Notices

how much wrap to do a classic 3" decat downpie

Thread Tools
 
Search this Thread
 
Old 03 January 2008, 04:54 PM
  #1  
Ian
Scooby Regular
Thread Starter
iTrader: (10)
 
Ian's Avatar
 
Join Date: Jul 2005
Location: Cambridge
Posts: 7,845
Likes: 0
Received 1 Like on 1 Post
Default how much wrap to do a classic 3" decat downpie

bellmouth design.

if 2" wide, how long would i need, or what wrap/width would you recomend?

thanks
ian
Old 03 January 2008, 04:57 PM
  #2  
satpink
Scooby Regular
iTrader: (9)
 
satpink's Avatar
 
Join Date: Sep 2004
Posts: 2,202
Likes: 0
Received 0 Likes on 0 Posts
Default

i did my headers up-pipe & downpipe used a roll & half 50m roll 50mm wide, half a roll would easily do downpipe
Old 03 January 2008, 06:57 PM
  #3  
Ian
Scooby Regular
Thread Starter
iTrader: (10)
 
Ian's Avatar
 
Join Date: Jul 2005
Location: Cambridge
Posts: 7,845
Likes: 0
Received 1 Like on 1 Post
Default

and if it was 2 inch wide wrap, what would you think i would need with a 50% over lap
Old 04 January 2008, 07:16 AM
  #4  
Az Sti Type R
Scooby Regular
 
Az Sti Type R's Avatar
 
Join Date: Oct 2007
Location: Feeding my car's addiction of V Power.
Posts: 552
Likes: 0
Received 0 Likes on 0 Posts
Default

I wrapped my de-cat down pipe the other day before fitting it and I used 3" wide roll and 5 meter length, it covered just the right amount, covered it just underneith the car, I would of liked it to be a bit longer tho, maybe 7 meter length or something, if you want to wrap the whole pipe them I think you'll need around 10 meter length.
Old 05 January 2008, 01:56 PM
  #5  
Ian
Scooby Regular
Thread Starter
iTrader: (10)
 
Ian's Avatar
 
Join Date: Jul 2005
Location: Cambridge
Posts: 7,845
Likes: 0
Received 1 Like on 1 Post
Default

so would a 2" wide wrap with 50% overlaping,
would 30ft be enough? for 3" decat downpipe?

need to know asap
Old 05 January 2008, 03:40 PM
  #6  
wrxhewitson
Scooby Regular
 
wrxhewitson's Avatar
 
Join Date: Aug 2007
Location: newcastle
Posts: 136
Likes: 0
Received 0 Likes on 0 Posts
Default

wot exactly does the wrap do? is it just to shield the heat???
Old 05 January 2008, 03:43 PM
  #7  
Ian
Scooby Regular
Thread Starter
iTrader: (10)
 
Ian's Avatar
 
Join Date: Jul 2005
Location: Cambridge
Posts: 7,845
Likes: 0
Received 1 Like on 1 Post
Default

Originally Posted by wrxhewitson
wot exactly does the wrap do? is it just to shield the heat???

yes keeps the heat in the exhaust, and out of the engine bay, and if you keep the down pipe gasses hotter, they will flow faster, this will help with power, and turbo spool up etc.


worth doing i think
Old 05 January 2008, 05:09 PM
  #8  
ianc61
Scooby Regular
 
ianc61's Avatar
 
Join Date: Oct 2003
Location: Gloucester
Posts: 312
Likes: 0
Received 0 Likes on 0 Posts
Default

Is there any benefit wrapping down / up pipes with cats still in or is it not worth it?
Old 05 January 2008, 05:57 PM
  #9  
harvey
Former Sponsor
iTrader: (48)
 
harvey's Avatar
 
Join Date: Mar 2001
Location: Darlington
Posts: 10,419
Likes: 0
Received 1 Like on 1 Post
Default

3" open neck D/P will take over three quarters of a 2" x 50' roll of wrap with the recommended overlap. DO NOT go for a 50% overlap.
I use DEI wrap which I have in stock here and it has a stitching about 6mm in along the edge and that is the target overlap.
Excess overlap is not necessary and you will use more material.
Excess overlap closer to the cylinders will result in excess heat retention and on tubular headers this will greatly reduce service life.
Old 05 January 2008, 06:19 PM
  #10  
Ian
Scooby Regular
Thread Starter
iTrader: (10)
 
Ian's Avatar
 
Join Date: Jul 2005
Location: Cambridge
Posts: 7,845
Likes: 0
Received 1 Like on 1 Post
Default

hi harvey, when you say 2" x 50' is that 50 ft?

so would 30 ft be enough or would i need more?

thanks
ian
Old 05 January 2008, 09:53 PM
  #11  
Ian
Scooby Regular
Thread Starter
iTrader: (10)
 
Ian's Avatar
 
Join Date: Jul 2005
Location: Cambridge
Posts: 7,845
Likes: 0
Received 1 Like on 1 Post
Default

or does anyone know how long the decat down pipe is?
Old 05 January 2008, 10:16 PM
  #12  
harvey
Former Sponsor
iTrader: (48)
 
harvey's Avatar
 
Join Date: Mar 2001
Location: Darlington
Posts: 10,419
Likes: 0
Received 1 Like on 1 Post
Default

50 feet. 30 feet is not enough even with only trying to follow a 6mm overlap.
You would be as well to get a 50 foot roll of DEI wrap. It is relatively easy to use because of the stitch guide and from the roll you will have 10' (10 feet) or just a fraction more left over if the job is done properly and kept tight.
Alternatively, use what you have but do not wrap the first 18" from the end that couples to the exhaust.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
serpico
ScoobyNet General
20
01 April 2019 07:47 AM
Frizzle-Dee
Essex Subaru Owners Club
13
09 March 2019 07:35 PM
Abx
Subaru
22
09 January 2016 05:42 PM
Mattybr5@MB Developments
Full Cars Breaking For Spares
28
28 December 2015 11:07 PM



Quick Reply: how much wrap to do a classic 3" decat downpie



All times are GMT +1. The time now is 05:45 AM.