Finally got the cats removed... Not happy
09-01-2004 | 03:14 PM
#11
TECH Veteran
Joined: Mar 2004
Posts: 4,632
Likes: 2
From: Sun Diego
Originally Posted by sawedoff
I would put the catalytic converters back in place or find an aftermarket brand of converter that you feel comfortable with. That drone and rasp that you hear so much about, is from an improperly designed and tuned exhaust system.Even some aftermarket ones will do that. That's the challenge of designing an exhaust system. Exhaust systems are heat and sound frequency interrelated. Plus you have a closed system that pulses as each valve opens and closes. The OEM manufactures do alot of testing to reduce noise levels when they sell a car. So everything is tuned for the cats in place. There are alot of very powerful cars that have catalytic converters in place, so you're not really giving up anything by remving it. You can tune in a different way to compensate for having them. The turbo usually will quiet some things down, so you can usually get away with a louder muffler. Hmmmmm...
But hopefully this is just a leak. I'm curious as to how this turns out for you.
09-01-2004 | 03:23 PM
#12
TECH Apprentice
Joined: Oct 2003
Posts: 369
Likes: 0
From: oklahoma city
whenever you free the exhaust up your boost will lower. the air is flowing through the engine more freely and manifold pressure wont be as high. i dont see why it lags though. may be from the egt's have lowered since removing the cats.
09-01-2004 | 04:04 PM
#13
Originally Posted by hink9
whenever you free the exhaust up your boost will lower. the air is flowing through the engine more freely and manifold pressure wont be as high. i dont see why it lags though. may be from the egt's have lowered since removing the cats.
If anything you should have gained boost and/or shortened spool time. You have a leak somewhere.
I went from open down pipe to a full 3" back with single dynomax 16" race muffler and LOST a full pound due to the INCREASE in backpressure after the turbo.
The old car setup would gain 1.5 psi when i opened the cutouts. Turbos don't like backpressure after the turbine, and love greater flow before. Pulling the CAT will only help the turbo.
09-01-2004 | 08:27 PM
#15
Long story short... 1.5" leak found in one of the cat pipe welds. All the STS Y pipe welds suddenly leak too... THe shop that did the work wants to wait until Friday to fix it...
3 hours under the truck with my welder and its better but still leaking at wot. I'm going to take it to another shop in the am since chances are I will be under mandatory evac by tomorrow afternoon.
3 hours under the truck with my welder and its better but still leaking at wot. I'm going to take it to another shop in the am since chances are I will be under mandatory evac by tomorrow afternoon.
09-01-2004 | 08:33 PM
#16
TECH Fanatic
iTrader: (1)
Joined: Sep 2003
Posts: 1,009
Likes: 0
From: Chesapeake, VA
That's actually good news, right Erik? The part about the leak? At least you know it's not from removing the cats.
Sorry to hear about the possible evac thing. Looks like Orlando is in major threat. Take care down there and hope everybody stays safe.
Hard to fathom that DW could get dessimated.
Sorry to hear about the possible evac thing. Looks like Orlando is in major threat. Take care down there and hope everybody stays safe.
Hard to fathom that DW could get dessimated.
09-01-2004 | 08:43 PM
#17
12 Second Truck Club
Joined: Feb 2002
Posts: 5,575
Likes: 0
From: Sacramento, CA
You're giving me hope Erik. I found a pretty big exhaust leak in one of my manifold to cat sections. I thought it was pretty small at first but it has gotten worse as most exhaust leaks do 
I'm gonna fix all that junk tomorrow and I'll post up the results..
Crossing my fingers for ya down there man. Be safe
I'm gonna fix all that junk tomorrow and I'll post up the results..
Crossing my fingers for ya down there man. Be safe
Thread
Thread Starter
Forum
Replies
Last Post