lordfinesse

Hi there,
(first, sorry for my bad english, i´m a german...)
has anybody removed his catalytic converter on his V6? (i´ve got a camaro 1991, 3.1liter all original!)
does it improve the horsepower or torque?
and what´s about the sound?

thanks in advance, Philip from Germany

Ragnarok_Tyr

First, welcome to the v6 board! I'm pretty sure you're going to like this site. Second, I have not removed my cat, and am probably just going to install a high-flow version. Most of the people I have talked to about it say that there is a marginal improvement iin performance (it won't drop your car into the 15-second bracket). The sound is usually real good. The cat-less F-bodys I've heard are definitely louder, but not too much. The overall sound is going to depend on what the rest of your exhuast setup is like. I don't know what your emissions laws are like there in Germany, but as long as your car is in good tune, you shouldn't have a problem with that. In the future, you can do a search, and get results from old message threads/tech articles MUCH faster than waiting for someone to respond to a new message. Good luck.

lordfinesse

thanks for fast reply.
my exhaust is like all other thinks on my car -original!
there is no modification.
here in Germany they are very strictly for the exhaust gases .
we must every two years go to examine to come whether everything is correct.
our police examined usually every car, if it seems to them "too loud" if, can it be one gets a fine because of tax evasion. my luck is, with the American vehicles they don´t can check most thinks, because they don´t know....


thanks

Kj Rockz

I hope you can read this...

Es sollte nicht ein Problem mit dem Entfernen des katalytischen Konverters geben. Er erhöht den Ton, aber nicht zuviel.
Überprüfen gerade, ob alles geschweißt wird, oder tightend Rückseite zusammen. Ich habe meine gerade ausgeweidet, im Allgemeinen die gleiche Sache. Ich habe keine Probleme. Ich hoffe Sie kann dieses lesen, ließ mich weiß.
KJ

lordfinesse

Hi,
i think it´s better to write in english, because the german you´ve writte is very incomprehensibly- but i think i´ve understand what you are meaning!
Ok, i think i will change the stock airfilter, to an open K&N-Filter,
and the second i will do is to change the cat to an empty pipe who fit´s without welding. - do you know any manufacturer who sell´s empty exhaust-pipes who fit´s exactly on the place of the original cat?

thanks. (& i hope you can understand my broken english)

Philip from Germany :lala:

KED85

Here's what I suggest.
Find a VOLVO WAGON and grab the "Y" pipe junction.
Use that piping to create a new smooth flow "Y" pipe from the ends of the factory exhaust manifolds to the connection of the pipe.
Expect a 10 hp gain from freer flow exhaust (find a good new muffler, too!), add the air filter helper and you're back in business again. Be prepared to spend some more effort for extra horsepower.
Ignition/timing chain/waterpump replacement is good effort for max HP gain right now, too. Like 6+HP.
From one with German heritage

Horst

Rj is easy to understand, same as Karl from Dresden.
one prob will be the emission control in germany (ASU) without a catalytic converter your in trouble.
Horst

KED85

If so, shop on line for the CC.
Then find a pipe bender for the free flow "Y" Pipe.

lordfinesse

hi,

i know that i´m in trouble without cat when i must go in germany to the "ASU", because of this i don´t want to empty my cat, i will take him in my garage in original, that i can change quick the empty pipe with the cat when i must go there!

but i don´t understand what´s about the Y-Pipe, because my original cat is only a straight line, and no "two in one" collector.
do i understand anything wrong ?

Philip

Ragnarok_Tyr

By 'Y-Pipe', we mean the pipe that collects the exhaust from each of the two exhaust manifolds, and directs them into a single pipe, which then flows to the catalytic converter. You might also look into an aftermarket high-flow catalytic converter, which will give you better performance, but you won't have to deal with the hassle of changing parts when you have your car emissions tested.

lordfinesse

allright,

all clear what´s about the Y-Pipe.

good idea with the high-flow catalytic converter, but i think i´ll get a better sound without ANY cat.

...i think i will test soon an empty pipe, but before i must go to the emmission test (ASU) ...

Philip

TomP

If the convertor is very old, or the car has many miles (or kilometers), the "pellet bed" inside might be breaking up. That can clog the catalytic convertor and reduce performance. Is there a rattle noise coming from the catalytic? That usually means a broken pellet bed.

lordfinesse

hi,

no, there ist no rattle noise coming from the catalytic converter!

the emmissions are allright, that means the cat works (and should not be clogged....)
my car has 106.000 miles.

TomP

If the catalytic convertor is fine, I would say to leave it on. The GM original catalytic convertors of the 80's and 90's are much more free-flowing than those of the 70's. On a 70's car, the catalytic convertors choked the engine, and you could remove those and feel more power. If you removed the cat, you might only get 1-2 horsepower, not too much.

If your car was a 1975 Camaro, you would feel power.

KED85

IF it ain't broke, don't fix it!
Change the oil-really mean that tip!
Install fresh air filters
Drive fast on the freeway (oh break my heart drive fast-from one with an old Corvette! & Old Camaros!!)
Then go for your testing. You should do very well. Use High grade gas for the test period, too.
After you pass, ask us for performance upgrades, ONLY if you supply air freight tickets for us to "try our ideas" on your ride & test drive on the Autobahn.
You'll do fine, I'll bet.
But those older cc's from the early 80's are as bad a design as the original design from 1975 forward.
The CC's got better/more OEM efficent about 1987 & later.
About that time, GM in their "wisdom" discovered HP sells cars again (The 350 was reintroduced in the Camaro/Firebird, Corvette got standard aluminum heads).

lordfinesse

Allright, i´ve allready ordered new
oil & oilfilter, airfilter, spark-plugs, and i will use high-grade gas too when i will go next time to emmission-check.
but when i was last week, they meaned the fuel-air ratio are very to lean! not a little, VERY to lean-
i don´t know what´s to fix, it seem all to work probably, inclusive the cat, - i think i must bring my car to Opel-Service-Station (Is the Same distributer who sells pontiac, chevy, buick, cadillac here in germany).


Philip

KED85

Say hello to Adam Opel for me.
I had a 1975 Opel Fuel Injected SportWagon for 11 years & 151,000 happy miles.
See any Bitters?

lordfinesse

...no, unfortunately not- Bitter are very, very rare here!
what´s about Opel in the Staates, are they so rarely like chevrolet in germany ?

KED85

I loved Bitters when I found out about them in the States. SUPERB design studio work.
Opels back then (70's-80's) were "common" as a necessary gas crisis car.
I found my 1975 Opel FI SportWagon extremly sporty & agile, quick, surefooted & utilitarian.
Probably, yeah, like Chevy's in the 70's & 80's in Germany.
BUT a larger (even in Germany) dealer network for service.
Opels out here in SoCal?
Please, internet parts shopping, now. Or a few stray Opel GT's in the yards.
I was kinda happy when my Opel front wheel suspension fell apart & the wheel spring went "Boing".
At 151,000 miles, 12 years, I finally had a good reason to let it go.
Damn engine/tranny wouldn't die, tho!
I really wanted to give it to someone, but.... No one wanted it.
It's crushed by Los Angeles towing yard (this was 1990). I put it on blocks on the street after I stripped it!
One part lives on in my 1985 Firebird, I'm using the Opel Fuel Injection Air inlet hose to plumb more air into the Firebird air cleaner. Firebird Air cleaners are very air entry restricted.
Know anyone that needs a factory Shop Manual?
Give a shout by email I have the 1974 & 1975 suppliment factory shop manuals from GM.