I'm looking to buy a high flow 3" cat. What are my options? How much are they? Where can I buy one? I'm looking to spend little money but get decent flow. Any help would be much appreciated. Thanks.

 

Flowmaster I know makes a nice 3" system. Just remember to get the cat too cause a 3" system will not fit onto a stock cat.

------------------
Eric Natzke
91 Firebird 305 TBI
"It Ain't Stock"
http://members.aol.com/j007golden/91firebird.html
For info on certain parts or mods go to the site below
http://members.aol.com/j007golden/modeval.html

 

No, I already have a cat-back picked out. I'm just looking for a high-flow 3" catalytic converter. Thanks.

 

Oh, well I know of one that is free and is FREE-FLOWING. Its called "The 3" pipe" Easy to install and its free. Check it out sometime.

------------------
Eric Natzke
91 Firebird 305 TBI
"It Ain't Stock"
http://members.aol.com/j007golden/91firebird.html
For info on certain parts or mods go to the site below
http://members.aol.com/j007golden/modeval.html

 

I suggest the catco from summit, its a universal 3 inch inlet and outlet with the air tube and goes for about $62.00. Their product seems good.

------------------
92' camaro
New 305 block TPI conversion, Forged parts all around,Edelbrock intake,ported plennum,ported corvette alluminum heads, accel cam,52mm throttle bodie, SLP runners,ford SVO 19lb injectors,fuel regulator,cloys timing chain, comp alluminum roller rocker arms and pushrods MSD 8.5 mm wires, bosch plattinum plugs, hypertech cap & rotor and coil, Edelbrock TES headers, free flowing catalytic converter and a 3 inch force II flowmaster exhaust system.
Soon to come!!!
Procharger system 12lbs o boost.
Favorite quote: "where ever u go, there u are"

Other car;
1971 plymouth Duster
Mods:340,edelbrock victor jr. intake, 650 4 barrel holley, heddman headers,40 series dual flowmasters, cold air intake,4:10 gears, just got a new paint job and cragar rims with 315 tires in the back.
:Yeah its not a chevy but damn how many 71' dusters have u seen in the streets.

 

what about random tech? any comments on them?

 

The Random Tech is a good piece but is just way too expensive in my opinion. I got the Mor-Flo cat from www.racenet.net for $100. It is a universal 3 inch piece with no air tube. I believe you can also get one with the tube if you want.

------------------
1991 Z28 - 350 TPI, T56, McLeod street clutch, ported plenum & runners, AFPR, Holley Annihilator ignition box and wires, Hooker shorty headers w/o AIR, Flowmaster muffler, homeade ram-air, SSM subframe connectors, Kenny Brown STB, Global West steering box brace, Steve Spohn adjustable torque arm and T56 crossmember

 

sure RT is expensive but well worth it..i have heard many bad things about mor-flo, and a pipe in place of a cat sounds like *** . its also not very legal. catco...EH? i dunno. its kinda like SLP if ya think its worth the extra cash then go for it.

------------------
Rick
90 Camaro RS 305 TBI
400 small block, Hooker 1 3/4 LTs, Random Tech Cat, Hooker aero chamber cat back on the way!!
TH700-R4 with Trans-Go shift kit (corvette servo here...but not installed yet)
MacEwen Motorsports White Gauge Overlays
14" K&N X-Stream Open Element
GTS Headlight and Taillight covers
5% Limo Tint all around
Classic White Chevy Bowtie sticker on rear window
http://www.geocities.com/esvalenz

Man if my camaro were a rice-rocket all those mods would give me what...easily 50-60 hp!!!

"Just because I've done it, doesn't mean I knew what I was doing!" - Me

 

The Catco 3 incher is actually $99. The $62 price is the base starting price for Catco cats, meaning 2 inchers I guess. 3 incher is $99 last time I ordered. I have one on each of my 3rd gens. Been really happy with them. On my 87Z it did not noticeably decrease power over the stock 3incher that was totally gutted. Allowed my Vortec headed carbed 350 to pass the IM240 dyno test w/ no other emissions equipoment on the car too BTW (failed on CO I believe it was or maybe NO w/ the gutted cat. Went from like 3 times the limit down to a mere fraction w/ the Catco cat lol)

------------------
Ray87Z
-Vortec headed 350.
86 IROC w/ a cammed 305 TPI.
Formerly Ray86IROC.
www.inter-scape.com/Ray

[This message has been edited by Ray87Z (edited February 27, 2001).]

 

Hey Ray87z I want a cat too and was looking at the catco cats and RT's. I dont know if there is a sound difference in cats but I want a cat that will let let my exhaust be as loud as possble. Does your cat sound good. Or did it quite it down too much.

------------------

1987 Iroc 350
GTS headlight/tail light covers
Camaro SS Wheels w/Sumitomo HTR ZII 275 rear, 255's in front
K&N filters
Adjustable Borla cat back
Large tube runners
ported plenum
Holley afpr
SLP 1 3/4" headders (not installed yet)
FUTURE GOAL:
To go really F'in fast!!!

Some pics of it at
http://albums.photopoint.com/j/Album...949&Auth=false

 

I found this at some point in my surfing career...



