poodlemuffer

i just recently bought my first subaru , a shiny blue 2002 wrx sti prodrive. i really dont have much knowledge of subarus but thought i would try somthing new.

i understand the prodrive package adds a 100 cell sports cat , which i think is on the downpipe ?. how restrictive is the 100 cell ? and would swapping to a straight through 3" pipe make a great deal of difference . performance and noise levels ??.

stonejedi

iTrader: (51)

to be honest the prodrive cat is very good,good power and mot friendly but is still a partial restriction but not much.fitting a bigger down pipe in conjunction with a complete 3 inch pipe is the best way to do it.try not to mismatch sizes like 2.5 mixed up with 3 inch piping if your going to change just get a complete 3 inch system from the downpipe to the back box job done.

Billet

iTrader: (60)

most people say it is not majorly restrictive until about 360 bhp and when running normal power you only loose 3 or 4 bhp. i guess the decatted 3 inch pipe would be slightly louder and you would hear turbo whistle etc more as the exhaust gases would be freer flowing.

MikeWood

If it was a 3" 100 cell cat then it would be restrictive but as it's 5" (4x the surface area of the std 2.5" dia pipe!) it's not restrictive at all.