Notices
Drivetrain Gearbox, Diffs & Driveshafts etc

Decat exhausts - how good can it be?

Thread Tools
 
Search this Thread
 
Old 26 April 2002, 12:44 PM
  #1  
globbits
Scooby Regular
Thread Starter
 
globbits's Avatar
 
Join Date: Jan 2002
Posts: 275
Likes: 0
Received 0 Likes on 0 Posts
Question

Okay, I've got a 2.5 normally-aspirated Legacy estate, running LPG. This thing has got 3 cats in it - which is at least 2 too many as far as I'm concerned - particularly since the emissions from LPG are so low

As standard, the bloody car seems asthmatic, with no torque below 3,500rpm. I'm not looking to go loopy with performance (after all, it's a non-turbo running on gas!) but I miss the torque I had on my old turbo-diesels - nice to be able to accelerate hard, in 5th, at 60

So, Scoobysport are talking about £800+VAT for a custom replacement exhaust system, taking out all 3 cats and giving me much better breathing. What do you lot reckon? Worth it? Much improvement in torque/performance?

Thanks guys

[Edited by globbits - 4/26/2002 2:34:38 PM]
Old 26 April 2002, 07:24 PM
  #2  
globbits
Scooby Regular
Thread Starter
 
globbits's Avatar
 
Join Date: Jan 2002
Posts: 275
Likes: 0
Received 0 Likes on 0 Posts
Exclamation

Or, of course, have you got any suggestions on how I can get some low-end grunt out of the car!

Ta
Old 26 April 2002, 08:16 PM
  #3  
Julian
Scooby Regular
 
Julian's Avatar
 
Join Date: Jan 1999
Posts: 136
Likes: 0
Received 0 Likes on 0 Posts
Post

If it's running sole on LPG then I would guess that the cats aren't needed (could be worng - have been before) for emmision reasons and would certainly be restricting things. There are a few other LPG users on the BBS so maybe they can comment. You may also want to check out soem of the LPG fitters and get their comments on the need for cats on converted cars. As for performance increase - you will get some, but couldn't put any figures to it.

Julian.

Old 26 April 2002, 08:32 PM
  #4  
john banks
Scooby Regular
 
john banks's Avatar
 
Join Date: Nov 2000
Location: 32 cylinders and many cats
Posts: 18,658
Likes: 0
Received 1 Like on 1 Post
Post

You can turbocharge the EJ25 quite effectively at least on the Impreza 2.5 RS - see the Aftermarket Forced Induction Forum on I-club

[Edited by john banks - 4/26/2002 8:32:50 PM]
Old 26 April 2002, 10:17 PM
  #5  
globbits
Scooby Regular
Thread Starter
 
globbits's Avatar
 
Join Date: Jan 2002
Posts: 275
Likes: 0
Received 0 Likes on 0 Posts
Post

Hmmm, turbocharged 2.5..... (drools in a Homer Simpson styleee

Would love to, but the LPG system wouldn't deal with it properly. Apparently, the next LPG system (available later this year) works more like a fuel-injection, so doesn't mind about a turbo. But, the current, carburettor-like, systems won't cope. In any case, I get the feeling that would completely ruin the 3-year warranty on the car

According to the LPG people, removing the cats won't cause a problem with the MOT (which is the key thing, at the end of the day ) and there's a chance I can justify it to my insurers, saying it's part of the mods for the LPG system. Ditto for an induction kit of some form.

So, I guess the question I'm really asking is am I going to get significant improvements, for my £940 investment?

Comments?
Old 27 April 2002, 05:47 PM
  #6  
globbits
Scooby Regular
Thread Starter
 
globbits's Avatar
 
Join Date: Jan 2002
Posts: 275
Likes: 0
Received 0 Likes on 0 Posts
Unhappy

Noone can tell me if the performance difference in getting rid of all 3 catalytic converters is worth £800+VAT?
Someone must be able to shed some light?
Old 27 April 2002, 06:22 PM
  #7  
mike_s14
Scooby Regular
 
mike_s14's Avatar
 
Join Date: Mar 2002
Posts: 1,089
Likes: 0
Received 0 Likes on 0 Posts
Post

Ditch the cats, it'll give you bags more bottom end.
MOT will be no problem as I run a S14 on LPG with a straight through custom SS exhaust (rated 150mph and still pulling(off the Queens highway ))
Are you sure the new LPG systems can be put on a scooby???
Old 27 April 2002, 06:28 PM
  #8  
globbits
Scooby Regular
Thread Starter
 
globbits's Avatar
 
Join Date: Jan 2002
Posts: 275
Likes: 0
Received 0 Likes on 0 Posts
Post

The guy who fitted mine (very well, it has to be said) is involved (somehow) in an Impreza STi that's being trialled with the new system. Admittedly, they're having "issues" with getting it 100%, but it's working happily.

I've been promised an upgrade (for a suitable consideration) when the system's trustworthy, but I still miss low-end torque. Not after 150mph+ but the ability to accelerate hard from 60 without having to change down would be nice.....

PS Thanks Mike!

[Edited by globbits - 4/27/2002 6:28:58 PM]
Old 27 April 2002, 06:38 PM
  #9  
mike_s14
Scooby Regular
 
mike_s14's Avatar
 
Join Date: Mar 2002
Posts: 1,089
Likes: 0
Received 0 Likes on 0 Posts
Post

Richard I would be very intersted in the developments of the system as I believed the main reason that you couldn't run on LPG was the size of the turbo, can't feed gas that quick.

My next car will be a scooby or a Evo 5 or 6 but wether I gas it or not will depend on developments.
Mike.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
powerwrx
Subaru Parts
11
28 February 2022 03:07 PM
trapper2013
ScoobyNet General
6
30 October 2015 03:10 PM
Brett-wv14
Subaru
17
06 October 2015 09:03 PM
blackandz
General Technical
0
12 September 2015 07:01 PM



Quick Reply: Decat exhausts - how good can it be?



All times are GMT +1. The time now is 02:28 PM.