Mazda Rotary Club

Cars by Model Type => 2nd generation RX-7's => Topic started by: grinder on October 02, 2007, 01:04:15 PM

Title: decat pipe info
Post by: grinder on October 02, 2007, 01:04:15 PM
Hiya chaps

im looking at getting a decat pipe made for the TII

its a JDM so there is no cat in the down pipe - but the rest of the exhaust is like the UK models

when getting the decat made - is there any pipe diameter that i should be going for

do i need a 2.5 or 3 inch ID pipe ???

thanks chaps

Stu
Title: decat pipe info
Post by: colin5524 on November 09, 2007, 05:16:50 PM
not been on in a while, but i used higenic 3" stainless pipe from the turbo back, i got 2x3m lengths and 6 90 deg elbows(used the 90\'s to make the y-section) i think it cost about £130 quid for all the stainless although the price of stainless has gone up it still reasonable, it was all tig welded and done in a couple of nights and some :guinness
Title: decat pipe info
Post by: grinder on November 09, 2007, 07:37:42 PM
prob is - i dont have a tig :(

still not sure what to do to be honest - thought someone might have had one for sale - but nope

even a normal cat would do and i can smash the centre out ( would do it to mine - but i like to keep a spare ! )
Title: decat pipe info
Post by: travellinbob on November 09, 2007, 08:28:59 PM
Do you just want to replace the cat with a straight bit of pipe??  if so surely wouldnt you just see what diameter your normal exhaust is and match that size, measure the length needed, get some flanges made up using the gaskets from the cat for size etc and cannot possibly see how it could cost you more than £50-£75  froma nice engineering firm...
  it really freaks me out when I see people selling and people buying de-cat pipes for over a £100 !!!!!!!!!!!!!!!!!!!!!!11
  cheers, michael.
  oh you could also buy a large diameter hi flow cat if you wanted to. They sell them in oz, havt seen any for sale in the uk though.
Title: decat pipe info
Post by: grinder on November 10, 2007, 10:28:28 AM
yeah i know it should be dead simple

maybe im too lazy thats all - its not the best weather for working on the car outside - and we are in the process of moving house - so i dont want the car to be stuck on ramps with no exhaust and need to move it

maybe after xmas i will get the exhaust off and see what i can do :D

i can get a pipe delivered from USA for about £50 - what i dont want - is to do that and find it doesnt fit
Title: decat pipe info
Post by: sadgoth on November 12, 2007, 10:01:14 AM
I just ordered a mid silencer from pipe werx (//www.pipewerx.com) they will make up custom systems or sell individual sections or exhaust components and they are reasonable priced (I thought)
Title: decat pipe info
Post by: grinder on November 12, 2007, 10:02:49 AM
oohhhhh whats their prices like matey

they are in lancs - so must be near me somewhere :D
Title: decat pipe info
Post by: grinder on November 12, 2007, 10:03:47 AM
a quick check on auto route shows them about 25 miles away :D

one phone call coming up :D
Title: decat pipe info
Post by: sadgoth on November 12, 2007, 10:08:47 AM
that would save you the £12 delivery charge!
Title: decat pipe info
Post by: grinder on November 12, 2007, 10:20:57 AM
thats what im thinking

well powerflow said £65 fitted , WGT wanted £50 for the pipe - so gonna see what they say ( if they get off the phone )

i have 2 choices really -

1 - take the car to them and let them do it all
2 - remove the cat and just see if they can copy it

i will see what the price is like and work it from there

ideally - if they can do it , then it saves me the hassle of splitting the exhaust - but ££££££££££ can make a big difference :D

Stu
Title: decat pipe info
Post by: grinder on November 12, 2007, 10:58:03 AM
hummmmmmmmm

they reckon between £75 and £100 + vat for fitting - but thats taking the car to them and they doing it all - just not sure if i would leave the air pump pipe in place at that point - as i blocked it up on the coupe and it still passed the mot ???

