Restrictive centre section?

Level 5 User Joined: 04 May 2004 Posts: 107

If I replace my std. centre section with a 'performance' section, other than it being louder, will it be less restrictive too?

I just wondered if the extra silencer (the right-angled one before the axle) has a negative effect on gas flow?

Also when I took my cat off recently, I had a look down the centre pipe (looking towards rear of car) and inside the pipe there were metal 'restrictions' sticking out. Are these just to quieten noise further?

Retroholic Joined: 12 Feb 2004 Posts: 5685

They say the standard exhaust is very restrictive.

I've nice mongoose stainless system sittin in the corner of the workshop btw Wink

Level 5 User Joined: 04 May 2004 Posts: 107

Go on then how much?

Level 7 User Joined: 27 Feb 2004 Posts: 243

ive found the cat to be the biggest restriction in the zorst system. remove the cat, and it flies round the rev gauage. stainless sysrem jsut makes it noisy, especially a scorpians system with willy 4-1 manifold. makes it unbearable tbh

jimbo

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

the right angle exhaust box is merely a resonance chamber, and yes it does imapart a restriction.

If you merely remove this box and weld up the hole you will get a better noise and more power.

The spikey restrictions of which you speak (proper english here eh!) young man are indeed baffles of a kind. they restrict and slow the gasses so they are forced to go through the mesh that forms the actual silencer.

I have to say a nice quiet exhaust is grand if you cover any sort of distance.

Stainless steel will though, last, it will be louder.

As for actual power gains, well if you stuck a decent aftermarket exhaust on then stuck a new standard one on you may indeed find the stock one makes the car faster.

Depends on the quality of the system etc.

Mr Quoter-vator Joined: 16 Feb 2004 Posts: 7405

i have a decat within a standard system and im heppy with it...noisy when u want it to be...ik helps too...but if u drive light footed its nice and quiet....

Level 5 User Joined: 04 May 2004 Posts: 107

That's the setup I have at the moment; standard centre + rear box with K-tec decat.

The noise is just right for me to be honest, but I don't like the droopy rear tailpipe. Spose I could find somewhere to bend it up so it sits straight, but was thinking of just getting a subtle rear box, maybe piper or summat with just a 3" round.

One other thing, people often talk about their exhaust 'popping' when they decat it.

Well mine now makes this (here come some more technical terms) metallic 'clicky' noise when you lift off at high revs. At first I thought it was the exhaust hitting the under-carriage, but now i am not sure because it sounds like it's coming from the decat and doesn't sound 'clangy' enough for it to be that.

If you lift off then quickly tap the throttle it does it successively until the revs drop down. It's definitely relative to engine speed and not road speed.

Any ideas?

Retroholic Joined: 12 Feb 2004 Posts: 5685

My mongoose is very quiet, just a bit deeper than a standard one

Niose could be fuel igniting in the exhaust

Forum Moderator Joined: 16 Feb 2004 Posts: 1356

There are standard R19 midsections with no silencers. Thats what I want to get hold of.

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

where George they are not on the dialogys.

Anyway, it will always pop, the cat just shields it, its also blowing the exhaust putty I put on to bits.

The renault ph1 chamade back box doesn't droop, its level unless the mounts are gone.

Forum Moderator Joined: 16 Feb 2004 Posts: 1356

They are on the dialogys Chris. The midsection has no bafflers and zig zags

Level 5 User Joined: 04 May 2004 Posts: 107

Zig zags! That's the techy term I was after.

By droop I mean ust the tailpipe. It's actually bent downwards and looks silly.

Anyone got a pic of a std. one?

Mr Quoter-vator Joined: 16 Feb 2004 Posts: 7405

i found a s/s mid section for Â£114 ...think it was from demon tweeks....but cant remember...what car uses a straight thru centre section thats compatible with 16v then? same dia.?