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Is 3" Exhaust Overkill on My T/A?

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Old Jun 4, 2013 | 12:28 PM
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Default Is 3" Exhaust Overkill on My T/A?

Hey guys, I've been reading the forums regarding 3" exhaust. I feel like my car is borderline approriate for 3" exhaust. I am looking at a 3" magna flow. Just wanted to get some thoughts from you guys.

Setup:

Slowhawk Custom Grind Cam (mild cam)
Pacesetter Headers
Texas Speed Catted Y-Pipe
Larger Throttle Body
SLP Lid / K&N Filter
Custom Exhaust System from Lou's Custom Exhaust (absolutely terrible decision)

Dyno'd just over 400hp IIRC

(Below is for clearance purposes and possible banging against suspension parts)
Lowered with SLP lowering package (eibach/bilsteins)
Sub Fram Connectors
Lower Control Arms
Stock 17" Wheels


First question:
Will it help/hurt/or no change, if I put the 3" Magna Flow on?

Second question:
Will I have any issue with banging or rattling on the lowered car and the larger exhaust? Mainly against the panhard bar?
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Old Jun 4, 2013 | 12:36 PM
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sopes's Avatar
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I have 3" from the cat back but mine dumps just past the axle. I think you would be just fine with 3" and you have more done than I do
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Old Jun 4, 2013 | 12:53 PM
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A 3 inch exhaust is going to help you given the mods you have and work well for any future mods you throw at it. In my opinion, 3 inch true duals is the way to go. I sure as hell love mine.
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Old Jun 4, 2013 | 01:15 PM
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A 3" catback is usually one of the first mods that people do to these cars.
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Old Jun 4, 2013 | 01:44 PM
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Originally Posted by WS6Guy25
Hey guys, I've been reading the forums regarding 3" exhaust. I feel like my car is borderline approriate for 3" exhaust. I am looking at a 3" magna flow. Just wanted to get some thoughts from you guys.

Setup:

Slowhawk Custom Grind Cam (mild cam)
Pacesetter Headers
Texas Speed Catted Y-Pipe
Larger Throttle Body
SLP Lid / K&N Filter
Custom Exhaust System from Lou's Custom Exhaust (absolutely terrible decision)

Dyno'd just over 400hp IIRC

(Below is for clearance purposes and possible banging against suspension parts)
Lowered with SLP lowering package (eibach/bilsteins)
Sub Fram Connectors
Lower Control Arms
Stock 17" Wheels


First question:
Will it help/hurt/or no change, if I put the 3" Magna Flow on?
I would cut the cats off. The Magnaflow will help out alot. Get that Lou's garbage off quick. Those shops do half *** work and always manage to hack everything.
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Old Jun 4, 2013 | 02:16 PM
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3" duals are somewhat overkill but no adverse effects, 3" y pipe/catback is in no way overkill...if anything I would be looking at 4" from the y back.
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Old Jun 4, 2013 | 02:18 PM
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4" over here, the bigger the better.
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Old Jun 4, 2013 | 03:08 PM
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Thanks Gents. I was going to go with a catless y-pipe but I was worried about passing inspection in MA.

I'm assuming that the Magna Flow should bolt right up to my y-pipe correct?
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Old Jun 4, 2013 | 04:03 PM
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Not a overkill at all. It will let your car breathe in good! Lol a Full 3" Y-Pipe will be good enough but if you can get away with 3" True Duals then go for it.
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Old Jun 4, 2013 | 05:20 PM
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Originally Posted by MikeWS6
Mine passed MA inspection today with this setup.


You passed inspection without cats?
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Old Jun 4, 2013 | 07:34 PM
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Originally Posted by MikeWS6
Mine passed MA inspection today with this setup.


Ws6 heads/cam idle - YouTube


What kind of exhaust are you running?
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Old Jun 4, 2013 | 07:50 PM
  #12  
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Originally Posted by WS6Guy25
What kind of exhaust are you running?
Long tubes, off road y, loudmouth
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Old Jun 4, 2013 | 08:14 PM
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Originally Posted by homerz28
You passed inspection without cats?
I got mine inspected here in MO yesterday with no cats and running way rich lol. You just have to look around for a shop that will turn their heads the other way. I spent two hours running around town trying to get "hot rod friendly" shops to pass me. Finally called a buddy who sent me to a shop that passed him without him even bringing his car there . I pulled in and the guy literally wrote my name, address, make and model down, and the odometer reading and slapped a sticker in my windshield

Not to hijack the thread, but yes 3" exhaust is the way to go
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Old Jun 4, 2013 | 09:15 PM
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I did a dyno with the stock catback pipe and a straight through Magnaflow muffler(one tip on the drivers side) and then with a SLP 2OTL, no other changes. It made not quite 5 more RWHP with the 2OTL vs the stock pipe and the Magnaflow muffler.

375rwhp vs 380rwhp.
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Old Jun 5, 2013 | 09:35 AM
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3" is fine if you are worried about inspections, get some electric cutouts.

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Old Jun 5, 2013 | 12:33 PM
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Originally Posted by bandit1transam01
I got mine inspected here in MO yesterday with no cats and running way rich lol. You just have to look around for a shop that will turn their heads the other way. I spent two hours running around town trying to get "hot rod friendly" shops to pass me. Finally called a buddy who sent me to a shop that passed him without him even bringing his car there . I pulled in and the guy literally wrote my name, address, make and model down, and the odometer reading and slapped a sticker in my windshield

Not to hijack the thread, but yes 3" exhaust is the way to go
In JC MO and mine passed with long tubes, no cats and a 3 inch dual exhaust from Texas Speed. Untuned at that time to. Now she's got a lopey *** cam and AI Dart/RHS heads and I'm not one bit worried about it passing again.
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Old Jun 5, 2013 | 01:31 PM
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I think it was JRP who said in one of the stickies that 3" exhaust will support 400 ft lbs TQ with zero loss.

I think that it all depends on how much $$$ you have to invest and will this investment support the power you have or plan to add in the near future. If your Y necks down to 2.75" and you buy a 3" catback made to fit this restriction does it really help? I would say a little unless you are looking for sound. I would go 3" true duals out the back but do not have the money. My modding pace is slow and focused on the driveline right now so I kept my factory stainless catback and added a dump and removed the 2.75" restriction. This is off the end of my Kooks Y mind you. I bought all the stainless items (pipe, dump, clamps) off ebay and Amazon and had Lou's in Westport do the install. I think they did a great job (look at my thread if you are interested here) so I guess it may be the person performing the work that matters.
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