Is 3 inch exhaust too much?

66stangmeister

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Apr 14, 2004

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Lafayette, LA

Dec 18, 2005

#1

• Dec 18, 2005

• #1

Hey dudes,

I've begun my next project for my car and that is a new exhaust system.

I have a mild 302 in her right now with 2-1/4" exhaust. My friend is insisting that I get a 3 inch exhaust, but I'm wondering if that is too much for this application and if 2-1/2" exhaust would work the best.

I am not sure on what other info you may need so just ask if u need it

thanks guys

 

Max Power

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Jul 31, 2003

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St Paul

Dec 18, 2005

#2

• Dec 18, 2005

• #2

Actually, 2-1/4" is fine for most mild 302s.

3" is way too big.

 

66stangmeister

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Apr 14, 2004

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Lafayette, LA

Dec 18, 2005

#3

• Dec 18, 2005

• #3

well the thing is i might want to do alittle modifications to my 302 down the road, so i'm thinking 2-1/2" would work best.... 3" would be more suited to hi performance motors and big blocks correct? would having too large an exhaust effectly hurt performance?

 

1

10secgoal

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Dec 1, 2003

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San Diego

Dec 18, 2005

#4

• Dec 18, 2005

• #4

I have a 302 that ran low 12's and I went to a 3in X-pipe. I think it was a tad bit to big. 2.5 woulda been perfect.

 

K

KreagerM

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Nov 24, 2005

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Dec 18, 2005

#5

• Dec 18, 2005

• #5

Go with the 2.5

 

iskwezm

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May 24, 2005

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Rowland Heights,California

Dec 18, 2005

#6

• Dec 18, 2005

• #6

unless you have a power adder,just use a 2.5",if you go to0 big,you might end up with dog on the bottom end

 

5

57fairlane

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Apr 2, 2005

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Dec 18, 2005

#7

• Dec 18, 2005

• #7

2.5" can support up to 500 fwhp.

I guess it depends on how wild your 302 will be . . .

 

HistoricMustang

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#8

• Dec 18, 2005

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For what it is worth, I run a 2.5................

HistoricMustang
www.historicmustang.com

 

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steel1212

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Frankfort, Ky

Dec 18, 2005

#9

• Dec 18, 2005

• #9

another vote for 2.5

 

66stangmeister

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Dec 18, 2005

#10

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• #10

thanks for your opinions guys. i think i'll go with the 2.5, and tell my friend to shut up...hahaha

i won't be making the 302 too wild as i don't have a million dollars to put into it haha

do u recommend buying like...a kit type deal, or just go to a muffler shop and let them throw it together?

 

HistoricMustang

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#11

• Dec 18, 2005

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66stangmeister said:

thanks for your opinions guys. i think i'll go with the 2.5, and tell my friend to shut up...hahaha

i won't be making the 302 too wild as i don't have a million dollars to put into it haha

do u recommend buying like...a kit type deal, or just go to a muffler shop and let them throw it together?

Click to expand...

Do the muffler shop.........................

HistoricMustang
www.historicmustang.com

 

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jdowen2

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Dec 18, 2005

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Mesa, Az

Dec 18, 2005

#12

• Dec 18, 2005

• #12

Go with the 2 1/2, you need a little back pressure. 3 inch is too big and would be loud as well.

 

T

tylerrocks

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Big Spring, TX

Dec 18, 2005

#13

• Dec 18, 2005

• #13

Only go to a reputable muffler shop, even then be weary. I have been burned bad by trusting 3 DIFFRENT "reputable" muffler shops. Wound up spending $450-550 for an exhaust that STILL wouldn't pass inspection and hung by a thread. We have some rat-bastard shops in big spring. I finally gave up on them, hocked up the money for an American Thunder kit from flowmaster AND new headders (the old ones cracked when the only exhaust hanger let loose). Its been gravy ever since and I haven't been back to a mechanic of any kind. YOU care the the MOST about YOUR CAR!

Tyler

 

BullittStangV8

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#14

• Dec 18, 2005

• #14

Buy a kit. You know it will fit, and be of higher quality then a local shop could usually make.
Mike

 

65 fastback

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Dec 18, 2005

#15

• Dec 18, 2005

• #15

Max Power is the only one that got it right. Three inch exhaust is way to big and 2.5" is probably overkill for your current set up.

Give us some specs on your engine. What intake, cam and heads are you running? If your running a performer, stock cam and stock heads, your 2-1/4" exhaust is sized right.

Oversized exhaust is one of the biggest mistakes people make. You need to size your exhaust to your engine's flow capabilities. If your exhaust is to large for your engine, you risk loosing bottom end torque (which is what these cars are all about).

Tim

 

66stangmeister

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Lafayette, LA

Dec 18, 2005

#16

• Dec 18, 2005

• #16

thats for the tip Tim

i'm just looking ahead to the future so that I won't have to get a new exhaust when i make modifications to my motor.

right now it is just a 1968? 302 with a mild cam...probably stock, and stock heads and stock intake. I plan on getting a new intake (probably a weiend or edelbrock), a new cam and finally new heads down the road.

would 2.5" hurt it while i have the stock parts on my motor? i don't really do a lot of performance running of any kind.

what other kits are there? besides flowmaster? dr. gas?

 

dodgestang

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Dec 15, 2003

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Dec 18, 2005

#17

• Dec 18, 2005

• #17

Here's what I recommend

 

Edbert

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Austin TX

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#18

• Dec 18, 2005

• #18

I got to ask...if you have a 2.25 why spend money to get a 2.5, the difference is quite small.

 

66stangmeister

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Lafayette, LA

Dec 18, 2005

#19

• Dec 18, 2005

• #19

well the exhaust that i have on it now it's pretty much shot, it leaks in a few spots and plus i accidently purchased 2.5 inlet mufflers haha

but yeah, i don't know how old the exhaust is on there now, but it's had it's better days.

 

mdjay

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Dec 18, 2005

#20

• Dec 18, 2005

• #20

I might be maxing out but I run 2.5" as well...