Thread: Exhaust Pipe Size

Results 1 to 4 of 4
  1. #1 Exhaust Pipe Size 
    SE Level Member
    Join Date
    Feb 2017
    Location
    USA
    Posts
    9
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    1999 Pontiac Grand Prix SE - 3.1L

    I am wanting to buy a cheap universal muffler for my car as the factory muffler has just about rusted off. What size should the inlet side of the aftermarket muffler be which would allow the stock exhaust pipe to fit into the inlet side of the muffler? I plan to just clamp it on.

    Also, I suppose it would be helpful to know what the inside and outside diameter of the stock pipe is before it enters the muffler. Thanks y'all.
    Reply With Quote  
     

  2. #2 Re: Exhaust Pipe Size 
    Turbo is the way to go. Fivefingerdeathpunch's Avatar
    Join Date
    Sep 2009
    Location
    Rogers, MN
    Posts
    21,022
    Thanks (Received)
    21
    Likes (Received)
    45
    Dislikes (Received)
    0
    On the single pipes all the way back it should be a 2.25in OD pipe. You can slide under there and just measure it yourself with a tape measure or a micrometer caliper.

    A GT/P with dual exhaust is smaller at 1 7/8th as it enters the mufflers.

    SMGPFC Member #1
    Reply With Quote  
     

  3. #3 Re: Exhaust Pipe Size 
    SE Level Member
    Join Date
    Feb 2017
    Location
    USA
    Posts
    9
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    Quote Originally Posted by Fivefingerdeathpunch View Post
    On the single pipes all the way back it should be a 2.25in OD pipe. You can slide under there and just measure it yourself with a tape measure or a micrometer caliper.
    Thank you. So, just to be clear I need to order a muffler with a 2.5" ID on the inlet side of the muffler, correct? 'Cause I need to have the stock pipe slide into the muffler some so I can securely get the clamp on there. OR, do I need to get a muffler with a 2.25" ID on the inlet side?

    The reason I haven't measured it myself is because the muffler is still attached to the stock pipe, but only by a thread and I want to leave the muffler on the car until the one I order arrives.
    Reply With Quote  
     

  4. #4 Re: Exhaust Pipe Size 
    SE Level Member
    Join Date
    Feb 2017
    Location
    USA
    Posts
    9
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    Well... I bought the Thrush muffler #17713 which has a 2.25" offset inlet and a 2.25" center outlet. I cut out the stock muffler (what was left of it at least) and unfortunately the Thrush muffler was not flared so it didn't fit, it just butted up even with the factory pipe. I have a few scrap pieces of pipe so I'll have to rig it up, but wanted to let anyone else know that if you need to get a muffler make sure its OD is larger than the stock pipe's 2.25" or at least verify that the replacement muffler is flared.
    Reply With Quote  
     

Similar Threads

  1. Down Pipe Bolt Size
    By Quicker1 in forum 3.8L V6 Naturally Aspirated (L36)(L26)
    Replies: 3
    Last Post: 09-14-2015, 06:03 AM
  2. Exhaust Down Pipe
    By tgarison in forum 3.8L V6 Naturally Aspirated (L36)(L26)
    Replies: 7
    Last Post: 08-12-2012, 03:10 AM
  3. Size of exhaust pipe before cat
    By ryanm in forum 5.3L V8 (LS4)
    Replies: 6
    Last Post: 07-20-2011, 06:27 PM
  4. Stock resonator and pipe size?
    By benner in forum 3.8L V6 Supercharged (L67)(L32)
    Replies: 13
    Last Post: 04-23-2011, 09:15 PM
  5. What size is the I-pipe
    By slow94formula in forum General Tech Discussion
    Replies: 22
    Last Post: 12-18-2009, 08:47 AM
Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •