Eliminating Catalytic Converters
Thread Starter
Racer
Joined: May 2017
Posts: 452
Likes: 136
Eliminating Catalytic Converters
...,so if the Cats are removed and replaced with straight pipe...do I need to make tuning adjustments based on what the O2 sensors will see?
1994 C4 LT-1 Automatic Convertible...67K miles.
1994 C4 LT-1 Automatic Convertible...67K miles.
Last edited by sprink94; Jun 2, 2017 at 09:13 AM.
Melting Slicks
Joined: Jul 2011
Posts: 2,605
Likes: 202
From: Trinity FL
Nope, and I did exactly what you are describing on my 94' back in 2012. I just cut off the cats with a saw and welded in pipe. Rest of the system was stock. Sounded great at wide open throttle, but horrible just cruising. It took all the refinement out of the car, and smelled horrible with no noticeable performance gain. If you don't want to go long tubes then leave the manifolds/cats and do something different "cat-back".
Thread Starter
Racer
Joined: May 2017
Posts: 452
Likes: 136
Nope, and I did exactly what you are describing on my 94' back in 2012. I just cut off the cats with a saw and welded in pipe. Rest of the system was stock. Sounded great at wide open throttle, but horrible just cruising. It took all the refinement out of the car, and smelled horrible with no noticeable performance gain. If you don't want to go long tubes then leave the manifolds/cats and do something different "cat-back".
I am at the crossroads of heads and cam for the LT-1 to get 450 HP or do a LS swap. I've only had the car a month so I'm kicking a few ideas around....I know one thing for sure...these sucky 2.59 gears have got to go!!! I will probably move to 3:42 or 3:55 gears before I do anything else...lots of bang for the buck with gearing !!
Team Owner
Joined: Sep 2001
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
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For just removing the cats, no retune is required. You could do it if you choose, but its not needed.
The car will wake up quite a bit from heads/cam and a gear ratio and torque converter upgrade. 3.73s are a common choice if remaining with the D36 carrier, however if you are going to seriously upgrade the torque output over 450-500, then a D44 should be in the long term budget, and that affords more gear ratio choices.
The car will wake up quite a bit from heads/cam and a gear ratio and torque converter upgrade. 3.73s are a common choice if remaining with the D36 carrier, however if you are going to seriously upgrade the torque output over 450-500, then a D44 should be in the long term budget, and that affords more gear ratio choices.
Thread Starter
Racer
Joined: May 2017
Posts: 452
Likes: 136
For just removing the cats, no retune is required. You could do it if you choose, but its not needed.
The car will wake up quite a bit from heads/cam and a gear ratio and torque converter upgrade. 3.73s are a common choice if remaining with the D36 carrier, however if you are going to seriously upgrade the torque output over 450-500, then a D44 should be in the long term budget, and that affords more gear ratio choices.
The car will wake up quite a bit from heads/cam and a gear ratio and torque converter upgrade. 3.73s are a common choice if remaining with the D36 carrier, however if you are going to seriously upgrade the torque output over 450-500, then a D44 should be in the long term budget, and that affords more gear ratio choices.
