Decat pipes
Author
Discussion

afcb

Original Poster:

5,132 posts

259 months

Wednesday 1st June 2005
quotequote all
Hi, i've been considering getting a decat pipe but was wondering what peoples thoughts were with regards to reliability, driveability, noise?

I know they have to be swapped over for MOT time but apart from this, are they worth it?

djroadboy

1,183 posts

266 months

Wednesday 1st June 2005
quotequote all
Far too loud IMHO. I put the cat back in but the car felt a bit flat so I had a straight through silencer custom made to fit in place of the cat. Now it sounds much better and there is no loss of power.

Just my 2p.

HTH

Dan

poptosis

850 posts

276 months

Wednesday 1st June 2005
quotequote all
Depends on your exhaust and induction system I guess. I have a cat replacement pipe and drive to work everyday and it doesnt bother me in the slightest.

bogie

17,100 posts

302 months

Thursday 2nd June 2005
quotequote all
personally I dont think they are worth it for the power gain alone - the cat is not really that restrictive until you are 200bhp+

If you want the extra noise too then go for it.....

afcb

Original Poster:

5,132 posts

259 months

Thursday 2nd June 2005
quotequote all
cheers for the reply lads. Is there any meets in Bournemouth arranged for the next months?

TCee

11 posts

257 months

Thursday 2nd June 2005
quotequote all
Another option is the sportscat. I've a Janspeed one fitted and it gives the noise/bhp gain and helps give a better pickup on the throttle - more expensive than a pipe but you don't have to replace it at MOT time!

paulwakinshaw

436 posts

270 months

Thursday 2nd June 2005
quotequote all
Don't listen to Dan!

I have a 4-2-1 manifold, de-cat and eliseparts exhaust and my S1 sounds wicked. OK I don't use it every day and it is VERY loud (Dan can confirm!) but changing the cat for the MOT is an easy job.

As Dan said, a silenced cat pipe is an alternative, gets rid of the restrictive cat but keep noise levels sensible.

Wako

dss123

351 posts

266 months

Thursday 2nd June 2005
quotequote all
I agree with Paul,

CRP is a must IMOH!

Can't get enough of that howl at high revs!

(and the pops, bangs, burbbles etc)

Never bothers me and I've got the MOT swap time down to half an hour!

Worth saying that it can be too loud for some track days i think though?


Cheers


Dunc

ninjadave

2,101 posts

286 months

Thursday 2nd June 2005
quotequote all
bogie said:
personally I dont think they are worth it for the power gain alone - the cat is not really that restrictive until you are 200bhp+
If you want the extra noise too then go for it.....


I don't really see the point in them either, especially with a N/A engine as the lack of back-pressure can reduce engine power.
In a turbo car, they are usful if you want to increase the capacity/potential engine power output.

To that end I've always thought they were used more to allow the engine to change revs quicker with lower flow resistance, rather than for actual power gain with any induction system.

Having said all that, I have one on my old banger - the engine tech in it is similar to the VVC and Toyota engines.
I would say I get next to a gnats ass of power gain with it and very little extra noise according to 'er indoors, though I think it's louder.
On the other hand I do get a better throttle response which is a much needed improvment with my wet TC in the tiptronic gearbox.

If you want to improve the noise and don't mind the extra loudness, improve the throttle response and get a little bit of extra power, possibly, then go for it.
If you don't think it's worth the cost of the part, fitting and the extra insurance for the modification, don't bother.

cinqster

1,057 posts

309 months

Thursday 2nd June 2005
quotequote all
I must be deaf. Just fitted a Raceline box and CRP and it's still too quiet for me!