or no cat with your header order.

**Timing** · 01-10-2014

Lets make this easy. Sd headers come with a straight downpipe no cat that bolts to the stock resonator assembly.

See the 3 pipes on the bottom? The straight pipe, the flanged pipe and the one with the bend in it? Those are 3 inch and are the downpipe. They clamp together and clamp from the flex on the rear header to the flange on the res assembly.
Now the straight part of this can be replaced with a 3 inch cat. Your best bet is to get it welded in. Just go to your local auto parts store and ask them for a 3 inch cat that would be cal compliant.