Welcome to the North American Subaru Impreza Owners Club Monday November 20, 2017
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
Go Back   NASIOC > NASIOC Technical > Normally Aspirated Powertrain

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads. 
Thread Tools Display Modes
Old 04-23-2001, 06:14 PM   #1
Scooby Specialist
Member#: 1744
Join Date: Jun 2000
Chapter/Region: VIC
Location: Vancouver
'11 STi

Question Wrapping exhaust?

Anyhow, a pretty stupid question.... I've seen a lot of people wrap their headers w/fibreglass - i'm thinking that this is to keep exhaust gasses up, hence speeding up their flow backwards. Therfore, i'm thinking of maybe wrapping my exhaust to see if there is a diff. I'm currently running a 2.5" catback on an na engine - would wrapping the exhaust alleviate "some" of the backpressure problems due to the large diam. of the exhaust piping? Just a thought, please don't flame me. Also, if i did decide to wrap the exhaust, would there be problems w/ rust due to moisture and debris sandwiched up between the fibre and exhaust? Thanks.

tmr is offline   Reply With Quote
Old 04-23-2001, 06:59 PM   #2
Scooby Newbie
Member#: 5385
Join Date: Apr 2001
Location: Rapid City, SD
2012 WRX Base
Ice Silver


I don't know about the WRX, but the 2.5RS is pretty much wrapped already down to the cats.

The metal "housing" around the exhaust appears to have insulation inside it between it and the exhaust pipe.

As far as whether or not wrapping the exhaust is helpful, I would say yes. Keeping the gasses at a higher temperature will keep velocity up. How much it helps is a question that only a dyno would answer. Nothing compares to real world testing.
IowaRS is offline   Reply With Quote
Old 04-23-2001, 08:24 PM   #3
Scooby Specialist
Member#: 3198
Join Date: Dec 2000
Location: Portland, OR USA
2005 GT LTD Wagon
Garnet Red


Wrapping will rot your exhaust. If you're really going to do it, spring for ceramic coating, it's cheaper than a new exhaust.
gavin is offline   Reply With Quote
Old 04-23-2001, 08:36 PM   #4
Scooby Newbie
Member#: 5385
Join Date: Apr 2001
Location: Rapid City, SD
2012 WRX Base
Ice Silver


The only reason the pipe would "rot" would be rusting through. That usually requires moisture. Exhaust tends to get kind of warm and generally evaporates most of the moisture on it. True the wrap will tend to hold the moisture more than without the wrap, but I have wrapped exhaust in the past without any excessive rust problems.
IowaRS is offline   Reply With Quote
Old 04-23-2001, 09:14 PM   #5
Scooby Specialist
Member#: 4063
Join Date: Feb 2001
Chapter/Region: MWSOC
Location: Michigan

I have seen regular mild-steel headers rust through over the period of 6 month. These were mild steel and were brand new... not the stainless alloy a new car exhaust is made of. I don't know what it would do to any other material. Personally, I wouldn't go near the stuff based on experience. The benifits don't outweigh the potentional losses.
MrHorspwer is offline   Reply With Quote
Old 04-26-2001, 05:58 PM   #6
Scooby Newbie
Member#: 6110
Join Date: Apr 2001
Location: Lonaconing, MD USA
98 Impreza L


I have GSXR that had wrapped headers on it, they rusted like crazy. I could tell no discernable difference in the power output. I know I'm comparing apples to oranges, but to me it seems the hassle of wrapping them doesn't make up for the slight advantage that would be gained. Just my humble opinion
pottsie350 is offline   Reply With Quote

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
NJ: Wrapped Exhaust Manifold underpowerd Engine/Power/Exhaust 12 03-15-2008 10:29 PM
Help wrapping exhaust Lexington Mid West Subaru Owners Club Forum -- MWSOC 32 01-29-2007 10:33 PM
Heat wrapping exhaust... txl146 Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 7 03-28-2005 12:47 PM
What to wrap exhaust with(temporary fix)? joubtt Southern California Impreza Club Forum -- SCIC 2 12-24-2003 06:00 PM
thermo-wrap exhaust manifold or no? ride5000 Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 1 07-09-2003 12:05 PM

All times are GMT -4. The time now is 11:58 AM.

Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2017 Axivo Inc.
Copyright ©1999 - 2017, North American Subaru Impreza Owners Club, Inc.