didnt think it would be that much for a straight piece of pipe with 2 flanges on it :(

although he did try ( bless him ) to warn me of the it over boosting once its decatted ...errr yup - thats the whole point :D :D :D
Title: decat pipe info
Post by: sadgoth on November 12, 2007, 11:01:00 AM
If you look at the online shop bit, you can spec up what you need and see how much it would be to just buy the pipework
Title: decat pipe info
Post by: grinder on November 12, 2007, 12:31:32 PM
ahhhhhh - didnt see that bit :D
Title: decat pipe info
Post by: grinder on November 12, 2007, 12:38:18 PM
well looking at the shop ( i cant find the flanges )

but a 3 inch pipe is £26 inc VAT - and thats for 1 metre ( so thats tooo long )

they offer a free end forming service on the pipe - so that could be shrunk to 2.5 which i think is the flange size

so suddenly we are looking at between 50-75 for 2 flanges , some welding and then fitting ... humm doesnt seem right does it

i reckon £5 each per flange ( real rough guess ) so thats £35 , not sure how much they charge for welding - say 1 hr ( to include removing and refitting ) - so thats another £25 - so thats only £60 ??

i think whats prob best - is one day take the car to them and get them to quote me at that point - looking at the price for the bits - i could end up spending £40 in pipe work - then i would need someone to TIG it up

so maybe £75 isnt that bad of a price

it annoying , i only paid £100+vat for a clutch fitting - surely thats a bigger job than just welding up some metal ???
Title: decat pipe info
Post by: vinnythespud on November 12, 2007, 07:28:17 PM
that seems reasonable to me,i used to work at wunoff exhausts in bradford so i know what goes in to makeing decat pipes,the straight ones are easy enough but then it gets a bit more complicated for the bent/offset ones,if you dont get the angle of the dangle just right you can end up with the exhaust  knocking or not fitting properly,they can take a while to make,add to that the price of stainless steel and you can see where your money is going.
Title: decat pipe info
Post by: grinder on November 12, 2007, 07:33:25 PM
this is true - although it is just a straight peice of pipe !!
Title: decat pipe info
Post by: vinnythespud on November 12, 2007, 08:00:10 PM
we used to get a lot of stuff from burchills automotive (www.exhaust.uk.net/ (http://www.exhaust.uk.net/)). they might do flanges cheaper than where you are looking,try a local fabrication shop for an off cut of tube,do it the same diameter as the rest of the system,wont be too hard if its straight.
Title: decat pipe info
Post by: Grizzly on November 13, 2007, 02:54:50 PM
Another place to try ;) //www.jpexhausts.co.uk

I know they do RX7 exhausts as there is always at least one in there, The guy you want is Big Ric.
(http://i32.photobucket.com/albums/d26/Grizzly30/Picture017.jpg)
Title: decat pipe info
Post by: grinder on November 13, 2007, 03:08:50 PM
cheers matey - will have a nosey at the website
Title: decat pipe info
Post by: doddy on December 21, 2007, 02:31:37 PM
I took mine to a local exhaust shop and they welded in a bit of pipe in 25 minutes. £40 all in.  They even plumbed in the air pump pipe too.  It\'s not a big deal really.
Title: decat pipe info
Post by: grinder on December 21, 2007, 03:10:12 PM
thats not tooo bad

all the exhaust places near me will only deal with exhaust that they buy and supply - i dont think any of them know what a welder is , let alone us one !!
Title: decat pipe info
Post by: pdtaylor18 on December 21, 2007, 03:48:50 PM
You have to realise that some of these people want £40 an hour labour and it would maybe take an hour to make and put in a decat pipe. Add your materials and £100 is an easy price to pay.  I\'m on the look out for a tig welder,got a mig but tig is so much better and neater.
Title: decat pipe info
Post by: grinder on December 21, 2007, 03:50:18 PM
yeah i know what you mean Pete

i will get mine sorted out one day !
Title: decat pipe info
Post by: doddy on December 21, 2007, 03:55:20 PM
Quote from: pdtaylor18You have to realise that some of these people want £40 an hour labour and it would maybe take an hour to make
fair enough - depends what facilities you have access to where you are.  AFAIK we don\'t have anywhere in NI to acid dip a block for example...

But a decat pipe is just a pipe!  It\'s cut to length then welded on.  In my case they cut the cat itself out in about 5 mins.  Then three welds and it\'s done...