F-Body Europe

Once again I am turning to you guru's out there for some tech advice. I am looking into freeing up my exhaust some by gutting one or both of my cats when I put my hedders on.....(probably just one though) I have the cat coming off my headder which then leads into another one on the main pipe. I have done some looking around and it looks like that by gutting one or both of the cats that I'll lose back pressure... which leads to less horse power. Is there any truth to what I'm thinking?? Any advice or help would be appreciated.... and yes I am also looking into just putting Hi-Flow cats on but gutting is by far cheaper.

If you do it it will mess up the computer and make the car run like crap. So if you want a new setup, go with the high flow ones. I think the headers will impress you even with the stock cats. Mine did when I put them on. Go with some long tubes, I will be converting this winter;)

if you gut the cats, or put on 93-95 headers, just use 02 Simms to fool the PCM.

I've seen it go both ways as far as dyno with and without cats.

As a bonus if you bypass the cats, you dont need the AIR pump, or lines and hoses.

Cool thanks for the advice I'll wait and see what I want to do after I put the hedders on.... Dave you don't like the BBK hedders?? I was looking at the Edelbrock ones... Are you running short or mid length now... then switching to the long tube? Why are you switching to the long tubes? Not trying to probe you to much.. just looking for more info before I make my final hedder selection.

Mine are shorties. Just looking out for the long run. I might buy some custom long tube headers from this guy at k-town. Jet hot coated for $350. Then a true dual setup maybe. Depends on the final cost of the 396.

So what is the main difference between the Shorties and Long tubes... performance wise?

I've heard it's not that noticable until you get into some major engine mods. For your combo they will both be significant increases (about 30hp). I think I qualify in that area.

Cool... Thanks for the info.

JR, if you want to go shorties, go with the 95 style. I bought some Pace Setters, ceramic coated for $300. Rob, another friend and I had them on in about 8 hrs. SOTP was awsome and you can rid your cats, or you can buy just one, which is cheaper if you find the need to. You will need a S shaped pipe to fit the collector onto your 96' cat-back, not hard to make. I hear the Edelbrocks are good, as are MACs but I hear the BBK's are junk, other than that you will pay out the A$$ for headers. I reccomend these Pace Setters! For $365 ceramic coated, you cant beat them! I have had mine on for a year and they still look great!
If you want more info e-mail me and I will give you the skinny. Your car will maybe run rich but it will be alot faster. Hell, I ran my car with hotcam kit, no cats with 95' style headers and it ran good on the stock tuning, I just recently got a custom tuned PCM. IMHO 96' style headers are a waste of $$.

Jeff

Cool thanks for the help and suggestions!!! Youre quite right I would save lotsa $$ with the 95 hedders!

hey not saying these replies are wrong but this is what I did. Take off the air pump and throw it as hard as you can. You can buy a rubber plug to seal the whose and it won't leak I've had mine like that for 3yrs now. I punched out my cat with the stock sensors and it ran fine. The exhaust gets a bit louder and you can here more of a tink when you get on it. There may be some people who have had bad experiences with this but I had no problems at all.

That is part II of the exhaust install. If your running a offroad pipe, or a gutted cat, then you have no use for the AIR equipment. It will really help you out with plug access too. I would consider seriously some type of programing or O2 simms on a OBD II car though.

The LT's will zap some torque, but when you make a cam/heads change, it will pay you back with HP. A dyno on a bolt on LT1 showed 15hp over Mac 1 5/8 shorties (no cam or head change).

The only thing that isnt so cool, is you cant run your oil cooler if you have one, and ground clearance will suffer. Not to mention that even if you use cats, its still illegal because you have changed they're factory location. "Like every inspector knows where a 4th gen cats are supposed to be."

Hey Scott,

Just come on over and we will take care of those cats for ya!!!! It does make a diffrence in the sound. Along w/ making it louder, it gives it a "ping" sound when you get on it. Some people may lose HP but I did get gains from it garanteed. I tested it at the track in Florida before and after. But you do have a different year and that might make a difference.