Cat Back Recommendations
Thread Starter
Le Mans Master
Joined: Sep 2000
Posts: 6,303
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From: Bartlett IL
Cat Back Recommendations
I have TPIS headers on my 84 backed by the 3 in Y-pipe and a Random Tech Cat.
Currently, the cat back system is made up of a DynoMax rear Y with H-pipe crossover and 2.25" inlet Flowmasters. The motor is putting out about 350hp and several friends have told me the 2.25 Y-pipe and mufflers are inadequate for the power level I have. Any recommendations? Been seriously looking at TPIS Cat Back with 3.5" Ypipe and 3" inlet Flowmasters.
Currently, the cat back system is made up of a DynoMax rear Y with H-pipe crossover and 2.25" inlet Flowmasters. The motor is putting out about 350hp and several friends have told me the 2.25 Y-pipe and mufflers are inadequate for the power level I have. Any recommendations? Been seriously looking at TPIS Cat Back with 3.5" Ypipe and 3" inlet Flowmasters.
Le Mans Master
Joined: Jan 2002
Posts: 5,320
Likes: 4
From: Kyle TX (Because Mojo Made me fill it in)
Re: Cat Back Recommendations (Dominic Sorresso)
There is an ebayer that sells new Magnaflow L98 catbacks for $385+ship. Depending on your cat, if it is a 4 bolt flange cat it will not work. If it is the 86-90 cat (2 bolt ball flange), it will work fine.
Just do a search for "corvette magnaflow". Good luck.
Just do a search for "corvette magnaflow". Good luck.
Thread Starter
Le Mans Master
Joined: Sep 2000
Posts: 6,303
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From: Bartlett IL
Re: Cat Back Recommendations (VetteNoob)
Thanks Vettenoob. I'll check it out. Yes it is a 4bolt flange, but I guess I could always cut it and weld on the 4 bolt flange instead. Is the Magna Flow better than the TPIS unit IYO?
Le Mans Master
Joined: Jan 2002
Posts: 5,320
Likes: 4
From: Kyle TX (Because Mojo Made me fill it in)
Re: Cat Back Recommendations (Dominic Sorresso)
Magnaflow makes a purty stainless catback. Heard they sound great from others that have used them. The TPIS ones are Flowmasters. They are nice too, but cost more and not as purty.
On a budget, Id buy Magnaflows, no budget concerns... Id go with Power Effects.
On a budget, Id buy Magnaflows, no budget concerns... Id go with Power Effects.
Thread Starter
Le Mans Master
Joined: Sep 2000
Posts: 6,303
Likes: 714
From: Bartlett IL
Re: Cat Back Recommendations (VetteNoob)
Again, my problem is the 4bolt flange. Any idea what the diameter is for the Magnaflow? I see that Borlas makes a Y-pipe for the 4bolt that is a 2.5"dia.
The TPIS is pricey. Wonder if I culd convert the MagnaFlow to a 4bolt flange. I think I know someone who could cut and weld SS.
[Modified by Dominic Sorresso, 5:41 PM 7/25/2003]
The TPIS is pricey. Wonder if I culd convert the MagnaFlow to a 4bolt flange. I think I know someone who could cut and weld SS.
[Modified by Dominic Sorresso, 5:41 PM 7/25/2003]
Le Mans Master
Joined: Jan 2002
Posts: 5,320
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From: Kyle TX (Because Mojo Made me fill it in)
Re: Cat Back Recommendations (Dominic Sorresso)
Drifting
Joined: Mar 2001
Posts: 1,351
Likes: 1
From: Kingwood TX
Re: Cat Back Recommendations (VetteNoob)
In response to the original question I would either get a magnaflow or a B&B system. I have heard that both sound good and they both look great and appear to have good quality.
I want to get headers and either dual exhaust with two cats and maybe muffler eliminators or one high flow cat with the magnaflow catback. Does anyone know how much power you have to have to get a big gain out of a true dual system? Would there be more than a 5 or 10 hp difference in favor of the dual system with my mods (in sig).
I want to get headers and either dual exhaust with two cats and maybe muffler eliminators or one high flow cat with the magnaflow catback. Does anyone know how much power you have to have to get a big gain out of a true dual system? Would there be more than a 5 or 10 hp difference in favor of the dual system with my mods (in sig).
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Race Director
Joined: Feb 2003
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From: Everyday you must choose between the pain of discipline and the pain of regret. Fredericktown, OH
Re: Cat Back Recommendations (Dominic Sorresso)
I have the Magnaflows and I REALLY like them. There are some shots of the rear of the car at the link in my sig if you want to take a look.
Thread Starter
Le Mans Master
Joined: Sep 2000
Posts: 6,303
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From: Bartlett IL
Re: Cat Back Recommendations (LT-4 CE)
LT-4
Thanks. They do look great. But I am being told the Magna Flow is 3" at the Cat and 2.25" at the muffler. I was looking for something like 2.5 into 2.5 or 3" into 2.5. The TPIS is expensive but its 3.5 into 3".
I currently have the Dynomax which is 2 2.25's into 2.25 into the Flowmasters.
I see that Borla has a 2.5" Ypipe for the 4 bolt flange Cat. Not sure what it is at the muffler. If anyone knows, I'd appreciate it.
Thanks. They do look great. But I am being told the Magna Flow is 3" at the Cat and 2.25" at the muffler. I was looking for something like 2.5 into 2.5 or 3" into 2.5. The TPIS is expensive but its 3.5 into 3".
I currently have the Dynomax which is 2 2.25's into 2.25 into the Flowmasters.
I see that Borla has a 2.5" Ypipe for the 4 bolt flange Cat. Not sure what it is at the muffler. If anyone knows, I'd appreciate it.
