Headers, Intake, & Exhaust Custom Exhaust? New Headers? Need Opinions on Intakes? Discuss making your ride breathe better here.

Custom exhaust question

  #1  
Old 05-09-2014, 08:50 PM
Beginning Member
Thread Starter
Join Date: May 2013
Location: Stevensville MI
Posts: 49
someone11 is on a distinguished road
Question Custom exhaust question

First off let me say... Its MY truck and I can do what I want with it. Dont tell me im being stupid, just need a little advice. Ok, so I bought some headers for the truck (I know I know...the 4.3 doesnt benefit much from headers) But I got a great deal with them online at over half off. Next, my buddy is selling me his two flowmaster 40's for $30 a piece. Also, my dad is a welder and my grandpa has a car hoist in his garage and pipe benders. So my question is this... if the two flowmasters are 3" in/out would it hurt the 4.3" Going straight 3" from the headers all the way back? Im assuming the flowmasters are 3". They are coming off of an 04 gto which has the 5.7 v8. Obviously im not spending much here so im going big or going home. I already have a CAI and am planning on doing a performance tune.

Oh...truck is an 01 ZR2
 
  #2  
Old 05-09-2014, 11:54 PM
Badco's Avatar
Starting Member
Join Date: Oct 2012
Location: Elmwood, OH
Posts: 225
Badco is on a distinguished road
Default

You always want to maintain an equal ratio of in to out. Is your intake stock?
 
  #3  
Old 05-10-2014, 02:50 AM
newguy's Avatar
BF Veteran
Join Date: Feb 2012
Location: Easthampton, ma.
Posts: 4,206
newguy will become famous soon enoughnewguy will become famous soon enough
Default

Dont know where but I think Read somewhere that you dont want to go over 2.5 because of needed back pressure
 
  #4  
Old 05-10-2014, 07:42 AM
Beginning Member
Thread Starter
Join Date: May 2013
Location: Stevensville MI
Posts: 49
someone11 is on a distinguished road
Default

No I have a cold air intake, otherwise all stock. Ive read on this site both ways about back pressure. Some have said you need a certain amount and others say you dont. Going 3" wont cost much extra for me so ill do it if its safe.
 
  #5  
Old 05-10-2014, 07:52 AM
newguy's Avatar
BF Veteran
Join Date: Feb 2012
Location: Easthampton, ma.
Posts: 4,206
newguy will become famous soon enoughnewguy will become famous soon enough
Default

Keep researching before you start. Like I said I`m not sure. Wouldn`t want to lose any gains made with headers and duals by going up to 3 inch
 
  #6  
Old 05-10-2014, 11:25 AM
Badco's Avatar
Starting Member
Join Date: Oct 2012
Location: Elmwood, OH
Posts: 225
Badco is on a distinguished road
Default

It could be a good experiment. If you keep all your original stuff you could always mix and match your pipes, or go back to what you had pre 3"
 
  #7  
Old 05-10-2014, 12:04 PM
Beginning Member
Join Date: Apr 2014
Posts: 36
Nyccooldude is on a distinguished road
Default

OK let me help out here, NO! its not a good idea to go 3'' at all! If your under 250hp than 2-1/2 would be max! At 150hp 2'' is best. Now anything above 250hp-300hp than 3'' is fine and of course the more power the bigger the pipes. Now if your going with a dual set up than 2-1/4'' is best. Remember our trucks have only one cat so unless your going catless a dual muffler set up is a waste of money. You can do a single inlet to a double out let (my set up) Or run pipes all the way back and have the muffler as resonators
I hope this helps and post a pic of the headers I'm looking for some just for sound

Also posted a helpful clip below
 

Last edited by Nyccooldude; 05-10-2014 at 12:08 PM.
  #8  
Old 05-10-2014, 12:05 PM
Beginning Member
Join Date: Apr 2014
Posts: 36
Nyccooldude is on a distinguished road
  #9  
Old 05-10-2014, 06:23 PM
Beginning Member
Thread Starter
Join Date: May 2013
Location: Stevensville MI
Posts: 49
someone11 is on a distinguished road
Default

Well I do plan on doing some internal engine mods but that wont be for a while. Ill keep doing some digging and see what I can find about 3" for our motors. Probably be going with 2 1/2" though.

These are the headers I got.. 96-01 Chevy S10 / Blazer GMC Sonoma 4.3L Ohv 4Wd Stainless Manifold Header Exhaust
 
  #10  
Old 05-10-2014, 06:28 PM
Beginning Member
Thread Starter
Join Date: May 2013
Location: Stevensville MI
Posts: 49
someone11 is on a distinguished road
Default

As for cats...for the purposes of this forum and not getting this thread locked ill be running cats
 

Thread Tools
Search this Thread
Quick Reply: Custom exhaust question


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.