3 inch exhaust- MORE HP - Team Camaro Tech
Engine General Engine Discussion.

 
LinkBack Thread Tools Display Modes
post #1 of 8 (permalink) Old Oct 11th, 14, 05:14 AM Thread Starter
Tech Team
 
Join Date: Sep 2006
Posts: 62
3 inch exhaust- MORE HP

I have 2 1-2 inch on now with 40 series flowmasters, just wondering how much louder (if any) it would be, and will i gain any more HP with 3 inch ,,,,.,505 bbc 587 hp, 1971 pro-tour thanks

1973 Camaro RS / Clone Z28, 350 40 over, 700 R4 Trans. Completely restored.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
jjjcamaro is offline  
Sponsored Links
Advertisement
 
post #2 of 8 (permalink) Old Oct 11th, 14, 07:49 AM
Senior Tech
Dave
 
Join Date: Dec 2005
Location: Tampa, Florida
Posts: 4,684
Re: 3 inch exhaust- MORE HP

Yes you will gain more rear wheel horsepower which is why drag cars run uncapped (the "muffler" that Pro Stock cars use is a four inch piece of pipe six inches long wrapped on the out side with fiberglass and a manufacture's decal slapped on it with the word muffler so people will know they tried to comply with the muffler rule).

However it will not pass the decimeter restrictions on some tracks. By the same token many states have adopted California's law on noise emissions from vehicles (mostly to curb loud stereo's in kids cars). In Florida where every one carries a concealed weapon the citizens just shoot and kill kids with loud cars.

Florida adopted the Calf. law that requires two passes by a decimeter set a fixed distance from the road way with the set decimeter on top of a tripod five feet off the ground. The two passes have to be at 15-20 mph and again at 45-60 mph to include truck tire noise in the statute. The odds of a cop having the equipment in his trunk and the time to set up the test is nil; so anybody in this state can drive a top fueler on the street and a cop can't say it is too loud with out the test as defined by law, hence it is totally unenforceable, and citizens shoot offending kids with thumping stereos in "self defense".

Will you gain enough horse power to feel it in the seat of your pants, no! Will you gain enough horsepower to justify the expense, in my opinion no. And you have to ask yourself will you miss being able to talk to your wife or friends in your Camaro with the louder three inch pipes and "mufflers"?

Big Dave
Larger Dave is offline  
post #3 of 8 (permalink) Old Oct 11th, 14, 08:15 AM
Gold Lifetime Member
Bob
 
Join Date: Oct 2005
Location: New England
Posts: 433
Re: 3 inch exhaust- MORE HP

I have a 505cid with 3" exhaust and it isnt at all excessively loud. It actually sounds really nice. And Im an old fart who hates loud, droning exhaust!

68 RS/SS 496 T56 6 Speed Tuxedo black w/ white bumblebee. Strange Dana 60, Spicer 3.73 Helical Gears
mxquattro is offline  
 
post #4 of 8 (permalink) Old Oct 11th, 14, 11:40 PM
Senior Tech
Sean
 
Join Date: Feb 2002
Location: N.W. Washington
Posts: 7,964
Re: 3 inch exhaust- MORE HP

It will definitely make more power. Add an X pipe and a different muffler (I like Magnaflows) and it will be pretty reasonable.
I have 3 1/2" to 3" reduced at the X pipe and Magnaflows then turn downs at the axle and it's not bad at all, no drone and pretty mellow until you hit the throttle.

Sean

1968 rs with an old school 354" SB2.2 pump gas motor.

Repetition does not transform a lie into a truth.

Franklin D. Roosevelt
68rs406 is offline  
post #5 of 8 (permalink) Old Oct 12th, 14, 03:51 AM
Senior Tech
Steve
 
Join Date: Dec 2012
Location: Toronto
Posts: 777
Re: 3 inch exhaust- MORE HP

Sean has it right ... add an X pipe, get rid of the Flowmasters and add a set of Magnaflows
NO droning, loud when you get on it, but quiet when cruising

Steve

Steve
69' SS/RS X11 PRO-TOURING E-FORCE LS7, DSE Sub, T56 MAG, Recaro, Wilwood disc, Racepak IQ3S, SpeedTech TA/JRI CO's, Pro-Venom 250s, Forgeline CV3C 20/19 - SOLD
Sheck44 is offline  
post #6 of 8 (permalink) Old Oct 12th, 14, 03:56 AM
Moderator
____
 
DOUG G's Avatar
 
Join Date: Mar 1999
Location: Maryland, USA
Posts: 19,439
Garage
Send a message via MSN to DOUG G
Re: 3 inch exhaust- MORE HP

HP ??? no clue, never dyno'd

2.5" American Thunder system in my 68....been 11.30's more than once.

Kept being told my exhaust was too small....dropped mufflers back running just the H-pipe....less than a tenth difference.

Was told that wasn't a real test....dropped the whole system from the headers back...went just over a tenth faster (best guess was due to weight).

Wasn't worth the noise for that little increase. IMO

68 Camaro~LSx ~all motor
1.54 60'--6.95 @ 98.45 660'--10.96 @ 121.53
DOUG G is offline  
post #7 of 8 (permalink) Old Oct 12th, 14, 02:53 PM
Senior Tech
Steve
 
Join Date: Jan 2002
Location: Northern VA
Posts: 208
Re: 3 inch exhaust- MORE HP

3" exhaust will definitely help a BBC breath over 2.5". I'm running a 10:1 compression 383 stroked SBC with 3" tubes from the headers back. At first I was running 40 series Flowmasters and they were just a tad loud for my taste. I switched to 50 series Flowmasters and it is just right. I have to say mufflers are a personal preference. I personally don't like the sound of Magnaflow mufflers.

Speed has never killed anyone. Suddenly becoming stationary, that's what gets you! Jeremy Clarkson


Headshake is offline  
post #8 of 8 (permalink) Old Oct 12th, 14, 05:44 PM
Senior Tech
kevin
 
Join Date: Mar 2012
Location: virginia
Posts: 3,757
Re: 3 inch exhaust- MORE HP

Quote:
Originally Posted by Headshake View Post
3" exhaust will definitely help a BBC breath over 2.5". I'm running a 10:1 compression 383 stroked SBC with 3" tubes from the headers back. At first I was running 40 series Flowmasters and they were just a tad loud for my taste. I switched to 50 series Flowmasters and it is just right. I have to say mufflers are a personal preference. I personally don't like the sound of Magnaflow mufflers.
neither do I.
I happen to have 2 polished stainless steel
magna flow that only have 15 miles on them. if some one is interested e mail me
flat tire is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Team Camaro Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.



Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome