2.5 or 3.0 exhaust - Chevy Nova Forum
Visit our sponsor, National Nostalgic Nova
 
Steve's Nova Site is an automotive enthusiast website dedicated to the 1962 - 1979 Chevrolet Nova, Chevy II and Acadian automobiles. We work together to preserve, restore, drive, show, race and provide fellowship for these classic cars. This is one of the best places to find information about parts, rebuilding, restoration and racing. This website is not affiliated with GM, General Motors or Chevrolet in any capacity.

Go Back   Chevy Nova Forum > Body, Chassis and Mechanical > Drivetrain & Performance


StevesNovaSite.com is the premier Chevrolet Nova Forum on the internet. Registered Users do not see the above ads.
Reply
 
Thread Tools Display Modes
Old 11th-January-2017, 02:45 PM   #1
70chevybb

Title: Nova Junior Member
iTrader: (0)
Status: Offline
Join Date: Oct 2013
Location: chillicothe, il
Nova(s): 72 ss
Posts: 137
2.5 or 3.0 exhaust

not wanting a loud car but i also want it to sound good. 350 hp 396 with a magnum 280 cam headers and a few other goodies. I can do 2.5 or 3.0 just cant decide. any sound clips I can here? magna flows or regular turbo mufflers? changing the exhaust is never a problem as I have been custom bending exhaust for 29 years so If i do not like it I can change it. not looking for all kinds of power this will be driven everyday other than snow.
  Reply With Quote
Sponsored Links
Advertisement
 
Old 11th-January-2017, 02:48 PM   #2
sbc1320
 
sbc1320's Avatar

Title: Nova Guru
iTrader: (0)
Status: Offline
Join Date: May 2008
Location: Houston,Texas
Nova(s): 1972 Nova
Posts: 18,667
Sounds like the 2.5" would do for you and a little quieter than a full 3" system.
__________________
72 Nova 383
72 Nova 383(11.70s)
71 Nova 406(11.60s)
71 Nova 350
70 Nova 350
  Reply With Quote
Old 11th-January-2017, 02:48 PM   #3
63SS_Fanatic
 
63SS_Fanatic's Avatar

Title: Nova Newbie
iTrader: (0)
Status: Offline
Join Date: Mar 2015
Location: New Hampshire
Nova(s): 1963 SS
Posts: 25
Garage
I've been running a 2.5" in most of my hotrods and it seems to be about right.

I am about to install another, and recent reading suggests 2.5" is ideal until your running major HP and high RPM.
__________________
JB


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
  Reply With Quote
Old 11th-January-2017, 03:06 PM   #4
bracketchev70

Title: Nova Junior Member
iTrader: (0)
Status: Offline
Join Date: Jul 2016
Location: Pa
Nova(s): 70 Nova (sold)
Posts: 143
I would go 2.5". Go with a small muffler if you want it louder.
__________________
Used to be bracketchev1221
70 Chevelle 540, t-400. 9.03 at 148 1.24 60' and still 3200 lbs.
Ray
  Reply With Quote
Old 11th-January-2017, 03:32 PM   #5
bptactical
 
bptactical's Avatar

Title: Nova Guru
iTrader: (4)
Status: Offline
Join Date: Nov 2014
Location: Colorado
Nova(s): 1970
Posts: 646
2.5" on a street car will give you higher exhaust gas velocity and that will just help it breath better=runs better
__________________
You can't fix "Stupid", but you can make it bleed, scream and flop around on the floor.
  Reply With Quote
Old 11th-January-2017, 04:19 PM   #6
Pragmatist
 
Pragmatist's Avatar

Title: Nova Guru
iTrader: (3)
Status: Offline
Join Date: Nov 2006
Location: NE Florida
Posts: 3,098
Garage
I ran 3" to the X then 2.5". Best of both worlds.
__________________
66 & 67 hard top,
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
My 1980 avatar pic.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.




To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
  Reply With Quote
Old 11th-January-2017, 08:47 PM   #7
65novaken
 
65novaken's Avatar

Title: Nova Guru
iTrader: (15)
Status: Offline
Join Date: Oct 2010
Location: manitoba,canada
Nova(s): 65 ss
Posts: 6,616
I regret putting on the 3" system,it cost me some power,to loud while driving.
the only thing I like about it is the idling sound.
__________________
my build

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
  Reply With Quote
Old 11th-January-2017, 11:16 PM   #8
smoothdawg

Title: Nova Junior Member
iTrader: (0)
Status: Offline
Join Date: Mar 2014
Location: spokane wa.
Nova(s): 68-72
Posts: 56
My vote is for the 3" exhaust. I put it on every car I do. I love the deeper tone/sound. I have used magnaflow and the pypes race pro mufflers. Like them both. JMO.
  Reply With Quote
Old 12th-January-2017, 12:16 AM   #9
2K ONE
 
