OK...

I took my car to Wicked Motorsports in NJ to get the header gasket replaced and have my SFC's welded on.

The guy said that the whoever installed my headers really butchered them and it is really restrictive(downsized the pipes like crazy). Plus, he said that he bent the exhaust to make everything fit and becaue of that the SFC's wont fit.

His recommendation to fix both problems at once is to get rid o the dual cats, order a 3'' Y pipe, and then run that into a single 3'' high flow cat back to the cat back. He said this will flow way better than dual cats and that it will also allow the SFC's to fit.

I don't really wanna do this... the dual cats is a good option on 3rd gens and I would lose it. Also, I am dangerously close to failing emissions now... a single cat can't possibly clean the emissions as well as two cats (one for each engine bank), right??? The dual cats also bumped bhp up by 10.

What does everyone think? Will it flow better? Will I have a less throaty sound? Will my emissions go up? Which will flow better??

------------------
1989 Chevrolet Camaro IROC-Z
L98 - 350c.i. TPI, rebuilt 700R4 auto w/shift kit, Dual catalyst Monza PaceSetter Cat-Back, SLP 1 5/8 Coated Headers, 3.23 Posi rear, Hypertech Thermomaster chip with 160stat, MSD 6A, March Under-Drive pulleys, AFPR, K&N's, !Air Box w/ Ram Air, moddified MAF, !TB Coolant, Spohn Dual Cat SubFrame Connectors, Alarm, Keyless entry, remote starter, 92 Z28 AeroWing, Brand New Paint (6/21/01)

Future: ZZ4 TPI w/EGR, T56, 3.42 or 3.73, Spohn strut tower brace and LCA's, Accell Universal 24# injectors

More info and pics on my webpage:http://go.to/iroc-z

AOL IMer: GPA 0point0

 

That's a pisser you got there. I'd have to see how f'd up the pipes are.

------------------
-Tas
'89 Formula WS-6

305, TBI, 700R4, P.A.W. 14x3 open element with K&N, Milodon 160* thermo, functional Formula hood, cross-flow Flowmaster, '99z28 rear pipes and tips, Hooker 1-5/8" 50 state legal headers, Dynomax 3" I pipe (PN 44063 and 43248)
Super GRK_Taz World
F-Body Dual Exaust
EFI & Intake Options

 

you could always line up two high flow cats back to back and run it that way

 

It is possible for one good 3" cat to both flow as well as and clean the exhaust gases better than two 2-1/4" cats. Here's why:
Flow is a function of restriction as the gases pass through the cat. A well-designed cat brick will keep turns to a minium and total flow area at a maximum, typically better in a 3" aftermarket model than the 2-1/4" factory models.
Emissions reduction is a function of catalyst surface area and effeciency. The latest aftermarket stuff is again typically better at that than the 10-years old and older factory stuff.

If you are serious about the ZZ4 swap, you might want wait until you do that and get SLP 1-3/4" primaries with whichever cat/cats you decide to go with.

------------------
82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4, 2300 stall TC. Ported World 305 heads, Crane PowerMax 2050 cam. ZZ3/4 intake, oil pump, pan & baffle. Accel HEI SuperCoil & module. Hooker 2055 headers, 3" Catco cat & 3" catback w/dual-opposite Flowmaster 80. 2.93 limited slip. Spohn SFCs waiting to be installed. AMSOIL syn lubes bumper-to-bumper. Daily year-round driver. Best ET, speed TBD...
57 Bel Air, my 1st car. '66 396, 9.7:1 forged TRWs, Weiand Action+, Holley 750VS w/4150 conversion, GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlocks, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, MegaShifter, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Idles smooth @ 700 RPM in D. Best 15.02/95.06 @ 5800' Bandimere (corrected 13.93/102.4 @ sea level).