New Exhaust
I drove a cat-less Firebird around for a few years and I hated showing up to a GTG smelling like unburt fuel all the time.As far a power, my little STU-legal fully emissions legal stock-boosted IX made 302 whp with no smell, popping, etc. IMHO, removing the cat is just not worth much, especially when you consider the hassels it causes, inspecting being the biggest.
Ok, prove it to me. Show me some hard data (not just "I read it on the internet" or "do a search") on exactly what power is to be gained going from a hi-flow cat to no cat. Enlighten me with some real tech and not just a silly lol statement.
I'd say its less than 5 hp, which again is worthless vs. all the drawbacks. Let me give you another data point. When I worked at LGM, we dynoed a 450 rwhp camaro back to back through the cat and then again with an open exhaust and again the difference was negligible, maybe 5hp.
I'd say its less than 5 hp, which again is worthless vs. all the drawbacks. Let me give you another data point. When I worked at LGM, we dynoed a 450 rwhp camaro back to back through the cat and then again with an open exhaust and again the difference was negligible, maybe 5hp.
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Well it depends on the car. Turbo cars are much more sensitive to exhaust changes than NA...with great potential. But we used to see as much as 10-15whp on our NA C5 Corvettes (2 cats except CARB models) with highly modified engines (500+hp)...if tuned for the change.
As for Evos, here's some Dyno results from high-flow cat to test pipe with tuning. But again it depends on the platform and mods.
https://www.evolutionm.net/forums/sh...d.php?t=277110
As for Evos, here's some Dyno results from high-flow cat to test pipe with tuning. But again it depends on the platform and mods.
https://www.evolutionm.net/forums/sh...d.php?t=277110
Ok, prove it to me. Show me some hard data (not just "I read it on the internet" or "do a search") on exactly what power is to be gained going from a hi-flow cat to no cat. Enlighten me with some real tech and not just a silly lol statement.
I'd say its less than 5 hp, which again is worthless vs. all the drawbacks. Let me give you another data point. When I worked at LGM, we dynoed a 450 rwhp camaro back to back through the cat and then again with an open exhaust and again the difference was negligible, maybe 5hp.
I'd say its less than 5 hp, which again is worthless vs. all the drawbacks. Let me give you another data point. When I worked at LGM, we dynoed a 450 rwhp camaro back to back through the cat and then again with an open exhaust and again the difference was negligible, maybe 5hp.
Ok, prove it to me. Show me some hard data (not just "I read it on the internet" or "do a search") on exactly what power is to be gained going from a hi-flow cat to no cat. Enlighten me with some real tech and not just a silly lol statement.
I'd say its less than 5 hp, which again is worthless vs. all the drawbacks. Let me give you another data point. When I worked at LGM, we dynoed a 450 rwhp camaro back to back through the cat and then again with an open exhaust and again the difference was negligible, maybe 5hp.
I'd say its less than 5 hp, which again is worthless vs. all the drawbacks. Let me give you another data point. When I worked at LGM, we dynoed a 450 rwhp camaro back to back through the cat and then again with an open exhaust and again the difference was negligible, maybe 5hp.
Would you put cats on a 60's musclecar? Yet they have carbs and polute 50 times more and I never hear them complain about the exhaust smell? What about the average lawnmower or weed trimmer or chainsaw running 2 strokes they emit far more.
Last edited by PlanoEvo; Aug 31, 2007 at 05:31 PM.
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From: Dallas, Tx
And some of us wouldn't be able to get an inspection even with a cat 
...
It makes for a pretty uphill battle to argue the merits for putting the old lump back on.
... and no, smells don't make me "car-insecure"
.
...It makes for a pretty uphill battle to argue the merits for putting the old lump back on.
... and no, smells don't make me "car-insecure"
.
I saw a Skyline back-to-back dynoed with a high-flow cat and test pipe. On an 800 hp car, there was some 7 hp difference.
My car came with a 3" test-pipe, and I went out and purchased a cat for her. Sure I take it off for track days, but if I put myself in a situation where I'm missing that small amount of hp (regardless of how much it is) on the street, I'm participating in a banned thread anyway...
My car came with a 3" test-pipe, and I went out and purchased a cat for her. Sure I take it off for track days, but if I put myself in a situation where I'm missing that small amount of hp (regardless of how much it is) on the street, I'm participating in a banned thread anyway...
