Most power WITH cats...force fed or n/a
Most power WITH cats...force fed or n/a So...I'm kinda in the middle of my turbo'd 5.3 build, and am at the point of trying to plan the "emission legal" exhaust. Obviously, I have to maintain the use of a cat(s), but have been thinking some really disturbing (at least to me) thoughts in the pursuit of the goal of max power and DEQ compliance.
I've been looking at everything from a 5" dump splitting into dual 4"cats while somehow trying to run it all out the back over the axle (oval pipe ??)....to running a 5" dump into a 4" cat into 4" single pipe all the way back.......and every "conceivable" option in between. I'm hoping to build a system that will work with the 5.3 for now, yet support 750-850rwhp that I'm shooting for with my ffi stroker engine once it's done.
What I'm wondering is: who here is making in excess of 500rwhp WITH the use of cats AND what your setup consists of. I've got some hard choices to make soon, and would really like to know what's working for other folks here. I'd particularly be interested to hear from the FFI folks that are running cats.
So...let's hear it! Whaddya got , and what are ya hittin' at the wheels??
I've been looking at everything from a 5" dump splitting into dual 4"cats while somehow trying to run it all out the back over the axle (oval pipe ??)....to running a 5" dump into a 4" cat into 4" single pipe all the way back.......and every "conceivable" option in between. I'm hoping to build a system that will work with the 5.3 for now, yet support 750-850rwhp that I'm shooting for with my ffi stroker engine once it's done.
What I'm wondering is: who here is making in excess of 500rwhp WITH the use of cats AND what your setup consists of. I've got some hard choices to make soon, and would really like to know what's working for other folks here. I'd particularly be interested to hear from the FFI folks that are running cats.
So...let's hear it! Whaddya got , and what are ya hittin' at the wheels??
I'm sure you have heard this thousands of times, but you can always have the rear O2s tuned out and a comple of these picked up. 
I tried to post the image without saying who sells them because they aren't a board sponsor but just an example.
I have seen vehicles that push 500+RWHP that are "completely street legal."
I use quotes because that's what they said.
Dual 4" cats should support at least 600RWHP, but I'm no expert.
I tried to post the image without saying who sells them because they aren't a board sponsor but just an example.
I have seen vehicles that push 500+RWHP that are "completely street legal."
I use quotes because that's what they said.
Dual 4" cats should support at least 600RWHP, but I'm no expert.
Yeah, but the rear O2's need to "show" as active when the vehicle is scanned at the DEQ testing station. In addition, it is likely that the car will have to pass a visual inspection as well.
LOL I appreciate the info 
...but I'm sure that depends on the state/locale doing the testing. I'm really wanting to be as "legit" as possible with regards to the install...cuz once this car is done, I don't want to have to screw with it any more. Also, whatever configuration I end up going with, it'll be built from stainless...so get's kinda spendy. I just want to make sure it's right the first time. The tough part of all of this seems to be determining what size/qty of pipe/cats I need to use to reach my power goal.....but I'm still searching.
...but I'm sure that depends on the state/locale doing the testing. I'm really wanting to be as "legit" as possible with regards to the install...cuz once this car is done, I don't want to have to screw with it any more. Also, whatever configuration I end up going with, it'll be built from stainless...so get's kinda spendy. I just want to make sure it's right the first time. The tough part of all of this seems to be determining what size/qty of pipe/cats I need to use to reach my power goal.....but I'm still searching. 