Steve

------------------
Steve's Trans Am Temple

 

Um, I will be the one to tell u that a total 3" exaust system does not sound like a$$.

 

Thank you. I was flamed in another post because I noted that I got a 3" Catco from JC Whitney for right at $100 w/discount including shipping. Responder claimed they got same from Summit for $42.

Also just purchased a Maremont from Parts America for my van (2-1/2"). Looked identical to the Catco, just smaller. Dropped my emissions similar to your experience (failed CO w/factory cat, but dropped all readings dramatically). Sounds better, too.

------------------
82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R. 2.93 limited slip. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 w/LB9 block, ZZ3 cam and intake, WP 305 heads ported & polished, Hooker headers & y-pipe, 3" Catco cat).
57 Bel Air, my 1st car. 0.030 over 396, Weiand Action+, Edelbrock 1901 Q-Jet, Jacobs Omnipack, 1-3/4" headers, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, 3.08 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Best 15.1 @ 5800' Bandimere. Daily driver while Camaro was being put together.

 

Well hold on a second. I just looked at the box and it isn't a Mor'Flo cat like they advertise on their website. It is actually a Car Sound cat. So if those flow numbers you gave are correct then I guess I lucked out.

------------------
1991 Z28 - 350 TPI, T56, McLeod street clutch, ported plenum & runners, AFPR, Holley Annihilator ignition box and wires, Hooker shorty headers w/o AIR, Flowmaster muffler, homeade ram-air, SSM subframe connectors, Kenny Brown STB, Global West steering box brace, Steve Spohn adjustable torque arm and T56 crossmember

 

Well the guys at summit must not like u or something cause i bought my Single 3 inch and outlet for 62 dollars with shipping and handling. Dont believe me i would post a pic but i have no damn idea how to.

------------------
92' camaro
New 305 block TPI conversion, Forged parts all around,Edelbrock intake,ported plennum,ported corvette alluminum heads, accel cam,52mm throttle bodie, SLP runners,ford SVO 19lb injectors,fuel regulator,cloys timing chain, comp alluminum roller rocker arms and pushrods MSD 8.5 mm wires, bosch plattinum plugs, hypertech cap & rotor and coil, Edelbrock TES headers, free flowing catalytic converter and a 3 inch force II flowmaster exhaust system.
Soon to come!!!
Procharger system 12lbs o boost.
Favorite quote: "where ever u go, there u are"

Other car;
1971 plymouth Duster
Mods:340,edelbrock victor jr. intake, 650 4 barrel holley, heddman headers,40 series dual flowmasters, cold air intake,4:10 gears, just got a new paint job and cragar rims with 315 tires in the back.
:Yeah its not a chevy but damn how many 71' dusters have u seen in the streets.

 

I've used Random Tech, Catco and Car sound. The car sound lasted all of three months then broke up, the Random and CAtco still are living comfortably. I can't really comment on which is better as they are on two different cars, but IMO the Randoms are only if you want to pull every little pony out emissions legally. The cat co. one is fine for a street strip vehicle making under 400 HP, again, IMO.

------------------
"A lawyer with his briefcase can steal more than a hundred men with guns."

-Mario Puzo

 

I think it's more like you got lucky vortec305. The salesperson probably screwed up the pricing, giving you the 2 incher price. The add says starting at $60 or whatever it is, doesn't make much sense that the largest one they sell, the 3 incher, comes it at the base price... I ordered both of mine a good 6 months apart, both were the same $99.

------------------
Ray87Z
-Vortec headed 350.
86 IROC w/ a cammed 305 TPI.
Formerly Ray86IROC.
www.inter-scape.com/Ray

 

Just a thought, why not get one from a scrap yard?? my 91 came stock with 2 3" cats.They clean up nice and it sounds good.

 

One thing to remember,If you get a cat make sure it hooks up to the tranny for support like the stocker.If not it hangs a little more.Not good over bumps.

 

He didnt get lucky its true. I called up twice this week and both times the 3" universal was $49.39 to be exact. I ordered it and it just came in today. The direct fit for my car was $100 they told me but it wasn't a 3 incher.



------------------

1987 Iroc 350
GTS headlight/tail light covers
Camaro SS Wheels w/Sumitomo HTR ZII 275 rear, 255's in front
K&N filters
Adjustable Borla cat back
Large tube runners
ported plenum
Holley afpr
SLP 1 3/4" headders (not installed yet)
FUTURE GOAL:
To go really F'in fast!!!

Some pics of it at
http://albums.photopoint.com/j/Album...949&Auth=false

 

How exactly did you get it for under the "starting at" price?

If that is indeed the same converter I got for $99 then it's an even better deal now. Guess they had a price drop.

This is the direct replacement 3" cat that bolts up to the I pipe, slip fit on the y pipe right? Darn good price now if that's right.

------------------
Ray87Z
-Vortec headed 350.
86 IROC w/ a cammed 305 TPI.
Formerly Ray86IROC.
www.inter-scape.com/Ray

 

Dont know but I am glad I got it for that price.


