3" vs 2.5" exhaust systems

[67barracuda]

How much H.P. can I expect to lose going for a 3" t0 2.5" exhaust system? I am really thinking of going to a 2.5" system in order to move the system under the car between the frame rails and out to the rear axle to quite it down. I don't know what to do running fenderwell headers and 3" exhaust out the side before the rear tires, it's just to loud for me on the street.

 

[Scampin]

Very little if any.

 

[TMP67]

Very little if any.

It may even step up.

 

[412 Stroker]

horsepower for each pipe size:
Max HP For
Pipe Diameter/ Pipe Area/ Total CFM/ Max HP Per Pipe/ Dual Pipe
1 1/2 1.48 171 78 155
1 5/8 1.77 203 92 185
1 3/4 2.07 239 108 217
2 2.76 318 144 289
2 1/4 3.55 408 185 371
2 1/2 4.43 509 232 463
2 3/4 5.41 622 283 566
3 6.49 747 339 679
3 1/4 7.67 882 401 802
3 1/2 8.95 1029 468 935
NOTE: These numbers are just estimates. All pipes are assumed to be 16 gauge steel.

How To Calculate Muffler Size and Exhaust Pipe Diameter

http://www.exhaustvideos.com/faq/how-to-calculate-muffler-size-pipe-diameter/

 

[Hadahemi]

subscribed

 

[805moparkid]

this is a rigged question... kinda like which cam i should run...

WE NEED ALL THE INFO IN ORDER TO TELL YOU ANYTHING...

is a 170 slant six or a 600ci Hemi?

 

[Abodybomber]

X2, on 805s comment.Also the idea of running a tailpipe over the axle.That. tells me you are at least concerned with noise.A lot of Late model stuff making huge h.p. with mandrel bent 2.5.

 

[Rice Nuker]

How's about the muffler cfm correlation? Seems the challenge is also getting muffler(s) which sustain pipe rated flow and might be quiet as well.. And thanks very much for the link to the pipe charts!