2K ONE's Avatar

Title: Nova Newbie
iTrader: (0)
Status: Online
Join Date: Sep 2007
Location: Missouri
Nova(s): 1967 2dr HT Pro Mod 3
Posts: 23
Exhaust size

Have always went with 2.5" on small blocks and 3" on a big block...
  Reply With Quote
Old 12th-January-2017, 04:37 AM   #10
g2072

Title: Nova Junior Member
iTrader: (0)
Status: Offline
Join Date: Dec 2015
Location: carthage
Nova(s): 1965 2 door hard top
Posts: 88
I'm going 2.5. It is going to be hard enough making the 2.5 fit around the four link, shocks/cross member and sway bar. I think a well thought out 2.5 is plenty for a street car.
  Reply With Quote
Old 12th-January-2017, 08:27 AM   #11
dunrite66
 
dunrite66's Avatar

Title: Nova Junior Member
iTrader: (0)
Status: Offline
Join Date: Mar 2016
Location: LOST SOMEWHERE
Nova(s): 1970..454 for now
Posts: 94
have the same dilemma at the moment... car is a 454 with hooker 2'' primary pipes to 3.5'' collectors... car arrived with a 2.5'' system all the way through with Thrush mufflers... we are thinking this system will give better back pressure for street use and make better torque in low to mid.. looking at doing a balance pipe to take a bit of the bark out the sound and probably get rid of the over axle pipes and run dump pipes before the diff to make up for smaller 2.5'' pipes... trial and error i guess... its already there so why not see before i go spending... was going twin 3'' with x pipe and then 2.5'' over the diff and all the way out the back ..but i'm sure once motor comes out and 496 work gets done then 2.5'' will no longer do the job..
  Reply With Quote
Old 12th-January-2017, 12:21 PM   #12
taz3
 
taz3's Avatar

Title: Moderator
iTrader: (10)
Status: Offline
Join Date: Feb 2006
Location: Southern On
Nova(s): 2 69 SS BB L78's & 69 4dr
Posts: 29,711
I run a Magnaflow stainless 2.5" exhaust behind my 396, it is in the mid 400hp range and is perfect IMO.
__________________
3 69's, 2 L78's, 51 Fathom & 71 Lemans #'s match both w/4spds & 69, 53 glacier blue 4 door
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.




To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
  Reply With Quote
Old 12th-January-2017, 01:12 PM   #13
tx71nova
 
tx71nova's Avatar

Title: Nova Guru
iTrader: (0)
Status: Offline
Join Date: Aug 2011
Location: Roseau,MN
Nova(s): 71 Nova
Posts: 551
There is a show on youtube that tested this out on the engine dyno,
your application is different but still a good watch

__________________
1971 Nova 6.0 LQ9, Carb, Saginaw 3 speed

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
  Reply With Quote
Old 12th-January-2017, 01:37 PM   #14
sbc1320
 
sbc1320's Avatar

Title: Nova Guru
iTrader: (0)
Status: Offline
Join Date: May 2008
Location: Houston,Texas
Nova(s): 1972 Nova
Posts: 18,667
Quote:
Originally Posted by tx71nova View Post
There is a show on youtube that tested this out on the engine dyno,
your application is different but still a good watch
Yeap I watched that one a while back.

__________________
72 Nova 383
72 Nova 383(11.70s)
71 Nova 406(11.60s)
71 Nova 350
70 Nova 350
  Reply With Quote
Old 12th-January-2017, 01:50 PM   #15
taz3
 
taz3's Avatar

Title: Moderator
iTrader: (10)
Status: Offline
Join Date: Feb 2006
Location: Southern On
Nova(s): 2 69 SS BB L78's & 69 4dr
Posts: 29,711
I haven't found anywhere to run my car at WOT through all for gears on the street legally lol!
__________________
3 69's, 2 L78's, 51 Fathom & 71 Lemans #'s match both w/4spds & 69, 53 glacier blue 4 door
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.




To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
  Reply With Quote
Sponsored Links
Advertisement
 
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Dish exhaust valves and flat top exhaust valves 7dtree4door Drivetrain & Performance 4 11th-April-2016 05:05 PM
How was the exhaust for a 72 ss? bandronaco07 3rd Generation Chevy II/Nova's 9 7th-September-2015 11:33 AM
What Exhaust Manifolds will work with the Gardner Exhaust L79 system ctipton09 Drivetrain & Performance 1 29th-August-2013 12:58 PM
sb exhaust kane Drivetrain & Performance 6 31st-March-2008 04:21 PM


Site best viewed set to 1024 x 768.

All times are GMT -4. The time now is 01:40 AM.

Custom Designed for Steve's Nova Site by: vBSkinworks

 
Powered by vBulletin® Copyright ©2000 - 2017, Jelsoft Enterprises Lt
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
 

Garage Plus vBulletin Plugins by Drive Thru Online, Inc.