No this isnt the same one then. direct replacement cat is $100. Its not 3" though more like 2 3/4".

 

If it's 2 3/4 inch then so is the Edelbrock TES header's y-pipe and the Hooker cat-back's I-pipe... Both are advertised as being 3" and they slipped on/bolted up respectively to the replacement cat perfectly... I think I measured the diameter to confirm 3" but I can't remember for sure now.

------------------
Ray87Z
-Vortec headed 350.
86 IROC w/ a cammed 305 TPI.
Formerly Ray86IROC.
www.inter-scape.com/Ray

[This message has been edited by Ray87Z (edited March 04, 2001).]

 

The truth is any aftermarket cat, even a stock replacement from Napa will out flow the one thats on your car now. The converter that is on your car now is clogged after years and years of exhaust traveling through it. If you replace it, you'll have an un-clogged cat and it will flow much better, but after time it will clog up again and you'll have to replace it again. Thats why I didn't get a high flow catalyst for my car, that and its not much more of an improvement anyway. Thats just my opinion.

------------------
1987 Chevy Camaro IROC-Z
L98 TPI 350 (5.7L)
TH 700R-4 Transmission
Borg Warner 7.75" 9 Bolt Rear End

Current Mods: LT4 Hot Cam, Comp Cams 1.52:1 Roller Rocker Arms, Edelbrock TES 1 5/8" Headers, Hooker 3" Aerochamber Cat-Back System, Performance Resource Chip, Accel Ignition Coil, Cap, Rotor, 8.8mm Wires, K&N Filters, JET TPI Air Foil, All Free Mods, Falken ZIEX Z-Rated Tires.

Best ET (w/o LT4 cam): 14.32 @ 97.7mph
(corrected for elevation)

7.5" 10 Bolt with 3.42s soon to come!

 

I kinda agree with Dan.I ve heard many times that the converters on our year cars flow very well for stock.

 

my only question is your engine needs some back presure so how many cfm does your cat need to flow? one thing you forget is there was an engineer and some point who speced the stock cat. it wasn't done to rob horsepower but to meet emisions (witch does rob horspower)but on a stock engine just addin a cat isn't going to give you much. once you have updated your exhaust you will they need a higher flowing cat but only one that matches your engine. the flow numbers on the random are exsesive for a mild engine with updated exhaust in my opinion. to make an analogy it remids me of people adding a 58mm throttle body to a stock engine. it isn't going to give you more power until you change other components. once you have went ***** out on your engine and want to keep a cat then buy the expensive one. if you are just throwing headers and a catback on I would go for the $100 converter. just my .02

 

I think you may be right. I was under my car doing work and the inlet on my stock converter looks like a 3" but the outlet looks smaller like a 2 3/4" this was with holding a 3" pipe in my hand too compare.

What makes a 3" cat from catco and a 3" random tech different? What would make a Random tech "better"?


------------------

1987 Iroc 350
GTS headlight/tail light covers
Camaro SS Wheels w/Sumitomo HTR ZII 275 rear, 255's in front
K&N filters
Adjustable Borla cat back
Large tube runners
ported plenum
Holley afpr
SLP 1 3/4" headders (not installed yet)
FUTURE GOAL:
To go really F'in fast!!!

Some pics of it at
http://albums.photopoint.com/j/Album...949&Auth=false

 

IIIII'm still gonna have to go with the free-flow method.




------------------
Eric Natzke
91 Firebird 305 TBI
"It Ain't Stock"
http://members.aol.com/j007golden/91firebird.html
For info on certain parts or mods go to the site below
http://members.aol.com/j007golden/modeval.html

 

OK, I went out real quick and measured it. It is a solid 3" on the y-pipe side (actually a little over for outer-diameter, so internal diameter after slipping over the y-pipe would appear to be dead on 3"). On the I-pipe side the tubing is 3" all the way to where it mates w/ the I-pipe, Although it may neck down where it mates just inside the lip of the I-pipe, I can't see that. Since the Hooker system is apparently made to mate right up to that surface (my hooker system is the 3" kit listed for 86-92 single cat 305 TPIs and single cat 350 TPIs BTW) I assume it's no biggie if it does neck down an 1/8 of an inch of so.

------------------
Ray87Z
-Vortec headed 350.
86 IROC w/ a cammed 305 TPI.
Formerly Ray86IROC.
www.inter-scape.com/Ray

[This message has been edited by Ray87Z (edited March 05, 2001).]

 

best cat huh?? 3" srtait pipe!!


------------------
89 firebird formula


356 10.5:1compression
comp cams xe262 cam
performer rpm intake
#1405 edlebrock 600
434 casting completely redone with bronze guides and 202/160 valves 64cc chambers. decked .0005 thousandths
msd 6al
h.e.i. proform 50,000 volt vac. advance ditributor
700r-4 with 3.08 first gear and 3.23 posi 7 5/8 rear end.
b trans shift kit(will kill shifts...suck dong!!)
shorty heddman hedders with custom 3" pipe y-pipe back(no damn cat!) with 40 series flowmaster!

future mods: 406 roller REALLY REALLY REALLY RADICAL!!!!!