Le Mans Master
Joined: Jan 2002
Posts: 5,320
Likes: 4
From: Kyle TX (Because Mojo Made me fill it in)
Re: Cat Back Recommendations (Dominic Sorresso)
[QUOTE]But I am being told the Magna Flow is 3" at the Cat and 2.25" at the muffler./QUOTE]
Not true. Copied from the URL I pasted.
86-91 5.7L V8, L98, Cat-Back System With Y-Pipe,
4x9x14" Mufflers, 2.5" Tubing, Rear Exit, 3.5" Dual Tips 15658 $702.56
MagnaFlow's C4 systems come in two versions. The early version (86-91) features 2.5" fast-flowing mandrel-bent stainless steel tubing and comes with a high-flow after-cat Y-Pipe. The late version (92-96) features 3" mandrel-bent tubing and bolts to the factory Y-Pipe. Both system versions include a matched set of single-in, dual-out stainless steel MagnaFlow Performance Mufflers and polished, rolled edge, stainless steel tips. MagnaFlow's C4 systems have logged gains of 16.6 horsepower and 13.4 ft.-lbs. of torque on the dyno. Replace your failed OEM cat with a MagnaFlow Performance Converter and you'll see even better results.
Not true. Copied from the URL I pasted.
86-91 5.7L V8, L98, Cat-Back System With Y-Pipe,
4x9x14" Mufflers, 2.5" Tubing, Rear Exit, 3.5" Dual Tips 15658 $702.56
MagnaFlow's C4 systems come in two versions. The early version (86-91) features 2.5" fast-flowing mandrel-bent stainless steel tubing and comes with a high-flow after-cat Y-Pipe. The late version (92-96) features 3" mandrel-bent tubing and bolts to the factory Y-Pipe. Both system versions include a matched set of single-in, dual-out stainless steel MagnaFlow Performance Mufflers and polished, rolled edge, stainless steel tips. MagnaFlow's C4 systems have logged gains of 16.6 horsepower and 13.4 ft.-lbs. of torque on the dyno. Replace your failed OEM cat with a MagnaFlow Performance Converter and you'll see even better results.
Thread Starter
Le Mans Master
Joined: Sep 2000
Posts: 6,303
Likes: 714
From: Bartlett IL
Re: Cat Back Recommendations (VetteNoob)
Vettenoob,
You were correct. I had mixed up the Flowmaster Cat Back for the 84-85. with the Magnaflow. The problem with the Magnaflow is that they don't come with 4bolt cat flange. However, that can be solved. Not sure that Corsa makes anything for my car.
You were correct. I had mixed up the Flowmaster Cat Back for the 84-85. with the Magnaflow. The problem with the Magnaflow is that they don't come with 4bolt cat flange. However, that can be solved. Not sure that Corsa makes anything for my car.
Racer
Joined: Jun 2002
Posts: 428
Likes: 0
From: Dallas Tx
Re: Cat Back Recommendations (Dominic Sorresso)
I've got the TPIS catback, with 3" dual from 3" Random Cats, a 3.5" siamesed pipe, and 3" inlet Flowmasters. TPIS long tube headers on the engine side.
Very pleased. Great sound.
Very pleased. Great sound.
Thread Starter
Le Mans Master
Joined: Sep 2000
Posts: 6,303
Likes: 714
From: Bartlett IL
Re: Cat Back Recommendations (tkrussell)
TK,
That's one that I have seriously considered given the fact that I also have the TPIS longtubes and a Random Tech Cat. How's the resonance on that setup? Did you find the 3.5" to be too big? I am not crazy about the square tips tho. Was there any power increase you could determine?
[Modified by Dominic Sorresso, 5:48 PM 8/1/2003]
That's one that I have seriously considered given the fact that I also have the TPIS longtubes and a Random Tech Cat. How's the resonance on that setup? Did you find the 3.5" to be too big? I am not crazy about the square tips tho. Was there any power increase you could determine?
[Modified by Dominic Sorresso, 5:48 PM 8/1/2003]
Racer
Joined: Jun 2002
Posts: 428
Likes: 0
From: Dallas Tx
Re: Cat Back Recommendations (Dominic Sorresso)
I have a 388 (stroked), so it is definitely not too big for me. On a stock 350, I would think the 3"/3.5" perhaps a little larger than necessary. If you wrap the pipes, I don't see that it would cost much low/mid hp on a stock 350.
I have put LT headers and largish exhausts on several cars (69 Vette, 79 BMW, 67 Mustang) with stock displacement. The BMW engine was otherwise stock. I have consistently picked up torque and hp across the RPM band. SOP and Dyno agreed on the gains. Good engines need to breathe freely, and low restriction exhaust systems are absolutely required. Nice thing is that with ECM fuel control, mixture adjustment is so much easier. Just need to check WOT mix and correct with fuel pressure (or injector size). Part throttle mix then gets adjusted automatically.
The square tip exhausts are supposed to emulate the ZR1, I guess. I don't favor them either, so I fabricated a LT1 look-alike tip to encompass the two square tips.
I have put LT headers and largish exhausts on several cars (69 Vette, 79 BMW, 67 Mustang) with stock displacement. The BMW engine was otherwise stock. I have consistently picked up torque and hp across the RPM band. SOP and Dyno agreed on the gains. Good engines need to breathe freely, and low restriction exhaust systems are absolutely required. Nice thing is that with ECM fuel control, mixture adjustment is so much easier. Just need to check WOT mix and correct with fuel pressure (or injector size). Part throttle mix then gets adjusted automatically.
The square tip exhausts are supposed to emulate the ZR1, I guess. I don't favor them either, so I fabricated a LT1 look-alike tip to encompass the two square tips.